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 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package javax.swing.plaf.basic;

import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.datatransfer.*;
import java.beans.*;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.UIResource;
import javax.swing.plaf.TreeUI;
import javax.swing.tree.*;
import javax.swing.text.Position;
import javax.swing.plaf.basic.DragRecognitionSupport.BeforeDrag;
import sun.awt.AWTAccessor;
import sun.swing.SwingUtilities2;

import sun.swing.DefaultLookup;
import sun.swing.UIAction;

The basic L&F for a hierarchical data structure.
Author:
Scott Violet, Shannon Hickey (drag and drop)/**
 * The basic L&F for a hierarchical data structure.
 *
 * @author Scott Violet
 * @author Shannon Hickey (drag and drop)
 */

public class BasicTreeUI extends TreeUI
{
    private static final StringBuilder BASELINE_COMPONENT_KEY =
        new StringBuilder("Tree.baselineComponent");

    // Old actions forward to an instance of this.
    private static final Actions SHARED_ACTION = new Actions();

    
The collapsed icon.
/**
     * The collapsed icon.
     */
    protected transient Icon        collapsedIcon;
    
The expanded icon.
/**
     * The expanded icon.
     */
    protected transient Icon        expandedIcon;

    
Color used to draw hash marks.  If null no hash marks
will be drawn.
/**
      * Color used to draw hash marks.  If <code>null</code> no hash marks
      * will be drawn.
      */
    private Color hashColor;

    
Distance between left margin and where vertical dashes will be
drawn. /** Distance between left margin and where vertical dashes will be
      * drawn. */
    protected int               leftChildIndent;
    
Distance to add to leftChildIndent to determine where cell
contents will be drawn. /** Distance to add to leftChildIndent to determine where cell
      * contents will be drawn. */
    protected int               rightChildIndent;
    
Total distance that will be indented.  The sum of leftChildIndent
and rightChildIndent. /** Total distance that will be indented.  The sum of leftChildIndent
      * and rightChildIndent. */
    protected int               totalChildIndent;

    
Minimum preferred size. /** Minimum preferred size. */
    protected Dimension         preferredMinSize;

    
Index of the row that was last selected. /** Index of the row that was last selected. */
    protected int               lastSelectedRow;

    
Component that we're going to be drawing into. /** Component that we're going to be drawing into. */
    protected JTree             tree;

    
Renderer that is being used to do the actual cell drawing. /** Renderer that is being used to do the actual cell drawing. */
    protected transient TreeCellRenderer   currentCellRenderer;

    
Set to true if the renderer that is currently in the tree was
created by this instance. /** Set to true if the renderer that is currently in the tree was
     * created by this instance. */
    protected boolean           createdRenderer;

    
Editor for the tree. /** Editor for the tree. */
    protected transient TreeCellEditor     cellEditor;

    
Set to true if editor that is currently in the tree was
created by this instance. /** Set to true if editor that is currently in the tree was
     * created by this instance. */
    protected boolean           createdCellEditor;

    
Set to false when editing and shouldSelectCell() returns true meaning
the node should be selected before editing, used in completeEditing. /** Set to false when editing and shouldSelectCell() returns true meaning
      * the node should be selected before editing, used in completeEditing. */
    protected boolean           stopEditingInCompleteEditing;

    
Used to paint the TreeCellRenderer. /** Used to paint the TreeCellRenderer. */
    protected CellRendererPane  rendererPane;

    
Size needed to completely display all the nodes. /** Size needed to completely display all the nodes. */
    protected Dimension         preferredSize;

    
Is the preferredSize valid? /** Is the preferredSize valid? */
    protected boolean           validCachedPreferredSize;

    
Object responsible for handling sizing and expanded issues. /** Object responsible for handling sizing and expanded issues. */
    // WARNING: Be careful with the bounds held by treeState. They are
    // always in terms of left-to-right. They get mapped to right-to-left
    // by the various methods of this class.
    protected AbstractLayoutCache  treeState;


    
Used for minimizing the drawing of vertical lines. /** Used for minimizing the drawing of vertical lines. */
    protected Hashtable<TreePath,Boolean> drawingCache;

    
True if doing optimizations for a largeModel. Subclasses that
don't support this may wish to override createLayoutCache to not
return a FixedHeightLayoutCache instance. /** True if doing optimizations for a largeModel. Subclasses that
     * don't support this may wish to override createLayoutCache to not
     * return a FixedHeightLayoutCache instance. */
    protected boolean           largeModel;

    
Reponsible for telling the TreeState the size needed for a node. /** Reponsible for telling the TreeState the size needed for a node. */
    protected AbstractLayoutCache.NodeDimensions     nodeDimensions;

    
Used to determine what to display. /** Used to determine what to display. */
    protected TreeModel         treeModel;

    
Model maintaining the selection. /** Model maintaining the selection. */
    protected TreeSelectionModel treeSelectionModel;

    
How much the depth should be offset to properly calculate
x locations. This is based on whether or not the root is visible,
and if the root handles are visible. /** How much the depth should be offset to properly calculate
     * x locations. This is based on whether or not the root is visible,
     * and if the root handles are visible. */
    protected int               depthOffset;

    // Following 4 ivars are only valid when editing.

    
When editing, this will be the Component that is doing the actual
editing. /** When editing, this will be the Component that is doing the actual
      * editing. */
    protected Component         editingComponent;

    
Path that is being edited. /** Path that is being edited. */
    protected TreePath          editingPath;

    
Row that is being edited. Should only be referenced if
editingComponent is not null. /** Row that is being edited. Should only be referenced if
     * editingComponent is not null. */
    protected int               editingRow;

    
Set to true if the editor has a different size than the renderer. /** Set to true if the editor has a different size than the renderer. */
    protected boolean           editorHasDifferentSize;

    
Row correspondin to lead path. /** Row correspondin to lead path. */
    private int                 leadRow;
    
If true, the property change event for LEAD_SELECTION_PATH_PROPERTY,
or ANCHOR_SELECTION_PATH_PROPERTY will not generate a repaint. /** If true, the property change event for LEAD_SELECTION_PATH_PROPERTY,
     * or ANCHOR_SELECTION_PATH_PROPERTY will not generate a repaint. */
    private boolean             ignoreLAChange;

    
Indicates the orientation. /** Indicates the orientation. */
    private boolean             leftToRight;

    // Cached listeners
    private PropertyChangeListener propertyChangeListener;
    private PropertyChangeListener selectionModelPropertyChangeListener;
    private MouseListener mouseListener;
    private FocusListener focusListener;
    private KeyListener keyListener;
    
Used for large models, listens for moved/resized events and
updates the validCachedPreferredSize bit accordingly. /** Used for large models, listens for moved/resized events and
     * updates the validCachedPreferredSize bit accordingly. */
    private ComponentListener   componentListener;
    
Listens for CellEditor events. /** Listens for CellEditor events. */
    private CellEditorListener  cellEditorListener;
    
Updates the display when the selection changes. /** Updates the display when the selection changes. */
    private TreeSelectionListener treeSelectionListener;
    
Is responsible for updating the display based on model events. /** Is responsible for updating the display based on model events. */
    private TreeModelListener treeModelListener;
    
Updates the treestate as the nodes expand. /** Updates the treestate as the nodes expand. */
    private TreeExpansionListener treeExpansionListener;

    
UI property indicating whether to paint lines /** UI property indicating whether to paint lines */
    private boolean paintLines = true;

    
UI property for painting dashed lines /** UI property for painting dashed lines */
    private boolean lineTypeDashed;

    
The time factor to treate the series of typed alphanumeric key
as prefix for first letter navigation.
/**
     * The time factor to treate the series of typed alphanumeric key
     * as prefix for first letter navigation.
     */
    private long timeFactor = 1000L;

    private Handler handler;

    
A temporary variable for communication between startEditingOnRelease
and startEditing.
/**
     * A temporary variable for communication between startEditingOnRelease
     * and startEditing.
     */
    private MouseEvent releaseEvent;

    
Constructs a new instance of BasicTreeUI. 
Params:
x – a component
Returns:
a new instance of BasicTreeUI/**
     * Constructs a new instance of {@code BasicTreeUI}.
     *
     * @param x a component
     * @return a new instance of {@code BasicTreeUI}
     */
    public static ComponentUI createUI(JComponent x) {
        return new BasicTreeUI();
    }


    static void loadActionMap(LazyActionMap map) {
        map.put(new Actions(Actions.SELECT_PREVIOUS));
        map.put(new Actions(Actions.SELECT_PREVIOUS_CHANGE_LEAD));
        map.put(new Actions(Actions.SELECT_PREVIOUS_EXTEND_SELECTION));

        map.put(new Actions(Actions.SELECT_NEXT));
        map.put(new Actions(Actions.SELECT_NEXT_CHANGE_LEAD));
        map.put(new Actions(Actions.SELECT_NEXT_EXTEND_SELECTION));

        map.put(new Actions(Actions.SELECT_CHILD));
        map.put(new Actions(Actions.SELECT_CHILD_CHANGE_LEAD));

        map.put(new Actions(Actions.SELECT_PARENT));
        map.put(new Actions(Actions.SELECT_PARENT_CHANGE_LEAD));

        map.put(new Actions(Actions.SCROLL_UP_CHANGE_SELECTION));
        map.put(new Actions(Actions.SCROLL_UP_CHANGE_LEAD));
        map.put(new Actions(Actions.SCROLL_UP_EXTEND_SELECTION));

        map.put(new Actions(Actions.SCROLL_DOWN_CHANGE_SELECTION));
        map.put(new Actions(Actions.SCROLL_DOWN_EXTEND_SELECTION));
        map.put(new Actions(Actions.SCROLL_DOWN_CHANGE_LEAD));

        map.put(new Actions(Actions.SELECT_FIRST));
        map.put(new Actions(Actions.SELECT_FIRST_CHANGE_LEAD));
        map.put(new Actions(Actions.SELECT_FIRST_EXTEND_SELECTION));

        map.put(new Actions(Actions.SELECT_LAST));
        map.put(new Actions(Actions.SELECT_LAST_CHANGE_LEAD));
        map.put(new Actions(Actions.SELECT_LAST_EXTEND_SELECTION));

        map.put(new Actions(Actions.TOGGLE));

        map.put(new Actions(Actions.CANCEL_EDITING));

        map.put(new Actions(Actions.START_EDITING));

        map.put(new Actions(Actions.SELECT_ALL));

        map.put(new Actions(Actions.CLEAR_SELECTION));

        map.put(new Actions(Actions.SCROLL_LEFT));
        map.put(new Actions(Actions.SCROLL_RIGHT));

        map.put(new Actions(Actions.SCROLL_LEFT_EXTEND_SELECTION));
        map.put(new Actions(Actions.SCROLL_RIGHT_EXTEND_SELECTION));

        map.put(new Actions(Actions.SCROLL_RIGHT_CHANGE_LEAD));
        map.put(new Actions(Actions.SCROLL_LEFT_CHANGE_LEAD));

        map.put(new Actions(Actions.EXPAND));
        map.put(new Actions(Actions.COLLAPSE));
        map.put(new Actions(Actions.MOVE_SELECTION_TO_PARENT));

        map.put(new Actions(Actions.ADD_TO_SELECTION));
        map.put(new Actions(Actions.TOGGLE_AND_ANCHOR));
        map.put(new Actions(Actions.EXTEND_TO));
        map.put(new Actions(Actions.MOVE_SELECTION_TO));

        map.put(TransferHandler.getCutAction());
        map.put(TransferHandler.getCopyAction());
        map.put(TransferHandler.getPasteAction());
    }

    
Constructs a new instance of BasicTreeUI. /**
     * Constructs a new instance of {@code BasicTreeUI}.
     */
    public BasicTreeUI() {
        super();
    }

    
Returns the hash color.
Returns:
the hash color/**
     * Returns the hash color.
     *
     * @return the hash color
     */
    protected Color getHashColor() {
        return hashColor;
    }

    
Sets the hash color.
Params:
color – the hash color/**
     * Sets the hash color.
     *
     * @param color the hash color
     */
    protected void setHashColor(Color color) {
        hashColor = color;
    }

    
Sets the left child indent.
Params:
newAmount – the left child indent/**
     * Sets the left child indent.
     *
     * @param newAmount the left child indent
     */
    public void setLeftChildIndent(int newAmount) {
        leftChildIndent = newAmount;
        totalChildIndent = leftChildIndent + rightChildIndent;
        if(treeState != null)
            treeState.invalidateSizes();
        updateSize();
    }

    
Returns the left child indent.
Returns:
the left child indent/**
     * Returns the left child indent.
     *
     * @return the left child indent
     */
    public int getLeftChildIndent() {
        return leftChildIndent;
    }

    
Sets the right child indent.
Params:
newAmount – the right child indent/**
     * Sets the right child indent.
     *
     * @param newAmount the right child indent
     */
    public void setRightChildIndent(int newAmount) {
        rightChildIndent = newAmount;
        totalChildIndent = leftChildIndent + rightChildIndent;
        if(treeState != null)
            treeState.invalidateSizes();
        updateSize();
    }

    
Returns the right child indent.
Returns:
the right child indent/**
     * Returns the right child indent.
     *
     * @return the right child indent
     */
    public int getRightChildIndent() {
        return rightChildIndent;
    }

    
Sets the expanded icon.
Params:
newG – the expanded icon/**
     * Sets the expanded icon.
     *
     * @param newG the expanded icon
     */
    public void setExpandedIcon(Icon newG) {
        expandedIcon = newG;
    }

    
Returns the expanded icon.
Returns:
the expanded icon/**
     * Returns the expanded icon.
     *
     * @return the expanded icon
     */
    public Icon getExpandedIcon() {
        return expandedIcon;
    }

    
Sets the collapsed icon.
Params:
newG – the collapsed icon/**
     * Sets the collapsed icon.
     *
     * @param newG the collapsed icon
     */
    public void setCollapsedIcon(Icon newG) {
        collapsedIcon = newG;
    }

    
Returns the collapsed icon.
Returns:
the collapsed icon/**
     * Returns the collapsed icon.
     *
     * @return the collapsed icon
     */
    public Icon getCollapsedIcon() {
        return collapsedIcon;
    }

    //
    // Methods for configuring the behavior of the tree. None of them
    // push the value to the JTree instance. You should really only
    // call these methods on the JTree.
    //

    
Updates the componentListener, if necessary.
Params:
largeModel – the new value/**
     * Updates the componentListener, if necessary.
     *
     * @param largeModel the new value
     */
    protected void setLargeModel(boolean largeModel) {
        if(getRowHeight() < 1)
            largeModel = false;
        if(this.largeModel != largeModel) {
            completeEditing();
            this.largeModel = largeModel;
            treeState = createLayoutCache();
            configureLayoutCache();
            updateLayoutCacheExpandedNodesIfNecessary();
            updateSize();
        }
    }

    
Returns true if large model is set. 
Returns:
true if large model is set/**
     * Returns {@code true} if large model is set.
     *
     * @return {@code true} if large model is set
     */
    protected boolean isLargeModel() {
        return largeModel;
    }

    
Sets the row height, this is forwarded to the treeState.
Params:
rowHeight – the row height/**
     * Sets the row height, this is forwarded to the treeState.
     *
     * @param rowHeight the row height
     */
    protected void setRowHeight(int rowHeight) {
        completeEditing();
        if(treeState != null) {
            setLargeModel(tree.isLargeModel());
            treeState.setRowHeight(rowHeight);
            updateSize();
        }
    }

    
Returns the row height.
Returns:
the row height/**
     * Returns the row height.
     *
     * @return the row height
     */
    protected int getRowHeight() {
        return (tree == null) ? -1 : tree.getRowHeight();
    }

    
Sets the TreeCellRenderer to tcr. This invokes updateRenderer. 
Params:
tcr – the new value/**
     * Sets the {@code TreeCellRenderer} to {@code tcr}. This invokes
     * {@code updateRenderer}.
     *
     * @param tcr the new value
     */
    protected void setCellRenderer(TreeCellRenderer tcr) {
        completeEditing();
        updateRenderer();
        if(treeState != null) {
            treeState.invalidateSizes();
            updateSize();
        }
    }

    
Return currentCellRenderer, which will either be the trees renderer, or defaultCellRenderer, which ever wasn't null. 
Returns:
an instance of TreeCellRenderer/**
     * Return {@code currentCellRenderer}, which will either be the trees
     * renderer, or {@code defaultCellRenderer}, which ever wasn't null.
     *
     * @return an instance of {@code TreeCellRenderer}
     */
    protected TreeCellRenderer getCellRenderer() {
        return currentCellRenderer;
    }

    
Sets the TreeModel. 
Params:
model – the new value/**
     * Sets the {@code TreeModel}.
     *
     * @param model the new value
     */
    protected void setModel(TreeModel model) {
        completeEditing();
        if(treeModel != null && treeModelListener != null)
            treeModel.removeTreeModelListener(treeModelListener);
        treeModel = model;
        if(treeModel != null) {
            if(treeModelListener != null)
                treeModel.addTreeModelListener(treeModelListener);
        }
        if(treeState != null) {
            treeState.setModel(model);
            updateLayoutCacheExpandedNodesIfNecessary();
            updateSize();
        }
    }

    
Returns the tree model.
Returns:
the tree model/**
     * Returns the tree model.
     *
     * @return the tree model
     */
    protected TreeModel getModel() {
        return treeModel;
    }

    
Sets the root to being visible.
Params:
newValue – the new value/**
     * Sets the root to being visible.
     *
     * @param newValue the new value
     */
    protected void setRootVisible(boolean newValue) {
        completeEditing();
        updateDepthOffset();
        if(treeState != null) {
            treeState.setRootVisible(newValue);
            treeState.invalidateSizes();
            updateSize();
        }
    }

    
Returns true if the tree root is visible. 
Returns:
true if the tree root is visible/**
     * Returns {@code true} if the tree root is visible.
     *
     * @return {@code true} if the tree root is visible
     */
    protected boolean isRootVisible() {
        return (tree != null) ? tree.isRootVisible() : false;
    }

    
Determines whether the node handles are to be displayed.
Params:
newValue – the new value/**
     * Determines whether the node handles are to be displayed.
     *
     * @param newValue the new value
     */
    protected void setShowsRootHandles(boolean newValue) {
        completeEditing();
        updateDepthOffset();
        if(treeState != null) {
            treeState.invalidateSizes();
            updateSize();
        }
    }

    
Returns true if the root handles are to be displayed. 
Returns:
true if the root handles are to be displayed/**
     * Returns {@code true} if the root handles are to be displayed.
     *
     * @return {@code true} if the root handles are to be displayed
     */
    protected boolean getShowsRootHandles() {
        return (tree != null) ? tree.getShowsRootHandles() : false;
    }

    
Sets the cell editor.
Params:
editor – the new cell editor/**
     * Sets the cell editor.
     *
     * @param editor the new cell editor
     */
    protected void setCellEditor(TreeCellEditor editor) {
        updateCellEditor();
    }

    
Returns an instance of TreeCellEditor. 
Returns:
an instance of TreeCellEditor/**
     * Returns an instance of {@code TreeCellEditor}.
     *
     * @return an instance of {@code TreeCellEditor}
     */
    protected TreeCellEditor getCellEditor() {
        return (tree != null) ? tree.getCellEditor() : null;
    }

    
Configures the receiver to allow, or not allow, editing.
Params:
newValue – the new value/**
     * Configures the receiver to allow, or not allow, editing.
     *
     * @param newValue the new value
     */
    protected void setEditable(boolean newValue) {
        updateCellEditor();
    }

    
Returns true if the tree is editable. 
Returns:
true if the tree is editable/**
     * Returns {@code true} if the tree is editable.
     *
     * @return {@code true} if the tree is editable
     */
    protected boolean isEditable() {
        return (tree != null) ? tree.isEditable() : false;
    }

    
Resets the selection model. The appropriate listener are installed
on the model.
Params:
newLSM – new selection model/**
     * Resets the selection model. The appropriate listener are installed
     * on the model.
     *
     * @param newLSM new selection model
     */
    protected void setSelectionModel(TreeSelectionModel newLSM) {
        completeEditing();
        if(selectionModelPropertyChangeListener != null &&
           treeSelectionModel != null)
            treeSelectionModel.removePropertyChangeListener
                              (selectionModelPropertyChangeListener);
        if(treeSelectionListener != null && treeSelectionModel != null)
            treeSelectionModel.removeTreeSelectionListener
                               (treeSelectionListener);
        treeSelectionModel = newLSM;
        if(treeSelectionModel != null) {
            if(selectionModelPropertyChangeListener != null)
                treeSelectionModel.addPropertyChangeListener
                              (selectionModelPropertyChangeListener);
            if(treeSelectionListener != null)
                treeSelectionModel.addTreeSelectionListener
                                   (treeSelectionListener);
            if(treeState != null)
                treeState.setSelectionModel(treeSelectionModel);
        }
        else if(treeState != null)
            treeState.setSelectionModel(null);
        if(tree != null)
            tree.repaint();
    }

    
Returns the tree selection model.
Returns:
the tree selection model/**
     * Returns the tree selection model.
     *
     * @return the tree selection model
     */
    protected TreeSelectionModel getSelectionModel() {
        return treeSelectionModel;
    }

    //
    // TreeUI methods
    //

    
Returns the Rectangle enclosing the label portion that the
last item in path will be drawn into.  Will return null if
any component in path is currently valid.
/**
      * Returns the Rectangle enclosing the label portion that the
      * last item in path will be drawn into.  Will return null if
      * any component in path is currently valid.
      */
    public Rectangle getPathBounds(JTree tree, TreePath path) {
        if(tree != null && treeState != null) {
            return getPathBounds(path, tree.getInsets(), new Rectangle());
        }
        return null;
    }

    private Rectangle getPathBounds(TreePath path, Insets insets,
                                    Rectangle bounds) {
        bounds = treeState.getBounds(path, bounds);
        if (bounds != null) {
            if (leftToRight) {
                bounds.x += insets.left;
            } else {
                bounds.x = tree.getWidth() - (bounds.x + bounds.width) -
                        insets.right;
            }
            bounds.y += insets.top;
        }
        return bounds;
    }

    
Returns the path for passed in row.  If row is not visible
null is returned.
/**
      * Returns the path for passed in row.  If row is not visible
      * null is returned.
      */
    public TreePath getPathForRow(JTree tree, int row) {
        return (treeState != null) ? treeState.getPathForRow(row) : null;
    }

    
Returns the row that the last item identified in path is visible
at.  Will return -1 if any of the elements in path are not
currently visible.
/**
      * Returns the row that the last item identified in path is visible
      * at.  Will return -1 if any of the elements in path are not
      * currently visible.
      */
    public int getRowForPath(JTree tree, TreePath path) {
        return (treeState != null) ? treeState.getRowForPath(path) : -1;
    }

    
Returns the number of rows that are being displayed.
/**
      * Returns the number of rows that are being displayed.
      */
    public int getRowCount(JTree tree) {
        return (treeState != null) ? treeState.getRowCount() : 0;
    }

    
Returns the path to the node that is closest to x,y.  If
there is nothing currently visible this will return null, otherwise
it'll always return a valid path.  If you need to test if the
returned object is exactly at x, y you should get the bounds for
the returned path and test x, y against that.
/**
      * Returns the path to the node that is closest to x,y.  If
      * there is nothing currently visible this will return null, otherwise
      * it'll always return a valid path.  If you need to test if the
      * returned object is exactly at x, y you should get the bounds for
      * the returned path and test x, y against that.
      */
    public TreePath getClosestPathForLocation(JTree tree, int x, int y) {
        if(tree != null && treeState != null) {
            // TreeState doesn't care about the x location, hence it isn't
            // adjusted
            y -= tree.getInsets().top;
            return treeState.getPathClosestTo(x, y);
        }
        return null;
    }

    
Returns true if the tree is being edited.  The item that is being
edited can be returned by getEditingPath().
/**
      * Returns true if the tree is being edited.  The item that is being
      * edited can be returned by getEditingPath().
      */
    public boolean isEditing(JTree tree) {
        return (editingComponent != null);
    }

    
Stops the current editing session.  This has no effect if the
tree isn't being edited.  Returns true if the editor allows the
editing session to stop.
/**
      * Stops the current editing session.  This has no effect if the
      * tree isn't being edited.  Returns true if the editor allows the
      * editing session to stop.
      */
    public boolean stopEditing(JTree tree) {
        if(editingComponent != null && cellEditor.stopCellEditing()) {
            completeEditing(false, false, true);
            return true;
        }
        return false;
    }

    
Cancels the current editing session.
/**
      * Cancels the current editing session.
      */
    public void cancelEditing(JTree tree) {
        if(editingComponent != null) {
            completeEditing(false, true, false);
        }
    }

    
Selects the last item in path and tries to edit it.  Editing will
fail if the CellEditor won't allow it for the selected item.
/**
      * Selects the last item in path and tries to edit it.  Editing will
      * fail if the CellEditor won't allow it for the selected item.
      */
    public void startEditingAtPath(JTree tree, TreePath path) {
        tree.scrollPathToVisible(path);
        if(path != null && tree.isVisible(path))
            startEditing(path, null);
    }

    
Returns the path to the element that is being edited.
/**
     * Returns the path to the element that is being edited.
     */
    public TreePath getEditingPath(JTree tree) {
        return editingPath;
    }

    //
    // Install methods
    //

    public void installUI(JComponent c) {
        if ( c == null ) {
            throw new NullPointerException( "null component passed to BasicTreeUI.installUI()" );
        }

        tree = (JTree)c;

        prepareForUIInstall();

        // Boilerplate install block
        installDefaults();
        installKeyboardActions();
        installComponents();
        installListeners();

        completeUIInstall();
    }

    
Invoked after the tree instance variable has been set, but before any defaults/listeners have been installed. /**
     * Invoked after the {@code tree} instance variable has been
     * set, but before any defaults/listeners have been installed.
     */
    protected void prepareForUIInstall() {
        drawingCache = new Hashtable<TreePath,Boolean>(7);

        // Data member initializations
        leftToRight = BasicGraphicsUtils.isLeftToRight(tree);
        stopEditingInCompleteEditing = true;
        lastSelectedRow = -1;
        leadRow = -1;
        preferredSize = new Dimension();

        largeModel = tree.isLargeModel();
        if(getRowHeight() <= 0)
            largeModel = false;
        setModel(tree.getModel());
    }

    
Invoked from installUI after all the defaults/listeners have been
installed.
/**
     * Invoked from installUI after all the defaults/listeners have been
     * installed.
     */
    protected void completeUIInstall() {
        // Custom install code

        this.setShowsRootHandles(tree.getShowsRootHandles());

        updateRenderer();

        updateDepthOffset();

        setSelectionModel(tree.getSelectionModel());

        // Create, if necessary, the TreeState instance.
        treeState = createLayoutCache();
        configureLayoutCache();

        updateSize();
    }

    
Installs default properties.
/**
     * Installs default properties.
     */
    protected void installDefaults() {
        if(tree.getBackground() == null ||
           tree.getBackground() instanceof UIResource) {
            tree.setBackground(UIManager.getColor("Tree.background"));
        }
        if(getHashColor() == null || getHashColor() instanceof UIResource) {
            setHashColor(UIManager.getColor("Tree.hash"));
        }
        if (tree.getFont() == null || tree.getFont() instanceof UIResource)
            tree.setFont( UIManager.getFont("Tree.font") );
        // JTree's original row height is 16.  To correctly display the
        // contents on Linux we should have set it to 18, Windows 19 and
        // Solaris 20.  As these values vary so much it's too hard to
        // be backward compatable and try to update the row height, we're
        // therefor NOT going to adjust the row height based on font.  If the
        // developer changes the font, it's there responsibility to update
        // the row height.

        setExpandedIcon( (Icon)UIManager.get( "Tree.expandedIcon" ) );
        setCollapsedIcon( (Icon)UIManager.get( "Tree.collapsedIcon" ) );

        setLeftChildIndent(((Integer)UIManager.get("Tree.leftChildIndent")).
                           intValue());
        setRightChildIndent(((Integer)UIManager.get("Tree.rightChildIndent")).
                           intValue());

        LookAndFeel.installProperty(tree, "rowHeight",
                                    UIManager.get("Tree.rowHeight"));

        largeModel = (tree.isLargeModel() && tree.getRowHeight() > 0);

        Object scrollsOnExpand = UIManager.get("Tree.scrollsOnExpand");
        if (scrollsOnExpand != null) {
            LookAndFeel.installProperty(tree, "scrollsOnExpand", scrollsOnExpand);
        }

        paintLines = UIManager.getBoolean("Tree.paintLines");
        lineTypeDashed = UIManager.getBoolean("Tree.lineTypeDashed");

        Long l = (Long)UIManager.get("Tree.timeFactor");
        timeFactor = (l!=null) ? l.longValue() : 1000L;

        Object showsRootHandles = UIManager.get("Tree.showsRootHandles");
        if (showsRootHandles != null) {
            LookAndFeel.installProperty(tree,
                    JTree.SHOWS_ROOT_HANDLES_PROPERTY, showsRootHandles);
        }
    }

    
Registers listeners.
/**
     * Registers listeners.
     */
    protected void installListeners() {
        if ( (propertyChangeListener = createPropertyChangeListener())
             != null ) {
            tree.addPropertyChangeListener(propertyChangeListener);
        }
        if ( (mouseListener = createMouseListener()) != null ) {
            tree.addMouseListener(mouseListener);
            if (mouseListener instanceof MouseMotionListener) {
                tree.addMouseMotionListener((MouseMotionListener)mouseListener);
            }
        }
        if ((focusListener = createFocusListener()) != null ) {
            tree.addFocusListener(focusListener);
        }
        if ((keyListener = createKeyListener()) != null) {
            tree.addKeyListener(keyListener);
        }
        if((treeExpansionListener = createTreeExpansionListener()) != null) {
            tree.addTreeExpansionListener(treeExpansionListener);
        }
        if((treeModelListener = createTreeModelListener()) != null &&
           treeModel != null) {
            treeModel.addTreeModelListener(treeModelListener);
        }
        if((selectionModelPropertyChangeListener =
            createSelectionModelPropertyChangeListener()) != null &&
           treeSelectionModel != null) {
            treeSelectionModel.addPropertyChangeListener
                (selectionModelPropertyChangeListener);
        }
        if((treeSelectionListener = createTreeSelectionListener()) != null &&
           treeSelectionModel != null) {
            treeSelectionModel.addTreeSelectionListener(treeSelectionListener);
        }

        TransferHandler th = tree.getTransferHandler();
        if (th == null || th instanceof UIResource) {
            tree.setTransferHandler(defaultTransferHandler);
            // default TransferHandler doesn't support drop
            // so we don't want drop handling
            if (tree.getDropTarget() instanceof UIResource) {
                tree.setDropTarget(null);
            }
        }

        LookAndFeel.installProperty(tree, "opaque", Boolean.TRUE);
    }

    
Registers keyboard actions.
/**
     * Registers keyboard actions.
     */
    protected void installKeyboardActions() {
        InputMap km = getInputMap(JComponent.
                                  WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);

        SwingUtilities.replaceUIInputMap(tree, JComponent.
                                         WHEN_ANCESTOR_OF_FOCUSED_COMPONENT,
                                         km);
        km = getInputMap(JComponent.WHEN_FOCUSED);
        SwingUtilities.replaceUIInputMap(tree, JComponent.WHEN_FOCUSED, km);

        LazyActionMap.installLazyActionMap(tree, BasicTreeUI.class,
                                           "Tree.actionMap");
    }

    InputMap getInputMap(int condition) {
        if (condition == JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT) {
            return (InputMap)DefaultLookup.get(tree, this,
                                               "Tree.ancestorInputMap");
        }
        else if (condition == JComponent.WHEN_FOCUSED) {
            InputMap keyMap = (InputMap)DefaultLookup.get(tree, this,
                                                      "Tree.focusInputMap");
            InputMap rtlKeyMap;

            if (tree.getComponentOrientation().isLeftToRight() ||
                  ((rtlKeyMap = (InputMap)DefaultLookup.get(tree, this,
                  "Tree.focusInputMap.RightToLeft")) == null)) {
                return keyMap;
            } else {
                rtlKeyMap.setParent(keyMap);
                return rtlKeyMap;
            }
        }
        return null;
    }

    
Intalls the subcomponents of the tree, which is the renderer pane.
/**
     * Intalls the subcomponents of the tree, which is the renderer pane.
     */
    protected void installComponents() {
        if ((rendererPane = createCellRendererPane()) != null) {
            tree.add( rendererPane );
        }
    }

    //
    // Create methods.
    //

    
Creates an instance of NodeDimensions that is able to determine the size of a given node in the tree. 
Returns:
an instance of NodeDimensions/**
     * Creates an instance of {@code NodeDimensions} that is able to determine
     * the size of a given node in the tree.
     *
     * @return an instance of {@code NodeDimensions}
     */
    protected AbstractLayoutCache.NodeDimensions createNodeDimensions() {
        return new NodeDimensionsHandler();
    }

    
Creates a listener that is responsible that updates the UI based on
how the tree changes.
Returns:
an instance of the PropertyChangeListener/**
     * Creates a listener that is responsible that updates the UI based on
     * how the tree changes.
     *
     * @return an instance of the {@code PropertyChangeListener}
     */
    protected PropertyChangeListener createPropertyChangeListener() {
        return getHandler();
    }

    private Handler getHandler() {
        if (handler == null) {
            handler = new Handler();
        }
        return handler;
    }

    
Creates the listener responsible for updating the selection based on
mouse events.
Returns:
an instance of the MouseListener/**
     * Creates the listener responsible for updating the selection based on
     * mouse events.
     *
     * @return an instance of the {@code MouseListener}
     */
    protected MouseListener createMouseListener() {
        return getHandler();
    }

    
Creates a listener that is responsible for updating the display
when focus is lost/gained.
Returns:
an instance of the FocusListener/**
     * Creates a listener that is responsible for updating the display
     * when focus is lost/gained.
     *
     * @return an instance of the {@code FocusListener}
     */
    protected FocusListener createFocusListener() {
        return getHandler();
    }

    
Creates the listener responsible for getting key events from
the tree.
Returns:
an instance of the KeyListener/**
     * Creates the listener responsible for getting key events from
     * the tree.
     *
     * @return an instance of the {@code KeyListener}
     */
    protected KeyListener createKeyListener() {
        return getHandler();
    }

    
Creates the listener responsible for getting property change
events from the selection model.
Returns:
an instance of the PropertyChangeListener/**
     * Creates the listener responsible for getting property change
     * events from the selection model.
     *
     * @return an instance of the {@code PropertyChangeListener}
     */
    protected PropertyChangeListener createSelectionModelPropertyChangeListener() {
        return getHandler();
    }

    
Creates the listener that updates the display based on selection change
methods.
Returns:
an instance of the TreeSelectionListener/**
     * Creates the listener that updates the display based on selection change
     * methods.
     *
     * @return an instance of the {@code TreeSelectionListener}
     */
    protected TreeSelectionListener createTreeSelectionListener() {
        return getHandler();
    }

    
Creates a listener to handle events from the current editor.
Returns:
an instance of the CellEditorListener/**
     * Creates a listener to handle events from the current editor.
     *
     * @return an instance of the {@code CellEditorListener}
     */
    protected CellEditorListener createCellEditorListener() {
        return getHandler();
    }

    
Creates and returns a new ComponentHandler. This is used for
the large model to mark the validCachedPreferredSize as invalid
when the component moves.
Returns:
an instance of the ComponentListener/**
     * Creates and returns a new ComponentHandler. This is used for
     * the large model to mark the validCachedPreferredSize as invalid
     * when the component moves.
     *
     * @return an instance of the {@code ComponentListener}
     */
    protected ComponentListener createComponentListener() {
        return new ComponentHandler();
    }

    
Creates and returns the object responsible for updating the treestate
when nodes expanded state changes.
Returns:
an instance of the TreeExpansionListener/**
     * Creates and returns the object responsible for updating the treestate
     * when nodes expanded state changes.
     *
     * @return an instance of the {@code TreeExpansionListener}
     */
    protected TreeExpansionListener createTreeExpansionListener() {
        return getHandler();
    }

    
Creates the object responsible for managing what is expanded, as
well as the size of nodes.
Returns:
the object responsible for managing what is expanded/**
     * Creates the object responsible for managing what is expanded, as
     * well as the size of nodes.
     *
     * @return the object responsible for managing what is expanded
     */
    protected AbstractLayoutCache createLayoutCache() {
        if(isLargeModel() && getRowHeight() > 0) {
            return new FixedHeightLayoutCache();
        }
        return new VariableHeightLayoutCache();
    }

    
Returns the renderer pane that renderer components are placed in.
Returns:
an instance of the CellRendererPane/**
     * Returns the renderer pane that renderer components are placed in.
     *
     * @return an instance of the {@code CellRendererPane}
     */
    protected CellRendererPane createCellRendererPane() {
        return new CellRendererPane();
    }

    
Creates a default cell editor.
Returns:
a default cell editor/**
     * Creates a default cell editor.
     *
     * @return a default cell editor
     */
    protected TreeCellEditor createDefaultCellEditor() {
        if(currentCellRenderer != null &&
           (currentCellRenderer instanceof DefaultTreeCellRenderer)) {
            DefaultTreeCellEditor editor = new DefaultTreeCellEditor
                        (tree, (DefaultTreeCellRenderer)currentCellRenderer);

            return editor;
        }
        return new DefaultTreeCellEditor(tree, null);
    }

    
Returns the default cell renderer that is used to do the
stamping of each node.
Returns:
an instance of TreeCellRenderer/**
     * Returns the default cell renderer that is used to do the
     * stamping of each node.
     *
     * @return an instance of {@code TreeCellRenderer}
     */
    protected TreeCellRenderer createDefaultCellRenderer() {
        return new DefaultTreeCellRenderer();
    }

    
Returns a listener that can update the tree when the model changes.
Returns:
an instance of the TreeModelListener./**
     * Returns a listener that can update the tree when the model changes.
     *
     * @return an instance of the {@code TreeModelListener}.
     */
    protected TreeModelListener createTreeModelListener() {
        return getHandler();
    }

    //
    // Uninstall methods
    //

    public void uninstallUI(JComponent c) {
        completeEditing();

        prepareForUIUninstall();

        uninstallDefaults();
        uninstallListeners();
        uninstallKeyboardActions();
        uninstallComponents();

        completeUIUninstall();
    }

    
Invoked before unstallation of UI.
/**
     * Invoked before unstallation of UI.
     */
    protected void prepareForUIUninstall() {
    }

    
Uninstalls UI.
/**
     * Uninstalls UI.
     */
    protected void completeUIUninstall() {
        if(createdRenderer) {
            tree.setCellRenderer(null);
        }
        if(createdCellEditor) {
            tree.setCellEditor(null);
        }
        cellEditor = null;
        currentCellRenderer = null;
        rendererPane = null;
        componentListener = null;
        propertyChangeListener = null;
        mouseListener = null;
        focusListener = null;
        keyListener = null;
        setSelectionModel(null);
        treeState = null;
        drawingCache = null;
        selectionModelPropertyChangeListener = null;
        tree = null;
        treeModel = null;
        treeSelectionModel = null;
        treeSelectionListener = null;
        treeExpansionListener = null;
    }

    
Uninstalls default properties.
/**
     * Uninstalls default properties.
     */
    protected void uninstallDefaults() {
        if (tree.getTransferHandler() instanceof UIResource) {
            tree.setTransferHandler(null);
        }
    }

    
Unregisters listeners.
/**
     * Unregisters listeners.
     */
    protected void uninstallListeners() {
        if(componentListener != null) {
            tree.removeComponentListener(componentListener);
        }
        if (propertyChangeListener != null) {
            tree.removePropertyChangeListener(propertyChangeListener);
        }
        if (mouseListener != null) {
            tree.removeMouseListener(mouseListener);
            if (mouseListener instanceof MouseMotionListener) {
                tree.removeMouseMotionListener((MouseMotionListener)mouseListener);
            }
        }
        if (focusListener != null) {
            tree.removeFocusListener(focusListener);
        }
        if (keyListener != null) {
            tree.removeKeyListener(keyListener);
        }
        if(treeExpansionListener != null) {
            tree.removeTreeExpansionListener(treeExpansionListener);
        }
        if(treeModel != null && treeModelListener != null) {
            treeModel.removeTreeModelListener(treeModelListener);
        }
        if(selectionModelPropertyChangeListener != null &&
           treeSelectionModel != null) {
            treeSelectionModel.removePropertyChangeListener
                (selectionModelPropertyChangeListener);
        }
        if(treeSelectionListener != null && treeSelectionModel != null) {
            treeSelectionModel.removeTreeSelectionListener
                               (treeSelectionListener);
        }
        handler = null;
    }

    
Unregisters keyboard actions.
/**
     * Unregisters keyboard actions.
     */
    protected void uninstallKeyboardActions() {
        SwingUtilities.replaceUIActionMap(tree, null);
        SwingUtilities.replaceUIInputMap(tree, JComponent.
                                         WHEN_ANCESTOR_OF_FOCUSED_COMPONENT,
                                         null);
        SwingUtilities.replaceUIInputMap(tree, JComponent.WHEN_FOCUSED, null);
    }

    
Uninstalls the renderer pane.
/**
     * Uninstalls the renderer pane.
     */
    protected void uninstallComponents() {
        if(rendererPane != null) {
            tree.remove(rendererPane);
        }
    }

    
Recomputes the right margin, and invalidates any tree states
/**
     * Recomputes the right margin, and invalidates any tree states
     */
    private void redoTheLayout() {
        if (treeState != null) {
            treeState.invalidateSizes();
        }
    }

    
Returns the baseline.
Throws:
NullPointerException – {@inheritDoc}
IllegalArgumentException – {@inheritDoc}
See Also:
JComponent.getBaseline(int, int)
Since:
1.6/**
     * Returns the baseline.
     *
     * @throws NullPointerException {@inheritDoc}
     * @throws IllegalArgumentException {@inheritDoc}
     * @see javax.swing.JComponent#getBaseline(int, int)
     * @since 1.6
     */
    public int getBaseline(JComponent c, int width, int height) {
        super.getBaseline(c, width, height);
        UIDefaults lafDefaults = UIManager.getLookAndFeelDefaults();
        Component renderer = (Component)lafDefaults.get(
                BASELINE_COMPONENT_KEY);
        if (renderer == null) {
            TreeCellRenderer tcr = createDefaultCellRenderer();
            renderer = tcr.getTreeCellRendererComponent(
                    tree, "a", false, false, false, -1, false);
            lafDefaults.put(BASELINE_COMPONENT_KEY, renderer);
        }
        int rowHeight = tree.getRowHeight();
        int baseline;
        if (rowHeight > 0) {
            baseline = renderer.getBaseline(Integer.MAX_VALUE, rowHeight);
        }
        else {
            Dimension pref = renderer.getPreferredSize();
            baseline = renderer.getBaseline(pref.width, pref.height);
        }
        return baseline + tree.getInsets().top;
    }

    
Returns an enum indicating how the baseline of the component
changes as the size changes.
Throws:
NullPointerException – {@inheritDoc}
See Also:
JComponent.getBaseline(int, int)
Since:
1.6/**
     * Returns an enum indicating how the baseline of the component
     * changes as the size changes.
     *
     * @throws NullPointerException {@inheritDoc}
     * @see javax.swing.JComponent#getBaseline(int, int)
     * @since 1.6
     */
    public Component.BaselineResizeBehavior getBaselineResizeBehavior(
            JComponent c) {
        super.getBaselineResizeBehavior(c);
        return Component.BaselineResizeBehavior.CONSTANT_ASCENT;
    }

    //
    // Painting routines.
    //

    public void paint(Graphics g, JComponent c) {
        if (tree != c) {
            throw new InternalError("incorrect component");
        }

        // Should never happen if installed for a UI
        if(treeState == null) {
            return;
        }

        Rectangle        paintBounds = g.getClipBounds();
        Insets           insets = tree.getInsets();
        TreePath         initialPath = getClosestPathForLocation
                                       (tree, 0, paintBounds.y);
        Enumeration<?>   paintingEnumerator = treeState.getVisiblePathsFrom
                                              (initialPath);
        int              row = treeState.getRowForPath(initialPath);
        int              endY = paintBounds.y + paintBounds.height;

        drawingCache.clear();

        if(initialPath != null && paintingEnumerator != null) {
            TreePath   parentPath = initialPath;

            // Draw the lines, knobs, and rows

            // Find each parent and have them draw a line to their last child
            parentPath = parentPath.getParentPath();
            while(parentPath != null) {
                paintVerticalPartOfLeg(g, paintBounds, insets, parentPath);
                drawingCache.put(parentPath, Boolean.TRUE);
                parentPath = parentPath.getParentPath();
            }

            boolean         done = false;
            // Information for the node being rendered.
            boolean         isExpanded;
            boolean         hasBeenExpanded;
            boolean         isLeaf;
            Rectangle       boundsBuffer = new Rectangle();
            Rectangle       bounds;
            TreePath        path;
            boolean         rootVisible = isRootVisible();

            while(!done && paintingEnumerator.hasMoreElements()) {
                path = (TreePath)paintingEnumerator.nextElement();
                if(path != null) {
                    isLeaf = treeModel.isLeaf(path.getLastPathComponent());
                    if(isLeaf)
                        isExpanded = hasBeenExpanded = false;
                    else {
                        isExpanded = treeState.getExpandedState(path);
                        hasBeenExpanded = tree.hasBeenExpanded(path);
                    }
                    bounds = getPathBounds(path, insets, boundsBuffer);
                    if(bounds == null)
                        // This will only happen if the model changes out
                        // from under us (usually in another thread).
                        // Swing isn't multithreaded, but I'll put this
                        // check in anyway.
                        return;
                    // See if the vertical line to the parent has been drawn.
                    parentPath = path.getParentPath();
                    if(parentPath != null) {
                        if(drawingCache.get(parentPath) == null) {
                            paintVerticalPartOfLeg(g, paintBounds,
                                                   insets, parentPath);
                            drawingCache.put(parentPath, Boolean.TRUE);
                        }
                        paintHorizontalPartOfLeg(g, paintBounds, insets,
                                                 bounds, path, row,
                                                 isExpanded,
                                                 hasBeenExpanded, isLeaf);
                    }
                    else if(rootVisible && row == 0) {
                        paintHorizontalPartOfLeg(g, paintBounds, insets,
                                                 bounds, path, row,
                                                 isExpanded,
                                                 hasBeenExpanded, isLeaf);
                    }
                    if(shouldPaintExpandControl(path, row, isExpanded,
                                                hasBeenExpanded, isLeaf)) {
                        paintExpandControl(g, paintBounds, insets, bounds,
                                           path, row, isExpanded,
                                           hasBeenExpanded, isLeaf);
                    }
                    paintRow(g, paintBounds, insets, bounds, path,
                                 row, isExpanded, hasBeenExpanded, isLeaf);
                    if((bounds.y + bounds.height) >= endY)
                        done = true;
                }
                else {
                    done = true;
                }
                row++;
            }
        }

        paintDropLine(g);

        // Empty out the renderer pane, allowing renderers to be gc'ed.
        rendererPane.removeAll();

        drawingCache.clear();
    }

    
Tells if a DropLocation should be indicated by a line between nodes. This is meant for javax.swing.DropMode.INSERT and javax.swing.DropMode.ON_OR_INSERT drop modes. 
Params:
loc – a DropLocation
Returns:
true if the drop location should be shown as a line
Since:
1.7/**
     * Tells if a {@code DropLocation} should be indicated by a line between
     * nodes. This is meant for {@code javax.swing.DropMode.INSERT} and
     * {@code javax.swing.DropMode.ON_OR_INSERT} drop modes.
     *
     * @param loc a {@code DropLocation}
     * @return {@code true} if the drop location should be shown as a line
     * @since 1.7
     */
    protected boolean isDropLine(JTree.DropLocation loc) {
        return loc != null && loc.getPath() != null && loc.getChildIndex() != -1;
    }

    
Paints the drop line.
Params:
g – Graphics object to draw on
Since:
1.7/**
     * Paints the drop line.
     *
     * @param g {@code Graphics} object to draw on
     * @since 1.7
     */
    protected void paintDropLine(Graphics g) {
        JTree.DropLocation loc = tree.getDropLocation();
        if (!isDropLine(loc)) {
            return;
        }

        Color c = UIManager.getColor("Tree.dropLineColor");
        if (c != null) {
            g.setColor(c);
            Rectangle rect = getDropLineRect(loc);
            g.fillRect(rect.x, rect.y, rect.width, rect.height);
        }
    }

    
Returns a unbounding box for the drop line.
Params:
loc – a DropLocation
Returns:
bounding box for the drop line
Since:
1.7/**
     * Returns a unbounding box for the drop line.
     *
     * @param loc a {@code DropLocation}
     * @return bounding box for the drop line
     * @since 1.7
     */
    protected Rectangle getDropLineRect(JTree.DropLocation loc) {
        Rectangle rect;
        TreePath path = loc.getPath();
        int index = loc.getChildIndex();
        boolean ltr = leftToRight;

        Insets insets = tree.getInsets();

        if (tree.getRowCount() == 0) {
            rect = new Rectangle(insets.left,
                                 insets.top,
                                 tree.getWidth() - insets.left - insets.right,
                                 0);
        } else {
            TreeModel model = getModel();
            Object root = model.getRoot();

            if (path.getLastPathComponent() == root
                    && index >= model.getChildCount(root)) {

                rect = tree.getRowBounds(tree.getRowCount() - 1);
                rect.y = rect.y + rect.height;
                Rectangle xRect;

                if (!tree.isRootVisible()) {
                    xRect = tree.getRowBounds(0);
                } else if (model.getChildCount(root) == 0){
                    xRect = tree.getRowBounds(0);
                    xRect.x += totalChildIndent;
                    xRect.width -= totalChildIndent + totalChildIndent;
                } else {
                    TreePath lastChildPath = path.pathByAddingChild(
                        model.getChild(root, model.getChildCount(root) - 1));
                    xRect = tree.getPathBounds(lastChildPath);
                }

                rect.x = xRect.x;
                rect.width = xRect.width;
            } else {
                if (index >= model.getChildCount(path.getLastPathComponent())) {
                    rect = tree.getPathBounds(path.pathByAddingChild(
                            model.getChild(path.getLastPathComponent(),
                                    index - 1)));
                    rect.y = rect.y + rect.height;
                } else {
                    rect = tree.getPathBounds(path.pathByAddingChild(
                            model.getChild(path.getLastPathComponent(),
                                    index)));
                }
            }
        }

        if (rect.y != 0) {
            rect.y--;
        }

        if (!ltr) {
            rect.x = rect.x + rect.width - 100;
        }

        rect.width = 100;
        rect.height = 2;

        return rect;
    }

    
Paints the horizontal part of the leg. The receiver should NOT modify clipBounds, or insets.
 NOTE: parentRow can be -1 if the root is not visible. 
Params:
g – a graphics context
clipBounds – a clipped rectangle
insets – insets
bounds – a bounding rectangle
path – a tree path
row – a row
isExpanded – true if the path is expanded
hasBeenExpanded – true if the path has been expanded
isLeaf – true if the path is leaf/**
     * Paints the horizontal part of the leg. The receiver should
     * NOT modify {@code clipBounds}, or {@code insets}.<p>
     * NOTE: {@code parentRow} can be -1 if the root is not visible.
     *
     * @param g a graphics context
     * @param clipBounds a clipped rectangle
     * @param insets insets
     * @param bounds a bounding rectangle
     * @param path a tree path
     * @param row a row
     * @param isExpanded {@code true} if the path is expanded
     * @param hasBeenExpanded {@code true} if the path has been expanded
     * @param isLeaf {@code true} if the path is leaf
     */
    protected void paintHorizontalPartOfLeg(Graphics g, Rectangle clipBounds,
                                            Insets insets, Rectangle bounds,
                                            TreePath path, int row,
                                            boolean isExpanded,
                                            boolean hasBeenExpanded, boolean
                                            isLeaf) {
        if (!paintLines) {
            return;
        }

        // Don't paint the legs for the root'ish node if the
        int depth = path.getPathCount() - 1;
        if((depth == 0 || (depth == 1 && !isRootVisible())) &&
           !getShowsRootHandles()) {
            return;
        }

        int clipLeft = clipBounds.x;
        int clipRight = clipBounds.x + clipBounds.width;
        int clipTop = clipBounds.y;
        int clipBottom = clipBounds.y + clipBounds.height;
        int lineY = bounds.y + bounds.height / 2;

        if (leftToRight) {
            int leftX = bounds.x - getRightChildIndent();
            int nodeX = bounds.x - getHorizontalLegBuffer();

            if(lineY >= clipTop
                    && lineY < clipBottom
                    && nodeX >= clipLeft
                    && leftX < clipRight
                    && leftX < nodeX) {

                g.setColor(getHashColor());
                paintHorizontalLine(g, tree, lineY, leftX, nodeX - 1);
            }
        } else {
            int nodeX = bounds.x + bounds.width + getHorizontalLegBuffer();
            int rightX = bounds.x + bounds.width + getRightChildIndent();

            if(lineY >= clipTop
                    && lineY < clipBottom
                    && rightX >= clipLeft
                    && nodeX < clipRight
                    && nodeX < rightX) {

                g.setColor(getHashColor());
                paintHorizontalLine(g, tree, lineY, nodeX, rightX - 1);
            }
        }
    }

    
Paints the vertical part of the leg. The receiver should NOT modify clipBounds, insets. 
Params:
g – a graphics context
clipBounds – a clipped rectangle
insets – insets
path – a tree path/**
     * Paints the vertical part of the leg. The receiver should
     * NOT modify {@code clipBounds}, {@code insets}.
     *
     * @param g a graphics context
     * @param clipBounds a clipped rectangle
     * @param insets insets
     * @param path a tree path
     */
    protected void paintVerticalPartOfLeg(Graphics g, Rectangle clipBounds,
                                          Insets insets, TreePath path) {
        if (!paintLines) {
            return;
        }

        int depth = path.getPathCount() - 1;
        if (depth == 0 && !getShowsRootHandles() && !isRootVisible()) {
            return;
        }
        int lineX = getRowX(-1, depth + 1);
        if (leftToRight) {
            lineX = lineX - getRightChildIndent() + insets.left;
        }
        else {
            lineX = tree.getWidth() - lineX - insets.right +
                    getRightChildIndent() - 1;
        }
        int clipLeft = clipBounds.x;
        int clipRight = clipBounds.x + (clipBounds.width - 1);

        if (lineX >= clipLeft && lineX <= clipRight) {
            int clipTop = clipBounds.y;
            int clipBottom = clipBounds.y + clipBounds.height;
            Rectangle parentBounds = getPathBounds(tree, path);
            Rectangle lastChildBounds = getPathBounds(tree,
                                                     getLastChildPath(path));

            if(lastChildBounds == null)
                // This shouldn't happen, but if the model is modified
                // in another thread it is possible for this to happen.
                // Swing isn't multithreaded, but I'll add this check in
                // anyway.
                return;

            int       top;

            if(parentBounds == null) {
                top = Math.max(insets.top + getVerticalLegBuffer(),
                               clipTop);
            }
            else
                top = Math.max(parentBounds.y + parentBounds.height +
                               getVerticalLegBuffer(), clipTop);
            if(depth == 0 && !isRootVisible()) {
                TreeModel      model = getModel();

                if(model != null) {
                    Object        root = model.getRoot();

                    if(model.getChildCount(root) > 0) {
                        parentBounds = getPathBounds(tree, path.
                                  pathByAddingChild(model.getChild(root, 0)));
                        if(parentBounds != null)
                            top = Math.max(insets.top + getVerticalLegBuffer(),
                                           parentBounds.y +
                                           parentBounds.height / 2);
                    }
                }
            }

            int bottom = Math.min(lastChildBounds.y +
                                  (lastChildBounds.height / 2), clipBottom);

            if (top <= bottom) {
                g.setColor(getHashColor());
                paintVerticalLine(g, tree, lineX, top, bottom);
            }
        }
    }

    
Paints the expand (toggle) part of a row. The receiver should NOT modify clipBounds, or insets. 
Params:
g – a graphics context
clipBounds – a clipped rectangle
insets – insets
bounds – a bounding rectangle
path – a tree path
row – a row
isExpanded – true if the path is expanded
hasBeenExpanded – true if the path has been expanded
isLeaf – true if the row is leaf/**
     * Paints the expand (toggle) part of a row. The receiver should
     * NOT modify {@code clipBounds}, or {@code insets}.
     *
     * @param g a graphics context
     * @param clipBounds a clipped rectangle
     * @param insets insets
     * @param bounds a bounding rectangle
     * @param path a tree path
     * @param row a row
     * @param isExpanded {@code true} if the path is expanded
     * @param hasBeenExpanded {@code true} if the path has been expanded
     * @param isLeaf {@code true} if the row is leaf
     */
    protected void paintExpandControl(Graphics g,
                                      Rectangle clipBounds, Insets insets,
                                      Rectangle bounds, TreePath path,
                                      int row, boolean isExpanded,
                                      boolean hasBeenExpanded,
                                      boolean isLeaf) {
        Object       value = path.getLastPathComponent();

        // Draw icons if not a leaf and either hasn't been loaded,
        // or the model child count is > 0.
        if (!isLeaf && (!hasBeenExpanded ||
                        treeModel.getChildCount(value) > 0)) {
            int middleXOfKnob;
            if (leftToRight) {
                middleXOfKnob = bounds.x - getRightChildIndent() + 1;
            } else {
                middleXOfKnob = bounds.x + bounds.width + getRightChildIndent() - 1;
            }
            int middleYOfKnob = bounds.y + (bounds.height / 2);

            if (isExpanded) {
                Icon expandedIcon = getExpandedIcon();
                if(expandedIcon != null)
                  drawCentered(tree, g, expandedIcon, middleXOfKnob,
                               middleYOfKnob );
            }
            else {
                Icon collapsedIcon = getCollapsedIcon();
                if(collapsedIcon != null)
                  drawCentered(tree, g, collapsedIcon, middleXOfKnob,
                               middleYOfKnob);
            }
        }
    }

    
Paints the renderer part of a row. The receiver should NOT modify clipBounds, or insets. 
Params:
g – a graphics context
clipBounds – a clipped rectangle
insets – insets
bounds – a bounding rectangle
path – a tree path
row – a row
isExpanded – true if the path is expanded
hasBeenExpanded – true if the path has been expanded
isLeaf – true if the path is leaf/**
     * Paints the renderer part of a row. The receiver should
     * NOT modify {@code clipBounds}, or {@code insets}.
     *
     * @param g a graphics context
     * @param clipBounds a clipped rectangle
     * @param insets insets
     * @param bounds a bounding rectangle
     * @param path a tree path
     * @param row a row
     * @param isExpanded {@code true} if the path is expanded
     * @param hasBeenExpanded {@code true} if the path has been expanded
     * @param isLeaf {@code true} if the path is leaf
     */
    protected void paintRow(Graphics g, Rectangle clipBounds,
                            Insets insets, Rectangle bounds, TreePath path,
                            int row, boolean isExpanded,
                            boolean hasBeenExpanded, boolean isLeaf) {
        // Don't paint the renderer if editing this row.
        if(editingComponent != null && editingRow == row)
            return;

        int leadIndex;

        if(tree.hasFocus()) {
            leadIndex = getLeadSelectionRow();
        }
        else
            leadIndex = -1;

        Component component;

        component = currentCellRenderer.getTreeCellRendererComponent
                      (tree, path.getLastPathComponent(),
                       tree.isRowSelected(row), isExpanded, isLeaf, row,
                       (leadIndex == row));

        rendererPane.paintComponent(g, component, tree, bounds.x, bounds.y,
                                    bounds.width, bounds.height, true);
    }

    
Returns true if the expand (toggle) control should be drawn for the specified row. 
Params:
path – a tree path
row – a row
isExpanded – true if the path is expanded
hasBeenExpanded – true if the path has been expanded
isLeaf – true if the row is leaf
Returns:
true if the expand (toggle) control should be drawn for the specified row/**
     * Returns {@code true} if the expand (toggle) control should be drawn for
     * the specified row.
     *
     * @param path a tree path
     * @param row a row
     * @param isExpanded {@code true} if the path is expanded
     * @param hasBeenExpanded {@code true} if the path has been expanded
     * @param isLeaf {@code true} if the row is leaf
     * @return {@code true} if the expand (toggle) control should be drawn
     *         for the specified row
     */
    protected boolean shouldPaintExpandControl(TreePath path, int row,
                                               boolean isExpanded,
                                               boolean hasBeenExpanded,
                                               boolean isLeaf) {
        if(isLeaf)
            return false;

        int              depth = path.getPathCount() - 1;

        if((depth == 0 || (depth == 1 && !isRootVisible())) &&
           !getShowsRootHandles())
            return false;
        return true;
    }

    
Paints a vertical line.
Params:
g – a graphics context
c – a component
x – an X coordinate
top – an Y1 coordinate
bottom – an Y2 coordinate/**
     * Paints a vertical line.
     *
     * @param g a graphics context
     * @param c a component
     * @param x an X coordinate
     * @param top an Y1 coordinate
     * @param bottom an Y2 coordinate
     */
    protected void paintVerticalLine(Graphics g, JComponent c, int x, int top,
                                    int bottom) {
        if (lineTypeDashed) {
            drawDashedVerticalLine(g, x, top, bottom);
        } else {
            g.drawLine(x, top, x, bottom);
        }
    }

    
Paints a horizontal line.
Params:
g – a graphics context
c – a component
y – an Y coordinate
left – an X1 coordinate
right – an X2 coordinate/**
     * Paints a horizontal line.
     *
     * @param g a graphics context
     * @param c a component
     * @param y an Y coordinate
     * @param left an X1 coordinate
     * @param right an X2 coordinate
     */
    protected void paintHorizontalLine(Graphics g, JComponent c, int y,
                                      int left, int right) {
        if (lineTypeDashed) {
            drawDashedHorizontalLine(g, y, left, right);
        } else {
            g.drawLine(left, y, right, y);
        }
    }

    
The vertical element of legs between nodes starts at the bottom of the
parent node by default.  This method makes the leg start below that.
Returns:
the vertical leg buffer/**
     * The vertical element of legs between nodes starts at the bottom of the
     * parent node by default.  This method makes the leg start below that.
     *
     * @return the vertical leg buffer
     */
    protected int getVerticalLegBuffer() {
        return 0;
    }

    
The horizontal element of legs between nodes starts at the
right of the left-hand side of the child node by default.  This
method makes the leg end before that.
Returns:
the horizontal leg buffer/**
     * The horizontal element of legs between nodes starts at the
     * right of the left-hand side of the child node by default.  This
     * method makes the leg end before that.
     *
     * @return the horizontal leg buffer
     */
    protected int getHorizontalLegBuffer() {
        return 0;
    }

    private int findCenteredX(int x, int iconWidth) {
        return leftToRight
               ? x - (int)Math.ceil(iconWidth / 2.0)
               : x - (int)Math.floor(iconWidth / 2.0);
    }

    //
    // Generic painting methods
    //

    
Draws the icon centered at (x,y). 
Params:
c – a component
graphics – a graphics context
icon – an icon
x – an X coordinate
y – an Y coordinate/**
     * Draws the {@code icon} centered at (x,y).
     *
     * @param c a component
     * @param graphics a graphics context
     * @param icon an icon
     * @param x an X coordinate
     * @param y an Y coordinate
     */
    protected void drawCentered(Component c, Graphics graphics, Icon icon,
                                int x, int y) {
        icon.paintIcon(c, graphics,
                      findCenteredX(x, icon.getIconWidth()),
                      y - icon.getIconHeight() / 2);
    }

    
Draws a horizontal dashed line. It is assumed x1 <= x2. If x1 is greater than x2, the method draws nothing. 
Params:
g – an instance of Graphics
y – an Y coordinate
x1 – an X1 coordinate
x2 – an X2 coordinate/**
     * Draws a horizontal dashed line. It is assumed {@code x1} &lt;= {@code x2}.
     * If {@code x1} is greater than {@code x2}, the method draws nothing.
     *
     * @param g an instance of {@code Graphics}
     * @param y an Y coordinate
     * @param x1 an X1 coordinate
     * @param x2 an X2 coordinate
     */
    protected void drawDashedHorizontalLine(Graphics g, int y, int x1, int x2) {
        // Drawing only even coordinates helps join line segments so they
        // appear as one line.  This can be defeated by translating the
        // Graphics by an odd amount.
        drawDashedLine(g, y, x1, x2, false);
    }

    
Draws a vertical dashed line. It is assumed y1 <= y2. If y1 is greater than y2, the method draws nothing. 
Params:
g – an instance of Graphics
x – an X coordinate
y1 – an Y1 coordinate
y2 – an Y2 coordinate/**
     * Draws a vertical dashed line. It is assumed {@code y1} &lt;= {@code y2}.
     * If {@code y1} is greater than {@code y2}, the method draws nothing.
     *
     * @param g an instance of {@code Graphics}
     * @param x an X coordinate
     * @param y1 an Y1 coordinate
     * @param y2 an Y2 coordinate
     */
    protected void drawDashedVerticalLine(Graphics g, int x, int y1, int y2) {
        // Drawing only even coordinates helps join line segments so they
        // appear as one line.  This can be defeated by translating the
        // Graphics by an odd amount.
        drawDashedLine(g, x, y1, y2, true);
    }

    private void drawDashedLine(Graphics g, int v, int v1, int v2, boolean isVertical) {
        if (v1 >= v2) {
            return;
        }
        v1 += (v1 % 2);
        Graphics2D g2d = (Graphics2D) g;
        Stroke oldStroke = g2d.getStroke();

        BasicStroke dashedStroke = new BasicStroke(1, BasicStroke.CAP_BUTT,
                BasicStroke.JOIN_ROUND, 0, new float[]{1}, 0);
        g2d.setStroke(dashedStroke);
        if (isVertical) {
            g2d.drawLine(v, v1, v, v2);
        } else {
            g2d.drawLine(v1, v, v2, v);
        }

        g2d.setStroke(oldStroke);
    }
    //
    // Various local methods
    //

    
Returns the location, along the x-axis, to render a particular row
at. The return value does not include any Insets specified on the JTree.
This does not check for the validity of the row or depth, it is assumed
to be correct and will not throw an Exception if the row or depth
doesn't match that of the tree.
Params:
row – Row to return x location for
depth – Depth of the row
Returns:
amount to indent the given row.
Since:
1.5/**
     * Returns the location, along the x-axis, to render a particular row
     * at. The return value does not include any Insets specified on the JTree.
     * This does not check for the validity of the row or depth, it is assumed
     * to be correct and will not throw an Exception if the row or depth
     * doesn't match that of the tree.
     *
     * @param row Row to return x location for
     * @param depth Depth of the row
     * @return amount to indent the given row.
     * @since 1.5
     */
    protected int getRowX(int row, int depth) {
        return totalChildIndent * (depth + depthOffset);
    }

    
Makes all the nodes that are expanded in JTree expanded in LayoutCache.
This invokes updateExpandedDescendants with the root path.
/**
     * Makes all the nodes that are expanded in JTree expanded in LayoutCache.
     * This invokes updateExpandedDescendants with the root path.
     */
    protected void updateLayoutCacheExpandedNodes() {
        if(treeModel != null && treeModel.getRoot() != null)
            updateExpandedDescendants(new TreePath(treeModel.getRoot()));
    }

    private void updateLayoutCacheExpandedNodesIfNecessary() {
        if (treeModel != null && treeModel.getRoot() != null) {
            TreePath rootPath = new TreePath(treeModel.getRoot());
            if (tree.isExpanded(rootPath)) {
                updateLayoutCacheExpandedNodes();
            } else {
                treeState.setExpandedState(rootPath, false);
            }
        }
    }

    
Updates the expanded state of all the descendants of path by getting the expanded descendants from the tree and forwarding to the tree state. 
Params:
path – a tree path/**
     * Updates the expanded state of all the descendants of {@code path}
     * by getting the expanded descendants from the tree and forwarding
     * to the tree state.
     *
     * @param path a tree path
     */
    protected void updateExpandedDescendants(TreePath path) {
        completeEditing();
        if(treeState != null) {
            treeState.setExpandedState(path, true);

            Enumeration<?> descendants = tree.getExpandedDescendants(path);

            if(descendants != null) {
                while(descendants.hasMoreElements()) {
                    path = (TreePath)descendants.nextElement();
                    treeState.setExpandedState(path, true);
                }
            }
            updateLeadSelectionRow();
            updateSize();
        }
    }

    
Returns a path to the last child of parent. 
Params:
parent – a tree path
Returns:
a path to the last child of parent/**
     * Returns a path to the last child of {@code parent}.
     *
     * @param parent a tree path
     * @return a path to the last child of {@code parent}
     */
    protected TreePath getLastChildPath(TreePath parent) {
        if(treeModel != null) {
            int         childCount = treeModel.getChildCount
                (parent.getLastPathComponent());

            if(childCount > 0)
                return parent.pathByAddingChild(treeModel.getChild
                           (parent.getLastPathComponent(), childCount - 1));
        }
        return null;
    }

    
Updates how much each depth should be offset by.
/**
     * Updates how much each depth should be offset by.
     */
    protected void updateDepthOffset() {
        if(isRootVisible()) {
            if(getShowsRootHandles())
                depthOffset = 1;
            else
                depthOffset = 0;
        }
        else if(!getShowsRootHandles())
            depthOffset = -1;
        else
            depthOffset = 0;
    }

    
Updates the cellEditor based on the editability of the JTree that
we're contained in.  If the tree is editable but doesn't have a
cellEditor, a basic one will be used.
/**
      * Updates the cellEditor based on the editability of the JTree that
      * we're contained in.  If the tree is editable but doesn't have a
      * cellEditor, a basic one will be used.
      */
    protected void updateCellEditor() {
        TreeCellEditor        newEditor;

        completeEditing();
        if(tree == null)
            newEditor = null;
        else {
            if(tree.isEditable()) {
                newEditor = tree.getCellEditor();
                if(newEditor == null) {
                    newEditor = createDefaultCellEditor();
                    if(newEditor != null) {
                        tree.setCellEditor(newEditor);
                        createdCellEditor = true;
                    }
                }
            }
            else
                newEditor = null;
        }
        if(newEditor != cellEditor) {
            if(cellEditor != null && cellEditorListener != null)
                cellEditor.removeCellEditorListener(cellEditorListener);
            cellEditor = newEditor;
            if(cellEditorListener == null)
                cellEditorListener = createCellEditorListener();
            if(newEditor != null && cellEditorListener != null)
                newEditor.addCellEditorListener(cellEditorListener);
            createdCellEditor = false;
        }
    }

    
Messaged from the tree we're in when the renderer has changed.
/**
      * Messaged from the tree we're in when the renderer has changed.
      */
    protected void updateRenderer() {
        if(tree != null) {
            TreeCellRenderer      newCellRenderer;

            newCellRenderer = tree.getCellRenderer();
            if(newCellRenderer == null) {
                tree.setCellRenderer(createDefaultCellRenderer());
                createdRenderer = true;
            }
            else {
                createdRenderer = false;
                currentCellRenderer = newCellRenderer;
                if(createdCellEditor) {
                    tree.setCellEditor(null);
                }
            }
        }
        else {
            createdRenderer = false;
            currentCellRenderer = null;
        }
        updateCellEditor();
    }

    
Resets the TreeState instance based on the tree we're providing the
look and feel for.
/**
     * Resets the TreeState instance based on the tree we're providing the
     * look and feel for.
     */
    protected void configureLayoutCache() {
        if(treeState != null && tree != null) {
            if(nodeDimensions == null)
                nodeDimensions = createNodeDimensions();
            treeState.setNodeDimensions(nodeDimensions);
            treeState.setRootVisible(tree.isRootVisible());
            treeState.setRowHeight(tree.getRowHeight());
            treeState.setSelectionModel(getSelectionModel());
            // Only do this if necessary, may loss state if call with
            // same model as it currently has.
            if(treeState.getModel() != tree.getModel())
                treeState.setModel(tree.getModel());
            updateLayoutCacheExpandedNodesIfNecessary();
            // Create a listener to update preferred size when bounds
            // changes, if necessary.
            if(isLargeModel()) {
                if(componentListener == null) {
                    componentListener = createComponentListener();
                    if(componentListener != null)
                        tree.addComponentListener(componentListener);
                }
            }
            else if(componentListener != null) {
                tree.removeComponentListener(componentListener);
                componentListener = null;
            }
        }
        else if(componentListener != null) {
            tree.removeComponentListener(componentListener);
            componentListener = null;
        }
    }

    
Marks the cached size as being invalid, and messages the
tree with treeDidChange.
/**
     * Marks the cached size as being invalid, and messages the
     * tree with <code>treeDidChange</code>.
     */
    protected void updateSize() {
        validCachedPreferredSize = false;
        tree.treeDidChange();
    }

    private void updateSize0() {
        validCachedPreferredSize = false;
        tree.revalidate();
    }

    
Updates the preferredSize instance variable,
which is returned from getPreferredSize().

For left to right orientations, the size is determined from the
current AbstractLayoutCache. For RTL orientations, the preferred size
becomes the width minus the minimum x position.
/**
     * Updates the <code>preferredSize</code> instance variable,
     * which is returned from <code>getPreferredSize()</code>.<p>
     * For left to right orientations, the size is determined from the
     * current AbstractLayoutCache. For RTL orientations, the preferred size
     * becomes the width minus the minimum x position.
     */
    protected void updateCachedPreferredSize() {
        if(treeState != null) {
            Insets               i = tree.getInsets();

            if(isLargeModel()) {
                Rectangle            visRect = tree.getVisibleRect();

                if (visRect.x == 0 && visRect.y == 0 &&
                        visRect.width == 0 && visRect.height == 0 &&
                        tree.getVisibleRowCount() > 0) {
                    // The tree doesn't have a valid bounds yet. Calculate
                    // based on visible row count.
                    visRect.width = 1;
                    visRect.height = tree.getRowHeight() *
                            tree.getVisibleRowCount();
                } else {
                    visRect.x -= i.left;
                    visRect.y -= i.top;
                }
                // we should consider a non-visible area above
                Component component = SwingUtilities.getUnwrappedParent(tree);
                if (component instanceof JViewport) {
                    component = component.getParent();
                    if (component instanceof JScrollPane) {
                        JScrollPane pane = (JScrollPane) component;
                        JScrollBar bar = pane.getHorizontalScrollBar();
                        if ((bar != null) && bar.isVisible()) {
                            int height = bar.getHeight();
                            visRect.y -= height;
                            visRect.height += height;
                        }
                    }
                }
                preferredSize.width = treeState.getPreferredWidth(visRect);
            }
            else {
                preferredSize.width = treeState.getPreferredWidth(null);
            }
            preferredSize.height = treeState.getPreferredHeight();
            preferredSize.width += i.left + i.right;
            preferredSize.height += i.top + i.bottom;
        }
        validCachedPreferredSize = true;
    }

    
Messaged from the VisibleTreeNode after it has been expanded. 
Params:
path – a tree path/**
     * Messaged from the {@code VisibleTreeNode} after it has been expanded.
     *
     * @param path a tree path
     */
    protected void pathWasExpanded(TreePath path) {
        if(tree != null) {
            tree.fireTreeExpanded(path);
        }
    }

    
Messaged from the VisibleTreeNode after it has collapsed. 
Params:
path – a tree path/**
     * Messaged from the {@code VisibleTreeNode} after it has collapsed.
     *
     * @param path a tree path
     */
    protected void pathWasCollapsed(TreePath path) {
        if(tree != null) {
            tree.fireTreeCollapsed(path);
        }
    }

    
Ensures that the rows identified by beginRow through endRow are visible. 
Params:
beginRow – the begin row
endRow – the end row/**
     * Ensures that the rows identified by {@code beginRow} through
     * {@code endRow} are visible.
     *
     * @param beginRow the begin row
     * @param endRow the end row
     */
    protected void ensureRowsAreVisible(int beginRow, int endRow) {
        if(tree != null && beginRow >= 0 && endRow < getRowCount(tree)) {
            boolean scrollVert = DefaultLookup.getBoolean(tree, this,
                              "Tree.scrollsHorizontallyAndVertically", false);
            if(beginRow == endRow) {
                Rectangle     scrollBounds = getPathBounds(tree, getPathForRow
                                                           (tree, beginRow));

                if(scrollBounds != null) {
                    if (!scrollVert) {
                        scrollBounds.x = tree.getVisibleRect().x;
                        scrollBounds.width = 1;
                    }
                    tree.scrollRectToVisible(scrollBounds);
                }
            }
            else {
                Rectangle   beginRect = getPathBounds(tree, getPathForRow
                                                      (tree, beginRow));
                if (beginRect != null) {
                    Rectangle   visRect = tree.getVisibleRect();
                    Rectangle   testRect = beginRect;
                    int         beginY = beginRect.y;
                    int         maxY = beginY + visRect.height;

                    for(int counter = beginRow + 1; counter <= endRow; counter++) {
                            testRect = getPathBounds(tree,
                                    getPathForRow(tree, counter));
                        if (testRect == null) {
                            return;
                        }
                        if((testRect.y + testRect.height) > maxY)
                                counter = endRow;
                            }
                        tree.scrollRectToVisible(new Rectangle(visRect.x, beginY, 1,
                                                      testRect.y + testRect.height-
                                                      beginY));
                }
            }
        }
    }

    
Sets the preferred minimum size.
Params:
newSize – the new preferred size/**
     * Sets the preferred minimum size.
     *
     * @param newSize the new preferred size
     */
    public void setPreferredMinSize(Dimension newSize) {
        preferredMinSize = newSize;
    }

    
Returns the minimum preferred size.
Returns:
the minimum preferred size/**
     * Returns the minimum preferred size.
     *
     * @return the minimum preferred size
     */
    public Dimension getPreferredMinSize() {
        if(preferredMinSize == null)
            return null;
        return new Dimension(preferredMinSize);
    }

    
Returns the preferred size to properly display the tree, this is a cover method for getPreferredSize(c, true). 
Params:
c – a component
Returns:
the preferred size to represent the tree in the component/**
     * Returns the preferred size to properly display the tree,
     * this is a cover method for {@code getPreferredSize(c, true)}.
     *
     * @param c a component
     * @return the preferred size to represent the tree in the component
     */
    public Dimension getPreferredSize(JComponent c) {
        return getPreferredSize(c, true);
    }

    
Returns the preferred size to represent the tree in
c.  If checkConsistency is true checkConsistency is messaged first.
Params:
c – a component
checkConsistency – if true consistency is checked
Returns:
the preferred size to represent the tree in the component/**
     * Returns the preferred size to represent the tree in
     * <I>c</I>.  If <I>checkConsistency</I> is {@code true}
     * <b>checkConsistency</b> is messaged first.
     *
     * @param c a component
     * @param checkConsistency if {@code true} consistency is checked
     * @return the preferred size to represent the tree in the component
     */
    public Dimension getPreferredSize(JComponent c,
                                      boolean checkConsistency) {
        Dimension       pSize = this.getPreferredMinSize();

        if(!validCachedPreferredSize)
            updateCachedPreferredSize();
        if(tree != null) {
            if(pSize != null)
                return new Dimension(Math.max(pSize.width,
                                              preferredSize.width),
                              Math.max(pSize.height, preferredSize.height));
            return new Dimension(preferredSize.width, preferredSize.height);
        }
        else if(pSize != null)
            return pSize;
        else
            return new Dimension(0, 0);
    }

    
Returns the minimum size for this component.  Which will be
the min preferred size or 0, 0.
/**
      * Returns the minimum size for this component.  Which will be
      * the min preferred size or 0, 0.
      */
    public Dimension getMinimumSize(JComponent c) {
        if(this.getPreferredMinSize() != null)
            return this.getPreferredMinSize();
        return new Dimension(0, 0);
    }

    
Returns the maximum size for this component, which will be the
preferred size if the instance is currently in a JTree, or 0, 0.
/**
      * Returns the maximum size for this component, which will be the
      * preferred size if the instance is currently in a JTree, or 0, 0.
      */
    public Dimension getMaximumSize(JComponent c) {
        if(tree != null)
            return getPreferredSize(tree);
        if(this.getPreferredMinSize() != null)
            return this.getPreferredMinSize();
        return new Dimension(0, 0);
    }


    
Messages to stop the editing session. If the UI the receiver
is providing the look and feel for returns true from
getInvokesStopCellEditing, stopCellEditing will
invoked on the current editor. Then completeEditing will
be messaged with false, true, false to cancel any lingering
editing.
/**
     * Messages to stop the editing session. If the UI the receiver
     * is providing the look and feel for returns true from
     * <code>getInvokesStopCellEditing</code>, stopCellEditing will
     * invoked on the current editor. Then completeEditing will
     * be messaged with false, true, false to cancel any lingering
     * editing.
     */
    protected void completeEditing() {
        /* If should invoke stopCellEditing, try that */
        if(tree.getInvokesStopCellEditing() &&
           stopEditingInCompleteEditing && editingComponent != null) {
            cellEditor.stopCellEditing();
        }
        /* Invoke cancelCellEditing, this will do nothing if stopCellEditing
           was successful. */
        completeEditing(false, true, false);
    }

    
Stops the editing session. If messageStop is true the editor is messaged with stopEditing, if messageCancel is true the editor is messaged with cancelEditing. If messageTree is true the treeModel is messaged with valueForPathChanged. 
Params:
messageStop – message to stop editing
messageCancel – message to cancel editing
messageTree – message to tree/**
     * Stops the editing session. If {@code messageStop} is {@code true} the editor
     * is messaged with {@code stopEditing}, if {@code messageCancel}
     * is {@code true} the editor is messaged with {@code cancelEditing}.
     * If {@code messageTree} is {@code true} the {@code treeModel} is messaged
     * with {@code valueForPathChanged}.
     *
     * @param messageStop message to stop editing
     * @param messageCancel message to cancel editing
     * @param messageTree message to tree
     */
    @SuppressWarnings("deprecation")
    protected void completeEditing(boolean messageStop,
                                   boolean messageCancel,
                                   boolean messageTree) {
        if(stopEditingInCompleteEditing && editingComponent != null) {
            Component             oldComponent = editingComponent;
            TreePath              oldPath = editingPath;
            TreeCellEditor        oldEditor = cellEditor;
            Object                newValue = oldEditor.getCellEditorValue();
            Rectangle             editingBounds = getPathBounds(tree,
                                                                editingPath);
            boolean               requestFocus = (tree != null &&
                                   (tree.hasFocus() || SwingUtilities.
                                    findFocusOwner(editingComponent) != null));

            editingComponent = null;
            editingPath = null;
            if(messageStop)
                oldEditor.stopCellEditing();
            else if(messageCancel)
                oldEditor.cancelCellEditing();
            tree.remove(oldComponent);
            if(editorHasDifferentSize) {
                treeState.invalidatePathBounds(oldPath);
                updateSize();
            }
            else if (editingBounds != null) {
                editingBounds.x = 0;
                editingBounds.width = tree.getSize().width;
                tree.repaint(editingBounds);
            }
            if(requestFocus)
                tree.requestFocus();
            if(messageTree)
                treeModel.valueForPathChanged(oldPath, newValue);
        }
    }

    // cover method for startEditing that allows us to pass extra
    // information into that method via a class variable
    private boolean startEditingOnRelease(TreePath path,
                                          MouseEvent event,
                                          MouseEvent releaseEvent) {
        this.releaseEvent = releaseEvent;
        try {
            return startEditing(path, event);
        } finally {
            this.releaseEvent = null;
        }
    }

    
Will start editing for node if there is a cellEditor and shouldSelectCell returns true.

This assumes that path is valid and visible.
Params:
path – a tree path
event – a mouse event
Returns:
true if the editing is successful/**
     * Will start editing for node if there is a {@code cellEditor} and
     * {@code shouldSelectCell} returns {@code true}.<p>
     * This assumes that path is valid and visible.
     *
     * @param path a tree path
     * @param event a mouse event
     * @return {@code true} if the editing is successful
     */
    protected boolean startEditing(TreePath path, MouseEvent event) {
        if (isEditing(tree) && tree.getInvokesStopCellEditing() &&
                               !stopEditing(tree)) {
            return false;
        }
        completeEditing();
        if(cellEditor != null && tree.isPathEditable(path)) {
            int           row = getRowForPath(tree, path);

            if(cellEditor.isCellEditable(event)) {
                editingComponent = cellEditor.getTreeCellEditorComponent
                      (tree, path.getLastPathComponent(),
                       tree.isPathSelected(path), tree.isExpanded(path),
                       treeModel.isLeaf(path.getLastPathComponent()), row);
                Rectangle           nodeBounds = getPathBounds(tree, path);
                if (nodeBounds == null) {
                    return false;
                }

                editingRow = row;

                Dimension editorSize = editingComponent.getPreferredSize();

                // Only allow odd heights if explicitly set.
                if(editorSize.height != nodeBounds.height &&
                   getRowHeight() > 0)
                    editorSize.height = getRowHeight();

                if(editorSize.width != nodeBounds.width ||
                   editorSize.height != nodeBounds.height) {
                    // Editor wants different width or height, invalidate
                    // treeState and relayout.
                    editorHasDifferentSize = true;
                    treeState.invalidatePathBounds(path);
                    updateSize();
                    // To make sure x/y are updated correctly, fetch
                    // the bounds again.
                    nodeBounds = getPathBounds(tree, path);
                    if (nodeBounds == null) {
                        return false;
                    }
                }
                else
                    editorHasDifferentSize = false;
                tree.add(editingComponent);
                editingComponent.setBounds(nodeBounds.x, nodeBounds.y,
                                           nodeBounds.width,
                                           nodeBounds.height);
                editingPath = path;
                AWTAccessor.getComponentAccessor().revalidateSynchronously(editingComponent);
                editingComponent.repaint();
                if(cellEditor.shouldSelectCell(event)) {
                    stopEditingInCompleteEditing = false;
                    tree.setSelectionRow(row);
                    stopEditingInCompleteEditing = true;
                }

                Component focusedComponent = SwingUtilities2.
                                 compositeRequestFocus(editingComponent);
                boolean selectAll = true;

                if(event != null) {
                    /* Find the component that will get forwarded all the
                       mouse events until mouseReleased. */
                    Point          componentPoint = SwingUtilities.convertPoint
                        (tree, new Point(event.getX(), event.getY()),
                         editingComponent);

                    /* Create an instance of BasicTreeMouseListener to handle
                       passing the mouse/motion events to the necessary
                       component. */
                    // We really want similar behavior to getMouseEventTarget,
                    // but it is package private.
                    Component activeComponent = SwingUtilities.
                                    getDeepestComponentAt(editingComponent,
                                       componentPoint.x, componentPoint.y);
                    if (activeComponent != null) {
                        MouseInputHandler handler =
                            new MouseInputHandler(tree, activeComponent,
                                                  event, focusedComponent);

                        if (releaseEvent != null) {
                            handler.mouseReleased(releaseEvent);
                        }

                        selectAll = false;
                    }
                }
                if (selectAll && focusedComponent instanceof JTextField) {
                    ((JTextField)focusedComponent).selectAll();
                }
                return true;
            }
            else
                editingComponent = null;
        }
        return false;
    }

    //
    // Following are primarily for handling mouse events.
    //

    
If the mouseX and mouseY are in the expand/collapse region of the row, this will toggle the row. 
Params:
path – a tree path
mouseX – an X coordinate
mouseY – an Y coordinate/**
     * If the {@code mouseX} and {@code mouseY} are in the
     * expand/collapse region of the {@code row}, this will toggle
     * the row.
     *
     * @param path a tree path
     * @param mouseX an X coordinate
     * @param mouseY an Y coordinate
     */
    protected void checkForClickInExpandControl(TreePath path,
                                                int mouseX, int mouseY) {
      if (isLocationInExpandControl(path, mouseX, mouseY)) {
          handleExpandControlClick(path, mouseX, mouseY);
        }
    }

    
Returns true if mouseX and mouseY fall in the area of row that is used to expand/collapse the node and the node at row does not represent a leaf. 
Params:
path – a tree path
mouseX – an X coordinate
mouseY – an Y coordinate
Returns:
true if the mouse cursor fall in the area of row that is used to expand/collapse the node and the node is not a leaf./**
     * Returns {@code true} if {@code mouseX} and {@code mouseY} fall
     * in the area of row that is used to expand/collapse the node and
     * the node at {@code row} does not represent a leaf.
     *
     * @param path a tree path
     * @param mouseX an X coordinate
     * @param mouseY an Y coordinate
     * @return {@code true} if the mouse cursor fall in the area of row that
     *         is used to expand/collapse the node and the node is not a leaf.
     */
    protected boolean isLocationInExpandControl(TreePath path,
                                                int mouseX, int mouseY) {
        if(path != null && !treeModel.isLeaf(path.getLastPathComponent())){
            int                     boxWidth;
            Insets                  i = tree.getInsets();

            if(getExpandedIcon() != null)
                boxWidth = getExpandedIcon().getIconWidth();
            else
                boxWidth = 8;

            int boxLeftX = getRowX(tree.getRowForPath(path),
                                   path.getPathCount() - 1);

            if (leftToRight) {
                boxLeftX = boxLeftX + i.left - getRightChildIndent() + 1;
            } else {
                boxLeftX = tree.getWidth() - boxLeftX - i.right + getRightChildIndent() - 1;
            }

            boxLeftX = findCenteredX(boxLeftX, boxWidth);

            return (mouseX >= boxLeftX && mouseX < (boxLeftX + boxWidth));
        }
        return false;
    }

    
Messaged when the user clicks the particular row, this invokes toggleExpandState. 
Params:
path – a tree path
mouseX – an X coordinate
mouseY – an Y coordinate/**
     * Messaged when the user clicks the particular row, this invokes
     * {@code toggleExpandState}.
     *
     * @param path a tree path
     * @param mouseX an X coordinate
     * @param mouseY an Y coordinate
     */
    protected void handleExpandControlClick(TreePath path, int mouseX,
                                            int mouseY) {
        toggleExpandState(path);
    }

    
Expands path if it is not expanded, or collapses row if it is expanded. If expanding a path and JTree scrolls on expand, ensureRowsAreVisible is invoked to scroll as many of the children to visible as possible (tries to scroll to last visible descendant of path). 
Params:
path – a tree path/**
     * Expands path if it is not expanded, or collapses row if it is expanded.
     * If expanding a path and {@code JTree} scrolls on expand,
     * {@code ensureRowsAreVisible} is invoked to scroll as many of the children
     * to visible as possible (tries to scroll to last visible descendant of path).
     *
     * @param path a tree path
     */
    protected void toggleExpandState(TreePath path) {
        if(!tree.isExpanded(path)) {
            int       row = getRowForPath(tree, path);

            tree.expandPath(path);
            updateSize();
            if(row != -1) {
                if(tree.getScrollsOnExpand())
                    ensureRowsAreVisible(row, row + treeState.
                                         getVisibleChildCount(path));
                else
                    ensureRowsAreVisible(row, row);
            }
        }
        else {
            tree.collapsePath(path);
            updateSize();
        }
    }

    
Returning true signifies a mouse event on the node should toggle the selection of only the row under mouse. 
Params:
event – a mouse event
Returns:
true if a mouse event on the node should toggle the selection/**
     * Returning {@code true} signifies a mouse event on the node should toggle
     * the selection of only the row under mouse.
     *
     * @param event a mouse event
     * @return {@code true} if a mouse event on the node should toggle the selection
     */
    protected boolean isToggleSelectionEvent(MouseEvent event) {
        return (SwingUtilities.isLeftMouseButton(event) &&
                BasicGraphicsUtils.isMenuShortcutKeyDown(event));
    }

    
Returning true signifies a mouse event on the node should select from the anchor point. 
Params:
event – a mouse event
Returns:
true if a mouse event on the node should select from the anchor point/**
     * Returning {@code true} signifies a mouse event on the node should select
     * from the anchor point.
     *
     * @param event a mouse event
     * @return {@code true} if a mouse event on the node should select
     *         from the anchor point
     */
    protected boolean isMultiSelectEvent(MouseEvent event) {
        return (SwingUtilities.isLeftMouseButton(event) &&
                event.isShiftDown());
    }

    
Returning true indicates the row under the mouse should be toggled based on the event. This is invoked after checkForClickInExpandControl, implying the location is not in the expand (toggle) control. 
Params:
event – a mouse event
Returns:
true if the row under the mouse should be toggled/**
     * Returning {@code true} indicates the row under the mouse should be toggled
     * based on the event. This is invoked after {@code checkForClickInExpandControl},
     * implying the location is not in the expand (toggle) control.
     *
     * @param event a mouse event
     * @return {@code true} if the row under the mouse should be toggled
     */
    protected boolean isToggleEvent(MouseEvent event) {
        if(!SwingUtilities.isLeftMouseButton(event)) {
            return false;
        }
        int           clickCount = tree.getToggleClickCount();

        if(clickCount <= 0) {
            return false;
        }
        return ((event.getClickCount() % clickCount) == 0);
    }

    
Messaged to update the selection based on a MouseEvent over a particular row. If the event is a toggle selection event, the row is either selected, or deselected. If the event identifies a multi selection event, the selection is updated from the anchor point. Otherwise the row is selected, and if the event specified a toggle event the row is expanded/collapsed. 
Params:
path – the selected path
event – the mouse event/**
     * Messaged to update the selection based on a {@code MouseEvent} over a
     * particular row. If the event is a toggle selection event, the
     * row is either selected, or deselected. If the event identifies
     * a multi selection event, the selection is updated from the
     * anchor point. Otherwise the row is selected, and if the event
     * specified a toggle event the row is expanded/collapsed.
     *
     * @param path the selected path
     * @param event the mouse event
     */
    protected void selectPathForEvent(TreePath path, MouseEvent event) {
        /* Adjust from the anchor point. */
        if(isMultiSelectEvent(event)) {
            TreePath    anchor = getAnchorSelectionPath();
            int         anchorRow = (anchor == null) ? -1 :
                                    getRowForPath(tree, anchor);

            if(anchorRow == -1 || tree.getSelectionModel().
                      getSelectionMode() == TreeSelectionModel.
                      SINGLE_TREE_SELECTION) {
                tree.setSelectionPath(path);
            }
            else {
                int          row = getRowForPath(tree, path);
                TreePath     lastAnchorPath = anchor;

                if (isToggleSelectionEvent(event)) {
                    if (tree.isRowSelected(anchorRow)) {
                        tree.addSelectionInterval(anchorRow, row);
                    } else {
                        tree.removeSelectionInterval(anchorRow, row);
                        tree.addSelectionInterval(row, row);
                    }
                } else if(row < anchorRow) {
                    tree.setSelectionInterval(row, anchorRow);
                } else {
                    tree.setSelectionInterval(anchorRow, row);
                }
                lastSelectedRow = row;
                setAnchorSelectionPath(lastAnchorPath);
                setLeadSelectionPath(path);
            }
        }

        // Should this event toggle the selection of this row?
        /* Control toggles just this node. */
        else if(isToggleSelectionEvent(event)) {
            if(tree.isPathSelected(path))
                tree.removeSelectionPath(path);
            else
                tree.addSelectionPath(path);
            lastSelectedRow = getRowForPath(tree, path);
            setAnchorSelectionPath(path);
            setLeadSelectionPath(path);
        }

        /* Otherwise set the selection to just this interval. */
        else if(SwingUtilities.isLeftMouseButton(event)) {
            tree.setSelectionPath(path);
            if(isToggleEvent(event)) {
                toggleExpandState(path);
            }
        }
    }

    
Returns true if the node at row is a leaf. 
Params:
row – a row
Returns:
true if the node at row is a leaf/**
     * Returns {@code true} if the node at {@code row} is a leaf.
     *
     * @param row a row
     * @return {@code true} if the node at {@code row} is a leaf
     */
    protected boolean isLeaf(int row) {
        TreePath          path = getPathForRow(tree, row);

        if(path != null)
            return treeModel.isLeaf(path.getLastPathComponent());
        // Have to return something here...
        return true;
    }

    //
    // The following selection methods (lead/anchor) are covers for the
    // methods in JTree.
    //
    private void setAnchorSelectionPath(TreePath newPath) {
        ignoreLAChange = true;
        try {
            tree.setAnchorSelectionPath(newPath);
        } finally{
            ignoreLAChange = false;
        }
    }

    private TreePath getAnchorSelectionPath() {
        return tree.getAnchorSelectionPath();
    }

    private void setLeadSelectionPath(TreePath newPath) {
        setLeadSelectionPath(newPath, false);
    }

    private void setLeadSelectionPath(TreePath newPath, boolean repaint) {
        Rectangle       bounds = repaint ?
                            getPathBounds(tree, getLeadSelectionPath()) : null;

        ignoreLAChange = true;
        try {
            tree.setLeadSelectionPath(newPath);
        } finally {
            ignoreLAChange = false;
        }
        leadRow = getRowForPath(tree, newPath);

        if (repaint) {
            if (bounds != null) {
                tree.repaint(getRepaintPathBounds(bounds));
            }
            bounds = getPathBounds(tree, newPath);
            if (bounds != null) {
                tree.repaint(getRepaintPathBounds(bounds));
            }
        }
    }

    private Rectangle getRepaintPathBounds(Rectangle bounds) {
        if (UIManager.getBoolean("Tree.repaintWholeRow")) {
           bounds.x = 0;
           bounds.width = tree.getWidth();
        }
        return bounds;
    }

    private TreePath getLeadSelectionPath() {
        return tree.getLeadSelectionPath();
    }

    
Updates the lead row of the selection.
Since:
1.7/**
     * Updates the lead row of the selection.
     * @since 1.7
     */
    protected void updateLeadSelectionRow() {
        leadRow = getRowForPath(tree, getLeadSelectionPath());
    }

    
Returns the lead row of the selection.
Returns:
selection lead row
Since:
1.7/**
     * Returns the lead row of the selection.
     *
     * @return selection lead row
     * @since 1.7
     */
    protected int getLeadSelectionRow() {
        return leadRow;
    }

    
Extends the selection from the anchor to make newLead
the lead of the selection. This does not scroll.
/**
     * Extends the selection from the anchor to make <code>newLead</code>
     * the lead of the selection. This does not scroll.
     */
    private void extendSelection(TreePath newLead) {
        TreePath           aPath = getAnchorSelectionPath();
        int                aRow = (aPath == null) ? -1 :
                                  getRowForPath(tree, aPath);
        int                newIndex = getRowForPath(tree, newLead);

        if(aRow == -1) {
            tree.setSelectionRow(newIndex);
        }
        else {
            if(aRow < newIndex) {
                tree.setSelectionInterval(aRow, newIndex);
            }
            else {
                tree.setSelectionInterval(newIndex, aRow);
            }
            setAnchorSelectionPath(aPath);
            setLeadSelectionPath(newLead);
        }
    }

    
Invokes repaint on the JTree for the passed in TreePath,
path.
/**
     * Invokes <code>repaint</code> on the JTree for the passed in TreePath,
     * <code>path</code>.
     */
    private void repaintPath(TreePath path) {
        if (path != null) {
            Rectangle bounds = getPathBounds(tree, path);
            if (bounds != null) {
                tree.repaint(bounds.x, bounds.y, bounds.width, bounds.height);
            }
        }
    }

    
Updates the TreeState in response to nodes expanding/collapsing.
/**
     * Updates the TreeState in response to nodes expanding/collapsing.
     */
    public class TreeExpansionHandler implements TreeExpansionListener {
        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        
Called whenever an item in the tree has been expanded.
/**
         * Called whenever an item in the tree has been expanded.
         */
        public void treeExpanded(TreeExpansionEvent event) {
            getHandler().treeExpanded(event);
        }

        
Called whenever an item in the tree has been collapsed.
/**
         * Called whenever an item in the tree has been collapsed.
         */
        public void treeCollapsed(TreeExpansionEvent event) {
            getHandler().treeCollapsed(event);
        }
    } // BasicTreeUI.TreeExpansionHandler


    
Updates the preferred size when scrolling (if necessary).
/**
     * Updates the preferred size when scrolling (if necessary).
     */
    public class ComponentHandler extends ComponentAdapter implements
                 ActionListener {
        
Timer used when inside a scrollpane and the scrollbar is
adjusting. /** Timer used when inside a scrollpane and the scrollbar is
         * adjusting. */
        protected Timer                timer;
        
ScrollBar that is being adjusted. /** ScrollBar that is being adjusted. */
        protected JScrollBar           scrollBar;

        public void componentMoved(ComponentEvent e) {
            if(timer == null) {
                JScrollPane   scrollPane = getScrollPane();

                if(scrollPane == null)
                    updateSize();
                else {
                    scrollBar = scrollPane.getVerticalScrollBar();
                    if(scrollBar == null ||
                        !scrollBar.getValueIsAdjusting()) {
                        // Try the horizontal scrollbar.
                        if((scrollBar = scrollPane.getHorizontalScrollBar())
                            != null && scrollBar.getValueIsAdjusting())
                            startTimer();
                        else
                            updateSize();
                    }
                    else
                        startTimer();
                }
            }
        }

        
Creates, if necessary, and starts a Timer to check if need to
resize the bounds.
/**
         * Creates, if necessary, and starts a Timer to check if need to
         * resize the bounds.
         */
        protected void startTimer() {
            if(timer == null) {
                timer = new Timer(200, this);
                timer.setRepeats(true);
            }
            timer.start();
        }

        
Returns the JScrollPane housing the JTree, or null if one isn't found. 
Returns:
the JScrollPane housing the JTree/**
         * Returns the {@code JScrollPane} housing the {@code JTree},
         * or null if one isn't found.
         *
         * @return the {@code JScrollPane} housing the {@code JTree}
         */
        protected JScrollPane getScrollPane() {
            Component       c = tree.getParent();

            while(c != null && !(c instanceof JScrollPane))
                c = c.getParent();
            if(c instanceof JScrollPane)
                return (JScrollPane)c;
            return null;
        }

        
Public as a result of Timer. If the scrollBar is null, or
not adjusting, this stops the timer and updates the sizing.
/**
         * Public as a result of Timer. If the scrollBar is null, or
         * not adjusting, this stops the timer and updates the sizing.
         */
        public void actionPerformed(ActionEvent ae) {
            if(scrollBar == null || !scrollBar.getValueIsAdjusting()) {
                if(timer != null)
                    timer.stop();
                updateSize();
                timer = null;
                scrollBar = null;
            }
        }
    } // End of BasicTreeUI.ComponentHandler


    
Forwards all TreeModel events to the TreeState.
/**
     * Forwards all TreeModel events to the TreeState.
     */
    public class TreeModelHandler implements TreeModelListener {

        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        public void treeNodesChanged(TreeModelEvent e) {
            getHandler().treeNodesChanged(e);
        }

        public void treeNodesInserted(TreeModelEvent e) {
            getHandler().treeNodesInserted(e);
        }

        public void treeNodesRemoved(TreeModelEvent e) {
            getHandler().treeNodesRemoved(e);
        }

        public void treeStructureChanged(TreeModelEvent e) {
            getHandler().treeStructureChanged(e);
        }
    } // End of BasicTreeUI.TreeModelHandler


    
Listens for changes in the selection model and updates the display
accordingly.
/**
     * Listens for changes in the selection model and updates the display
     * accordingly.
     */
    public class TreeSelectionHandler implements TreeSelectionListener {

        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        
Messaged when the selection changes in the tree we're displaying
for.  Stops editing, messages super and displays the changed paths.
/**
         * Messaged when the selection changes in the tree we're displaying
         * for.  Stops editing, messages super and displays the changed paths.
         */
        public void valueChanged(TreeSelectionEvent event) {
            getHandler().valueChanged(event);
        }
    }// End of BasicTreeUI.TreeSelectionHandler


    
Listener responsible for getting cell editing events and updating
the tree accordingly.
/**
     * Listener responsible for getting cell editing events and updating
     * the tree accordingly.
     */
    public class CellEditorHandler implements CellEditorListener {

        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        
Messaged when editing has stopped in the tree. /** Messaged when editing has stopped in the tree. */
        public void editingStopped(ChangeEvent e) {
            getHandler().editingStopped(e);
        }

        
Messaged when editing has been canceled in the tree. /** Messaged when editing has been canceled in the tree. */
        public void editingCanceled(ChangeEvent e) {
            getHandler().editingCanceled(e);
        }
    } // BasicTreeUI.CellEditorHandler


    
This is used to get multiple key down events to appropriately generate
events.
/**
     * This is used to get multiple key down events to appropriately generate
     * events.
     */
    public class KeyHandler extends KeyAdapter {

        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        // Also note these fields aren't use anymore, nor does Handler have
        // the old functionality. This behavior worked around an old bug
        // in JComponent that has long since been fixed.

        
Key code that is being generated for. /** Key code that is being generated for. */
        protected Action              repeatKeyAction;

        
Set to true while keyPressed is active. /** Set to true while keyPressed is active. */
        protected boolean            isKeyDown;

        
Invoked when a key has been typed.
Moves the keyboard focus to the first element
whose first letter matches the alphanumeric key
pressed by the user. Subsequent same key presses
move the keyboard focus to the next object that
starts with the same letter.
/**
         * Invoked when a key has been typed.
         *
         * Moves the keyboard focus to the first element
         * whose first letter matches the alphanumeric key
         * pressed by the user. Subsequent same key presses
         * move the keyboard focus to the next object that
         * starts with the same letter.
         */
        public void keyTyped(KeyEvent e) {
            getHandler().keyTyped(e);
        }

        public void keyPressed(KeyEvent e) {
            getHandler().keyPressed(e);
        }

        public void keyReleased(KeyEvent e) {
            getHandler().keyReleased(e);
        }
    } // End of BasicTreeUI.KeyHandler


    
Repaints the lead selection row when focus is lost/gained.
/**
     * Repaints the lead selection row when focus is lost/gained.
     */
    public class FocusHandler implements FocusListener {
        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        
Invoked when focus is activated on the tree we're in, redraws the
lead row.
/**
         * Invoked when focus is activated on the tree we're in, redraws the
         * lead row.
         */
        public void focusGained(FocusEvent e) {
            getHandler().focusGained(e);
        }

        
Invoked when focus is activated on the tree we're in, redraws the
lead row.
/**
         * Invoked when focus is activated on the tree we're in, redraws the
         * lead row.
         */
        public void focusLost(FocusEvent e) {
            getHandler().focusLost(e);
        }
    } // End of class BasicTreeUI.FocusHandler


    
Class responsible for getting size of node, method is forwarded
to BasicTreeUI method. X location does not include insets, that is
handled in getPathBounds.
/**
     * Class responsible for getting size of node, method is forwarded
     * to BasicTreeUI method. X location does not include insets, that is
     * handled in getPathBounds.
     */
    // This returns locations that don't include any Insets.
    public class NodeDimensionsHandler extends
                 AbstractLayoutCache.NodeDimensions {
        
Responsible for getting the size of a particular node.
/**
         * Responsible for getting the size of a particular node.
         */
        public Rectangle getNodeDimensions(Object value, int row,
                                           int depth, boolean expanded,
                                           Rectangle size) {
            // Return size of editing component, if editing and asking
            // for editing row.
            if(editingComponent != null && editingRow == row) {
                Dimension        prefSize = editingComponent.
                                              getPreferredSize();
                int              rh = getRowHeight();

                if(rh > 0 && rh != prefSize.height)
                    prefSize.height = rh;
                if(size != null) {
                    size.x = getRowX(row, depth);
                    size.width = prefSize.width;
                    size.height = prefSize.height;
                }
                else {
                    size = new Rectangle(getRowX(row, depth), 0,
                                         prefSize.width, prefSize.height);
                }
                return size;
            }
            // Not editing, use renderer.
            if(currentCellRenderer != null) {
                Component          aComponent;

                aComponent = currentCellRenderer.getTreeCellRendererComponent
                    (tree, value, tree.isRowSelected(row),
                     expanded, treeModel.isLeaf(value), row,
                     false);
                if(tree != null) {
                    // Only ever removed when UI changes, this is OK!
                    rendererPane.add(aComponent);
                    aComponent.validate();
                }
                Dimension        prefSize = aComponent.getPreferredSize();

                if(size != null) {
                    size.x = getRowX(row, depth);
                    size.width = prefSize.width;
                    size.height = prefSize.height;
                }
                else {
                    size = new Rectangle(getRowX(row, depth), 0,
                                         prefSize.width, prefSize.height);
                }
                return size;
            }
            return null;
        }

        
Returns amount to indent the given row.
Params:
row – a row
depth – a depth
Returns:
amount to indent the given row/**
         * Returns amount to indent the given row.
         *
         * @param row a row
         * @param depth a depth
         * @return amount to indent the given row
         */
        protected int getRowX(int row, int depth) {
            return BasicTreeUI.this.getRowX(row, depth);
        }

    } // End of class BasicTreeUI.NodeDimensionsHandler


    
TreeMouseListener is responsible for updating the selection
based on mouse events.
/**
     * TreeMouseListener is responsible for updating the selection
     * based on mouse events.
     */
    public class MouseHandler extends MouseAdapter implements MouseMotionListener
 {
        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        
Invoked when a mouse button has been pressed on a component.
/**
         * Invoked when a mouse button has been pressed on a component.
         */
        public void mousePressed(MouseEvent e) {
            getHandler().mousePressed(e);
        }

        public void mouseDragged(MouseEvent e) {
            getHandler().mouseDragged(e);
        }

        
Invoked when the mouse button has been moved on a component
(with no buttons no down).
Since:
1.4/**
         * Invoked when the mouse button has been moved on a component
         * (with no buttons no down).
         * @since 1.4
         */
        public void mouseMoved(MouseEvent e) {
            getHandler().mouseMoved(e);
        }

        public void mouseReleased(MouseEvent e) {
            getHandler().mouseReleased(e);
        }
    } // End of BasicTreeUI.MouseHandler


    
PropertyChangeListener for the tree. Updates the appropriate
variable, or TreeState, based on what changes.
/**
     * PropertyChangeListener for the tree. Updates the appropriate
     * variable, or TreeState, based on what changes.
     */
    public class PropertyChangeHandler implements
                       PropertyChangeListener {

        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        public void propertyChange(PropertyChangeEvent event) {
            getHandler().propertyChange(event);
        }
    } // End of BasicTreeUI.PropertyChangeHandler


    
Listener on the TreeSelectionModel, resets the row selection if
any of the properties of the model change.
/**
     * Listener on the TreeSelectionModel, resets the row selection if
     * any of the properties of the model change.
     */
    public class SelectionModelPropertyChangeHandler implements
                      PropertyChangeListener {

        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        public void propertyChange(PropertyChangeEvent event) {
            getHandler().propertyChange(event);
        }
    } // End of BasicTreeUI.SelectionModelPropertyChangeHandler


    
TreeTraverseAction is the action used for left/right keys.
Will toggle the expandedness of a node, as well as potentially
incrementing the selection.
/**
     * <code>TreeTraverseAction</code> is the action used for left/right keys.
     * Will toggle the expandedness of a node, as well as potentially
     * incrementing the selection.
     */
    @SuppressWarnings("serial") // Superclass is not serializable across versions
    public class TreeTraverseAction extends AbstractAction {
        
Determines direction to traverse, 1 means expand, -1 means
collapse. /** Determines direction to traverse, 1 means expand, -1 means
          * collapse. */
        protected int direction;
        
True if the selection is reset, false means only the lead path
changes. /** True if the selection is reset, false means only the lead path
         * changes. */
        private boolean changeSelection;

        
Constructs a new instance of TreeTraverseAction. 
Params:
direction – the direction
name – the name of action/**
         * Constructs a new instance of {@code TreeTraverseAction}.
         *
         * @param direction the direction
         * @param name the name of action
         */
        public TreeTraverseAction(int direction, String name) {
            this(direction, name, true);
        }

        private TreeTraverseAction(int direction, String name,
                                   boolean changeSelection) {
            this.direction = direction;
            this.changeSelection = changeSelection;
        }

        public void actionPerformed(ActionEvent e) {
            if (tree != null) {
                SHARED_ACTION.traverse(tree, BasicTreeUI.this, direction,
                                       changeSelection);
            }
        }

        public boolean isEnabled() { return (tree != null &&
                                             tree.isEnabled()); }
    } // BasicTreeUI.TreeTraverseAction


    
TreePageAction handles page up and page down events.
/** TreePageAction handles page up and page down events.
      */
    @SuppressWarnings("serial") // Superclass is not serializable across versions
    public class TreePageAction extends AbstractAction {
        
Specifies the direction to adjust the selection by. /** Specifies the direction to adjust the selection by. */
        protected int         direction;
        
True indicates should set selection from anchor path. /** True indicates should set selection from anchor path. */
        private boolean       addToSelection;
        private boolean       changeSelection;

        
Constructs a new instance of TreePageAction. 
Params:
direction – the direction
name – the name of action/**
         * Constructs a new instance of {@code TreePageAction}.
         *
         * @param direction the direction
         * @param name the name of action
         */
        public TreePageAction(int direction, String name) {
            this(direction, name, false, true);
        }

        private TreePageAction(int direction, String name,
                               boolean addToSelection,
                               boolean changeSelection) {
            this.direction = direction;
            this.addToSelection = addToSelection;
            this.changeSelection = changeSelection;
        }

        public void actionPerformed(ActionEvent e) {
            if (tree != null) {
                SHARED_ACTION.page(tree, BasicTreeUI.this, direction,
                                   addToSelection, changeSelection);
            }
        }

        public boolean isEnabled() { return (tree != null &&
                                             tree.isEnabled()); }

    } // BasicTreeUI.TreePageAction


    
TreeIncrementAction is used to handle up/down actions.  Selection
is moved up or down based on direction.
/** TreeIncrementAction is used to handle up/down actions.  Selection
      * is moved up or down based on direction.
      */
    @SuppressWarnings("serial") // Superclass is not serializable across versions
    public class TreeIncrementAction extends AbstractAction  {
        
Specifies the direction to adjust the selection by. /** Specifies the direction to adjust the selection by. */
        protected int         direction;
        
If true the new item is added to the selection, if false the
selection is reset. /** If true the new item is added to the selection, if false the
         * selection is reset. */
        private boolean       addToSelection;
        private boolean       changeSelection;

        
Constructs a new instance of TreeIncrementAction. 
Params:
direction – the direction
name – the name of action/**
         * Constructs a new instance of {@code TreeIncrementAction}.
         *
         * @param direction the direction
         * @param name the name of action
         */
        public TreeIncrementAction(int direction, String name) {
            this(direction, name, false, true);
        }

        private TreeIncrementAction(int direction, String name,
                                   boolean addToSelection,
                                    boolean changeSelection) {
            this.direction = direction;
            this.addToSelection = addToSelection;
            this.changeSelection = changeSelection;
        }

        public void actionPerformed(ActionEvent e) {
            if (tree != null) {
                SHARED_ACTION.increment(tree, BasicTreeUI.this, direction,
                                        addToSelection, changeSelection);
            }
        }

        public boolean isEnabled() { return (tree != null &&
                                             tree.isEnabled()); }

    } // End of class BasicTreeUI.TreeIncrementAction

    
TreeHomeAction is used to handle end/home actions.
Scrolls either the first or last cell to be visible based on
direction.
/**
      * TreeHomeAction is used to handle end/home actions.
      * Scrolls either the first or last cell to be visible based on
      * direction.
      */
    @SuppressWarnings("serial") // Superclass is not serializable across versions
    public class TreeHomeAction extends AbstractAction {
        
The direction.
/**
         * The direction.
         */
        protected int            direction;
        
Set to true if append to selection. /** Set to true if append to selection. */
        private boolean          addToSelection;
        private boolean          changeSelection;

        
Constructs a new instance of TreeHomeAction. 
Params:
direction – the direction
name – the name of action/**
         * Constructs a new instance of {@code TreeHomeAction}.
         *
         * @param direction the direction
         * @param name the name of action
         */
        public TreeHomeAction(int direction, String name) {
            this(direction, name, false, true);
        }

        private TreeHomeAction(int direction, String name,
                               boolean addToSelection,
                               boolean changeSelection) {
            this.direction = direction;
            this.changeSelection = changeSelection;
            this.addToSelection = addToSelection;
        }

        public void actionPerformed(ActionEvent e) {
            if (tree != null) {
                SHARED_ACTION.home(tree, BasicTreeUI.this, direction,
                                   addToSelection, changeSelection);
            }
        }

        public boolean isEnabled() { return (tree != null &&
                                             tree.isEnabled()); }

    } // End of class BasicTreeUI.TreeHomeAction


    
For the first selected row expandedness will be toggled.
/**
      * For the first selected row expandedness will be toggled.
      */
    @SuppressWarnings("serial") // Superclass is not serializable across versions
    public class TreeToggleAction extends AbstractAction {
        
Constructs a new instance of TreeToggleAction. 
Params:
name – the name of action/**
         * Constructs a new instance of {@code TreeToggleAction}.
         *
         * @param name the name of action
         */
        public TreeToggleAction(String name) {
        }

        public void actionPerformed(ActionEvent e) {
            if(tree != null) {
                SHARED_ACTION.toggle(tree, BasicTreeUI.this);
            }
        }

        public boolean isEnabled() { return (tree != null &&
                                             tree.isEnabled()); }

    } // End of class BasicTreeUI.TreeToggleAction


    
ActionListener that invokes cancelEditing when action performed.
/**
     * ActionListener that invokes cancelEditing when action performed.
     */
    @SuppressWarnings("serial") // Superclass is not serializable across versions
    public class TreeCancelEditingAction extends AbstractAction {
        
Constructs a new instance of TreeCancelEditingAction. 
Params:
name – the name of action/**
         * Constructs a new instance of {@code TreeCancelEditingAction}.
         *
         * @param name the name of action
         */
        public TreeCancelEditingAction(String name) {
        }

        public void actionPerformed(ActionEvent e) {
            if(tree != null) {
                SHARED_ACTION.cancelEditing(tree, BasicTreeUI.this);
            }
        }

        public boolean isEnabled() { return (tree != null &&
                                             tree.isEnabled() &&
                                             isEditing(tree)); }
    } // End of class BasicTreeUI.TreeCancelEditingAction


    
MouseInputHandler handles passing all mouse events,
including mouse motion events, until the mouse is released to
the destination it is constructed with. It is assumed all the
events are currently target at source.
/**
      * MouseInputHandler handles passing all mouse events,
      * including mouse motion events, until the mouse is released to
      * the destination it is constructed with. It is assumed all the
      * events are currently target at source.
      */
    public class MouseInputHandler implements
                     MouseInputListener
    {
        
Source that events are coming from. /** Source that events are coming from. */
        protected Component        source;
        
Destination that receives all events. /** Destination that receives all events. */
        protected Component        destination;
        private Component          focusComponent;
        private boolean            dispatchedEvent;

        
Constructs a new instance of MouseInputHandler. 
Params:
source – a source component
destination – a destination component
event – a mouse event/**
         * Constructs a new instance of {@code MouseInputHandler}.
         *
         * @param source a source component
         * @param destination a destination component
         * @param event a mouse event
         */
        public MouseInputHandler(Component source, Component destination,
                                      MouseEvent event){
            this(source, destination, event, null);
        }

        MouseInputHandler(Component source, Component destination,
                          MouseEvent event, Component focusComponent) {
            this.source = source;
            this.destination = destination;
            this.source.addMouseListener(this);
            this.source.addMouseMotionListener(this);

            SwingUtilities2.setSkipClickCount(destination,
                                              event.getClickCount() - 1);

            /* Dispatch the editing event! */
            destination.dispatchEvent(SwingUtilities.convertMouseEvent
                                          (source, event, destination));
            this.focusComponent = focusComponent;
        }

        public void mouseClicked(MouseEvent e) {
            if(destination != null) {
                dispatchedEvent = true;
                destination.dispatchEvent(SwingUtilities.convertMouseEvent
                                          (source, e, destination));
            }
        }

        public void mousePressed(MouseEvent e) {
        }

        public void mouseReleased(MouseEvent e) {
            if(destination != null)
                destination.dispatchEvent(SwingUtilities.convertMouseEvent
                                          (source, e, destination));
            removeFromSource();
        }

        public void mouseEntered(MouseEvent e) {
            if (!SwingUtilities.isLeftMouseButton(e)) {
                removeFromSource();
            }
        }

        public void mouseExited(MouseEvent e) {
            if (!SwingUtilities.isLeftMouseButton(e)) {
                removeFromSource();
            }
        }

        public void mouseDragged(MouseEvent e) {
            if(destination != null) {
                dispatchedEvent = true;
                destination.dispatchEvent(SwingUtilities.convertMouseEvent
                                          (source, e, destination));
            }
        }

        public void mouseMoved(MouseEvent e) {
            removeFromSource();
        }

        
Removes an event from the source.
/**
         * Removes an event from the source.
         */
        protected void removeFromSource() {
            if(source != null) {
                source.removeMouseListener(this);
                source.removeMouseMotionListener(this);
                if (focusComponent != null &&
                      focusComponent == destination && !dispatchedEvent &&
                      (focusComponent instanceof JTextField)) {
                    ((JTextField)focusComponent).selectAll();
                }
            }
            source = destination = null;
        }

    } // End of class BasicTreeUI.MouseInputHandler

    private static final TransferHandler defaultTransferHandler = new TreeTransferHandler();

    @SuppressWarnings("serial") // JDK-implementation class
    static class TreeTransferHandler extends TransferHandler implements UIResource, Comparator<TreePath> {

        private JTree tree;

        
Create a Transferable to use as the source for a data transfer.
Params:
c –  The component holding the data to be transfered.  This
 argument is provided to enable sharing of TransferHandlers by
 multiple components.
Returns:
 The representation of the data to be transfered./**
         * Create a Transferable to use as the source for a data transfer.
         *
         * @param c  The component holding the data to be transfered.  This
         *  argument is provided to enable sharing of TransferHandlers by
         *  multiple components.
         * @return  The representation of the data to be transfered.
         *
         */
        protected Transferable createTransferable(JComponent c) {
            if (c instanceof JTree) {
                tree = (JTree) c;
                TreePath[] paths = tree.getSelectionPaths();

                if (paths == null || paths.length == 0) {
                    return null;
                }

                StringBuilder plainStr = new StringBuilder();
                StringBuilder htmlStr = new StringBuilder();

                htmlStr.append("<html>\n<body>\n<ul>\n");

                TreeModel model = tree.getModel();
                TreePath lastPath = null;
                TreePath[] displayPaths = getDisplayOrderPaths(paths);

                for (TreePath path : displayPaths) {
                    Object node = path.getLastPathComponent();
                    boolean leaf = model.isLeaf(node);
                    String label = getDisplayString(path, true, leaf);

                    plainStr.append(label).append('\n');
                    htmlStr.append("  <li>").append(label).append('\n');
                }

                // remove the last newline
                plainStr.deleteCharAt(plainStr.length() - 1);
                htmlStr.append("</ul>\n</body>\n</html>");

                tree = null;

                return new BasicTransferable(plainStr.toString(), htmlStr.toString());
            }

            return null;
        }

        public int compare(TreePath o1, TreePath o2) {
            int row1 = tree.getRowForPath(o1);
            int row2 = tree.getRowForPath(o2);
            return row1 - row2;
        }

        String getDisplayString(TreePath path, boolean selected, boolean leaf) {
            int row = tree.getRowForPath(path);
            boolean hasFocus = tree.getLeadSelectionRow() == row;
            Object node = path.getLastPathComponent();
            return tree.convertValueToText(node, selected, tree.isExpanded(row),
                                           leaf, row, hasFocus);
        }

        
Selection paths are in selection order.  The conversion to
HTML requires display order.  This method resorts the paths
to be in the display order.
/**
         * Selection paths are in selection order.  The conversion to
         * HTML requires display order.  This method resorts the paths
         * to be in the display order.
         */
        TreePath[] getDisplayOrderPaths(TreePath[] paths) {
            // sort the paths to display order rather than selection order
            ArrayList<TreePath> selOrder = new ArrayList<TreePath>();
            for (TreePath path : paths) {
                selOrder.add(path);
            }
            Collections.sort(selOrder, this);
            int n = selOrder.size();
            TreePath[] displayPaths = new TreePath[n];
            for (int i = 0; i < n; i++) {
                displayPaths[i] = selOrder.get(i);
            }
            return displayPaths;
        }

        public int getSourceActions(JComponent c) {
            return COPY;
        }

    }


    private class Handler implements CellEditorListener, FocusListener,
                  KeyListener, MouseListener, MouseMotionListener,
                  PropertyChangeListener, TreeExpansionListener,
                  TreeModelListener, TreeSelectionListener,
                  BeforeDrag {
        //
        // KeyListener
        //
        private String prefix = "";
        private String typedString = "";
        private long lastTime = 0L;

        
Invoked when a key has been typed.
Moves the keyboard focus to the first element whose prefix matches the
sequence of alphanumeric keys pressed by the user with delay less
than value of timeFactor property (or 1000 milliseconds
if it is not defined). Subsequent same key presses move the keyboard
focus to the next object that starts with the same letter until another
key is pressed, then it is treated as the prefix with appropriate number
of the same letters followed by first typed another letter.
/**
         * Invoked when a key has been typed.
         *
         * Moves the keyboard focus to the first element whose prefix matches the
         * sequence of alphanumeric keys pressed by the user with delay less
         * than value of <code>timeFactor</code> property (or 1000 milliseconds
         * if it is not defined). Subsequent same key presses move the keyboard
         * focus to the next object that starts with the same letter until another
         * key is pressed, then it is treated as the prefix with appropriate number
         * of the same letters followed by first typed another letter.
         */
        public void keyTyped(KeyEvent e) {
            // handle first letter navigation
            if(tree != null && tree.getRowCount()>0 && tree.hasFocus() &&
               tree.isEnabled()) {
                if (e.isAltDown() || BasicGraphicsUtils.isMenuShortcutKeyDown(e) ||
                    isNavigationKey(e)) {
                    return;
                }
                boolean startingFromSelection = true;

                char c = e.getKeyChar();

                long time = e.getWhen();
                int startingRow = tree.getLeadSelectionRow();
                if (time - lastTime < timeFactor) {
                    typedString += c;
                    if((prefix.length() == 1) && (c == prefix.charAt(0))) {
                        // Subsequent same key presses move the keyboard focus to the next
                        // object that starts with the same letter.
                        startingRow++;
                    } else {
                        prefix = typedString;
                    }
                } else {
                    startingRow++;
                    typedString = "" + c;
                    prefix = typedString;
                }
                lastTime = time;

                if (startingRow < 0 || startingRow >= tree.getRowCount()) {
                    startingFromSelection = false;
                    startingRow = 0;
                }
                TreePath path = tree.getNextMatch(prefix, startingRow,
                                                  Position.Bias.Forward);
                if (path != null) {
                    tree.setSelectionPath(path);
                    int row = getRowForPath(tree, path);
                    ensureRowsAreVisible(row, row);
                } else if (startingFromSelection) {
                    path = tree.getNextMatch(prefix, 0,
                                             Position.Bias.Forward);
                    if (path != null) {
                        tree.setSelectionPath(path);
                        int row = getRowForPath(tree, path);
                        ensureRowsAreVisible(row, row);
                    }
                }
            }
        }

        
Invoked when a key has been pressed.
Checks to see if the key event is a navigation key to prevent
dispatching these keys for the first letter navigation.
/**
         * Invoked when a key has been pressed.
         *
         * Checks to see if the key event is a navigation key to prevent
         * dispatching these keys for the first letter navigation.
         */
        public void keyPressed(KeyEvent e) {
            if (tree != null && isNavigationKey(e)) {
                prefix = "";
                typedString = "";
                lastTime = 0L;
            }
        }

        public void keyReleased(KeyEvent e) {
        }

        
Returns whether or not the supplied key event maps to a key that is used for
navigation.  This is used for optimizing key input by only passing non-
navigation keys to the first letter navigation mechanism.
/**
         * Returns whether or not the supplied key event maps to a key that is used for
         * navigation.  This is used for optimizing key input by only passing non-
         * navigation keys to the first letter navigation mechanism.
         */
        private boolean isNavigationKey(KeyEvent event) {
            InputMap inputMap = tree.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
            KeyStroke key = KeyStroke.getKeyStrokeForEvent(event);

            return inputMap != null && inputMap.get(key) != null;
        }


        //
        // PropertyChangeListener
        //
        public void propertyChange(PropertyChangeEvent event) {
            if (event.getSource() == treeSelectionModel) {
                treeSelectionModel.resetRowSelection();
            }
            else if(event.getSource() == tree) {
                String              changeName = event.getPropertyName();

                if (changeName == JTree.LEAD_SELECTION_PATH_PROPERTY) {
                    if (!ignoreLAChange) {
                        updateLeadSelectionRow();
                        repaintPath((TreePath)event.getOldValue());
                        repaintPath((TreePath)event.getNewValue());
                    }
                }
                else if (changeName == JTree.ANCHOR_SELECTION_PATH_PROPERTY) {
                    if (!ignoreLAChange) {
                        repaintPath((TreePath)event.getOldValue());
                        repaintPath((TreePath)event.getNewValue());
                    }
                }
                if(changeName == JTree.CELL_RENDERER_PROPERTY) {
                    setCellRenderer((TreeCellRenderer)event.getNewValue());
                    redoTheLayout();
                }
                else if(changeName == JTree.TREE_MODEL_PROPERTY) {
                    setModel((TreeModel)event.getNewValue());
                }
                else if(changeName == JTree.ROOT_VISIBLE_PROPERTY) {
                    setRootVisible(((Boolean)event.getNewValue()).
                                   booleanValue());
                }
                else if(changeName == JTree.SHOWS_ROOT_HANDLES_PROPERTY) {
                    setShowsRootHandles(((Boolean)event.getNewValue()).
                                        booleanValue());
                }
                else if(changeName == JTree.ROW_HEIGHT_PROPERTY) {
                    setRowHeight(((Integer)event.getNewValue()).
                                 intValue());
                }
                else if(changeName == JTree.CELL_EDITOR_PROPERTY) {
                    setCellEditor((TreeCellEditor)event.getNewValue());
                }
                else if(changeName == JTree.EDITABLE_PROPERTY) {
                    setEditable(((Boolean)event.getNewValue()).booleanValue());
                }
                else if(changeName == JTree.LARGE_MODEL_PROPERTY) {
                    setLargeModel(tree.isLargeModel());
                }
                else if(changeName == JTree.SELECTION_MODEL_PROPERTY) {
                    setSelectionModel(tree.getSelectionModel());
                }
                else if(changeName == "font"
                        || SwingUtilities2.isScaleChanged(event)) {
                    completeEditing();
                    if(treeState != null)
                        treeState.invalidateSizes();
                    updateSize();
                }
                else if (changeName == "componentOrientation") {
                    if (tree != null) {
                        leftToRight = BasicGraphicsUtils.isLeftToRight(tree);
                        redoTheLayout();
                        tree.treeDidChange();

                        InputMap km = getInputMap(JComponent.WHEN_FOCUSED);
                        SwingUtilities.replaceUIInputMap(tree,
                                                JComponent.WHEN_FOCUSED, km);
                    }
                } else if ("dropLocation" == changeName) {
                    JTree.DropLocation oldValue = (JTree.DropLocation)event.getOldValue();
                    repaintDropLocation(oldValue);
                    repaintDropLocation(tree.getDropLocation());
                }
            }
        }

        private void repaintDropLocation(JTree.DropLocation loc) {
            if (loc == null) {
                return;
            }

            Rectangle r;

            if (isDropLine(loc)) {
                r = getDropLineRect(loc);
            } else {
                r = tree.getPathBounds(loc.getPath());
            }

            if (r != null) {
                tree.repaint(r);
            }
        }

        //
        // MouseListener
        //

        // Whether or not the mouse press (which is being considered as part
        // of a drag sequence) also caused the selection change to be fully
        // processed.
        private boolean dragPressDidSelection;

        // Set to true when a drag gesture has been fully recognized and DnD
        // begins. Use this to ignore further mouse events which could be
        // delivered if DnD is cancelled (via ESCAPE for example)
        private boolean dragStarted;

        // The path over which the press occurred and the press event itself
        private TreePath pressedPath;
        private MouseEvent pressedEvent;

        // Used to detect whether the press event causes a selection change.
        // If it does, we won't try to start editing on the release.
        private boolean valueChangedOnPress;

        private boolean isActualPath(TreePath path, int x, int y) {
            if (path == null) {
                return false;
            }

            Rectangle bounds = getPathBounds(tree, path);
            if (bounds == null || y > (bounds.y + bounds.height)) {
                return false;
            }

            return (x >= bounds.x) && (x <= (bounds.x + bounds.width));
        }

        public void mouseClicked(MouseEvent e) {
        }

        public void mouseEntered(MouseEvent e) {
        }

        public void mouseExited(MouseEvent e) {
        }

        
Invoked when a mouse button has been pressed on a component.
/**
         * Invoked when a mouse button has been pressed on a component.
         */
        public void mousePressed(MouseEvent e) {
            if (SwingUtilities2.shouldIgnore(e, tree)) {
                return;
            }

            // if we can't stop any ongoing editing, do nothing
            if (isEditing(tree) && tree.getInvokesStopCellEditing()
                                && !stopEditing(tree)) {
                return;
            }

            completeEditing();

            pressedPath = getClosestPathForLocation(tree, e.getX(), e.getY());

            if (tree.getDragEnabled()) {
                mousePressedDND(e);
            } else {
                SwingUtilities2.adjustFocus(tree);
                handleSelection(e);
            }
        }

        private void mousePressedDND(MouseEvent e) {
            pressedEvent = e;
            boolean grabFocus = true;
            dragStarted = false;
            valueChangedOnPress = false;

            // if we have a valid path and this is a drag initiating event
            if (isActualPath(pressedPath, e.getX(), e.getY()) &&
                    DragRecognitionSupport.mousePressed(e)) {

                dragPressDidSelection = false;

                if (BasicGraphicsUtils.isMenuShortcutKeyDown(e)) {
                    // do nothing for control - will be handled on release
                    // or when drag starts
                    return;
                } else if (!e.isShiftDown() && tree.isPathSelected(pressedPath)) {
                    // clicking on something that's already selected
                    // and need to make it the lead now
                    setAnchorSelectionPath(pressedPath);
                    setLeadSelectionPath(pressedPath, true);
                    return;
                }

                dragPressDidSelection = true;

                // could be a drag initiating event - don't grab focus
                grabFocus = false;
            }

            if (grabFocus) {
                SwingUtilities2.adjustFocus(tree);
            }

            handleSelection(e);
        }

        void handleSelection(MouseEvent e) {
            if(pressedPath != null) {
                Rectangle bounds = getPathBounds(tree, pressedPath);

                if (bounds == null || e.getY() >= (bounds.y + bounds.height)) {
                    return;
                }

                // Preferably checkForClickInExpandControl could take
                // the Event to do this it self!
                if(SwingUtilities.isLeftMouseButton(e)) {
                    checkForClickInExpandControl(pressedPath, e.getX(), e.getY());
                }

                int x = e.getX();

                // Perhaps they clicked the cell itself. If so,
                // select it.
                if (x >= bounds.x && x < (bounds.x + bounds.width)) {
                    if (tree.getDragEnabled() || !startEditing(pressedPath, e)) {
                        selectPathForEvent(pressedPath, e);
                    }
                }
            }
        }

        public void dragStarting(MouseEvent me) {
            dragStarted = true;

            if (BasicGraphicsUtils.isMenuShortcutKeyDown(me)) {
                tree.addSelectionPath(pressedPath);
                setAnchorSelectionPath(pressedPath);
                setLeadSelectionPath(pressedPath, true);
            }

            pressedEvent = null;
            pressedPath = null;
        }

        public void mouseDragged(MouseEvent e) {
            if (SwingUtilities2.shouldIgnore(e, tree)) {
                return;
            }

            if (tree.getDragEnabled()) {
                DragRecognitionSupport.mouseDragged(e, this);
            }
        }

        
Invoked when the mouse button has been moved on a component
(with no buttons no down).
/**
         * Invoked when the mouse button has been moved on a component
         * (with no buttons no down).
         */
        public void mouseMoved(MouseEvent e) {
        }

        public void mouseReleased(MouseEvent e) {
            if (SwingUtilities2.shouldIgnore(e, tree)) {
                return;
            }

            if (tree.getDragEnabled()) {
                mouseReleasedDND(e);
            }

            pressedEvent = null;
            pressedPath = null;
        }

        private void mouseReleasedDND(MouseEvent e) {
            MouseEvent me = DragRecognitionSupport.mouseReleased(e);
            if (me != null) {
                SwingUtilities2.adjustFocus(tree);
                if (!dragPressDidSelection) {
                    handleSelection(me);
                }
            }

            if (!dragStarted) {

                // Note: We don't give the tree a chance to start editing if the
                // mouse press caused a selection change. Otherwise the default
                // tree cell editor will start editing on EVERY press and
                // release. If it turns out that this affects some editors, we
                // can always parameterize this with a client property. ex:
                //
                // if (pressedPath != null &&
                //         (Boolean.TRUE == tree.getClientProperty("Tree.DnD.canEditOnValueChange") ||
                //          !valueChangedOnPress) && ...
                if (pressedPath != null && !valueChangedOnPress &&
                        isActualPath(pressedPath, pressedEvent.getX(), pressedEvent.getY())) {

                    startEditingOnRelease(pressedPath, pressedEvent, e);
                }
            }
        }

        //
        // FocusListener
        //
        public void focusGained(FocusEvent e) {
            if(tree != null) {
                Rectangle                 pBounds;

                pBounds = getPathBounds(tree, tree.getLeadSelectionPath());
                if(pBounds != null)
                    tree.repaint(getRepaintPathBounds(pBounds));
                pBounds = getPathBounds(tree, getLeadSelectionPath());
                if(pBounds != null)
                    tree.repaint(getRepaintPathBounds(pBounds));
            }
        }

        public void focusLost(FocusEvent e) {
            focusGained(e);
        }

        //
        // CellEditorListener
        //
        public void editingStopped(ChangeEvent e) {
            completeEditing(false, false, true);
        }

        
Messaged when editing has been canceled in the tree. /** Messaged when editing has been canceled in the tree. */
        public void editingCanceled(ChangeEvent e) {
            completeEditing(false, false, false);
        }


        //
        // TreeSelectionListener
        //
        public void valueChanged(TreeSelectionEvent event) {
            valueChangedOnPress = true;

            // Stop editing
            completeEditing();
            // Make sure all the paths are visible, if necessary.
            // PENDING: This should be tweaked when isAdjusting is added
            if(tree.getExpandsSelectedPaths() && treeSelectionModel != null) {
                TreePath[]           paths = treeSelectionModel
                                         .getSelectionPaths();

                if(paths != null) {
                    for(int counter = paths.length - 1; counter >= 0;
                        counter--) {
                        TreePath path = paths[counter].getParentPath();
                        boolean expand = true;

                        while (path != null) {
                            // Indicates this path isn't valid anymore,
                            // we shouldn't attempt to expand it then.
                            if (treeModel.isLeaf(path.getLastPathComponent())){
                                expand = false;
                                path = null;
                            }
                            else {
                                path = path.getParentPath();
                            }
                        }
                        if (expand) {
                            tree.makeVisible(paths[counter]);
                        }
                    }
                }
            }

            TreePath oldLead = getLeadSelectionPath();
            lastSelectedRow = tree.getMinSelectionRow();
            TreePath lead = tree.getSelectionModel().getLeadSelectionPath();
            setAnchorSelectionPath(lead);
            setLeadSelectionPath(lead);

            TreePath[]       changedPaths = event.getPaths();
            Rectangle        nodeBounds;
            Rectangle        visRect = tree.getVisibleRect();
            boolean          paintPaths = true;
            int              nWidth = tree.getWidth();

            if(changedPaths != null) {
                int              counter, maxCounter = changedPaths.length;

                if(maxCounter > 4) {
                    tree.repaint();
                    paintPaths = false;
                }
                else {
                    for (counter = 0; counter < maxCounter; counter++) {
                        nodeBounds = getPathBounds(tree,
                                                   changedPaths[counter]);
                        if(nodeBounds != null &&
                           visRect.intersects(nodeBounds))
                            tree.repaint(0, nodeBounds.y, nWidth,
                                         nodeBounds.height);
                    }
                }
            }
            if(paintPaths) {
                nodeBounds = getPathBounds(tree, oldLead);
                if(nodeBounds != null && visRect.intersects(nodeBounds))
                    tree.repaint(0, nodeBounds.y, nWidth, nodeBounds.height);
                nodeBounds = getPathBounds(tree, lead);
                if(nodeBounds != null && visRect.intersects(nodeBounds))
                    tree.repaint(0, nodeBounds.y, nWidth, nodeBounds.height);
            }
        }


        //
        // TreeExpansionListener
        //
        public void treeExpanded(TreeExpansionEvent event) {
            if(event != null && tree != null) {
                TreePath      path = event.getPath();

                updateExpandedDescendants(path);
            }
        }

        public void treeCollapsed(TreeExpansionEvent event) {
            if(event != null && tree != null) {
                TreePath        path = event.getPath();

                completeEditing();
                if(path != null && tree.isVisible(path)) {
                    treeState.setExpandedState(path, false);
                    updateLeadSelectionRow();
                    updateSize();
                }
            }
        }

        //
        // TreeModelListener
        //
        public void treeNodesChanged(TreeModelEvent e) {
            if(treeState != null && e != null) {
                TreePath parentPath = SwingUtilities2.getTreePath(e, getModel());
                int[] indices = e.getChildIndices();
                if (indices == null || indices.length == 0) {
                    // The root has changed
                    treeState.treeNodesChanged(e);
                    updateSize();
                }
                else if (treeState.isExpanded(parentPath)) {
                    // Changed nodes are visible
                    // Find the minimum index, we only need paint from there
                    // down.
                    int minIndex = indices[0];
                    for (int i = indices.length - 1; i > 0; i--) {
                        minIndex = Math.min(indices[i], minIndex);
                    }
                    Object minChild = treeModel.getChild(
                            parentPath.getLastPathComponent(), minIndex);
                    TreePath minPath = parentPath.pathByAddingChild(minChild);
                    Rectangle minBounds = getPathBounds(tree, minPath);

                    // Forward to the treestate
                    treeState.treeNodesChanged(e);

                    // Mark preferred size as bogus.
                    updateSize0();

                    // And repaint
                    Rectangle newMinBounds = getPathBounds(tree, minPath);
                    if (minBounds == null || newMinBounds == null) {
                        return;
                    }

                    if (indices.length == 1 &&
                            newMinBounds.height == minBounds.height) {
                        tree.repaint(0, minBounds.y, tree.getWidth(),
                                     minBounds.height);
                    }
                    else {
                        tree.repaint(0, minBounds.y, tree.getWidth(),
                                     tree.getHeight() - minBounds.y);
                    }
                }
                else {
                    // Nodes that changed aren't visible.  No need to paint
                    treeState.treeNodesChanged(e);
                }
            }
        }

        public void treeNodesInserted(TreeModelEvent e) {
            if(treeState != null && e != null) {
                treeState.treeNodesInserted(e);

                updateLeadSelectionRow();

                TreePath       path = SwingUtilities2.getTreePath(e, getModel());

                if(treeState.isExpanded(path)) {
                    updateSize();
                }
                else {
                    // PENDING(sky): Need a method in TreeModelEvent
                    // that can return the count, getChildIndices allocs
                    // a new array!
                    int[]      indices = e.getChildIndices();
                    int        childCount = treeModel.getChildCount
                                            (path.getLastPathComponent());

                    if(indices != null && (childCount - indices.length) == 0)
                        updateSize();
                }
            }
        }

        public void treeNodesRemoved(TreeModelEvent e) {
            if(treeState != null && e != null) {
                treeState.treeNodesRemoved(e);

                updateLeadSelectionRow();

                TreePath       path = SwingUtilities2.getTreePath(e, getModel());

                if(treeState.isExpanded(path) ||
                   treeModel.getChildCount(path.getLastPathComponent()) == 0)
                    updateSize();
            }
        }

        public void treeStructureChanged(TreeModelEvent e) {
            if(treeState != null && e != null) {
                treeState.treeStructureChanged(e);

                updateLeadSelectionRow();

                TreePath       pPath = SwingUtilities2.getTreePath(e, getModel());

                if (pPath != null) {
                    pPath = pPath.getParentPath();
                }
                if(pPath == null || treeState.isExpanded(pPath))
                    updateSize();
            }
        }
    }



    private static class Actions extends UIAction {
        private static final String SELECT_PREVIOUS = "selectPrevious";
        private static final String SELECT_PREVIOUS_CHANGE_LEAD =
                             "selectPreviousChangeLead";
        private static final String SELECT_PREVIOUS_EXTEND_SELECTION =
                             "selectPreviousExtendSelection";
        private static final String SELECT_NEXT = "selectNext";
        private static final String SELECT_NEXT_CHANGE_LEAD =
                                    "selectNextChangeLead";
        private static final String SELECT_NEXT_EXTEND_SELECTION =
                                    "selectNextExtendSelection";
        private static final String SELECT_CHILD = "selectChild";
        private static final String SELECT_CHILD_CHANGE_LEAD =
                                    "selectChildChangeLead";
        private static final String SELECT_PARENT = "selectParent";
        private static final String SELECT_PARENT_CHANGE_LEAD =
                                    "selectParentChangeLead";
        private static final String SCROLL_UP_CHANGE_SELECTION =
                                    "scrollUpChangeSelection";
        private static final String SCROLL_UP_CHANGE_LEAD =
                                    "scrollUpChangeLead";
        private static final String SCROLL_UP_EXTEND_SELECTION =
                                    "scrollUpExtendSelection";
        private static final String SCROLL_DOWN_CHANGE_SELECTION =
                                    "scrollDownChangeSelection";
        private static final String SCROLL_DOWN_EXTEND_SELECTION =
                                    "scrollDownExtendSelection";
        private static final String SCROLL_DOWN_CHANGE_LEAD =
                                    "scrollDownChangeLead";
        private static final String SELECT_FIRST = "selectFirst";
        private static final String SELECT_FIRST_CHANGE_LEAD =
                                    "selectFirstChangeLead";
        private static final String SELECT_FIRST_EXTEND_SELECTION =
                                    "selectFirstExtendSelection";
        private static final String SELECT_LAST = "selectLast";
        private static final String SELECT_LAST_CHANGE_LEAD =
                                    "selectLastChangeLead";
        private static final String SELECT_LAST_EXTEND_SELECTION =
                                    "selectLastExtendSelection";
        private static final String TOGGLE = "toggle";
        private static final String CANCEL_EDITING = "cancel";
        private static final String START_EDITING = "startEditing";
        private static final String SELECT_ALL = "selectAll";
        private static final String CLEAR_SELECTION = "clearSelection";
        private static final String SCROLL_LEFT = "scrollLeft";
        private static final String SCROLL_RIGHT = "scrollRight";
        private static final String SCROLL_LEFT_EXTEND_SELECTION =
                                    "scrollLeftExtendSelection";
        private static final String SCROLL_RIGHT_EXTEND_SELECTION =
                                    "scrollRightExtendSelection";
        private static final String SCROLL_RIGHT_CHANGE_LEAD =
                                    "scrollRightChangeLead";
        private static final String SCROLL_LEFT_CHANGE_LEAD =
                                    "scrollLeftChangeLead";
        private static final String EXPAND = "expand";
        private static final String COLLAPSE = "collapse";
        private static final String MOVE_SELECTION_TO_PARENT =
                                    "moveSelectionToParent";

        // add the lead item to the selection without changing lead or anchor
        private static final String ADD_TO_SELECTION = "addToSelection";

        // toggle the selected state of the lead item and move the anchor to it
        private static final String TOGGLE_AND_ANCHOR = "toggleAndAnchor";

        // extend the selection to the lead item
        private static final String EXTEND_TO = "extendTo";

        // move the anchor to the lead and ensure only that item is selected
        private static final String MOVE_SELECTION_TO = "moveSelectionTo";

        Actions() {
            super(null);
        }

        Actions(String key) {
            super(key);
        }

        @Override
        public boolean accept(Object o) {
            if (o instanceof JTree) {
                if (getName() == CANCEL_EDITING) {
                    return ((JTree)o).isEditing();
                }
            }
            return true;
        }

        public void actionPerformed(ActionEvent e) {
            JTree tree = (JTree)e.getSource();
            BasicTreeUI ui = (BasicTreeUI)BasicLookAndFeel.getUIOfType(
                             tree.getUI(), BasicTreeUI.class);
            if (ui == null) {
                return;
            }
            String key = getName();
            if (key == SELECT_PREVIOUS) {
                increment(tree, ui, -1, false, true);
            }
            else if (key == SELECT_PREVIOUS_CHANGE_LEAD) {
                increment(tree, ui, -1, false, false);
            }
            else if (key == SELECT_PREVIOUS_EXTEND_SELECTION) {
                increment(tree, ui, -1, true, true);
            }
            else if (key == SELECT_NEXT) {
                increment(tree, ui, 1, false, true);
            }
            else if (key == SELECT_NEXT_CHANGE_LEAD) {
                increment(tree, ui, 1, false, false);
            }
            else if (key == SELECT_NEXT_EXTEND_SELECTION) {
                increment(tree, ui, 1, true, true);
            }
            else if (key == SELECT_CHILD) {
                traverse(tree, ui, 1, true);
            }
            else if (key == SELECT_CHILD_CHANGE_LEAD) {
                traverse(tree, ui, 1, false);
            }
            else if (key == SELECT_PARENT) {
                traverse(tree, ui, -1, true);
            }
            else if (key == SELECT_PARENT_CHANGE_LEAD) {
                traverse(tree, ui, -1, false);
            }
            else if (key == SCROLL_UP_CHANGE_SELECTION) {
                page(tree, ui, -1, false, true);
            }
            else if (key == SCROLL_UP_CHANGE_LEAD) {
                page(tree, ui, -1, false, false);
            }
            else if (key == SCROLL_UP_EXTEND_SELECTION) {
                page(tree, ui, -1, true, true);
            }
            else if (key == SCROLL_DOWN_CHANGE_SELECTION) {
                page(tree, ui, 1, false, true);
            }
            else if (key == SCROLL_DOWN_EXTEND_SELECTION) {
                page(tree, ui, 1, true, true);
            }
            else if (key == SCROLL_DOWN_CHANGE_LEAD) {
                page(tree, ui, 1, false, false);
            }
            else if (key == SELECT_FIRST) {
                home(tree, ui, -1, false, true);
            }
            else if (key == SELECT_FIRST_CHANGE_LEAD) {
                home(tree, ui, -1, false, false);
            }
            else if (key == SELECT_FIRST_EXTEND_SELECTION) {
                home(tree, ui, -1, true, true);
            }
            else if (key == SELECT_LAST) {
                home(tree, ui, 1, false, true);
            }
            else if (key == SELECT_LAST_CHANGE_LEAD) {
                home(tree, ui, 1, false, false);
            }
            else if (key == SELECT_LAST_EXTEND_SELECTION) {
                home(tree, ui, 1, true, true);
            }
            else if (key == TOGGLE) {
                toggle(tree, ui);
            }
            else if (key == CANCEL_EDITING) {
                cancelEditing(tree, ui);
            }
            else if (key == START_EDITING) {
                startEditing(tree, ui);
            }
            else if (key == SELECT_ALL) {
                selectAll(tree, ui, true);
            }
            else if (key == CLEAR_SELECTION) {
                selectAll(tree, ui, false);
            }
            else if (key == ADD_TO_SELECTION) {
                if (ui.getRowCount(tree) > 0) {
                    int lead = ui.getLeadSelectionRow();
                    if (!tree.isRowSelected(lead)) {
                        TreePath aPath = ui.getAnchorSelectionPath();
                        tree.addSelectionRow(lead);
                        ui.setAnchorSelectionPath(aPath);
                    }
                }
            }
            else if (key == TOGGLE_AND_ANCHOR) {
                if (ui.getRowCount(tree) > 0) {
                    int lead = ui.getLeadSelectionRow();
                    TreePath lPath = ui.getLeadSelectionPath();
                    if (!tree.isRowSelected(lead)) {
                        tree.addSelectionRow(lead);
                    } else {
                        tree.removeSelectionRow(lead);
                        ui.setLeadSelectionPath(lPath);
                    }
                    ui.setAnchorSelectionPath(lPath);
                }
            }
            else if (key == EXTEND_TO) {
                extendSelection(tree, ui);
            }
            else if (key == MOVE_SELECTION_TO) {
                if (ui.getRowCount(tree) > 0) {
                    int lead = ui.getLeadSelectionRow();
                    tree.setSelectionInterval(lead, lead);
                }
            }
            else if (key == SCROLL_LEFT) {
                scroll(tree, ui, SwingConstants.HORIZONTAL, -10);
            }
            else if (key == SCROLL_RIGHT) {
                scroll(tree, ui, SwingConstants.HORIZONTAL, 10);
            }
            else if (key == SCROLL_LEFT_EXTEND_SELECTION) {
                scrollChangeSelection(tree, ui, -1, true, true);
            }
            else if (key == SCROLL_RIGHT_EXTEND_SELECTION) {
                scrollChangeSelection(tree, ui, 1, true, true);
            }
            else if (key == SCROLL_RIGHT_CHANGE_LEAD) {
                scrollChangeSelection(tree, ui, 1, false, false);
            }
            else if (key == SCROLL_LEFT_CHANGE_LEAD) {
                scrollChangeSelection(tree, ui, -1, false, false);
            }
            else if (key == EXPAND) {
                expand(tree, ui);
            }
            else if (key == COLLAPSE) {
                collapse(tree, ui);
            }
            else if (key == MOVE_SELECTION_TO_PARENT) {
                moveSelectionToParent(tree, ui);
            }
        }

        private void scrollChangeSelection(JTree tree, BasicTreeUI ui,
                           int direction, boolean addToSelection,
                           boolean changeSelection) {
            int           rowCount;

            if((rowCount = ui.getRowCount(tree)) > 0 &&
                ui.treeSelectionModel != null) {
                TreePath          newPath;
                Rectangle         visRect = tree.getVisibleRect();

                if (direction == -1) {
                    newPath = ui.getClosestPathForLocation(tree, visRect.x,
                                                        visRect.y);
                    visRect.x = Math.max(0, visRect.x - visRect.width);
                }
                else {
                    visRect.x = Math.min(Math.max(0, tree.getWidth() -
                                   visRect.width), visRect.x + visRect.width);
                    newPath = ui.getClosestPathForLocation(tree, visRect.x,
                                                 visRect.y + visRect.height);
                }
                // Scroll
                tree.scrollRectToVisible(visRect);
                // select
                if (addToSelection) {
                    ui.extendSelection(newPath);
                }
                else if(changeSelection) {
                    tree.setSelectionPath(newPath);
                }
                else {
                    ui.setLeadSelectionPath(newPath, true);
                }
            }
        }

        private void scroll(JTree component, BasicTreeUI ui, int direction,
                            int amount) {
            Rectangle visRect = component.getVisibleRect();
            Dimension size = component.getSize();
            if (direction == SwingConstants.HORIZONTAL) {
                visRect.x += amount;
                visRect.x = Math.max(0, visRect.x);
                visRect.x = Math.min(Math.max(0, size.width - visRect.width),
                                     visRect.x);
            }
            else {
                visRect.y += amount;
                visRect.y = Math.max(0, visRect.y);
                visRect.y = Math.min(Math.max(0, size.width - visRect.height),
                                     visRect.y);
            }
            component.scrollRectToVisible(visRect);
        }

        private void extendSelection(JTree tree, BasicTreeUI ui) {
            if (ui.getRowCount(tree) > 0) {
                int       lead = ui.getLeadSelectionRow();

                if (lead != -1) {
                    TreePath      leadP = ui.getLeadSelectionPath();
                    TreePath      aPath = ui.getAnchorSelectionPath();
                    int           aRow = ui.getRowForPath(tree, aPath);

                    if(aRow == -1)
                        aRow = 0;
                    tree.setSelectionInterval(aRow, lead);
                    ui.setLeadSelectionPath(leadP);
                    ui.setAnchorSelectionPath(aPath);
                }
            }
        }

        private void selectAll(JTree tree, BasicTreeUI ui, boolean selectAll) {
            int                   rowCount = ui.getRowCount(tree);

            if(rowCount > 0) {
                if(selectAll) {
                    if (tree.getSelectionModel().getSelectionMode() ==
                            TreeSelectionModel.SINGLE_TREE_SELECTION) {

                        int lead = ui.getLeadSelectionRow();
                        if (lead != -1) {
                            tree.setSelectionRow(lead);
                        } else if (tree.getMinSelectionRow() == -1) {
                            tree.setSelectionRow(0);
                            ui.ensureRowsAreVisible(0, 0);
                        }
                        return;
                    }

                    TreePath      lastPath = ui.getLeadSelectionPath();
                    TreePath      aPath = ui.getAnchorSelectionPath();

                    if(lastPath != null && !tree.isVisible(lastPath)) {
                        lastPath = null;
                    }
                    tree.setSelectionInterval(0, rowCount - 1);
                    if(lastPath != null) {
                        ui.setLeadSelectionPath(lastPath);
                    }
                    if(aPath != null && tree.isVisible(aPath)) {
                        ui.setAnchorSelectionPath(aPath);
                    }
                }
                else {
                    TreePath      lastPath = ui.getLeadSelectionPath();
                    TreePath      aPath = ui.getAnchorSelectionPath();

                    tree.clearSelection();
                    ui.setAnchorSelectionPath(aPath);
                    ui.setLeadSelectionPath(lastPath);
                }
            }
        }

        private void startEditing(JTree tree, BasicTreeUI ui) {
            TreePath   lead = ui.getLeadSelectionPath();
            int        editRow = (lead != null) ?
                                     ui.getRowForPath(tree, lead) : -1;

            if(editRow != -1) {
                tree.startEditingAtPath(lead);
            }
        }

        private void cancelEditing(JTree tree, BasicTreeUI ui) {
            tree.cancelEditing();
        }

        private void toggle(JTree tree, BasicTreeUI ui) {
            int            selRow = ui.getLeadSelectionRow();

            if(selRow != -1 && !ui.isLeaf(selRow)) {
                TreePath aPath = ui.getAnchorSelectionPath();
                TreePath lPath = ui.getLeadSelectionPath();

                ui.toggleExpandState(ui.getPathForRow(tree, selRow));
                ui.setAnchorSelectionPath(aPath);
                ui.setLeadSelectionPath(lPath);
            }
        }

        private void expand(JTree tree, BasicTreeUI ui) {
            int selRow = ui.getLeadSelectionRow();
            tree.expandRow(selRow);
        }

        private void collapse(JTree tree, BasicTreeUI ui) {
            int selRow = ui.getLeadSelectionRow();
            tree.collapseRow(selRow);
        }

        private void increment(JTree tree, BasicTreeUI ui, int direction,
                               boolean addToSelection,
                               boolean changeSelection) {

            // disable moving of lead unless in discontiguous mode
            if (!addToSelection && !changeSelection &&
                    tree.getSelectionModel().getSelectionMode() !=
                        TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION) {
                changeSelection = true;
            }

            int              rowCount;

            if(ui.treeSelectionModel != null &&
                  (rowCount = tree.getRowCount()) > 0) {
                int                  selIndex = ui.getLeadSelectionRow();
                int                  newIndex;

                if(selIndex == -1) {
                    if(direction == 1)
                        newIndex = 0;
                    else
                        newIndex = rowCount - 1;
                }
                else
                    /* Aparently people don't like wrapping;( */
                    newIndex = Math.min(rowCount - 1, Math.max
                                        (0, (selIndex + direction)));
                if(addToSelection && ui.treeSelectionModel.
                        getSelectionMode() != TreeSelectionModel.
                        SINGLE_TREE_SELECTION) {
                    ui.extendSelection(tree.getPathForRow(newIndex));
                }
                else if(changeSelection) {
                    tree.setSelectionInterval(newIndex, newIndex);
                }
                else {
                    ui.setLeadSelectionPath(tree.getPathForRow(newIndex),true);
                }
                ui.ensureRowsAreVisible(newIndex, newIndex);
                ui.lastSelectedRow = newIndex;
            }
        }

        private void traverse(JTree tree, BasicTreeUI ui, int direction,
                              boolean changeSelection) {

            // disable moving of lead unless in discontiguous mode
            if (!changeSelection &&
                    tree.getSelectionModel().getSelectionMode() !=
                        TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION) {
                changeSelection = true;
            }

            int                rowCount;

            if((rowCount = tree.getRowCount()) > 0) {
                int               minSelIndex = ui.getLeadSelectionRow();
                int               newIndex;

                if(minSelIndex == -1)
                    newIndex = 0;
                else {
                    /* Try and expand the node, otherwise go to next
                       node. */
                    if(direction == 1) {
                        TreePath minSelPath = ui.getPathForRow(tree, minSelIndex);
                        int childCount = tree.getModel().
                            getChildCount(minSelPath.getLastPathComponent());
                        newIndex = -1;
                        if (!ui.isLeaf(minSelIndex)) {
                            if (!tree.isExpanded(minSelIndex)) {
                                ui.toggleExpandState(minSelPath);
                            }
                            else if (childCount > 0) {
                                newIndex = Math.min(minSelIndex + 1, rowCount - 1);
                            }
                        }
                    }
                    /* Try to collapse node. */
                    else {
                        if(!ui.isLeaf(minSelIndex) &&
                           tree.isExpanded(minSelIndex)) {
                            ui.toggleExpandState(ui.getPathForRow
                                              (tree, minSelIndex));
                            newIndex = -1;
                        }
                        else {
                            TreePath         path = ui.getPathForRow(tree,
                                                                  minSelIndex);

                            if(path != null && path.getPathCount() > 1) {
                                newIndex = ui.getRowForPath(tree, path.
                                                         getParentPath());
                            }
                            else
                                newIndex = -1;
                        }
                    }
                }
                if(newIndex != -1) {
                    if(changeSelection) {
                        tree.setSelectionInterval(newIndex, newIndex);
                    }
                    else {
                        ui.setLeadSelectionPath(ui.getPathForRow(
                                                    tree, newIndex), true);
                    }
                    ui.ensureRowsAreVisible(newIndex, newIndex);
                }
            }
        }

        private void moveSelectionToParent(JTree tree, BasicTreeUI ui) {
            int selRow = ui.getLeadSelectionRow();
            TreePath path = ui.getPathForRow(tree, selRow);
            if (path != null && path.getPathCount() > 1) {
                int  newIndex = ui.getRowForPath(tree, path.getParentPath());
                if (newIndex != -1) {
                    tree.setSelectionInterval(newIndex, newIndex);
                    ui.ensureRowsAreVisible(newIndex, newIndex);
                }
            }
        }

        private void page(JTree tree, BasicTreeUI ui, int direction,
                          boolean addToSelection, boolean changeSelection) {

            // disable moving of lead unless in discontiguous mode
            if (!addToSelection && !changeSelection &&
                    tree.getSelectionModel().getSelectionMode() !=
                        TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION) {
                changeSelection = true;
            }

            int           rowCount;

            if((rowCount = ui.getRowCount(tree)) > 0 &&
                           ui.treeSelectionModel != null) {
                Dimension         maxSize = tree.getSize();
                TreePath          lead = ui.getLeadSelectionPath();
                TreePath          newPath;
                Rectangle         visRect = tree.getVisibleRect();

                if(direction == -1) {
                    // up.
                    newPath = ui.getClosestPathForLocation(tree, visRect.x,
                                                         visRect.y);
                    if(newPath.equals(lead)) {
                        visRect.y = Math.max(0, visRect.y - visRect.height);
                        newPath = tree.getClosestPathForLocation(visRect.x,
                                                                 visRect.y);
                    }
                }
                else {
                    // down
                    visRect.y = Math.min(maxSize.height, visRect.y +
                                         visRect.height - 1);
                    newPath = tree.getClosestPathForLocation(visRect.x,
                                                             visRect.y);
                    if(newPath.equals(lead)) {
                        visRect.y = Math.min(maxSize.height, visRect.y +
                                             visRect.height - 1);
                        newPath = tree.getClosestPathForLocation(visRect.x,
                                                                 visRect.y);
                    }
                }
                Rectangle            newRect = ui.getPathBounds(tree, newPath);
                if (newRect != null) {
                    newRect.x = visRect.x;
                    newRect.width = visRect.width;
                    if(direction == -1) {
                        newRect.height = visRect.height;
                    }
                    else {
                        newRect.y -= (visRect.height - newRect.height);
                        newRect.height = visRect.height;
                    }

                    if(addToSelection) {
                        ui.extendSelection(newPath);
                    }
                    else if(changeSelection) {
                        tree.setSelectionPath(newPath);
                    }
                    else {
                        ui.setLeadSelectionPath(newPath, true);
                    }
                    tree.scrollRectToVisible(newRect);
                }
            }
        }

        private void home(JTree tree, final BasicTreeUI ui, int direction,
                          boolean addToSelection, boolean changeSelection) {

            // disable moving of lead unless in discontiguous mode
            if (!addToSelection && !changeSelection &&
                    tree.getSelectionModel().getSelectionMode() !=
                        TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION) {
                changeSelection = true;
            }

            final int rowCount = ui.getRowCount(tree);

            if (rowCount > 0) {
                if(direction == -1) {
                    ui.ensureRowsAreVisible(0, 0);
                    if (addToSelection) {
                        TreePath        aPath = ui.getAnchorSelectionPath();
                        int             aRow = (aPath == null) ? -1 :
                                        ui.getRowForPath(tree, aPath);

                        if (aRow == -1) {
                            tree.setSelectionInterval(0, 0);
                        }
                        else {
                            tree.setSelectionInterval(0, aRow);
                            ui.setAnchorSelectionPath(aPath);
                            ui.setLeadSelectionPath(ui.getPathForRow(tree, 0));
                        }
                    }
                    else if(changeSelection) {
                        tree.setSelectionInterval(0, 0);
                    }
                    else {
                        ui.setLeadSelectionPath(ui.getPathForRow(tree, 0),
                                                true);
                    }
                }
                else {
                    ui.ensureRowsAreVisible(rowCount - 1, rowCount - 1);
                    if (addToSelection) {
                        TreePath        aPath = ui.getAnchorSelectionPath();
                        int             aRow = (aPath == null) ? -1 :
                                        ui.getRowForPath(tree, aPath);

                        if (aRow == -1) {
                            tree.setSelectionInterval(rowCount - 1,
                                                      rowCount -1);
                        }
                        else {
                            tree.setSelectionInterval(aRow, rowCount - 1);
                            ui.setAnchorSelectionPath(aPath);
                            ui.setLeadSelectionPath(ui.getPathForRow(tree,
                                                               rowCount -1));
                        }
                    }
                    else if(changeSelection) {
                        tree.setSelectionInterval(rowCount - 1, rowCount - 1);
                    }
                    else {
                        ui.setLeadSelectionPath(ui.getPathForRow(tree,
                                                          rowCount - 1), true);
                    }
                    if (ui.isLargeModel()){
                        SwingUtilities.invokeLater(new Runnable() {
                            public void run() {
                                ui.ensureRowsAreVisible(rowCount - 1, rowCount - 1);
                            }
                        });
                    }
                }
            }
        }
    }
} // End of class BasicTreeUI