https://openjdk.java.net/ 
/*
 * Copyright (c) 1998, 2013, 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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 * questions.
 */

package javax.swing.tree;

import javax.swing.event.TreeModelEvent;
import java.awt.Dimension;
import java.awt.Rectangle;
import java.util.Enumeration;


Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing.  As of 1.4, support for long term storage
of all JavaBeans™
has been added to the java.beans package. Please see XMLEncoder. 
Author:Scott Violet
/**
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author Scott Violet
 */

public abstract class AbstractLayoutCache implements RowMapper {
    
Object responsible for getting the size of a node. 
/** Object responsible for getting the size of a node. */
    protected NodeDimensions     nodeDimensions;

    
Model providing information. 
/** Model providing information. */
    protected TreeModel          treeModel;

    
Selection model. 
/** Selection model. */
    protected TreeSelectionModel treeSelectionModel;

    
True if the root node is displayed, false if its children are
the highest visible nodes.

/**
     * True if the root node is displayed, false if its children are
     * the highest visible nodes.
     */
    protected boolean            rootVisible;

    
Height to use for each row.  If this is <= 0 the renderer will be
used to determine the height for each row.

/**
      * Height to use for each row.  If this is &lt;= 0 the renderer will be
      * used to determine the height for each row.
      */
    protected int                rowHeight;


    
Sets the renderer that is responsible for drawing nodes in the tree
and which is therefore responsible for calculating the dimensions of
individual nodes.

Params:
  • nd – a NodeDimensions object
/**
     * Sets the renderer that is responsible for drawing nodes in the tree
     * and which is therefore responsible for calculating the dimensions of
     * individual nodes.
     *
     * @param nd a <code>NodeDimensions</code> object
     */
    public void setNodeDimensions(NodeDimensions nd) {
        this.nodeDimensions = nd;
    }

    
Returns the object that renders nodes in the tree, and which is
responsible for calculating the dimensions of individual nodes.

Returns:the NodeDimensions object
/**
     * Returns the object that renders nodes in the tree, and which is
     * responsible for calculating the dimensions of individual nodes.
     *
     * @return the <code>NodeDimensions</code> object
     */
    public NodeDimensions getNodeDimensions() {
        return nodeDimensions;
    }

    
Sets the TreeModel that will provide the data.

Params:
  • newModel – the TreeModel that is to
         provide the data
/**
     * Sets the <code>TreeModel</code> that will provide the data.
     *
     * @param newModel the <code>TreeModel</code> that is to
     *          provide the data
     */
    public void setModel(TreeModel newModel) {
        treeModel = newModel;
    }

    
Returns the TreeModel that is providing the data.

Returns:the TreeModel that is providing the data
/**
     * Returns the <code>TreeModel</code> that is providing the data.
     *
     * @return the <code>TreeModel</code> that is providing the data
     */
    public TreeModel getModel() {
        return treeModel;
    }

    
Determines whether or not the root node from
the TreeModel is visible.

Params:
  • rootVisible – true if the root node of the tree is to be displayed
See Also:
@beaninfo
       bound: true
 description: Whether or not the root node
              from the TreeModel is visible.
/**
     * Determines whether or not the root node from
     * the <code>TreeModel</code> is visible.
     *
     * @param rootVisible true if the root node of the tree is to be displayed
     * @see #rootVisible
     * @beaninfo
     *        bound: true
     *  description: Whether or not the root node
     *               from the TreeModel is visible.
     */
    public void setRootVisible(boolean rootVisible) {
        this.rootVisible = rootVisible;
    }

    
Returns true if the root node of the tree is displayed.

See Also:
Returns:true if the root node of the tree is displayed
/**
     * Returns true if the root node of the tree is displayed.
     *
     * @return true if the root node of the tree is displayed
     * @see #rootVisible
     */
    public boolean isRootVisible() {
        return rootVisible;
    }

    
Sets the height of each cell.  If the specified value
is less than or equal to zero the current cell renderer is
queried for each row's height.

Params:
  • rowHeight – the height of each cell, in pixels
@beaninfo
       bound: true
 description: The height of each cell.
/**
     * Sets the height of each cell.  If the specified value
     * is less than or equal to zero the current cell renderer is
     * queried for each row's height.
     *
     * @param rowHeight the height of each cell, in pixels
     * @beaninfo
     *        bound: true
     *  description: The height of each cell.
     */
    public void setRowHeight(int rowHeight) {
        this.rowHeight = rowHeight;
    }

    
Returns the height of each row.  If the returned value is less than
or equal to 0 the height for each row is determined by the
renderer.

/**
     * Returns the height of each row.  If the returned value is less than
     * or equal to 0 the height for each row is determined by the
     * renderer.
     */
    public int getRowHeight() {
        return rowHeight;
    }

    
Sets the TreeSelectionModel used to manage the
selection to new LSM.

Params:
  • newLSM –  the new TreeSelectionModel
/**
     * Sets the <code>TreeSelectionModel</code> used to manage the
     * selection to new LSM.
     *
     * @param newLSM  the new <code>TreeSelectionModel</code>
     */
    public void setSelectionModel(TreeSelectionModel newLSM) {
        if(treeSelectionModel != null)
            treeSelectionModel.setRowMapper(null);
        treeSelectionModel = newLSM;
        if(treeSelectionModel != null)
            treeSelectionModel.setRowMapper(this);
    }

    
Returns the model used to maintain the selection.

Returns:the treeSelectionModel
/**
     * Returns the model used to maintain the selection.
     *
     * @return the <code>treeSelectionModel</code>
     */
    public TreeSelectionModel getSelectionModel() {
        return treeSelectionModel;
    }

    
Returns the preferred height.

Returns:the preferred height
/**
     * Returns the preferred height.
     *
     * @return the preferred height
     */
    public int getPreferredHeight() {
        // Get the height
        int           rowCount = getRowCount();

        if(rowCount > 0) {
            Rectangle     bounds = getBounds(getPathForRow(rowCount - 1),
                                             null);

            if(bounds != null)
                return bounds.y + bounds.height;
        }
        return 0;
    }

    
Returns the preferred width for the passed in region.
The region is defined by the path closest to
(bounds.x, bounds.y) and
ends at bounds.height + bounds.y.
If bounds is null,
the preferred width for all the nodes
will be returned (and this may be a VERY expensive
computation).

Params:
  • bounds – the region being queried
Returns:the preferred width for the passed in region
/**
     * Returns the preferred width for the passed in region.
     * The region is defined by the path closest to
     * <code>(bounds.x, bounds.y)</code> and
     * ends at <code>bounds.height + bounds.y</code>.
     * If <code>bounds</code> is <code>null</code>,
     * the preferred width for all the nodes
     * will be returned (and this may be a VERY expensive
     * computation).
     *
     * @param bounds the region being queried
     * @return the preferred width for the passed in region
     */
    public int getPreferredWidth(Rectangle bounds) {
        int           rowCount = getRowCount();

        if(rowCount > 0) {
            // Get the width
            TreePath      firstPath;
            int           endY;

            if(bounds == null) {
                firstPath = getPathForRow(0);
                endY = Integer.MAX_VALUE;
            }
            else {
                firstPath = getPathClosestTo(bounds.x, bounds.y);
                endY = bounds.height + bounds.y;
            }

            Enumeration   paths = getVisiblePathsFrom(firstPath);

            if(paths != null && paths.hasMoreElements()) {
                Rectangle   pBounds = getBounds((TreePath)paths.nextElement(),
                                                null);
                int         width;

                if(pBounds != null) {
                    width = pBounds.x + pBounds.width;
                    if (pBounds.y >= endY) {
                        return width;
                    }
                }
                else
                    width = 0;
                while (pBounds != null && paths.hasMoreElements()) {
                    pBounds = getBounds((TreePath)paths.nextElement(),
                                        pBounds);
                    if (pBounds != null && pBounds.y < endY) {
                        width = Math.max(width, pBounds.x + pBounds.width);
                    }
                    else {
                        pBounds = null;
                    }
                }
                return width;
            }
        }
        return 0;
    }

    //
    // Abstract methods that must be implemented to be concrete.
    //

    
Returns true if the value identified by row is currently expanded.

/**
      * Returns true if the value identified by row is currently expanded.
      */
    public abstract boolean isExpanded(TreePath path);

    
Returns a rectangle giving the bounds needed to draw path.

Params:
  • path –     a TreePath specifying a node
  • placeIn –  a Rectangle object giving the
         available space
Returns:a Rectangle object specifying the space to be used
/**
     * Returns a rectangle giving the bounds needed to draw path.
     *
     * @param path     a <code>TreePath</code> specifying a node
     * @param placeIn  a <code>Rectangle</code> object giving the
     *          available space
     * @return a <code>Rectangle</code> object specifying the space to be used
     */
    public abstract Rectangle getBounds(TreePath path, Rectangle placeIn);

    
Returns the path for passed in row.  If row is not visible
null is returned.

Params:
  • row –  the row being queried
Returns:the TreePath for the given row
/**
      * Returns the path for passed in row.  If row is not visible
      * <code>null</code> is returned.
      *
      * @param row  the row being queried
      * @return the <code>TreePath</code> for the given row
      */
    public abstract TreePath getPathForRow(int row);

    
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.

Params:
  • path – the TreePath being queried
Returns:the row where the last item in path is visible or -1
        if any elements in path aren't 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.
      *
      * @param path the <code>TreePath</code> being queried
      * @return the row where the last item in path is visible or -1
      *         if any elements in path aren't currently visible
      */
    public abstract int getRowForPath(TreePath path);

    
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.

Params:
  • x – the horizontal component of the desired location
  • y – the vertical component of the desired location
Returns:the TreePath closest to the specified point
/**
      * Returns the path to the node that is closest to x,y.  If
      * there is nothing currently visible this will return <code>null</code>,
      * 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.
      *
      * @param x the horizontal component of the desired location
      * @param y the vertical component of the desired location
      * @return the <code>TreePath</code> closest to the specified point
      */
    public abstract TreePath getPathClosestTo(int x, int y);

    
Returns an Enumerator that increments over the visible
paths starting at the passed in location. The ordering of the
enumeration is based on how the paths are displayed.
The first element of the returned enumeration will be path,
unless it isn't visible,
in which case null will be returned.

Params:
  • path – the starting location for the enumeration
Returns:the Enumerator starting at the desired location
/**
     * Returns an <code>Enumerator</code> that increments over the visible
     * paths starting at the passed in location. The ordering of the
     * enumeration is based on how the paths are displayed.
     * The first element of the returned enumeration will be path,
     * unless it isn't visible,
     * in which case <code>null</code> will be returned.
     *
     * @param path the starting location for the enumeration
     * @return the <code>Enumerator</code> starting at the desired location
     */
    public abstract Enumeration<TreePath> getVisiblePathsFrom(TreePath path);

    
Returns the number of visible children for row.

Params:
  • path –  the path being queried
Returns:the number of visible children for the specified path
/**
     * Returns the number of visible children for row.
     *
     * @param path  the path being queried
     * @return the number of visible children for the specified path
     */
    public abstract int getVisibleChildCount(TreePath path);

    
Marks the path path expanded state to
isExpanded.

Params:
  • path –  the path being expanded or collapsed
  • isExpanded – true if the path should be expanded, false otherwise
/**
     * Marks the path <code>path</code> expanded state to
     * <code>isExpanded</code>.
     *
     * @param path  the path being expanded or collapsed
     * @param isExpanded true if the path should be expanded, false otherwise
     */
    public abstract void setExpandedState(TreePath path, boolean isExpanded);

    
Returns true if the path is expanded, and visible.

Params:
  • path –  the path being queried
Returns:true if the path is expanded and visible, false otherwise
/**
     * Returns true if the path is expanded, and visible.
     *
     * @param path  the path being queried
     * @return true if the path is expanded and visible, false otherwise
     */
    public abstract boolean getExpandedState(TreePath path);

    
Number of rows being displayed.

Returns:the number of rows being displayed
/**
     * Number of rows being displayed.
     *
     * @return the number of rows being displayed
     */
    public abstract int getRowCount();

    
Informs the TreeState that it needs to recalculate
all the sizes it is referencing.

/**
     * Informs the <code>TreeState</code> that it needs to recalculate
     * all the sizes it is referencing.
     */
    public abstract void invalidateSizes();

    
Instructs the LayoutCache that the bounds for
path are invalid, and need to be updated.

Params:
  • path – the path being updated
/**
     * Instructs the <code>LayoutCache</code> that the bounds for
     * <code>path</code> are invalid, and need to be updated.
     *
     * @param path the path being updated
     */
    public abstract void invalidatePathBounds(TreePath path);

    //
    // TreeModelListener methods
    // AbstractTreeState does not directly become a TreeModelListener on
    // the model, it is up to some other object to forward these methods.
    //

    

Invoked after a node (or a set of siblings) has changed in some
way. The node(s) have not changed locations in the tree or
altered their children arrays, but other attributes have
changed and may affect presentation. Example: the name of a
file has changed, but it is in the same location in the file
system.


e.path() returns the path the parent of the changed node(s).


e.childIndices() returns the index(es) of the changed node(s).


Params:
  • e –  the TreeModelEvent
/**
     * <p>
     * Invoked after a node (or a set of siblings) has changed in some
     * way. The node(s) have not changed locations in the tree or
     * altered their children arrays, but other attributes have
     * changed and may affect presentation. Example: the name of a
     * file has changed, but it is in the same location in the file
     * system.</p>
     *
     * <p>e.path() returns the path the parent of the changed node(s).</p>
     *
     * <p>e.childIndices() returns the index(es) of the changed node(s).</p>
     *
     * @param e  the <code>TreeModelEvent</code>
     */
    public abstract void treeNodesChanged(TreeModelEvent e);

    
Invoked after nodes have been inserted into the tree.


e.path() returns the parent of the new nodes


e.childIndices() returns the indices of the new nodes in
ascending order.


Params:
  • e – the TreeModelEvent
/**
     * <p>Invoked after nodes have been inserted into the tree.</p>
     *
     * <p>e.path() returns the parent of the new nodes</p>
     * <p>e.childIndices() returns the indices of the new nodes in
     * ascending order.</p>
     *
     * @param e the <code>TreeModelEvent</code>
     */
    public abstract void treeNodesInserted(TreeModelEvent e);

    
Invoked after nodes have been removed from the tree.  Note that
if a subtree is removed from the tree, this method may only be
invoked once for the root of the removed subtree, not once for
each individual set of siblings removed.


e.path() returns the former parent of the deleted nodes.


e.childIndices() returns the indices the nodes had before they were deleted in ascending order.


Params:
  • e – the TreeModelEvent
/**
     * <p>Invoked after nodes have been removed from the tree.  Note that
     * if a subtree is removed from the tree, this method may only be
     * invoked once for the root of the removed subtree, not once for
     * each individual set of siblings removed.</p>
     *
     * <p>e.path() returns the former parent of the deleted nodes.</p>
     *
     * <p>e.childIndices() returns the indices the nodes had before they were deleted in ascending order.</p>
     *
     * @param e the <code>TreeModelEvent</code>
     */
    public abstract void treeNodesRemoved(TreeModelEvent e);

    
Invoked after the tree has drastically changed structure from a
given node down.  If the path returned by e.getPath()
is of length one and the first element does not identify the
current root node the first element should become the new root
of the tree.


e.path() holds the path to the node.


e.childIndices() returns null.


Params:
  • e – the TreeModelEvent
/**
     * <p>Invoked after the tree has drastically changed structure from a
     * given node down.  If the path returned by <code>e.getPath()</code>
     * is of length one and the first element does not identify the
     * current root node the first element should become the new root
     * of the tree.</p>
     *
     * <p>e.path() holds the path to the node.</p>
     * <p>e.childIndices() returns null.</p>
     *
     * @param e the <code>TreeModelEvent</code>
     */
    public abstract void treeStructureChanged(TreeModelEvent e);

    //
    // RowMapper
    //

    
Returns the rows that the TreePath instances in
path are being displayed at.
This method should return an array of the same length as that passed
in, and if one of the TreePaths
in path is not valid its entry in the array should
be set to -1.

Params:
  • paths – the array of TreePaths being queried
Returns:an array of the same length that is passed in containing
         the rows that each corresponding where each
         TreePath is displayed; if paths
         is null, null is returned
/**
     * Returns the rows that the <code>TreePath</code> instances in
     * <code>path</code> are being displayed at.
     * This method should return an array of the same length as that passed
     * in, and if one of the <code>TreePaths</code>
     * in <code>path</code> is not valid its entry in the array should
     * be set to -1.
     *
     * @param paths the array of <code>TreePath</code>s being queried
     * @return an array of the same length that is passed in containing
     *          the rows that each corresponding where each
     *          <code>TreePath</code> is displayed; if <code>paths</code>
     *          is <code>null</code>, <code>null</code> is returned
     */
    public int[] getRowsForPaths(TreePath[] paths) {
        if(paths == null)
            return null;

        int               numPaths = paths.length;
        int[]             rows = new int[numPaths];

        for(int counter = 0; counter < numPaths; counter++)
            rows[counter] = getRowForPath(paths[counter]);
        return rows;
    }

    //
    // Local methods that subclassers may wish to use that are primarly
    // convenience methods.
    //

    
Returns, by reference in placeIn,
the size needed to represent value.
If inPlace is null, a newly created
Rectangle should be returned, otherwise the value
should be placed in inPlace and returned. This will
return null if there is no renderer.

Params:
  • value – the value to be represented
  • row –  row being queried
  • depth – the depth of the row
  • expanded – true if row is expanded, false otherwise
  • placeIn –  a Rectangle containing the size needed
         to represent value
Returns:a Rectangle containing the node dimensions,
         or null if node has no dimension
/**
     * Returns, by reference in <code>placeIn</code>,
     * the size needed to represent <code>value</code>.
     * If <code>inPlace</code> is <code>null</code>, a newly created
     * <code>Rectangle</code> should be returned, otherwise the value
     * should be placed in <code>inPlace</code> and returned. This will
     * return <code>null</code> if there is no renderer.
     *
     * @param value the <code>value</code> to be represented
     * @param row  row being queried
     * @param depth the depth of the row
     * @param expanded true if row is expanded, false otherwise
     * @param placeIn  a <code>Rectangle</code> containing the size needed
     *          to represent <code>value</code>
     * @return a <code>Rectangle</code> containing the node dimensions,
     *          or <code>null</code> if node has no dimension
     */
    protected Rectangle getNodeDimensions(Object value, int row, int depth,
                                          boolean expanded,
                                          Rectangle placeIn) {
        NodeDimensions            nd = getNodeDimensions();

        if(nd != null) {
            return nd.getNodeDimensions(value, row, depth, expanded, placeIn);
        }
        return null;
    }

    
Returns true if the height of each row is a fixed size.

/**
      * Returns true if the height of each row is a fixed size.
      */
    protected boolean isFixedRowHeight() {
        return (rowHeight > 0);
    }


    
Used by AbstractLayoutCache to determine the size
and x origin of a particular node.

/**
     * Used by <code>AbstractLayoutCache</code> to determine the size
     * and x origin of a particular node.
     */
    static public abstract class NodeDimensions {
        
Returns, by reference in bounds, the size and x origin to
place value at. The calling method is responsible for determining
the Y location. If bounds is null, a newly created
Rectangle should be returned,
otherwise the value should be placed in bounds and returned.

Params:
  • value – the value to be represented
  • row – row being queried
  • depth – the depth of the row
  • expanded – true if row is expanded, false otherwise
  • bounds –  a Rectangle containing the size needed
             to represent value
Returns:a Rectangle containing the node dimensions,
             or null if node has no dimension
/**
         * Returns, by reference in bounds, the size and x origin to
         * place value at. The calling method is responsible for determining
         * the Y location. If bounds is <code>null</code>, a newly created
         * <code>Rectangle</code> should be returned,
         * otherwise the value should be placed in bounds and returned.
         *
         * @param value the <code>value</code> to be represented
         * @param row row being queried
         * @param depth the depth of the row
         * @param expanded true if row is expanded, false otherwise
         * @param bounds  a <code>Rectangle</code> containing the size needed
         *              to represent <code>value</code>
         * @return a <code>Rectangle</code> containing the node dimensions,
         *              or <code>null</code> if node has no dimension
         */
        public abstract Rectangle getNodeDimensions(Object value, int row,
                                                    int depth,
                                                    boolean expanded,
                                                    Rectangle bounds);
    }
}