https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2015, 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;

import java.beans.JavaBean;
import java.beans.BeanProperty;
import java.beans.ConstructorProperties;
import javax.swing.plaf.*;
import javax.accessibility.*;

import java.awt.*;

import java.io.ObjectOutputStream;
import java.io.IOException;


JSplitPane is used to divide two (and only two)
Components. The two Components
are graphically divided based on the look and feel
implementation, and the two Components can then be
interactively resized by the user.
Information on using JSplitPane is in
How to Use Split Panes in
The Java Tutorial.


The two Components in a split pane can be aligned
left to right using
JSplitPane.HORIZONTAL_SPLIT, or top to bottom using
JSplitPane.VERTICAL_SPLIT.
The preferred way to change the size of the Components
is to invoke
setDividerLocation where location is either
the new x or y position, depending on the orientation of the
JSplitPane.


To resize the Components to their preferred sizes invoke
resetToPreferredSizes.


When the user is resizing the Components the minimum
size of the Components is used to determine the
maximum/minimum position the Components
can be set to. If the minimum size of the two
components is greater than the size of the split pane the divider
will not allow you to resize it. To alter the minimum size of a
JComponent, see JComponent.setMinimumSize. 

When the user resizes the split pane the new space is distributed between
the two components based on the resizeWeight property.
A value of 0,
the default, indicates the right/bottom component gets all the space,
where as a value of 1 indicates the left/top component gets all the space.


Warning: Swing is not thread safe. For more
information see Swing's Threading
Policy.


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
See Also:
Since:1.2
/**
 * <code>JSplitPane</code> is used to divide two (and only two)
 * <code>Component</code>s. The two <code>Component</code>s
 * are graphically divided based on the look and feel
 * implementation, and the two <code>Component</code>s can then be
 * interactively resized by the user.
 * Information on using <code>JSplitPane</code> is in
 * <a
 href="https://docs.oracle.com/javase/tutorial/uiswing/components/splitpane.html">How to Use Split Panes</a> in
 * <em>The Java Tutorial</em>.
 * <p>
 * The two <code>Component</code>s in a split pane can be aligned
 * left to right using
 * <code>JSplitPane.HORIZONTAL_SPLIT</code>, or top to bottom using
 * <code>JSplitPane.VERTICAL_SPLIT</code>.
 * The preferred way to change the size of the <code>Component</code>s
 * is to invoke
 * <code>setDividerLocation</code> where <code>location</code> is either
 * the new x or y position, depending on the orientation of the
 * <code>JSplitPane</code>.
 * <p>
 * To resize the <code>Component</code>s to their preferred sizes invoke
 * <code>resetToPreferredSizes</code>.
 * <p>
 * When the user is resizing the <code>Component</code>s the minimum
 * size of the <code>Components</code> is used to determine the
 * maximum/minimum position the <code>Component</code>s
 * can be set to. If the minimum size of the two
 * components is greater than the size of the split pane the divider
 * will not allow you to resize it. To alter the minimum size of a
 * <code>JComponent</code>, see {@link JComponent#setMinimumSize}.
 * <p>
 * When the user resizes the split pane the new space is distributed between
 * the two components based on the <code>resizeWeight</code> property.
 * A value of 0,
 * the default, indicates the right/bottom component gets all the space,
 * where as a value of 1 indicates the left/top component gets all the space.
 * <p>
 * <strong>Warning:</strong> Swing is not thread safe. For more
 * information see <a
 * href="package-summary.html#threading">Swing's Threading
 * Policy</a>.
 * <p>
 * <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
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @see #setDividerLocation
 * @see #resetToPreferredSizes
 *
 * @author Scott Violet
 * @since 1.2
 */
@JavaBean(defaultProperty = "UI")
@SuppressWarnings("serial") // Same-version serialization only
public class JSplitPane extends JComponent implements Accessible
{
    
See Also:
/**
     * @see #getUIClassID
     * @see #readObject
     */
    private static final String uiClassID = "SplitPaneUI";

    
Vertical split indicates the Components are
split along the y axis.  For example the two
Components will be split one on top of the other.

/**
     * Vertical split indicates the <code>Component</code>s are
     * split along the y axis.  For example the two
     * <code>Component</code>s will be split one on top of the other.
     */
    public static final int VERTICAL_SPLIT = 0;

    
Horizontal split indicates the Components are
split along the x axis.  For example the two
Components will be split one to the left of the
other.

/**
     * Horizontal split indicates the <code>Component</code>s are
     * split along the x axis.  For example the two
     * <code>Component</code>s will be split one to the left of the
     * other.
     */
    public static final int HORIZONTAL_SPLIT = 1;

    
Used to add a Component to the left of the other
Component.

/**
     * Used to add a <code>Component</code> to the left of the other
     * <code>Component</code>.
     */
    public static final String LEFT = "left";

    
Used to add a Component to the right of the other
Component.

/**
     * Used to add a <code>Component</code> to the right of the other
     * <code>Component</code>.
     */
    public static final String RIGHT = "right";

    
Used to add a Component above the other
Component.

/**
     * Used to add a <code>Component</code> above the other
     * <code>Component</code>.
     */
    public static final String TOP = "top";

    
Used to add a Component below the other
Component.

/**
     * Used to add a <code>Component</code> below the other
     * <code>Component</code>.
     */
    public static final String BOTTOM = "bottom";

    
Used to add a Component that will represent the divider.

/**
     * Used to add a <code>Component</code> that will represent the divider.
     */
    public static final String DIVIDER = "divider";

    
Bound property name for orientation (horizontal or vertical).

/**
     * Bound property name for orientation (horizontal or vertical).
     */
    public static final String ORIENTATION_PROPERTY = "orientation";

    
Bound property name for continuousLayout.

/**
     * Bound property name for continuousLayout.
     */
    public static final String CONTINUOUS_LAYOUT_PROPERTY = "continuousLayout";

    
Bound property name for border.

/**
     * Bound property name for border.
     */
    public static final String DIVIDER_SIZE_PROPERTY = "dividerSize";

    
Bound property for oneTouchExpandable.

/**
     * Bound property for oneTouchExpandable.
     */
    public static final String ONE_TOUCH_EXPANDABLE_PROPERTY =
                               "oneTouchExpandable";

    
Bound property for lastLocation.

/**
     * Bound property for lastLocation.
     */
    public static final String LAST_DIVIDER_LOCATION_PROPERTY =
                               "lastDividerLocation";

    
Bound property for the dividerLocation.

Since:1.3
/**
     * Bound property for the dividerLocation.
     * @since 1.3
     */
    public static final String DIVIDER_LOCATION_PROPERTY = "dividerLocation";

    
Bound property for weight.

Since:1.3
/**
     * Bound property for weight.
     * @since 1.3
     */
    public static final String RESIZE_WEIGHT_PROPERTY = "resizeWeight";

    
How the views are split.

/**
     * How the views are split.
     */
    protected int orientation;

    
Whether or not the views are continuously redisplayed while
resizing.

/**
     * Whether or not the views are continuously redisplayed while
     * resizing.
     */
    protected boolean continuousLayout;

    
The left or top component.

/**
     * The left or top component.
     */
    protected Component leftComponent;

    
The right or bottom component.

/**
     * The right or bottom component.
     */
    protected Component rightComponent;

    
Size of the divider.

/**
     * Size of the divider.
     */
    protected int dividerSize;
    private boolean dividerSizeSet = false;

    
Is a little widget provided to quickly expand/collapse the
split pane?

/**
     * Is a little widget provided to quickly expand/collapse the
     * split pane?
     */
    protected boolean oneTouchExpandable;
    private boolean oneTouchExpandableSet;

    
Previous location of the split pane.

/**
     * Previous location of the split pane.
     */
    protected int lastDividerLocation;

    
How to distribute extra space.

/**
     * How to distribute extra space.
     */
    private double resizeWeight;

    
Location of the divider, at least the value that was set, the UI may
have a different value.

/**
     * Location of the divider, at least the value that was set, the UI may
     * have a different value.
     */
    private int dividerLocation;


    
Creates a new JSplitPane configured to arrange the child
components side-by-side horizontally, using two buttons for the components.

/**
     * Creates a new <code>JSplitPane</code> configured to arrange the child
     * components side-by-side horizontally, using two buttons for the components.
     */
    public JSplitPane() {
        this(JSplitPane.HORIZONTAL_SPLIT,
                UIManager.getBoolean("SplitPane.continuousLayout"),
                new JButton(UIManager.getString("SplitPane.leftButtonText")),
                new JButton(UIManager.getString("SplitPane.rightButtonText")));
    }


    
Creates a new JSplitPane configured with the
specified orientation.

Params:
  • newOrientation –  JSplitPane.HORIZONTAL_SPLIT or
                       JSplitPane.VERTICAL_SPLIT
Throws:
/**
     * Creates a new <code>JSplitPane</code> configured with the
     * specified orientation.
     *
     * @param newOrientation  <code>JSplitPane.HORIZONTAL_SPLIT</code> or
     *                        <code>JSplitPane.VERTICAL_SPLIT</code>
     * @exception IllegalArgumentException if <code>orientation</code>
     *          is not one of HORIZONTAL_SPLIT or VERTICAL_SPLIT.
     */
    @ConstructorProperties({"orientation"})
    public JSplitPane(int newOrientation) {
        this(newOrientation,
                UIManager.getBoolean("SplitPane.continuousLayout"));
    }


    
Creates a new JSplitPane with the specified
orientation and redrawing style.

Params:
  • newOrientation –  JSplitPane.HORIZONTAL_SPLIT or
                       JSplitPane.VERTICAL_SPLIT
  • newContinuousLayout –  a boolean, true for the components to
       redraw continuously as the divider changes position, false
       to wait until the divider position stops changing to redraw
Throws:
/**
     * Creates a new <code>JSplitPane</code> with the specified
     * orientation and redrawing style.
     *
     * @param newOrientation  <code>JSplitPane.HORIZONTAL_SPLIT</code> or
     *                        <code>JSplitPane.VERTICAL_SPLIT</code>
     * @param newContinuousLayout  a boolean, true for the components to
     *        redraw continuously as the divider changes position, false
     *        to wait until the divider position stops changing to redraw
     * @exception IllegalArgumentException if <code>orientation</code>
     *          is not one of HORIZONTAL_SPLIT or VERTICAL_SPLIT
     */
    public JSplitPane(int newOrientation,
                      boolean newContinuousLayout) {
        this(newOrientation, newContinuousLayout, null, null);
    }


    
Creates a new JSplitPane with the specified
orientation and the specified components.

Params:
  • newOrientation –  JSplitPane.HORIZONTAL_SPLIT or
                       JSplitPane.VERTICAL_SPLIT
  • newLeftComponent – the Component that will
         appear on the left
         of a horizontally-split pane, or at the top of a
         vertically-split pane
  • newRightComponent – the Component that will
         appear on the right
         of a horizontally-split pane, or at the bottom of a
         vertically-split pane
Throws:
/**
     * Creates a new <code>JSplitPane</code> with the specified
     * orientation and the specified components.
     *
     * @param newOrientation  <code>JSplitPane.HORIZONTAL_SPLIT</code> or
     *                        <code>JSplitPane.VERTICAL_SPLIT</code>
     * @param newLeftComponent the <code>Component</code> that will
     *          appear on the left
     *          of a horizontally-split pane, or at the top of a
     *          vertically-split pane
     * @param newRightComponent the <code>Component</code> that will
     *          appear on the right
     *          of a horizontally-split pane, or at the bottom of a
     *          vertically-split pane
     * @exception IllegalArgumentException if <code>orientation</code>
     *          is not one of: HORIZONTAL_SPLIT or VERTICAL_SPLIT
     */
    public JSplitPane(int newOrientation,
                      Component newLeftComponent,
                      Component newRightComponent){
        this(newOrientation,
                UIManager.getBoolean("SplitPane.continuousLayout"),
                newLeftComponent, newRightComponent);
    }


    
Creates a new JSplitPane with the specified
orientation and
redrawing style, and with the specified components.

Params:
  • newOrientation –  JSplitPane.HORIZONTAL_SPLIT or
                       JSplitPane.VERTICAL_SPLIT
  • newContinuousLayout –  a boolean, true for the components to
       redraw continuously as the divider changes position, false
       to wait until the divider position stops changing to redraw
  • newLeftComponent – the Component that will
         appear on the left
         of a horizontally-split pane, or at the top of a
         vertically-split pane
  • newRightComponent – the Component that will
         appear on the right
         of a horizontally-split pane, or at the bottom of a
         vertically-split pane
Throws:
/**
     * Creates a new <code>JSplitPane</code> with the specified
     * orientation and
     * redrawing style, and with the specified components.
     *
     * @param newOrientation  <code>JSplitPane.HORIZONTAL_SPLIT</code> or
     *                        <code>JSplitPane.VERTICAL_SPLIT</code>
     * @param newContinuousLayout  a boolean, true for the components to
     *        redraw continuously as the divider changes position, false
     *        to wait until the divider position stops changing to redraw
     * @param newLeftComponent the <code>Component</code> that will
     *          appear on the left
     *          of a horizontally-split pane, or at the top of a
     *          vertically-split pane
     * @param newRightComponent the <code>Component</code> that will
     *          appear on the right
     *          of a horizontally-split pane, or at the bottom of a
     *          vertically-split pane
     * @exception IllegalArgumentException if <code>orientation</code>
     *          is not one of HORIZONTAL_SPLIT or VERTICAL_SPLIT
     */
    public JSplitPane(int newOrientation,
                      boolean newContinuousLayout,
                      Component newLeftComponent,
                      Component newRightComponent){
        super();

        dividerLocation = -1;
        setLayout(null);
        setUIProperty("opaque", Boolean.TRUE);
        orientation = newOrientation;
        if (orientation != HORIZONTAL_SPLIT && orientation != VERTICAL_SPLIT)
            throw new IllegalArgumentException("cannot create JSplitPane, " +
                                               "orientation must be one of " +
                                               "JSplitPane.HORIZONTAL_SPLIT " +
                                               "or JSplitPane.VERTICAL_SPLIT");
        continuousLayout = newContinuousLayout;
        if (newLeftComponent != null)
            setLeftComponent(newLeftComponent);
        if (newRightComponent != null)
            setRightComponent(newRightComponent);
        updateUI();

    }


    
Sets the L&F object that renders this component.

Params:
  • ui –  the SplitPaneUI L&F object
See Also:
/**
     * Sets the L&amp;F object that renders this component.
     *
     * @param ui  the <code>SplitPaneUI</code> L&amp;F object
     * @see UIDefaults#getUI
     */
    public void setUI(SplitPaneUI ui) {
        if ((SplitPaneUI)this.ui != ui) {
            super.setUI(ui);
            revalidate();
        }
    }


    
Returns the SplitPaneUI that is providing the
current look and feel.

Returns:the SplitPaneUI object that renders this component
/**
     * Returns the <code>SplitPaneUI</code> that is providing the
     * current look and feel.
     *
     * @return the <code>SplitPaneUI</code> object that renders this component
     */
    @BeanProperty(bound = false, expert = true, description
            = "The L&F object that renders this component.")
    public SplitPaneUI getUI() {
        return (SplitPaneUI)ui;
    }


    
Notification from the UIManager that the L&F has changed.
Replaces the current UI object with the latest version from the
UIManager.

See Also:
  • updateUI.updateUI
/**
     * Notification from the <code>UIManager</code> that the L&amp;F has changed.
     * Replaces the current UI object with the latest version from the
     * <code>UIManager</code>.
     *
     * @see JComponent#updateUI
     */
    public void updateUI() {
        setUI((SplitPaneUI)UIManager.getUI(this));
        revalidate();
    }


    
Returns the name of the L&F class that renders this component.

See Also:
Returns:the string "SplitPaneUI"
/**
     * Returns the name of the L&amp;F class that renders this component.
     *
     * @return the string "SplitPaneUI"
     * @see JComponent#getUIClassID
     * @see UIDefaults#getUI
     */
    @BeanProperty(bound = false, expert = true, description
            = "A string that specifies the name of the L&F class.")
    public String getUIClassID() {
        return uiClassID;
    }


    
Sets the size of the divider.

Params:
  • newSize – an integer giving the size of the divider in pixels
/**
     * Sets the size of the divider.
     *
     * @param newSize an integer giving the size of the divider in pixels
     */
    @BeanProperty(description
            = "The size of the divider.")
    public void setDividerSize(int newSize) {
        int           oldSize = dividerSize;

        dividerSizeSet = true;
        if (oldSize != newSize) {
            dividerSize = newSize;
            firePropertyChange(DIVIDER_SIZE_PROPERTY, oldSize, newSize);
        }
    }


    
Returns the size of the divider.

Returns:an integer giving the size of the divider in pixels
/**
     * Returns the size of the divider.
     *
     * @return an integer giving the size of the divider in pixels
     */
    public int getDividerSize() {
        return dividerSize;
    }


    
Sets the component to the left (or above) the divider.

Params:
  • comp – the Component to display in that position
/**
     * Sets the component to the left (or above) the divider.
     *
     * @param comp the <code>Component</code> to display in that position
     */
    public void setLeftComponent(Component comp) {
        if (comp == null) {
            if (leftComponent != null) {
                remove(leftComponent);
                leftComponent = null;
            }
        } else {
            add(comp, JSplitPane.LEFT);
        }
    }


    
Returns the component to the left (or above) the divider.

Returns:the Component displayed in that position
/**
     * Returns the component to the left (or above) the divider.
     *
     * @return the <code>Component</code> displayed in that position
     */
    @BeanProperty(bound = false, preferred = true, description
            = "The component to the left (or above) the divider.")
    public Component getLeftComponent() {
        return leftComponent;
    }


    
Sets the component above, or to the left of the divider.

Params:
  • comp – the Component to display in that position
/**
     * Sets the component above, or to the left of the divider.
     *
     * @param comp the <code>Component</code> to display in that position
     */
    @BeanProperty(bound = false, description
            = "The component above, or to the left of the divider.")
    public void setTopComponent(Component comp) {
        setLeftComponent(comp);
    }


    
Returns the component above, or to the left of the divider.

Returns:the Component displayed in that position
/**
     * Returns the component above, or to the left of the divider.
     *
     * @return the <code>Component</code> displayed in that position
     */
    public Component getTopComponent() {
        return leftComponent;
    }


    
Sets the component to the right (or below) the divider.

Params:
  • comp – the Component to display in that position
/**
     * Sets the component to the right (or below) the divider.
     *
     * @param comp the <code>Component</code> to display in that position
     */
    @BeanProperty(bound = false, preferred = true, description
            = "The component to the right (or below) the divider.")
    public void setRightComponent(Component comp) {
        if (comp == null) {
            if (rightComponent != null) {
                remove(rightComponent);
                rightComponent = null;
            }
        } else {
            add(comp, JSplitPane.RIGHT);
        }
    }


    
Returns the component to the right (or below) the divider.

Returns:the Component displayed in that position
/**
     * Returns the component to the right (or below) the divider.
     *
     * @return the <code>Component</code> displayed in that position
     */
    public Component getRightComponent() {
        return rightComponent;
    }


    
Sets the component below, or to the right of the divider.

Params:
  • comp – the Component to display in that position
/**
     * Sets the component below, or to the right of the divider.
     *
     * @param comp the <code>Component</code> to display in that position
     */
    @BeanProperty(bound = false, description
            = "The component below, or to the right of the divider.")
    public void setBottomComponent(Component comp) {
        setRightComponent(comp);
    }


    
Returns the component below, or to the right of the divider.

Returns:the Component displayed in that position
/**
     * Returns the component below, or to the right of the divider.
     *
     * @return the <code>Component</code> displayed in that position
     */
    public Component getBottomComponent() {
        return rightComponent;
    }


    
Sets the value of the oneTouchExpandable property,
which must be true for the
JSplitPane to provide a UI widget
on the divider to quickly expand/collapse the divider.
The default value of this property is false.
Some look and feels might not support one-touch expanding;
they will ignore this property.

Params:
  • newValue – true to specify that the split pane should provide a
       collapse/expand widget
See Also:
/**
     * Sets the value of the <code>oneTouchExpandable</code> property,
     * which must be <code>true</code> for the
     * <code>JSplitPane</code> to provide a UI widget
     * on the divider to quickly expand/collapse the divider.
     * The default value of this property is <code>false</code>.
     * Some look and feels might not support one-touch expanding;
     * they will ignore this property.
     *
     * @param newValue <code>true</code> to specify that the split pane should provide a
     *        collapse/expand widget
     *
     * @see #isOneTouchExpandable
     */
    @BeanProperty(description
            = "UI widget on the divider to quickly expand/collapse the divider.")
    public void setOneTouchExpandable(boolean newValue) {
        boolean           oldValue = oneTouchExpandable;

        oneTouchExpandable = newValue;
        oneTouchExpandableSet = true;
        firePropertyChange(ONE_TOUCH_EXPANDABLE_PROPERTY, oldValue, newValue);
        repaint();
    }


    
Gets the oneTouchExpandable property.

See Also:
Returns:the value of the oneTouchExpandable property
/**
     * Gets the <code>oneTouchExpandable</code> property.
     *
     * @return the value of the <code>oneTouchExpandable</code> property
     * @see #setOneTouchExpandable
     */
    public boolean isOneTouchExpandable() {
        return oneTouchExpandable;
    }


    
Sets the last location the divider was at to
newLastLocation.

Params:
  • newLastLocation – an integer specifying the last divider location
       in pixels, from the left (or upper) edge of the pane to the
       left (or upper) edge of the divider
/**
     * Sets the last location the divider was at to
     * <code>newLastLocation</code>.
     *
     * @param newLastLocation an integer specifying the last divider location
     *        in pixels, from the left (or upper) edge of the pane to the
     *        left (or upper) edge of the divider
     */
    @BeanProperty(description
            = "The last location the divider was at.")
    public void setLastDividerLocation(int newLastLocation) {
        int               oldLocation = lastDividerLocation;

        lastDividerLocation = newLastLocation;
        firePropertyChange(LAST_DIVIDER_LOCATION_PROPERTY, oldLocation,
                           newLastLocation);
    }


    
Returns the last location the divider was at.

Returns:an integer specifying the last divider location as a count
      of pixels from the left (or upper) edge of the pane to the
      left (or upper) edge of the divider
/**
     * Returns the last location the divider was at.
     *
     * @return an integer specifying the last divider location as a count
     *       of pixels from the left (or upper) edge of the pane to the
     *       left (or upper) edge of the divider
     */
    public int getLastDividerLocation() {
        return lastDividerLocation;
    }


    
Sets the orientation, or how the splitter is divided. The options
are:
    

  • JSplitPane.VERTICAL_SPLIT  (above/below orientation of components)

  • JSplitPane.HORIZONTAL_SPLIT  (left/right orientation of components)



Params:
  • orientation – an integer specifying the orientation
Throws:
/**
     * Sets the orientation, or how the splitter is divided. The options
     * are:<ul>
     * <li>JSplitPane.VERTICAL_SPLIT  (above/below orientation of components)
     * <li>JSplitPane.HORIZONTAL_SPLIT  (left/right orientation of components)
     * </ul>
     *
     * @param orientation an integer specifying the orientation
     * @exception IllegalArgumentException if orientation is not one of:
     *        HORIZONTAL_SPLIT or VERTICAL_SPLIT.
     */
    @BeanProperty(enumerationValues = {
            "JSplitPane.HORIZONTAL_SPLIT",
            "JSplitPane.VERTICAL_SPLIT"}, description
            = "The orientation, or how the splitter is divided.")
    public void setOrientation(int orientation) {
        if ((orientation != VERTICAL_SPLIT) &&
            (orientation != HORIZONTAL_SPLIT)) {
           throw new IllegalArgumentException("JSplitPane: orientation must " +
                                              "be one of " +
                                              "JSplitPane.VERTICAL_SPLIT or " +
                                              "JSplitPane.HORIZONTAL_SPLIT");
        }

        int           oldOrientation = this.orientation;

        this.orientation = orientation;
        firePropertyChange(ORIENTATION_PROPERTY, oldOrientation, orientation);
    }


    
Returns the orientation.

See Also:
Returns:an integer giving the orientation
/**
     * Returns the orientation.
     *
     * @return an integer giving the orientation
     * @see #setOrientation
     */
    public int getOrientation() {
        return orientation;
    }


    
Sets the value of the continuousLayout property,
which must be true for the child components
to be continuously
redisplayed and laid out during user intervention.
The default value of this property is look and feel dependent.
Some look and feels might not support continuous layout;
they will ignore this property.

Params:
  • newContinuousLayout –  true if the components
       should continuously be redrawn as the divider changes position
See Also:
/**
     * Sets the value of the <code>continuousLayout</code> property,
     * which must be <code>true</code> for the child components
     * to be continuously
     * redisplayed and laid out during user intervention.
     * The default value of this property is look and feel dependent.
     * Some look and feels might not support continuous layout;
     * they will ignore this property.
     *
     * @param newContinuousLayout  <code>true</code> if the components
     *        should continuously be redrawn as the divider changes position
     * @see #isContinuousLayout
     */
    @BeanProperty(description
            = "Whether the child components are continuously redisplayed and laid out during user intervention.")
    public void setContinuousLayout(boolean newContinuousLayout) {
        boolean           oldCD = continuousLayout;

        continuousLayout = newContinuousLayout;
        firePropertyChange(CONTINUOUS_LAYOUT_PROPERTY, oldCD,
                           newContinuousLayout);
    }


    
Gets the continuousLayout property.

See Also:
Returns:the value of the continuousLayout property
/**
     * Gets the <code>continuousLayout</code> property.
     *
     * @return the value of the <code>continuousLayout</code> property
     * @see #setContinuousLayout
     */
    public boolean isContinuousLayout() {
        return continuousLayout;
    }

    
Specifies how to distribute extra space when the size of the split pane
changes. A value of 0, the default,
indicates the right/bottom component gets all the extra space (the
left/top component acts fixed), where as a value of 1 specifies the
left/top component gets all the extra space (the right/bottom component
acts fixed). Specifically, the left/top component gets (weight * diff)
extra space and the right/bottom component gets (1 - weight) * diff
extra space.

Params:
  • value – as described above
Throws:
Since:1.3
/**
     * Specifies how to distribute extra space when the size of the split pane
     * changes. A value of 0, the default,
     * indicates the right/bottom component gets all the extra space (the
     * left/top component acts fixed), where as a value of 1 specifies the
     * left/top component gets all the extra space (the right/bottom component
     * acts fixed). Specifically, the left/top component gets (weight * diff)
     * extra space and the right/bottom component gets (1 - weight) * diff
     * extra space.
     *
     * @param value as described above
     * @exception IllegalArgumentException if <code>value</code> is &lt; 0 or &gt; 1
     * @since 1.3
     */
    @BeanProperty(description
            = "Specifies how to distribute extra space when the split pane resizes.")
    public void setResizeWeight(double value) {
        if (value < 0 || value > 1) {
            throw new IllegalArgumentException("JSplitPane weight must be between 0 and 1");
        }
        double         oldWeight = resizeWeight;

        resizeWeight = value;
        firePropertyChange(RESIZE_WEIGHT_PROPERTY, oldWeight, value);
    }

    
Returns the number that determines how extra space is distributed.

Returns:how extra space is to be distributed on a resize of the
        split pane
Since:1.3
/**
     * Returns the number that determines how extra space is distributed.
     * @return how extra space is to be distributed on a resize of the
     *         split pane
     * @since 1.3
     */
    public double getResizeWeight() {
        return resizeWeight;
    }

    
Lays out the JSplitPane layout based on the preferred size
of the children components. This will likely result in changing
the divider location.

/**
     * Lays out the <code>JSplitPane</code> layout based on the preferred size
     * of the children components. This will likely result in changing
     * the divider location.
     */
    public void resetToPreferredSizes() {
        SplitPaneUI         ui = getUI();

        if (ui != null) {
            ui.resetToPreferredSizes(this);
        }
    }


    
Sets the divider location as a percentage of the
JSplitPane's size.


This method is implemented in terms of
setDividerLocation(int).
This method immediately changes the size of the split pane based on
its current size. If the split pane is not correctly realized and on
screen, this method will have no effect (new divider location will
become (current size * proportionalLocation) which is 0).

Params:
  • proportionalLocation –  a double-precision floating point value
       that specifies a percentage, from zero (top/left) to 1.0
       (bottom/right)
Throws:
/**
     * Sets the divider location as a percentage of the
     * <code>JSplitPane</code>'s size.
     * <p>
     * This method is implemented in terms of
     * <code>setDividerLocation(int)</code>.
     * This method immediately changes the size of the split pane based on
     * its current size. If the split pane is not correctly realized and on
     * screen, this method will have no effect (new divider location will
     * become (current size * proportionalLocation) which is 0).
     *
     * @param proportionalLocation  a double-precision floating point value
     *        that specifies a percentage, from zero (top/left) to 1.0
     *        (bottom/right)
     * @exception IllegalArgumentException if the specified location is &lt; 0
     *            or &gt; 1.0
     */
    @BeanProperty(description
            = "The location of the divider.")
    public void setDividerLocation(double proportionalLocation) {
        if (proportionalLocation < 0.0 ||
           proportionalLocation > 1.0) {
            throw new IllegalArgumentException("proportional location must " +
                                               "be between 0.0 and 1.0.");
        }
        if (getOrientation() == VERTICAL_SPLIT) {
            setDividerLocation((int)((double)(getHeight() - getDividerSize()) *
                                     proportionalLocation));
        } else {
            setDividerLocation((int)((double)(getWidth() - getDividerSize()) *
                                     proportionalLocation));
        }
    }


    
Sets the location of the divider. This is passed off to the
look and feel implementation, and then listeners are notified. A value
less than 0 implies the divider should be reset to a value that
attempts to honor the preferred size of the left/top component.
After notifying the listeners, the last divider location is updated,
via setLastDividerLocation.

Params:
  • location – an int specifying a UI-specific value (typically a
       pixel count)
/**
     * Sets the location of the divider. This is passed off to the
     * look and feel implementation, and then listeners are notified. A value
     * less than 0 implies the divider should be reset to a value that
     * attempts to honor the preferred size of the left/top component.
     * After notifying the listeners, the last divider location is updated,
     * via <code>setLastDividerLocation</code>.
     *
     * @param location an int specifying a UI-specific value (typically a
     *        pixel count)
     */
    @BeanProperty(description
            = "The location of the divider.")
    public void setDividerLocation(int location) {
        int                 oldValue = dividerLocation;

        dividerLocation = location;

        // Notify UI.
        SplitPaneUI         ui = getUI();

        if (ui != null) {
            ui.setDividerLocation(this, location);
        }

        // Then listeners
        firePropertyChange(DIVIDER_LOCATION_PROPERTY, oldValue, location);

        // And update the last divider location.
        setLastDividerLocation(oldValue);
    }


    
Returns the last value passed to setDividerLocation.
The value returned from this method may differ from the actual
divider location (if setDividerLocation was passed a
value bigger than the current size).

Returns:an integer specifying the location of the divider
/**
     * Returns the last value passed to <code>setDividerLocation</code>.
     * The value returned from this method may differ from the actual
     * divider location (if <code>setDividerLocation</code> was passed a
     * value bigger than the current size).
     *
     * @return an integer specifying the location of the divider
     */
    public int getDividerLocation() {
        return dividerLocation;
    }


    
Returns the minimum location of the divider from the look and feel
implementation.

Returns:an integer specifying a UI-specific value for the minimum
         location (typically a pixel count); or -1 if the UI is
         null
/**
     * Returns the minimum location of the divider from the look and feel
     * implementation.
     *
     * @return an integer specifying a UI-specific value for the minimum
     *          location (typically a pixel count); or -1 if the UI is
     *          <code>null</code>
     */
    @BeanProperty(bound = false, description
            = "The minimum location of the divider from the L&F.")
    public int getMinimumDividerLocation() {
        SplitPaneUI         ui = getUI();

        if (ui != null) {
            return ui.getMinimumDividerLocation(this);
        }
        return -1;
    }


    
Returns the maximum location of the divider from the look and feel
implementation.

Returns:an integer specifying a UI-specific value for the maximum
         location (typically a pixel count); or -1 if the  UI is
         null
/**
     * Returns the maximum location of the divider from the look and feel
     * implementation.
     *
     * @return an integer specifying a UI-specific value for the maximum
     *          location (typically a pixel count); or -1 if the  UI is
     *          <code>null</code>
     */
    @BeanProperty(bound = false)
    public int getMaximumDividerLocation() {
        SplitPaneUI         ui = getUI();

        if (ui != null) {
            return ui.getMaximumDividerLocation(this);
        }
        return -1;
    }


    
Removes the child component, component from the
pane. Resets the leftComponent or
rightComponent instance variable, as necessary.

Params:
  • component – the Component to remove
/**
     * Removes the child component, <code>component</code> from the
     * pane. Resets the <code>leftComponent</code> or
     * <code>rightComponent</code> instance variable, as necessary.
     *
     * @param component the <code>Component</code> to remove
     */
    public void remove(Component component) {
        if (component == leftComponent) {
            leftComponent = null;
        } else if (component == rightComponent) {
            rightComponent = null;
        }
        super.remove(component);

        // Update the JSplitPane on the screen
        revalidate();
        repaint();
    }


    
Removes the Component at the specified index.
Updates the leftComponent and rightComponent
instance variables as necessary, and then messages super.

Params:
  • index – an integer specifying the component to remove, where
       1 specifies the left/top component and 2 specifies the
       bottom/right component
/**
     * Removes the <code>Component</code> at the specified index.
     * Updates the <code>leftComponent</code> and <code>rightComponent</code>
     * instance variables as necessary, and then messages super.
     *
     * @param index an integer specifying the component to remove, where
     *        1 specifies the left/top component and 2 specifies the
     *        bottom/right component
     */
    public void remove(int index) {
        Component    comp = getComponent(index);

        if (comp == leftComponent) {
            leftComponent = null;
        } else if (comp == rightComponent) {
            rightComponent = null;
        }
        super.remove(index);

        // Update the JSplitPane on the screen
        revalidate();
        repaint();
    }


    
Removes all the child components from the split pane. Resets the
leftComonent and rightComponent
instance variables.

/**
     * Removes all the child components from the split pane. Resets the
     * <code>leftComonent</code> and <code>rightComponent</code>
     * instance variables.
     */
    public void removeAll() {
        leftComponent = rightComponent = null;
        super.removeAll();

        // Update the JSplitPane on the screen
        revalidate();
        repaint();
    }


    
Returns true, so that calls to revalidate
on any descendant of this JSplitPane
will cause a request to be queued that
will validate the JSplitPane and all its descendants.

See Also:
Returns:true
/**
     * Returns true, so that calls to <code>revalidate</code>
     * on any descendant of this <code>JSplitPane</code>
     * will cause a request to be queued that
     * will validate the <code>JSplitPane</code> and all its descendants.
     *
     * @return true
     * @see JComponent#revalidate
     * @see java.awt.Container#isValidateRoot
     */
    @Override
    @BeanProperty(hidden = true)
    public boolean isValidateRoot() {
        return true;
    }


    
Adds the specified component to this split pane.
If constraints identifies the left/top or
right/bottom child component, and a component with that identifier
was previously added, it will be removed and then comp
will be added in its place. If constraints is not
one of the known identifiers the layout manager may throw an
IllegalArgumentException.


The possible constraints objects (Strings) are:

    

  • JSplitPane.TOP

  • JSplitPane.LEFT

  • JSplitPane.BOTTOM

  • JSplitPane.RIGHT


If the constraints object is null,
the component is added in the
first available position (left/top if open, else right/bottom).

Params:
  • comp –        the component to add
  • constraints – an Object specifying the
                   layout constraints
                   (position) for this component
  • index –       an integer specifying the index in the container's
                   list.
Throws:
See Also:
/**
     * Adds the specified component to this split pane.
     * If <code>constraints</code> identifies the left/top or
     * right/bottom child component, and a component with that identifier
     * was previously added, it will be removed and then <code>comp</code>
     * will be added in its place. If <code>constraints</code> is not
     * one of the known identifiers the layout manager may throw an
     * <code>IllegalArgumentException</code>.
     * <p>
     * The possible constraints objects (Strings) are:
     * <ul>
     * <li>JSplitPane.TOP
     * <li>JSplitPane.LEFT
     * <li>JSplitPane.BOTTOM
     * <li>JSplitPane.RIGHT
     * </ul>
     * If the <code>constraints</code> object is <code>null</code>,
     * the component is added in the
     * first available position (left/top if open, else right/bottom).
     *
     * @param comp        the component to add
     * @param constraints an <code>Object</code> specifying the
     *                    layout constraints
     *                    (position) for this component
     * @param index       an integer specifying the index in the container's
     *                    list.
     * @exception IllegalArgumentException  if the <code>constraints</code>
     *          object does not match an existing component
     * @see java.awt.Container#addImpl(Component, Object, int)
     */
    protected void addImpl(Component comp, Object constraints, int index)
    {
        Component             toRemove;

        if (constraints != null && !(constraints instanceof String)) {
            throw new IllegalArgumentException("cannot add to layout: " +
                                               "constraint must be a string " +
                                               "(or null)");
        }

        /* If the constraints are null and the left/right component is
           invalid, add it at the left/right component. */
        if (constraints == null) {
            if (getLeftComponent() == null) {
                constraints = JSplitPane.LEFT;
            } else if (getRightComponent() == null) {
                constraints = JSplitPane.RIGHT;
            }
        }

        /* Find the Component that already exists and remove it. */
        if (constraints != null && (constraints.equals(JSplitPane.LEFT) ||
                                   constraints.equals(JSplitPane.TOP))) {
            toRemove = getLeftComponent();
            if (toRemove != null) {
                remove(toRemove);
            }
            leftComponent = comp;
            index = -1;
        } else if (constraints != null &&
                   (constraints.equals(JSplitPane.RIGHT) ||
                    constraints.equals(JSplitPane.BOTTOM))) {
            toRemove = getRightComponent();
            if (toRemove != null) {
                remove(toRemove);
            }
            rightComponent = comp;
            index = -1;
        } else if (constraints != null &&
                constraints.equals(JSplitPane.DIVIDER)) {
            index = -1;
        }
        /* LayoutManager should raise for else condition here. */

        super.addImpl(comp, constraints, index);

        // Update the JSplitPane on the screen
        revalidate();
        repaint();
    }


    
Subclassed to message the UI with finishedPaintingChildren
after super has been messaged, as well as painting the border.

Params:
  • g – the Graphics context within which to paint
/**
     * Subclassed to message the UI with <code>finishedPaintingChildren</code>
     * after super has been messaged, as well as painting the border.
     *
     * @param g the <code>Graphics</code> context within which to paint
     */
    protected void paintChildren(Graphics g) {
        super.paintChildren(g);

        SplitPaneUI        ui = getUI();

        if (ui != null) {
            Graphics           tempG = g.create();
            ui.finishedPaintingChildren(this, tempG);
            tempG.dispose();
        }
    }


    
See readObject and writeObject in
JComponent for more
information about serialization in Swing.

/**
     * See <code>readObject</code> and <code>writeObject</code> in
     * <code>JComponent</code> for more
     * information about serialization in Swing.
     */
    private void writeObject(ObjectOutputStream s) throws IOException {
        s.defaultWriteObject();
        if (getUIClassID().equals(uiClassID)) {
            byte count = JComponent.getWriteObjCounter(this);
            JComponent.setWriteObjCounter(this, --count);
            if (count == 0 && ui != null) {
                ui.installUI(this);
            }
        }
    }

    void setUIProperty(String propertyName, Object value) {
        if (propertyName == "dividerSize") {
            if (!dividerSizeSet) {
                setDividerSize(((Number)value).intValue());
                dividerSizeSet = false;
            }
        } else if (propertyName == "oneTouchExpandable") {
            if (!oneTouchExpandableSet) {
                setOneTouchExpandable(((Boolean)value).booleanValue());
                oneTouchExpandableSet = false;
            }
        } else {
            super.setUIProperty(propertyName, value);
        }
    }


    
Returns a string representation of this JSplitPane.
This method
is intended to be used only for debugging purposes, and the
content and format of the returned string may vary between
implementations. The returned string may be empty but may not
be null.

Returns: a string representation of this JSplitPane.
/**
     * Returns a string representation of this <code>JSplitPane</code>.
     * This method
     * is intended to be used only for debugging purposes, and the
     * content and format of the returned string may vary between
     * implementations. The returned string may be empty but may not
     * be <code>null</code>.
     *
     * @return  a string representation of this <code>JSplitPane</code>.
     */
    protected String paramString() {
        String orientationString = (orientation == HORIZONTAL_SPLIT ?
                                    "HORIZONTAL_SPLIT" : "VERTICAL_SPLIT");
        String continuousLayoutString = (continuousLayout ?
                                         "true" : "false");
        String oneTouchExpandableString = (oneTouchExpandable ?
                                           "true" : "false");

        return super.paramString() +
        ",continuousLayout=" + continuousLayoutString +
        ",dividerSize=" + dividerSize +
        ",lastDividerLocation=" + lastDividerLocation +
        ",oneTouchExpandable=" + oneTouchExpandableString +
        ",orientation=" + orientationString;
    }



    ///////////////////////////
    // Accessibility support //
    ///////////////////////////


    
Gets the AccessibleContext associated with this JSplitPane.
For split panes, the AccessibleContext takes the form of an
AccessibleJSplitPane.
A new AccessibleJSplitPane instance is created if necessary.

Returns:an AccessibleJSplitPane that serves as the
        AccessibleContext of this JSplitPane
/**
     * Gets the AccessibleContext associated with this JSplitPane.
     * For split panes, the AccessibleContext takes the form of an
     * AccessibleJSplitPane.
     * A new AccessibleJSplitPane instance is created if necessary.
     *
     * @return an AccessibleJSplitPane that serves as the
     *         AccessibleContext of this JSplitPane
     */
    @BeanProperty(bound = false, expert = true, description
            = "The AccessibleContext associated with this SplitPane.")
    public AccessibleContext getAccessibleContext() {
        if (accessibleContext == null) {
            accessibleContext = new AccessibleJSplitPane();
        }
        return accessibleContext;
    }


    
This class implements accessibility support for the
JSplitPane class.  It provides an implementation of the
Java Accessibility API appropriate to split pane user-interface elements.


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. 
/**
     * This class implements accessibility support for the
     * <code>JSplitPane</code> class.  It provides an implementation of the
     * Java Accessibility API appropriate to split pane user-interface elements.
     * <p>
     * <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
     * has been added to the <code>java.beans</code> package.
     * Please see {@link java.beans.XMLEncoder}.
     */
    @SuppressWarnings("serial") // Same-version serialization only
    protected class AccessibleJSplitPane extends AccessibleJComponent
        implements AccessibleValue {
        
Gets the state set of this object.

See Also:
Returns:an instance of AccessibleState containing the current state
of the object
/**
         * Gets the state set of this object.
         *
         * @return an instance of AccessibleState containing the current state
         * of the object
         * @see AccessibleState
         */
        public AccessibleStateSet getAccessibleStateSet() {
            AccessibleStateSet states = super.getAccessibleStateSet();
            // FIXME: [[[WDW - Should also add BUSY if this implements
            // Adjustable at some point.  If this happens, we probably
            // should also add actions.]]]
            if (getOrientation() == VERTICAL_SPLIT) {
                states.add(AccessibleState.VERTICAL);
            } else {
                states.add(AccessibleState.HORIZONTAL);
            }
            return states;
        }


        
Get the AccessibleValue associated with this object.  In the
implementation of the Java Accessibility API for this class,
return this object, which is responsible for implementing the
AccessibleValue interface on behalf of itself.

Returns:this object
/**
         * Get the AccessibleValue associated with this object.  In the
         * implementation of the Java Accessibility API for this class,
         * return this object, which is responsible for implementing the
         * AccessibleValue interface on behalf of itself.
         *
         * @return this object
         */
        public AccessibleValue getAccessibleValue() {
            return this;
        }


        
Gets the accessible value of this object.

Returns:a localized String describing the value of this object
/**
         * Gets the accessible value of this object.
         *
         * @return a localized String describing the value of this object
         */
        public Number getCurrentAccessibleValue() {
            return Integer.valueOf(getDividerLocation());
        }


        
Sets the value of this object as a Number.

Returns:True if the value was set.
/**
         * Sets the value of this object as a Number.
         *
         * @return True if the value was set.
         */
        public boolean setCurrentAccessibleValue(Number n) {
            // TIGER - 4422535
            if (n == null) {
                return false;
            }
            setDividerLocation(n.intValue());
            return true;
        }


        
Gets the minimum accessible value of this object.

Returns:The minimum value of this object.
/**
         * Gets the minimum accessible value of this object.
         *
         * @return The minimum value of this object.
         */
        public Number getMinimumAccessibleValue() {
            return Integer.valueOf(getUI().getMinimumDividerLocation(
                                                        JSplitPane.this));
        }


        
Gets the maximum accessible value of this object.

Returns:The maximum value of this object.
/**
         * Gets the maximum accessible value of this object.
         *
         * @return The maximum value of this object.
         */
        public Number getMaximumAccessibleValue() {
            return Integer.valueOf(getUI().getMaximumDividerLocation(
                                                        JSplitPane.this));
        }


        
Gets the role of this object.

See Also:
Returns:an instance of AccessibleRole describing the role of
the object
/**
         * Gets the role of this object.
         *
         * @return an instance of AccessibleRole describing the role of
         * the object
         * @see AccessibleRole
         */
        public AccessibleRole getAccessibleRole() {
            return AccessibleRole.SPLIT_PANE;
        }
    } // inner class AccessibleJSplitPane
}