jdk/src/share/classes/javax/swing/JSplitPane.java
changeset 2 90ce3da70b43
child 438 2ae294e4518c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/swing/JSplitPane.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1250 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+
+
+package javax.swing;
+
+
+
+import java.beans.ConstructorProperties;
+import javax.swing.plaf.*;
+import javax.accessibility.*;
+
+import java.awt.*;
+
+import java.io.ObjectOutputStream;
+import java.io.ObjectInputStream;
+import java.io.IOException;
+
+
+
+/**
+ * <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="http://java.sun.com/docs/books/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<sup><font size="-2">TM</font></sup>
+ * has been added to the <code>java.beans</code> package.
+ * Please see {@link java.beans.XMLEncoder}.
+ *
+ * @see #setDividerLocation
+ * @see #resetToPreferredSizes
+ *
+ * @author Scott Violet
+ */
+public class JSplitPane extends JComponent implements Accessible
+{
+    /**
+     * @see #getUIClassID
+     * @see #readObject
+     */
+    private static final String uiClassID = "SplitPaneUI";
+
+    /**
+     * 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 final static int VERTICAL_SPLIT = 0;
+
+    /**
+     * 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 final static int HORIZONTAL_SPLIT = 1;
+
+    /**
+     * Used to add a <code>Component</code> to the left of the other
+     * <code>Component</code>.
+     */
+    public final static String LEFT = "left";
+
+    /**
+     * Used to add a <code>Component</code> to the right of the other
+     * <code>Component</code>.
+     */
+    public final static String RIGHT = "right";
+
+    /**
+     * Used to add a <code>Component</code> above the other
+     * <code>Component</code>.
+     */
+    public final static String TOP = "top";
+
+    /**
+     * Used to add a <code>Component</code> below the other
+     * <code>Component</code>.
+     */
+    public final static String BOTTOM = "bottom";
+
+    /**
+     * Used to add a <code>Component</code> that will represent the divider.
+     */
+    public final static String DIVIDER = "divider";
+
+    /**
+     * Bound property name for orientation (horizontal or vertical).
+     */
+    public final static String ORIENTATION_PROPERTY = "orientation";
+
+    /**
+     * Bound property name for continuousLayout.
+     */
+    public final static String CONTINUOUS_LAYOUT_PROPERTY = "continuousLayout";
+
+    /**
+     * Bound property name for border.
+     */
+    public final static String DIVIDER_SIZE_PROPERTY = "dividerSize";
+
+    /**
+     * Bound property for oneTouchExpandable.
+     */
+    public final static String ONE_TOUCH_EXPANDABLE_PROPERTY =
+                               "oneTouchExpandable";
+
+    /**
+     * Bound property for lastLocation.
+     */
+    public final static String LAST_DIVIDER_LOCATION_PROPERTY =
+                               "lastDividerLocation";
+
+    /**
+     * Bound property for the dividerLocation.
+     * @since 1.3
+     */
+    public final static String DIVIDER_LOCATION_PROPERTY = "dividerLocation";
+
+    /**
+     * Bound property for weight.
+     * @since 1.3
+     */
+    public final static String RESIZE_WEIGHT_PROPERTY = "resizeWeight";
+
+    /**
+     * How the views are split.
+     */
+    protected int orientation;
+
+    /**
+     * Whether or not the views are continuously redisplayed while
+     * resizing.
+     */
+    protected boolean continuousLayout;
+
+    /**
+     * The left or top component.
+     */
+    protected Component leftComponent;
+
+    /**
+     * The right or bottom component.
+     */
+    protected Component rightComponent;
+
+    /**
+     * Size of the divider.
+     */
+    protected int dividerSize;
+    private boolean dividerSizeSet = false;
+
+    /**
+     * Is a little widget provided to quickly expand/collapse the
+     * split pane?
+     */
+    protected boolean oneTouchExpandable;
+    private boolean oneTouchExpandableSet;
+
+    /**
+     * Previous location of the split pane.
+     */
+    protected int lastDividerLocation;
+
+    /**
+     * 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.
+     */
+    private int dividerLocation;
+
+
+    /**
+     * Creates a new <code>JSplitPane</code> configured to arrange the child
+     * components side-by-side horizontally with no continuous
+     * layout, using two buttons for the components.
+     */
+    public JSplitPane() {
+        this(JSplitPane.HORIZONTAL_SPLIT, false,
+            new JButton(UIManager.getString("SplitPane.leftButtonText")),
+            new JButton(UIManager.getString("SplitPane.rightButtonText")));
+    }
+
+
+    /**
+     * Creates a new <code>JSplitPane</code> configured with the
+     * specified orientation and no continuous layout.
+     *
+     * @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, false);
+    }
+
+
+    /**
+     * 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 <code>JSplitPane</code> with the specified
+     * orientation and
+     * with the specified components that do not do continuous
+     * redrawing.
+     *
+     * @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, false, newLeftComponent, newRightComponent);
+    }
+
+
+    /**
+     * 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.
+     *
+     * @param ui  the <code>SplitPaneUI</code> L&F object
+     * @see UIDefaults#getUI
+     * @beaninfo
+     *        bound: true
+     *       hidden: true
+     *    attribute: visualUpdate true
+     *  description: The UI object that implements the Component's LookAndFeel.
+     */
+    public void setUI(SplitPaneUI ui) {
+        if ((SplitPaneUI)this.ui != ui) {
+            super.setUI(ui);
+            revalidate();
+        }
+    }
+
+
+    /**
+     * Returns the <code>SplitPaneUI</code> that is providing the
+     * current look and feel.
+     *
+     * @return the <code>SplitPaneUI</code> object that renders this component
+     * @beaninfo
+     *       expert: true
+     *  description: The L&F object that renders this component.
+     */
+    public SplitPaneUI getUI() {
+        return (SplitPaneUI)ui;
+    }
+
+
+    /**
+     * Notification from the <code>UIManager</code> that the L&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.
+     *
+     * @return the string "SplitPaneUI"
+     * @see JComponent#getUIClassID
+     * @see UIDefaults#getUI
+     * @beaninfo
+     *       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.
+     *
+     * @param newSize an integer giving the size of the divider in pixels
+     * @beaninfo
+     *        bound: true
+     *  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.
+     *
+     * @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.
+     *
+     * @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.
+     *
+     * @return the <code>Component</code> displayed in that position
+     * @beaninfo
+     *    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.
+     *
+     * @param comp the <code>Component</code> to display in that position
+     * @beaninfo
+     *  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.
+     *
+     * @return the <code>Component</code> displayed in that position
+     */
+    public Component getTopComponent() {
+        return leftComponent;
+    }
+
+
+    /**
+     * Sets the component to the right (or below) the divider.
+     *
+     * @param comp the <code>Component</code> to display in that position
+     * @beaninfo
+     *    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.
+     *
+     * @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.
+     *
+     * @param comp the <code>Component</code> to display in that position
+     * @beaninfo
+     *  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.
+     *
+     * @return the <code>Component</code> displayed in that position
+     */
+    public Component getBottomComponent() {
+        return rightComponent;
+    }
+
+
+    /**
+     * 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
+     * @beaninfo
+     *        bound: true
+     *  description: UI widget on the divider to quickly
+     *               expand/collapse the divider.
+     *
+     * @see #isOneTouchExpandable
+     */
+    public void setOneTouchExpandable(boolean newValue) {
+        boolean           oldValue = oneTouchExpandable;
+
+        oneTouchExpandable = newValue;
+        oneTouchExpandableSet = true;
+        firePropertyChange(ONE_TOUCH_EXPANDABLE_PROPERTY, oldValue, newValue);
+        repaint();
+    }
+
+
+    /**
+     * 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
+     * <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
+     * @beaninfo
+     *        bound: true
+     *  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.
+     *
+     * @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:<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.
+     * @beaninfo
+     *        bound: true
+     *  description: The orientation, or how the splitter is divided.
+     *         enum: HORIZONTAL_SPLIT JSplitPane.HORIZONTAL_SPLIT
+     *               VERTICAL_SPLIT   JSplitPane.VERTICAL_SPLIT
+     */
+    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.
+     *
+     * @return an integer giving the orientation
+     * @see #setOrientation
+     */
+    public int getOrientation() {
+        return orientation;
+    }
+
+
+    /**
+     * 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 <code>false</code>.
+     * 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
+     * @beaninfo
+     *        bound: true
+     *  description: Whether the child components are
+     *               continuously redisplayed and laid out during
+     *               user intervention.
+     * @see #isContinuousLayout
+     */
+    public void setContinuousLayout(boolean newContinuousLayout) {
+        boolean           oldCD = continuousLayout;
+
+        continuousLayout = newContinuousLayout;
+        firePropertyChange(CONTINUOUS_LAYOUT_PROPERTY, oldCD,
+                           newContinuousLayout);
+    }
+
+
+    /**
+     * 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.
+     *
+     * @param value as described above
+     * @exception IllegalArgumentException if <code>value</code> is < 0 or > 1
+     * @since 1.3
+     * @beaninfo
+     *        bound: true
+     *  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.
+     * @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 <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
+     * <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 < 0
+     *            or > 1.0
+     * @beaninfo
+     *  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 <code>setLastDividerLocation</code>.
+     *
+     * @param location an int specifying a UI-specific value (typically a
+     *        pixel count)
+     * @beaninfo
+     *        bound: true
+     *  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 <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 curent 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.
+     *
+     * @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>
+     * @beaninfo
+     *  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.
+     *
+     * @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>
+     */
+    public int getMaximumDividerLocation() {
+        SplitPaneUI         ui = getUI();
+
+        if (ui != null) {
+            return ui.getMaximumDividerLocation(this);
+        }
+        return -1;
+    }
+
+
+    /**
+     * 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 <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
+     * <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 <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
+     *
+     * @beaninfo
+     *    hidden: true
+     */
+    public boolean isValidateRoot() {
+        return true;
+    }
+
+
+    /**
+     * 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 <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 <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 <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.
+     *
+     * @return an AccessibleJSplitPane that serves as the
+     *         AccessibleContext of this JSplitPane
+     * @beaninfo
+     *       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
+     * <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<sup><font size="-2">TM</font></sup>
+     * has been added to the <code>java.beans</code> package.
+     * Please see {@link java.beans.XMLEncoder}.
+     */
+    protected class AccessibleJSplitPane extends AccessibleJComponent
+        implements AccessibleValue {
+        /**
+         * 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.
+         *
+         * @return this object
+         */
+        public AccessibleValue getAccessibleValue() {
+            return this;
+        }
+
+
+        /**
+         * Gets the accessible value of this object.
+         *
+         * @return a localized String describing the value of this object
+         */
+        public Number getCurrentAccessibleValue() {
+            return new Integer(getDividerLocation());
+        }
+
+
+        /**
+         * 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.
+         *
+         * @return The minimum value of this object.
+         */
+        public Number getMinimumAccessibleValue() {
+            return new Integer(getUI().getMinimumDividerLocation(
+                                                        JSplitPane.this));
+        }
+
+
+        /**
+         * Gets the maximum accessible value of this object.
+         *
+         * @return The maximum value of this object.
+         */
+        public Number getMaximumAccessibleValue() {
+            return new Integer(getUI().getMaximumDividerLocation(
+                                                        JSplitPane.this));
+        }
+
+
+        /**
+         * 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
+}