javax.swing.DefaultDesktopManager.java Source code

Java tutorial

Introduction

Here is the source code for javax.swing.DefaultDesktopManager.java

Source

/*
 * Copyright (c) 1997, 2017, 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.swing;

import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.Window;
import java.beans.PropertyVetoException;

import sun.awt.AWTAccessor;
import sun.awt.SunToolkit;

/** This is an implementation of the <code>DesktopManager</code>.
  * It currently implements the basic behaviors for managing
  * <code>JInternalFrame</code>s in an arbitrary parent.
  * <code>JInternalFrame</code>s that are not children of a
  * <code>JDesktop</code> will use this component
  * to handle their desktop-like actions.
  * <p>This class provides a policy for the various JInternalFrame methods,
  * it is not meant to be called directly rather the various JInternalFrame
  * methods will call into the DesktopManager.</p>
  * @see JDesktopPane
  * @see JInternalFrame
  * @author David Kloba
  * @author Steve Wilson
  * @since 1.2
  */
@SuppressWarnings("serial") // No Interesting Non-Transient State
public class DefaultDesktopManager implements DesktopManager, java.io.Serializable {
    static final String HAS_BEEN_ICONIFIED_PROPERTY = "wasIconOnce";

    static final int DEFAULT_DRAG_MODE = 0;
    static final int OUTLINE_DRAG_MODE = 1;
    static final int FASTER_DRAG_MODE = 2;

    int dragMode = DEFAULT_DRAG_MODE;

    private transient Rectangle currentBounds = null;
    private transient Graphics desktopGraphics = null;
    private transient Rectangle desktopBounds = null;
    private transient Rectangle[] floatingItems = {};

    /**
     * Set to true when the user actually drags a frame vs clicks on it
     * to start the drag operation.  This is only used when dragging with
     * FASTER_DRAG_MODE.
     */
    private transient boolean didDrag;

    /** Normally this method will not be called. If it is, it
      * tries to determine the appropriate parent from the desktopIcon of the frame.
      * Will remove the desktopIcon from its parent if it successfully adds the frame.
      */
    public void openFrame(JInternalFrame f) {
        if (f.getDesktopIcon().getParent() != null) {
            f.getDesktopIcon().getParent().add(f);
            removeIconFor(f);
        }
    }

    /**
     * Removes the frame, and, if necessary, the
     * <code>desktopIcon</code>, from its parent.
     * @param f the <code>JInternalFrame</code> to be removed
     */
    public void closeFrame(JInternalFrame f) {
        JDesktopPane d = f.getDesktopPane();
        if (d == null) {
            return;
        }
        boolean findNext = f.isSelected();
        Container c = f.getParent();
        JInternalFrame nextFrame = null;
        if (findNext) {
            nextFrame = d.getNextFrame(f);
            try {
                f.setSelected(false);
            } catch (PropertyVetoException e2) {
            }
        }
        if (c != null) {
            c.remove(f); // Removes the focus.
            c.repaint(f.getX(), f.getY(), f.getWidth(), f.getHeight());
        }
        removeIconFor(f);
        if (f.getNormalBounds() != null)
            f.setNormalBounds(null);
        if (wasIcon(f))
            setWasIcon(f, null);
        if (nextFrame != null) {
            try {
                nextFrame.setSelected(true);
            } catch (PropertyVetoException e2) {
            }
        } else if (findNext && d.getComponentCount() == 0) {
            // It was selected and was the last component on the desktop.
            d.requestFocus();
        }
    }

    /**
     * Resizes the frame to fill its parents bounds.
     * @param f the frame to be resized
     */
    public void maximizeFrame(JInternalFrame f) {
        if (f.isIcon()) {
            try {
                // In turn calls deiconifyFrame in the desktop manager.
                // That method will handle the maximization of the frame.
                f.setIcon(false);
            } catch (PropertyVetoException e2) {
            }
        } else {
            Container c = f.getParent();
            if (c == null) {
                return;
            }
            f.setNormalBounds(f.getBounds());
            Rectangle desktopBounds = c.getBounds();
            setBoundsForFrame(f, 0, 0, desktopBounds.width, desktopBounds.height);
        }

        // Set the maximized frame as selected.
        try {
            f.setSelected(true);
        } catch (PropertyVetoException e2) {
        }
    }

    /**
     * Restores the frame back to its size and position prior
     * to a <code>maximizeFrame</code> call.
     * @param f the <code>JInternalFrame</code> to be restored
     */
    public void minimizeFrame(JInternalFrame f) {
        // If the frame was an icon restore it back to an icon.
        if (f.isIcon()) {
            iconifyFrame(f);
            return;
        }

        if ((f.getNormalBounds()) != null) {
            Rectangle r = f.getNormalBounds();
            f.setNormalBounds(null);
            try {
                f.setSelected(true);
            } catch (PropertyVetoException e2) {
            }
            setBoundsForFrame(f, r.x, r.y, r.width, r.height);
        }
    }

    /**
     * Removes the frame from its parent and adds its
     * <code>desktopIcon</code> to the parent.
     * @param f the <code>JInternalFrame</code> to be iconified
     */
    public void iconifyFrame(JInternalFrame f) {
        JInternalFrame.JDesktopIcon desktopIcon;
        Container c = f.getParent();
        JDesktopPane d = f.getDesktopPane();
        boolean findNext = f.isSelected();
        desktopIcon = f.getDesktopIcon();
        if (!wasIcon(f)) {
            Rectangle r = getBoundsForIconOf(f);
            desktopIcon.setBounds(r.x, r.y, r.width, r.height);
            // we must validate the hierarchy to not break the hw/lw mixing
            desktopIcon.revalidate();
            setWasIcon(f, Boolean.TRUE);
        }

        if (c == null || d == null) {
            return;
        }

        if (c instanceof JLayeredPane) {
            JLayeredPane lp = (JLayeredPane) c;
            int layer = JLayeredPane.getLayer(f);
            JLayeredPane.putLayer(desktopIcon, layer);
        }
        d.setComponentOrderCheckingEnabled(true);
        c.remove(f);
        c.add(desktopIcon);
        if (findNext) {
            if (d.selectFrame(true) == null) {
                // The icon is the last frame.
                f.restoreSubcomponentFocus();
            }
        }
        c.repaint(f.getX(), f.getY(), f.getWidth(), f.getHeight());
    }

    /**
     * Removes the desktopIcon from its parent and adds its frame
     * to the parent.
     * @param f the <code>JInternalFrame</code> to be de-iconified
     */
    public void deiconifyFrame(JInternalFrame f) {
        JInternalFrame.JDesktopIcon desktopIcon = f.getDesktopIcon();
        Container c = desktopIcon.getParent();
        JDesktopPane d = f.getDesktopPane();
        if (c != null && d != null) {
            c.add(f);
            // If the frame is to be restored to a maximized state make
            // sure it still fills the whole desktop.
            if (f.isMaximum()) {
                Rectangle desktopBounds = c.getBounds();
                if (f.getWidth() != desktopBounds.width || f.getHeight() != desktopBounds.height) {
                    setBoundsForFrame(f, 0, 0, desktopBounds.width, desktopBounds.height);
                }
            }
            removeIconFor(f);
            if (f.isSelected()) {
                f.moveToFront();
                f.restoreSubcomponentFocus();
            } else {
                try {
                    f.setSelected(true);
                } catch (PropertyVetoException e2) {
                }

            }
        }
    }

    /** This will activate <b>f</b> moving it to the front. It will
      * set the current active frame's (if any)
      * <code>IS_SELECTED_PROPERTY</code> to <code>false</code>.
      * There can be only one active frame across all Layers.
      * @param f the <code>JInternalFrame</code> to be activated
      */
    public void activateFrame(JInternalFrame f) {
        Container p = f.getParent();
        Component[] c;
        JDesktopPane d = f.getDesktopPane();
        JInternalFrame currentlyActiveFrame = (d == null) ? null : d.getSelectedFrame();
        // fix for bug: 4162443
        if (p == null) {
            // If the frame is not in parent, its icon maybe, check it
            p = f.getDesktopIcon().getParent();
            if (p == null)
                return;
        }
        // we only need to keep track of the currentActive InternalFrame, if any
        if (currentlyActiveFrame == null) {
            if (d != null) {
                d.setSelectedFrame(f);
            }
        } else if (currentlyActiveFrame != f) {
            // if not the same frame as the current active
            // we deactivate the current
            if (currentlyActiveFrame.isSelected()) {
                try {
                    currentlyActiveFrame.setSelected(false);
                } catch (PropertyVetoException e2) {
                }
            }
            if (d != null) {
                d.setSelectedFrame(f);
            }
        }
        f.moveToFront();
    }

    // implements javax.swing.DesktopManager
    public void deactivateFrame(JInternalFrame f) {
        JDesktopPane d = f.getDesktopPane();
        JInternalFrame currentlyActiveFrame = (d == null) ? null : d.getSelectedFrame();
        if (currentlyActiveFrame == f)
            d.setSelectedFrame(null);
    }

    // implements javax.swing.DesktopManager
    public void beginDraggingFrame(JComponent f) {
        setupDragMode(f);

        if (dragMode == FASTER_DRAG_MODE) {
            Component desktop = f.getParent();
            floatingItems = findFloatingItems(f);
            currentBounds = f.getBounds();
            if (desktop instanceof JComponent) {
                desktopBounds = ((JComponent) desktop).getVisibleRect();
            } else {
                desktopBounds = desktop.getBounds();
                desktopBounds.x = desktopBounds.y = 0;
            }
            desktopGraphics = JComponent.safelyGetGraphics(desktop);
            ((JInternalFrame) f).isDragging = true;
            didDrag = false;
        }

    }

    private void setupDragMode(JComponent f) {
        JDesktopPane p = getDesktopPane(f);
        Container parent = f.getParent();
        dragMode = DEFAULT_DRAG_MODE;
        if (p != null) {
            String mode = (String) p.getClientProperty("JDesktopPane.dragMode");
            Window window = SwingUtilities.getWindowAncestor(f);
            if (window != null && !window.isOpaque()) {
                dragMode = DEFAULT_DRAG_MODE;
            } else if (mode != null && mode.equals("outline")) {
                dragMode = OUTLINE_DRAG_MODE;
            } else if (mode != null && mode.equals("faster") && f instanceof JInternalFrame
                    && ((JInternalFrame) f).isOpaque() && (parent == null || parent.isOpaque())) {
                dragMode = FASTER_DRAG_MODE;
            } else {
                if (p.getDragMode() == JDesktopPane.OUTLINE_DRAG_MODE) {
                    dragMode = OUTLINE_DRAG_MODE;
                } else if (p.getDragMode() == JDesktopPane.LIVE_DRAG_MODE && f instanceof JInternalFrame
                        && ((JInternalFrame) f).isOpaque()) {
                    dragMode = FASTER_DRAG_MODE;
                } else {
                    dragMode = DEFAULT_DRAG_MODE;
                }
            }
        }
    }

    private transient Point currentLoc = null;

    /**
      * Moves the visible location of the frame being dragged
      * to the location specified.  The means by which this occurs can vary depending
      * on the dragging algorithm being used.  The actual logical location of the frame
      * might not change until <code>endDraggingFrame</code> is called.
      */
    public void dragFrame(JComponent f, int newX, int newY) {

        if (dragMode == OUTLINE_DRAG_MODE) {
            JDesktopPane desktopPane = getDesktopPane(f);
            if (desktopPane != null) {
                Graphics g = JComponent.safelyGetGraphics(desktopPane);

                g.setXORMode(Color.white);
                if (currentLoc != null) {
                    g.drawRect(currentLoc.x, currentLoc.y, f.getWidth() - 1, f.getHeight() - 1);
                }
                g.drawRect(newX, newY, f.getWidth() - 1, f.getHeight() - 1);
                /* Work around for 6635462: XOR mode may cause a SurfaceLost on first use.
                * Swing doesn't expect that its XOR drawRect did
                * not complete, so believes that on re-entering at
                * the next update location, that there is an XOR rect
                * to draw out at "currentLoc". But in fact
                * its now got a new clean surface without that rect,
                * so drawing it "out" in fact draws it on, leaving garbage.
                * So only update/set currentLoc if the draw completed.
                */
                sun.java2d.SurfaceData sData = ((sun.java2d.SunGraphics2D) g).getSurfaceData();

                if (!sData.isSurfaceLost()) {
                    currentLoc = new Point(newX, newY);
                }
                ;
                g.dispose();
            }
        } else if (dragMode == FASTER_DRAG_MODE) {
            dragFrameFaster(f, newX, newY);
        } else {
            setBoundsForFrame(f, newX, newY, f.getWidth(), f.getHeight());
        }
    }

    // implements javax.swing.DesktopManager
    public void endDraggingFrame(JComponent f) {
        if (dragMode == OUTLINE_DRAG_MODE && currentLoc != null) {
            setBoundsForFrame(f, currentLoc.x, currentLoc.y, f.getWidth(), f.getHeight());
            currentLoc = null;
        } else if (dragMode == FASTER_DRAG_MODE) {
            currentBounds = null;
            if (desktopGraphics != null) {
                desktopGraphics.dispose();
                desktopGraphics = null;
            }
            desktopBounds = null;
            ((JInternalFrame) f).isDragging = false;
        }
    }

    // implements javax.swing.DesktopManager
    public void beginResizingFrame(JComponent f, int direction) {
        setupDragMode(f);
    }

    /**
     * Calls <code>setBoundsForFrame</code> with the new values.
     * @param f the component to be resized
     * @param newX the new x-coordinate
     * @param newY the new y-coordinate
     * @param newWidth the new width
     * @param newHeight the new height
     */
    public void resizeFrame(JComponent f, int newX, int newY, int newWidth, int newHeight) {

        if (dragMode == DEFAULT_DRAG_MODE || dragMode == FASTER_DRAG_MODE) {
            setBoundsForFrame(f, newX, newY, newWidth, newHeight);
        } else {
            JDesktopPane desktopPane = getDesktopPane(f);
            if (desktopPane != null) {
                Graphics g = JComponent.safelyGetGraphics(desktopPane);

                g.setXORMode(Color.white);
                if (currentBounds != null) {
                    g.drawRect(currentBounds.x, currentBounds.y, currentBounds.width - 1, currentBounds.height - 1);
                }
                g.drawRect(newX, newY, newWidth - 1, newHeight - 1);

                // Work around for 6635462, see comment in dragFrame()
                sun.java2d.SurfaceData sData = ((sun.java2d.SunGraphics2D) g).getSurfaceData();
                if (!sData.isSurfaceLost()) {
                    currentBounds = new Rectangle(newX, newY, newWidth, newHeight);
                }

                g.setPaintMode();
                g.dispose();
            }
        }

    }

    // implements javax.swing.DesktopManager
    public void endResizingFrame(JComponent f) {
        if (dragMode == OUTLINE_DRAG_MODE && currentBounds != null) {
            setBoundsForFrame(f, currentBounds.x, currentBounds.y, currentBounds.width, currentBounds.height);
            currentBounds = null;
        }
    }

    /** This moves the <code>JComponent</code> and repaints the damaged areas. */
    public void setBoundsForFrame(JComponent f, int newX, int newY, int newWidth, int newHeight) {
        f.setBounds(newX, newY, newWidth, newHeight);
        // we must validate the hierarchy to not break the hw/lw mixing
        f.revalidate();
    }

    /**
     * Convenience method to remove the desktopIcon of <b>f</b> is necessary.
     *
     * @param f the {@code JInternalFrame} for which to remove the
     *          {@code desktopIcon}
     */
    protected void removeIconFor(JInternalFrame f) {
        JInternalFrame.JDesktopIcon di = f.getDesktopIcon();
        Container c = di.getParent();
        if (c != null) {
            c.remove(di);
            c.repaint(di.getX(), di.getY(), di.getWidth(), di.getHeight());
        }
    }

    /**
     * The {@code iconifyFrame()} code calls this to determine the proper bounds
     * for the desktopIcon.
     *
     * @param f the {@code JInternalFrame} of interest
     * @return a {@code Rectangle} containing bounds for the {@code desktopIcon}
     */
    protected Rectangle getBoundsForIconOf(JInternalFrame f) {
        //
        // Get the icon for this internal frame and its preferred size
        //

        JInternalFrame.JDesktopIcon icon = f.getDesktopIcon();
        Dimension prefSize = icon.getPreferredSize();
        //
        // Get the parent bounds and child components.
        //

        Container c = f.getParent();
        if (c == null) {
            c = f.getDesktopIcon().getParent();
        }

        if (c == null) {
            /* the frame has not yet been added to the parent; how about (0,0) ?*/
            return new Rectangle(0, 0, prefSize.width, prefSize.height);
        }

        Rectangle parentBounds = c.getBounds();
        Component[] components = c.getComponents();

        //
        // Iterate through valid default icon locations and return the
        // first one that does not intersect any other icons.
        //

        Rectangle availableRectangle = null;
        JInternalFrame.JDesktopIcon currentIcon = null;

        int x = 0;
        int y = parentBounds.height - prefSize.height;
        int w = prefSize.width;
        int h = prefSize.height;

        boolean found = false;

        while (!found) {

            availableRectangle = new Rectangle(x, y, w, h);

            found = true;

            for (int i = 0; i < components.length; i++) {

                //
                // Get the icon for this component
                //

                if (components[i] instanceof JInternalFrame) {
                    currentIcon = ((JInternalFrame) components[i]).getDesktopIcon();
                } else if (components[i] instanceof JInternalFrame.JDesktopIcon) {
                    currentIcon = (JInternalFrame.JDesktopIcon) components[i];
                } else
                    /* found a child that's neither an internal frame nor
                       an icon. I don't believe this should happen, but at
                       present it does and causes a null pointer exception.
                       Even when that gets fixed, this code protects against
                       the npe. hania */
                    continue;

                //
                // If this icon intersects the current location, get next location.
                //

                if (!currentIcon.equals(icon)) {
                    if (availableRectangle.intersects(currentIcon.getBounds())) {
                        found = false;
                        break;
                    }
                }
            }

            if (currentIcon == null)
                /* didn't find any useful children above. This probably shouldn't
                 happen, but this check protects against an npe if it ever does
                 (and it's happening now) */
                return availableRectangle;

            x += currentIcon.getBounds().width;

            if (x + w > parentBounds.width) {
                x = 0;
                y -= h;
            }
        }

        return (availableRectangle);
    }

    /**
     * Stores the bounds of the component just before a maximize call.
     * @param f the component about to be resized
     * @param r the normal bounds to be saved away
     */
    protected void setPreviousBounds(JInternalFrame f, Rectangle r) {
        f.setNormalBounds(r);
    }

    /**
     * Gets the normal bounds of the component prior to the component
     * being maximized.
     * @param f the <code>JInternalFrame</code> of interest
     * @return the normal bounds of the component
     */
    protected Rectangle getPreviousBounds(JInternalFrame f) {
        return f.getNormalBounds();
    }

    /**
     * Sets that the component has been iconized and the bounds of the
     * <code>desktopIcon</code> are valid.
     *
     * @param f     the {@code JInternalFrame} of interest
     * @param value a {@code Boolean} signifying if component has been iconized
     */
    protected void setWasIcon(JInternalFrame f, Boolean value) {
        if (value != null) {
            f.putClientProperty(HAS_BEEN_ICONIFIED_PROPERTY, value);
        }
    }

    /**
     * Returns <code>true</code> if the component has been iconized
     * and the bounds of the <code>desktopIcon</code> are valid,
     * otherwise returns <code>false</code>.
     *
     * @param f the <code>JInternalFrame</code> of interest
     * @return <code>true</code> if the component has been iconized;
     *    otherwise returns <code>false</code>
     */
    protected boolean wasIcon(JInternalFrame f) {
        return (f.getClientProperty(HAS_BEEN_ICONIFIED_PROPERTY) == Boolean.TRUE);
    }

    JDesktopPane getDesktopPane(JComponent frame) {
        JDesktopPane pane = null;
        Component c = frame.getParent();

        // Find the JDesktopPane
        while (pane == null) {
            if (c instanceof JDesktopPane) {
                pane = (JDesktopPane) c;
            } else if (c == null) {
                break;
            } else {
                c = c.getParent();
            }
        }

        return pane;
    }

    // =========== stuff for faster frame dragging ===================

    private void dragFrameFaster(JComponent f, int newX, int newY) {

        Rectangle previousBounds = new Rectangle(currentBounds.x, currentBounds.y, currentBounds.width,
                currentBounds.height);

        // move the frame
        currentBounds.x = newX;
        currentBounds.y = newY;

        if (didDrag) {
            // Only initiate cleanup if we have actually done a drag.
            emergencyCleanup(f);
        } else {
            didDrag = true;
            // We reset the danger field as until now we haven't actually
            // moved the internal frame so we don't need to initiate repaint.
            ((JInternalFrame) f).danger = false;
        }

        boolean floaterCollision = isFloaterCollision(previousBounds, currentBounds);

        JComponent parent = (JComponent) f.getParent();
        Rectangle visBounds = previousBounds.intersection(desktopBounds);

        RepaintManager currentManager = RepaintManager.currentManager(f);

        currentManager.beginPaint();
        try {
            if (!floaterCollision) {
                currentManager.copyArea(parent, desktopGraphics, visBounds.x, visBounds.y, visBounds.width,
                        visBounds.height, newX - previousBounds.x, newY - previousBounds.y, true);
            }

            f.setBounds(currentBounds);

            if (!floaterCollision) {
                Rectangle r = currentBounds;
                currentManager.notifyRepaintPerformed(parent, r.x, r.y, r.width, r.height);
            }

            if (floaterCollision) {
                // since we couldn't blit we just redraw as fast as possible
                // the isDragging mucking is to avoid activating emergency
                // cleanup
                ((JInternalFrame) f).isDragging = false;
                parent.paintImmediately(currentBounds);
                ((JInternalFrame) f).isDragging = true;
            }

            // fake out the repaint manager.  We'll take care of everything

            currentManager.markCompletelyClean(parent);
            currentManager.markCompletelyClean(f);

            // compute the minimal newly exposed area
            // if the rects intersect then we use computeDifference.  Otherwise
            // we'll repaint the entire previous bounds
            Rectangle[] dirtyRects = null;
            if (previousBounds.intersects(currentBounds)) {
                dirtyRects = SwingUtilities.computeDifference(previousBounds, currentBounds);
            } else {
                dirtyRects = new Rectangle[1];
                dirtyRects[0] = previousBounds;
            }
            ;

            // Fix the damage
            for (int i = 0; i < dirtyRects.length; i++) {
                parent.paintImmediately(dirtyRects[i]);
                Rectangle r = dirtyRects[i];
                currentManager.notifyRepaintPerformed(parent, r.x, r.y, r.width, r.height);
            }

            // new areas of blit were exposed
            if (!(visBounds.equals(previousBounds))) {
                dirtyRects = SwingUtilities.computeDifference(previousBounds, desktopBounds);
                for (int i = 0; i < dirtyRects.length; i++) {
                    dirtyRects[i].x += newX - previousBounds.x;
                    dirtyRects[i].y += newY - previousBounds.y;
                    ((JInternalFrame) f).isDragging = false;
                    parent.paintImmediately(dirtyRects[i]);
                    ((JInternalFrame) f).isDragging = true;
                    Rectangle r = dirtyRects[i];
                    currentManager.notifyRepaintPerformed(parent, r.x, r.y, r.width, r.height);
                }

            }
        } finally {
            currentManager.endPaint();
        }

        // update window if it's non-opaque
        Window topLevel = SwingUtilities.getWindowAncestor(f);
        Toolkit tk = Toolkit.getDefaultToolkit();
        if (!topLevel.isOpaque() && (tk instanceof SunToolkit) && ((SunToolkit) tk).needUpdateWindow()) {
            AWTAccessor.getWindowAccessor().updateWindow(topLevel);
        }
    }

    private boolean isFloaterCollision(Rectangle moveFrom, Rectangle moveTo) {
        if (floatingItems.length == 0) {
            // System.out.println("no floaters");
            return false;
        }

        for (int i = 0; i < floatingItems.length; i++) {
            boolean intersectsFrom = moveFrom.intersects(floatingItems[i]);
            if (intersectsFrom) {
                return true;
            }
            boolean intersectsTo = moveTo.intersects(floatingItems[i]);
            if (intersectsTo) {
                return true;
            }
        }

        return false;
    }

    private Rectangle[] findFloatingItems(JComponent f) {
        Container desktop = f.getParent();
        Component[] children = desktop.getComponents();
        int i = 0;
        for (i = 0; i < children.length; i++) {
            if (children[i] == f) {
                break;
            }
        }
        // System.out.println(i);
        Rectangle[] floaters = new Rectangle[i];
        for (i = 0; i < floaters.length; i++) {
            floaters[i] = children[i].getBounds();
        }

        return floaters;
    }

    /**
      * This method is here to clean up problems associated
      * with a race condition which can occur when the full contents
      * of a copyArea's source argument is not available onscreen.
      * This uses brute force to clean up in case of possible damage
      */
    private void emergencyCleanup(final JComponent f) {

        if (((JInternalFrame) f).danger) {

            SwingUtilities.invokeLater(new Runnable() {
                public void run() {

                    ((JInternalFrame) f).isDragging = false;
                    f.paintImmediately(0, 0, f.getWidth(), f.getHeight());

                    //finalFrame.repaint();
                    ((JInternalFrame) f).isDragging = true;
                    // System.out.println("repair complete");
                }
            });

            ((JInternalFrame) f).danger = false;
        }

    }

}