2006-08-23 Roman Kennke <kennke@aicas.com>

	* javax/swing/JComponent.java
	(isRepainting): Made package private.
	(paintChild): New field.
	(findOpaqueParent): Removed method. This is now in
	paintImmediately().
	(findOverlapFreeParent): Removed method. This is now
	in paintImmediately2().
	(findPaintRoot): Removed method. This is now
	in paintImmediately2().
	(isCompletelyObscured): Changed to take rectangle as single
	ints as argument.
	(isPaintingDoubleBuffered): Removed method. This is now
	in paintImmediately2().
	(isPartiallyObscured): New helper method.
	(onTop): New helper method for optimization.
	(paintChildren): Paint only to specific child when
	requested like this from paintImmediately2().
	(paintDoubleBuffered): Changed to take rectangle as single int
	arguments.
	(paintImmediately2): Changed to take rectangle as single int
	arguments. Optimized determination of paint root.
	(paintImmediately(Rectangle)): Change to delegate to
	paintImmediately(int,int,int,int).
	(paintImmediately(int,int,int,int)): Look for opaque ancestor
	and start painting there.
	(paint): Call paintDoubleBuffered() with int arguments. Only
	paint component, when not completely occupied by opaque child.
	(processKeyBinding): Removed unnecessary cast.
	(isOccupiedByChild): New helper method.
	* javax/swing/RepaintManager.java
	(repaintUnderway): Removed obsolete field.
	(commitRequests): Removed obsolete field.
	(RepaintManager): Removed initialization of obsolete fields.
	(addDirtyRegion): Removed unused statement.
	(commitBuffer): Changed to take plain ints as argument.
	(compileRepaintRoots): Optimized to avoid use of Rectangle.
	Compute offsets in place, rather than using SwingUtilities.
	(paintDirtyRegions): Removed unused field.
	* javax/swing/JMenuItem.java
	(onTop): Return true when not descendant of JInternalFrame.
	* javax/swing/JPopupMenu.java
	(onTop): Return true.
	* javax/swing/JToolTip.java
	(onTop): Return true.
	* javax/swing/JViewport.java
	(paintImmediately2): Change signature to match the
	corresponding JComponent method.

7 files changed, 447 insertions, 211 deletions

diff --git a/ChangeLog b/ChangeLog
index cf660111d..4c541bcbf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,53 @@
+2006-08-23  Roman Kennke  <kennke@aicas.com>
+
+	* javax/swing/JComponent.java
+	(isRepainting): Made package private.
+	(paintChild): New field.
+	(findOpaqueParent): Removed method. This is now in
+	paintImmediately().
+	(findOverlapFreeParent): Removed method. This is now
+	in paintImmediately2().
+	(findPaintRoot): Removed method. This is now
+	in paintImmediately2().
+	(isCompletelyObscured): Changed to take rectangle as single
+	ints as argument.
+	(isPaintingDoubleBuffered): Removed method. This is now
+	in paintImmediately2().
+	(isPartiallyObscured): New helper method.
+	(onTop): New helper method for optimization.
+	(paintChildren): Paint only to specific child when
+	requested like this from paintImmediately2().
+	(paintDoubleBuffered): Changed to take rectangle as single int
+	arguments.
+	(paintImmediately2): Changed to take rectangle as single int
+	arguments. Optimized determination of paint root.
+	(paintImmediately(Rectangle)): Change to delegate to
+	paintImmediately(int,int,int,int).
+	(paintImmediately(int,int,int,int)): Look for opaque ancestor
+	and start painting there.
+	(paint): Call paintDoubleBuffered() with int arguments. Only
+	paint component, when not completely occupied by opaque child.
+	(processKeyBinding): Removed unnecessary cast.
+	(isOccupiedByChild): New helper method.
+	* javax/swing/RepaintManager.java
+	(repaintUnderway): Removed obsolete field.
+	(commitRequests): Removed obsolete field.
+	(RepaintManager): Removed initialization of obsolete fields.
+	(addDirtyRegion): Removed unused statement.
+	(commitBuffer): Changed to take plain ints as argument.
+	(compileRepaintRoots): Optimized to avoid use of Rectangle.
+	Compute offsets in place, rather than using SwingUtilities.
+	(paintDirtyRegions): Removed unused field.
+	* javax/swing/JMenuItem.java
+	(onTop): Return true when not descendant of JInternalFrame.
+	* javax/swing/JPopupMenu.java
+	(onTop): Return true.
+	* javax/swing/JToolTip.java
+	(onTop): Return true.
+	* javax/swing/JViewport.java
+	(paintImmediately2): Change signature to match the
+	corresponding JComponent method.
+
 2006-08-23  Tania Bento  <tbento@redhat.com>
 
 	* java/awt/Color.java
diff --git a/javax/swing/JComponent.java b/javax/swing/JComponent.java
index fc9353e06..91bb5428f 100644
--- a/javax/swing/JComponent.java
+++ b/javax/swing/JComponent.java
@@ -69,6 +69,7 @@ import java.beans.PropertyVetoException;
 import java.beans.VetoableChangeListener;
 import java.beans.VetoableChangeSupport;
 import java.io.Serializable;
+import java.util.ArrayList;
 import java.util.EventListener;
 import java.util.Hashtable;
 import java.util.Locale;
@@ -666,7 +667,7 @@ public abstract class JComponent extends Container implements Serializable
    * Indicates whether we are calling paintDoubleBuffered() from
    * paintImmadiately (RepaintManager) or from paint() (AWT refresh).
    */
-  static private boolean isRepainting = false;
+  static boolean isRepainting = false;
 
   /**
    * Listeners for events other than {@link PropertyChangeEvent} are
@@ -762,6 +763,13 @@ public abstract class JComponent extends Container implements Serializable
    */
   public static final int WHEN_IN_FOCUSED_WINDOW = 2;
 
+
+  /**
+   * Used to optimize painting. This is set in paintImmediately2() to specify
+   * the exact component path to be painted by paintChildren.
+   */
+  Component paintChild;
+
   /**
    * Indicates if the opaque property has been set by a client program or by
    * the UI.
@@ -1790,7 +1798,7 @@ public abstract class JComponent extends Container implements Serializable
         && rm.isDoubleBufferingEnabled())
       {
         Rectangle clip = g.getClipBounds();
-        paintDoubleBuffered(clip);
+        paintDoubleBuffered(clip.x, clip.y, clip.width, clip.height);
       }
     else
       {
@@ -1805,8 +1813,22 @@ public abstract class JComponent extends Container implements Serializable
             dragBuffer = null;
           }
 
-        if (g.getClip() == null)
-          g.setClip(0, 0, getWidth(), getHeight());
+        Rectangle clip = g.getClipBounds();
+        int clipX, clipY, clipW, clipH;
+        if (clip == null)
+          {
+            clipX = 0;
+            clipY = 0;
+            clipW = getWidth();
+            clipH = getHeight();
+          }
+        else
+          {
+            clipX = clip.x;
+            clipY = clip.y;
+            clipW = clip.width;
+            clipH = clip.height;
+          }
         if (dragBuffer != null && dragBufferInitialized)
           {
             g.drawImage(dragBuffer, 0, 0, this);
@@ -1814,14 +1836,51 @@ public abstract class JComponent extends Container implements Serializable
         else
           {
             Graphics g2 = getComponentGraphics(g);
-            paintComponent(g2);
-            paintBorder(g2);
+            if (! isOccupiedByChild(clipX, clipY, clipW, clipH))
+              {
+                paintComponent(g2);
+                paintBorder(g2);
+              }
             paintChildren(g2);
           }
       }
   }
 
   /**
+   * Determines if a region of this component is completely occupied by
+   * an opaque child component, in which case we don't need to bother
+   * painting this component at all.
+   *
+   * @param x the area, x coordinate
+   * @param y the area, y coordinate
+   * @param w the area, width
+   * @param h the area, height
+   *
+   * @return <code>true</code> if the specified area is completely covered
+   *         by a child component, <code>false</code> otherwise
+   */
+  private boolean isOccupiedByChild(int x, int y, int w, int h)
+  {
+    boolean occupied = false;
+    int count = getComponentCount();
+    for (int i = 0; i < count; i++)
+      {
+        Component child = getComponent(i);
+        int cx = child.getX();
+        int cy = child.getY();
+        int cw = child.getWidth();
+        int ch = child.getHeight();
+        if (child.isVisible() && x >= cx && x + w <= cx + cw && y >= cy
+            && y + h <= cy + ch)
+          {
+            occupied = child.isOpaque();
+            break;
+          }
+      }
+    return occupied;
+  }
+
+  /**
    * Initializes the drag buffer by creating a new image and painting this
    * component into it.
    */
@@ -1880,7 +1939,14 @@ public abstract class JComponent extends Container implements Serializable
         // Need to lock the tree to avoid problems with AWT and concurrency.
         synchronized (getTreeLock())
           {
-            for (int i = getComponentCount() - 1; i >= 0; i--)
+            // Fast forward to the child to paint, if set by
+            // paintImmediately2()
+            int i = getComponentCount() - 1;
+            if (paintChild != null && paintChild.isOpaque())
+              {
+                for (; i >= 0 && getComponent(i) != paintChild; i--);
+              }
+            for (; i >= 0; i--)
               {
                 Component child = getComponent(i);
                 if (child != null && child.isLightweight()
@@ -1898,7 +1964,8 @@ public abstract class JComponent extends Container implements Serializable
                             Rectangle clip = g.getClipBounds(); // A copy.
                             SwingUtilities.computeIntersection(cx, cy, cw, ch,
                                                                clip);
-                            if (isCompletelyObscured(i, clip))
+                            if (isCompletelyObscured(i, clip.x, clip.y,
+                                                     clip.width, clip.height))
                               continue; // Continues the for-loop.
                           }
                         Graphics cg = g.create(cx, cy, cw, ch);
@@ -1924,12 +1991,15 @@ public abstract class JComponent extends Container implements Serializable
    * of its siblings.
    *
    * @param index the index of the child component
-   * @param rect the region to check
+   * @param x the region to check, x coordinate
+   * @param y the region to check, y coordinate
+   * @param w the region to check, width
+   * @param h the region to check, height
    *
    * @return <code>true</code> if the region is completely obscured by a
    *         sibling, <code>false</code> otherwise
    */
-  private boolean isCompletelyObscured(int index, Rectangle rect)
+  private boolean isCompletelyObscured(int index, int x, int y, int w, int h)
   {
     boolean obscured = false;
     for (int i = index - 1; i >= 0 && obscured == false; i--)
@@ -1938,10 +2008,10 @@ public abstract class JComponent extends Container implements Serializable
         if (sib.isVisible())
           {
             Rectangle sibRect = sib.getBounds(rectCache);
-            if (sib.isOpaque() && rect.x >= sibRect.x
-                && (rect.x + rect.width) <= (sibRect.x + sibRect.width)
-                && rect.y >= sibRect.y
-                && (rect.y + rect.height) <= (sibRect.y + sibRect.height))
+            if (sib.isOpaque() && x >= sibRect.x
+                && (x + w) <= (sibRect.x + sibRect.width)
+                && y >= sibRect.y
+                && (y + h) <= (sibRect.y + sibRect.height))
               {
                 obscured = true;
               }
@@ -1951,6 +2021,39 @@ public abstract class JComponent extends Container implements Serializable
   }
 
   /**
+   * Checks if a component/rectangle is partially obscured by one of its
+   * siblings.
+   * Note that this doesn't check for completely obscured, this is
+   * done by isCompletelyObscured() and should probably also be checked.
+   *
+   * @param i the component index from which to start searching
+   * @param x the x coordinate of the rectangle to check
+   * @param y the y coordinate of the rectangle to check
+   * @param w the width of the rectangle to check
+   * @param h the height of the rectangle to check
+   *
+   * @return <code>true</code> if the rectangle is partially obscured
+   */
+  private boolean isPartiallyObscured(int i, int x, int y, int w, int h)
+  {
+    boolean obscured = false;
+    for (int j = i - 1; j >= 0 && ! obscured; j--)
+      {
+        Component sibl = getComponent(j);
+        if (sibl.isVisible())
+          {
+            Rectangle rect = sibl.getBounds(rectCache);
+            if (!(x + w <= rect.x)
+                  || (y + h <= rect.y)
+                  || (x >= rect.x + rect.width)
+                  || (y >= rect.y + rect.height))
+              obscured = true;
+          }
+      }
+    return obscured;
+  }
+
+  /**
    * Paint the component's body. This usually means calling {@link
    * ComponentUI#update} on the {@link #ui} property of the component, if
    * it is non-<code>null</code>. You may override this if you wish to
@@ -1990,7 +2093,26 @@ public abstract class JComponent extends Container implements Serializable
    */
   public void paintImmediately(int x, int y, int w, int h)
   {
-    paintImmediately(new Rectangle(x, y, w, h));
+    // Find opaque parent and call paintImmediately2() on it.
+    if (isShowing())
+      {
+        Component c = this;
+        Component p;
+        while (c != null && ! c.isOpaque())
+          {
+            p = c.getParent();
+            if (p != null)
+              {
+                x += c.getX();
+                y += c.getY();
+                c = p;
+              }
+          }
+        if (c instanceof JComponent)
+          ((JComponent) c).paintImmediately2(x, y, w, h);
+        else
+          c.repaint(x, y, w, h);
+      }
   }
 
   /**
@@ -2013,60 +2135,177 @@ public abstract class JComponent extends Container implements Serializable
    */
   public void paintImmediately(Rectangle r)
   {
-    // Try to find a root pane for this component.
-    //Component root = findPaintRoot(r);
-    Component root = findPaintRoot(r);
-    // If no paint root is found, then this component is completely overlapped
-    // by another component and we don't need repainting.
-    if (root == null|| !root.isShowing())
-      return;
-    SwingUtilities.convertRectangleToAncestor(this, r, root);
-    if (root instanceof JComponent)
-      ((JComponent) root).paintImmediately2(r);
-    else
-      root.repaint(r.x, r.y, r.width, r.height);
+    paintImmediately(r.x, r.y, r.width, r.height);
   }
 
   /**
    * Performs the actual work of paintImmediatly on the repaint root.
    *
-   * @param r the area to be repainted
+   * @param x the area to be repainted, X coordinate
+   * @param y the area to be repainted, Y coordinate
    */
-  void paintImmediately2(Rectangle r)
+  void paintImmediately2(int x, int y, int w, int h)
   {
-    isRepainting = true;
+    // Optimization for components that are always painted on top.
+    boolean onTop = onTop() && isOpaque();
+
+    // Fetch the RepaintManager.
     RepaintManager rm = RepaintManager.currentManager(this);
-    if (rm.isDoubleBufferingEnabled() && isPaintingDoubleBuffered())
-      paintDoubleBuffered(r);
-    else
-      paintSimple(r);
-    isRepainting = false;
+
+    // The painting clip;
+    int paintX = x;
+    int paintY = y;
+    int paintW = w;
+    int paintH = h;
+
+    // If we should paint buffered or not.
+    boolean haveBuffer = false;
+
+    // The component that is finally triggered for painting.
+    JComponent paintRoot = this;
+    
+    // Stores the component and all its parents. This will be used to limit
+    // the actually painted components in paintChildren by setting
+    // the field paintChild.
+    int pIndex = -1;
+    int pCount = 0;
+    ArrayList components = new ArrayList();
+
+    // Offset to subtract from the paintRoot rectangle when painting.
+    int offsX = 0;
+    int offsY = 0;
+
+    // The current component and its child.
+    Component child;
+    Container c;
+
+    // Find appropriate paint root.
+    for (c = this, child = null;
+         c != null && ! (c instanceof Window) && ! (c instanceof Applet);
+         child = c, c = c.getParent())
+      {
+        JComponent jc = c instanceof JComponent ? (JComponent) c : null;
+        components.add(c);
+        if (! onTop && jc != null  && ! jc.isOptimizedDrawingEnabled())
+          {
+            // Check obscured state of the child.
+            // Generally, we have 3 cases here:
+            // 1. Not obscured. No need to paint from the parent.
+            // 2. Partially obscured. Paint from the parent.
+            // 3. Completely obscured. No need to paint anything.
+            if (c != this)
+              {
+                int count = c.getComponentCount();
+                int i = 0;
+                for (; i < count && c.getComponent(i) != child; i++);
+
+                if (jc.isCompletelyObscured(i, paintX, paintY, paintW, paintH))
+                  return; // No need to paint anything.
+                else if (jc.isPartiallyObscured(i, paintX, paintY, paintW,
+                                                paintH))
+                  {
+                    // Paint from parent.
+                    paintRoot = jc;
+                    pIndex = pCount;
+                    offsX = 0;
+                    offsY = 0;
+                    haveBuffer = false;
+                  }
+              }
+          }
+        pCount++;
+        // Check if component is double buffered.
+        if (rm.isDoubleBufferingEnabled() && jc != null
+            && jc.isDoubleBuffered())
+          {
+            haveBuffer = true;
+          }
+
+        // Clip the paint region with the parent.
+        if (! onTop)
+          {
+            paintX = Math.max(0, paintX);
+            paintY = Math.max(0, paintY);
+            paintW = Math.min(c.getWidth(), paintW + paintX) - paintX;
+            paintH = Math.min(c.getHeight(), paintH + paintY) - paintY;
+            int dx = c.getX();
+            int dy = c.getY();
+            paintX += dx;
+            paintY += dy;
+            offsX += dx;
+            offsY += dy;
+          }
+      }
+    if (c != null && c.getPeer() != null && paintW > 0 && paintH > 0)
+      {
+        isRepainting = true;
+        paintX -= offsX;
+        paintY -= offsY;
+
+        // Set the painting path so that paintChildren paints only what we
+        // want.
+        if (paintRoot != this)
+          {
+            for (int i = pIndex; i > 0; i--)
+              {
+                Component paintParent = (Component) components.get(i);
+                if (paintParent instanceof JComponent)
+                  ((JComponent) paintParent).paintChild =
+                    (Component) components.get(i - 1);
+              }
+          }
+
+        // Actually trigger painting.
+        if (haveBuffer)
+          paintRoot.paintDoubleBuffered(paintX, paintY, paintW,
+                                                paintH);
+        else
+          {
+            Graphics g = paintRoot.getGraphics();
+            try
+              {
+                g.setClip(paintX, paintY, paintW, paintH);
+                paintRoot.paint(g);
+              }
+            finally
+              {
+                g.dispose();
+              }
+          }
+
+        // Reset the painting path.
+        if (paintRoot != this)
+          {
+            for (int i = pIndex; i > 0; i--)
+              {
+                Component paintParent = (Component) components.get(i);
+                if (paintParent instanceof JComponent)
+                  ((JComponent) paintParent).paintChild = null;
+              }
+          }
+
+        isRepainting = false;
+      }
   }
 
   /**
-   * Returns true if we must paint double buffered, that is, when this
-   * component or any of it's ancestors are double buffered.
+   * Returns <code>true</code> if the component is guaranteed to be painted
+   * on top of others. This returns false by default and is overridden by
+   * components like JMenuItem, JPopupMenu and JToolTip to return true for
+   * added efficiency.
    *
-   * @return true if we must paint double buffered, that is, when this
-   *         component or any of it's ancestors are double buffered
+   * @return <code>true</code> if the component is guaranteed to be painted
+   *         on top of others
    */
-  private boolean isPaintingDoubleBuffered()
+  boolean onTop()
   {
-    boolean doubleBuffered = isDoubleBuffered();
-    Component parent = getParent();
-    while (! doubleBuffered && parent != null)
-      {
-        doubleBuffered = parent instanceof JComponent
-                         && ((JComponent) parent).isDoubleBuffered();
-        parent = parent.getParent();
-      }
-    return doubleBuffered;
+    return false;
   }
 
   /**
    * Performs double buffered repainting.
    */
-  private void paintDoubleBuffered(Rectangle r)
+  private void paintDoubleBuffered(int x, int y, int w, int h)
   {
     RepaintManager rm = RepaintManager.currentManager(this);
 
@@ -2083,7 +2322,7 @@ public abstract class JComponent extends Container implements Serializable
     //Rectangle targetClip = SwingUtilities.convertRectangle(this, r, root);
     Graphics g2 = buffer.getGraphics();
     clipAndTranslateGraphics(root, this, g2);
-    g2.clipRect(r.x, r.y, r.width, r.height);
+    g2.clipRect(x, y, w, h);
     g2 = getComponentGraphics(g2);
     paintingDoubleBuffered = true;
     try
@@ -2104,7 +2343,7 @@ public abstract class JComponent extends Container implements Serializable
       }
 
     // Paint the buffer contents on screen.
-    rm.commitBuffer(this, r);
+    rm.commitBuffer(this, x, y, w, h);
   }
 
   /**
@@ -2531,7 +2770,7 @@ public abstract class JComponent extends Container implements Serializable
                 if (cmd instanceof ActionListenerProxy)
                   act = (Action) cmd;
                 else 
-                  act = (Action) getActionMap().get(cmd);
+                  act = getActionMap().get(cmd);
               }
           }
         if (act != null && act.isEnabled())
@@ -3476,130 +3715,6 @@ public abstract class JComponent extends Container implements Serializable
         jc.fireAncestorEvent(ancestor, id);
       }
   }
-
-  /**
-   * Finds a suitable paint root for painting this component. This method first
-   * checks if this component is overlapped using
-   * {@link #findOverlapFreeParent(Rectangle)}. The returned paint root is then
-   * feeded to {@link #findOpaqueParent(Component)} to find the nearest opaque
-   * component for this paint root. If no paint is necessary, then we return
-   * <code>null</code>.
-   *
-   * @param c the clip of this component
-   *
-   * @return the paint root or <code>null</code> if no painting is necessary
-   */
-  private Component findPaintRoot(Rectangle c)
-  {
-    Component p = findOverlapFreeParent(c);
-    if (p == null)
-      return null;
-    Component root = findOpaqueParent(p);
-    return root;
-  }
-
-  /**
-   * Scans the containment hierarchy upwards for components that overlap the
-   * this component in the specified clip. This method returns
-   * <code>this</code>, if no component overlaps this component. It returns
-   * <code>null</code> if another component completely covers this component
-   * in the specified clip (no repaint necessary). If another component partly
-   * overlaps this component in the specified clip, then the parent of this
-   * component is returned (this is the component that must be used as repaint
-   * root). For efficient lookup, the method
-   * {@link #isOptimizedDrawingEnabled()} is used.
-   *
-   * @param clip the clip of this component
-   *
-   * @return the paint root, or <code>null</code> if no paint is necessary
-   */
-  private Component findOverlapFreeParent(Rectangle clip)
-  {
-    Rectangle currentClip = clip;
-    Component found = this;
-    Container parent = this; 
-
-    while (parent != null && !(parent instanceof Window))
-      {
-        Container newParent = parent.getParent();
-        if (newParent == null || newParent instanceof Window)
-          break;
-        // If the parent is optimizedDrawingEnabled, then its children are
-        // tiled and cannot have an overlapping child. Go directly to next
-        // parent.
-        if ((newParent instanceof JComponent
-            && ((JComponent) newParent).isOptimizedDrawingEnabled()))
-          
-          {
-            parent = newParent;
-            continue;
-          }
-
-        // If the parent is not optimizedDrawingEnabled, we must check if the
-        // parent or some neighbor overlaps the current clip.
-
-        // This is the current clip converted to the parent's coordinate
-        // system. TODO: We can do this more efficiently by succesively
-        // cumulating the parent-child translations.
-        Rectangle target = SwingUtilities.convertRectangle(found,
-                                                           currentClip,
-                                                           newParent);
-
-        // We have an overlap if either:
-        // - The new parent itself doesn't completely cover the clip
-        //   (this can be the case with viewports).
-        // - If some higher-level (than the current) children of the new parent
-        //   intersect the target rectangle.
-        Rectangle parentRect = SwingUtilities.getLocalBounds(newParent);
-        boolean haveOverlap =
-          ! SwingUtilities.isRectangleContainingRectangle(parentRect, target);
-        if (! haveOverlap)
-          {
-            Component child;
-            for (int i = 0; (child = newParent.getComponent(i)) != parent && !haveOverlap; i++)
-              {
-                Rectangle childRect = child.getBounds();
-                haveOverlap = target.intersects(childRect);
-              }
-          }
-        if (haveOverlap)
-          {
-            found = newParent;
-            currentClip = target;
-          }
-        parent = newParent;
-      }
-    //System.err.println("overlapfree parent: " + found);
-    return found;
-  }
-
-  /**
-   * Finds the nearest component to <code>c</code> (upwards in the containment
-   * hierarchy), that is opaque. If <code>c</code> itself is opaque,
-   * this returns <code>c</code> itself.
-   *
-   * @param c the start component for the search
-   * @return the nearest component to <code>c</code> (upwards in the containment
-   *         hierarchy), that is opaque; If <code>c</code> itself is opaque,
-   *         this returns <code>c</code> itself
-   */
-  private Component findOpaqueParent(Component c)
-  {
-    Component found = c;
-    while (true)
-      {
-        if ((found instanceof JComponent) && ((JComponent) found).isOpaque())
-          break;
-        else if (!(found instanceof JComponent) && !found.isLightweight())
-          break;
-        Container p = found.getParent();
-        if (p == null)
-          break;
-        else
-          found = p;
-      }
-    return found;
-  }
   
   /**
    * This is the method that gets called when the WHEN_IN_FOCUSED_WINDOW map
diff --git a/javax/swing/JMenuItem.java b/javax/swing/JMenuItem.java
index f7f93bf00..324d61cd4 100644
--- a/javax/swing/JMenuItem.java
+++ b/javax/swing/JMenuItem.java
@@ -833,4 +833,20 @@ public class JMenuItem extends AbstractButton implements Accessible,
       return AccessibleRole.MENU_ITEM;
     }
   }
+
+  /**
+   * Returns <code>true</code> if the component is guaranteed to be painted
+   * on top of others. This returns false by default and is overridden by
+   * components like JMenuItem, JPopupMenu and JToolTip to return true for
+   * added efficiency.
+   *
+   * @return <code>true</code> if the component is guaranteed to be painted
+   *         on top of others
+   */
+  boolean onTop()
+  {
+    return SwingUtilities.getAncestorOfClass(JInternalFrame.class, this)
+           == null;
+  }
+
 }
diff --git a/javax/swing/JPopupMenu.java b/javax/swing/JPopupMenu.java
index 2e59d4767..1ae8adad0 100644
--- a/javax/swing/JPopupMenu.java
+++ b/javax/swing/JPopupMenu.java
@@ -902,6 +902,20 @@ public class JPopupMenu extends JComponent implements Accessible, MenuElement
     }
   }
 
+  /**
+   * Returns <code>true</code> if the component is guaranteed to be painted
+   * on top of others. This returns false by default and is overridden by
+   * components like JMenuItem, JPopupMenu and JToolTip to return true for
+   * added efficiency.
+   *
+   * @return <code>true</code> if the component is guaranteed to be painted
+   *         on top of others
+   */
+  boolean onTop()
+  {
+    return true;
+  }
+
   protected class AccessibleJPopupMenu extends AccessibleJComponent
   {
     private static final long serialVersionUID = 7423261328879849768L;
diff --git a/javax/swing/JToolTip.java b/javax/swing/JToolTip.java
index 836c122c6..3153894da 100644
--- a/javax/swing/JToolTip.java
+++ b/javax/swing/JToolTip.java
@@ -225,4 +225,18 @@ public class JToolTip extends JComponent implements Accessible
   {
     setUI((ToolTipUI) UIManager.getUI(this));
   }
+
+  /**
+   * Returns <code>true</code> if the component is guaranteed to be painted
+   * on top of others. This returns false by default and is overridden by
+   * components like JMenuItem, JPopupMenu and JToolTip to return true for
+   * added efficiency.
+   *
+   * @return <code>true</code> if the component is guaranteed to be painted
+   *         on top of others
+   */
+  boolean onTop()
+  {
+    return true;
+  }
 }
diff --git a/javax/swing/JViewport.java b/javax/swing/JViewport.java
index 7cf393996..babffb7ce 100644
--- a/javax/swing/JViewport.java
+++ b/javax/swing/JViewport.java
@@ -942,10 +942,10 @@ public class JViewport extends JComponent implements Accessible
    *
    * @param r the rectangle to paint
    */
-  void paintImmediately2(Rectangle r)
+  void paintImmediately2(int x, int y, int w, int h)
   {
     isPaintRoot = true;
-    super.paintImmediately2(r);
+    super.paintImmediately2(x, y, w, h);
     isPaintRoot = false;
   }
 }
diff --git a/javax/swing/RepaintManager.java b/javax/swing/RepaintManager.java
index 51f0f9b6a..99a733a5a 100644
--- a/javax/swing/RepaintManager.java
+++ b/javax/swing/RepaintManager.java
@@ -197,19 +197,6 @@ public class RepaintManager
   private WeakHashMap offscreenBuffers;
 
   /**
-   * Indicates if the RepaintManager is currently repainting an area.
-   */
-  private boolean repaintUnderway;
-
-  /**
-   * This holds buffer commit requests when the RepaintManager is working.
-   * This maps Component objects (the top level components) to Rectangle
-   * objects (the area of the corresponding buffer that must be blitted on
-   * the component).
-   */
-  private HashMap commitRequests;
-
-  /**
    * The maximum width and height to allocate as a double buffer. Requests
    * beyond this size are ignored.
    *
@@ -232,8 +219,6 @@ public class RepaintManager
     doubleBufferMaximumSize = new Dimension(2000,2000);
     doubleBufferingEnabled = true;
     offscreenBuffers = new WeakHashMap();
-    repaintUnderway = false;
-    commitRequests = new HashMap();
   }
 
   /**
@@ -398,8 +383,6 @@ public class RepaintManager
     if (w <= 0 || h <= 0 || !component.isShowing())
       return;
 
-    Component parent = component.getParent();
-    
     component.computeVisibleRect(rectCache);
     SwingUtilities.computeIntersection(x, y, w, h, rectCache);
 
@@ -557,7 +540,6 @@ public class RepaintManager
         compileRepaintRoots(dirtyComponentsWork, dirty, repaintRoots);
       }
 
-    repaintUnderway = true;
     for (Iterator i = repaintRoots.iterator(); i.hasNext();)
       {
         JComponent comp = (JComponent) i.next();
@@ -567,12 +549,11 @@ public class RepaintManager
         comp.paintImmediately(damaged);
       }
     dirtyComponentsWork.clear();
-    repaintUnderway = false;
   }
-  
+
   /**
    * Compiles a list of components that really get repainted. This is called
-   * once for each component in the dirtyComponents HashMap, each time with
+   * once for each component in the dirtyRegions HashMap, each time with
    * another <code>dirty</code> parameter. This searches up the component
    * hierarchy of <code>dirty</code> to find the highest parent that is also
    * marked dirty and merges the dirty regions.
@@ -587,6 +568,29 @@ public class RepaintManager
     Component current = dirty;
     Component root = dirty;
 
+    // This will contain the dirty region in the root coordinate system,
+    // possibly clipped by ancestor's bounds.
+    Rectangle originalDirtyRect = (Rectangle) dirtyRegions.get(dirty); 
+    rectCache.setBounds(originalDirtyRect);
+
+    // The bounds of the current component.
+    int x = dirty.getX();
+    int y = dirty.getY();
+    int w = dirty.getWidth();
+    int h = dirty.getHeight();
+
+    // Do nothing if dirty region is clipped away by the component's bounds.
+    rectCache = SwingUtilities.computeIntersection(0, 0, w, h, rectCache);
+    if (rectCache.isEmpty())
+      return;
+
+    // The cumulated offsets. 
+    int dx = 0;
+    int dy = 0;
+    // The actual offset for the found root.
+    int rootDx = 0;
+    int rootDy = 0;
+
     // Search the highest component that is also marked dirty.
     Component parent;
     while (true)
@@ -596,10 +600,29 @@ public class RepaintManager
           break;
 
         current = parent;
+        // Update the offset.
+        dx += x;
+        dy += y;
+        rectCache.x += x;
+        rectCache.y += y;
+        
+        x = current.getX();
+        y = current.getY();
+        w = current.getWidth();
+        h = current.getHeight();
+        rectCache = SwingUtilities.computeIntersection(0, 0, w, h, rectCache);
+
+        // Don't paint if the dirty regions is clipped away by any of
+        // its ancestors.
+        if (rectCache.isEmpty())
+          return;
+
         // We can skip to the next up when this parent is not dirty.
         if (dirtyRegions.containsKey(parent))
           {
             root = current;
+            rootDx = dx;
+            rootDy = dy;
           }
       }
 
@@ -607,15 +630,16 @@ public class RepaintManager
     // the are different.
     if (root != dirty)
       {
-        Rectangle dirtyRect = (Rectangle) dirtyRegions.get(dirty);
-        dirtyRect = SwingUtilities.convertRectangle(dirty, dirtyRect, root);
-        Rectangle rootRect = (Rectangle) dirtyRegions.get(root);
-        SwingUtilities.computeUnion(dirtyRect.x, dirtyRect.y, dirtyRect.width,
-                                    dirtyRect.height, rootRect);
+        rectCache.x += rootDx - dx;
+        rectCache.y += rootDy - dy;
+        Rectangle dirtyRect = (Rectangle) dirtyRegions.get(root);
+        SwingUtilities.computeUnion(rectCache.x, rectCache.y, rectCache.width,
+                                    rectCache.height, dirtyRect);
       }
 
     // Adds the root to the roots set.
-    roots.add(root);
+    if (! roots.contains(root))
+      roots.add(root);
   }
 
   /**
@@ -653,16 +677,19 @@ public class RepaintManager
    * This is package private because it must get called by JComponent.
    *
    * @param comp the component to be painted
-   * @param area the area to paint on screen, in comp coordinates
+   * @param x the area to paint on screen, in comp coordinates
+   * @param y the area to paint on screen, in comp coordinates
+   * @param w the area to paint on screen, in comp coordinates
+   * @param h the area to paint on screen, in comp coordinates
    */
-  void commitBuffer(Component comp, Rectangle area)
+  void commitBuffer(Component comp, int x, int y, int w, int h)
   {
     Component root = comp;
     while (root != null
 	   && ! (root instanceof Window || root instanceof Applet))
       {
-	area.x += root.getX();
-	area.y += root.getY();
+	x += root.getX();
+	y += root.getY();
 	root = root.getParent();
       }
 
@@ -670,7 +697,7 @@ public class RepaintManager
     Image buffer = (Image) offscreenBuffers.get(root);
 
     // Make sure we have a sane clip at this point.
-    g.clipRect(area.x, area.y, area.width, area.height);
+    g.clipRect(x, y, w, h);
     g.drawImage(buffer, 0, 0, root);
     g.dispose();
   }