6884960: java/awt/Window/TranslucentJAppletTest/TranslucentJAppletTest.java fails

Summary: Support painting heavyweight components in transparent windows.
Reviewed-by: art, alexp

src/share/classes/javax/swing/JComponent.java

@@ -795,7 +795,6 @@ public abstract class JComponent extends Container implements Serializable,
      * @see java.awt.Container#paint
      */
     protected void paintChildren(Graphics g) {
-        boolean isJComponent;
         Graphics sg = g;
 
         synchronized(getTreeLock()) {
@@ -826,12 +825,21 @@ public abstract class JComponent extends Container implements Serializable,
                 }
             }
             boolean printing = getFlag(IS_PRINTING);
+            final Window window = SwingUtilities.getWindowAncestor(this);
+            final boolean isWindowOpaque = window == null || window.isOpaque();
             for (; i >= 0 ; i--) {
                 Component comp = getComponent(i);
-                isJComponent = (comp instanceof JComponent);
-                if (comp != null &&
-                    (isJComponent || isLightweightComponent(comp)) &&
-                    (comp.isVisible() == true)) {
+                if (comp == null) {
+                    continue;
+                }
+
+                final boolean isJComponent = comp instanceof JComponent;
+
+                // Enable painting of heavyweights in non-opaque windows.
+                // See 6884960
+                if ((!isWindowOpaque || isJComponent ||
+                            isLightweightComponent(comp)) && comp.isVisible())
+                {
                     Rectangle cr;
 
                     cr = comp.getBounds(tmpRect);
@@ -887,6 +895,8 @@ public abstract class JComponent extends Container implements Serializable,
                                     }
                                 }
                             } else {
+                                // The component is either lightweight, or
+                                // heavyweight in a non-opaque window
                                 if (!printing) {
                                     comp.paint(cg);
                                 }

src/windows/classes/sun/awt/windows/WComponentPeer.java

@@ -551,8 +551,34 @@ public abstract class WComponentPeer extends WObjectPeer
     final static Font defaultFont = new Font(Font.DIALOG, Font.PLAIN, 12);
 
     public Graphics getGraphics() {
+        if (isDisposed()) {
+            return null;
+        }
+
+        Component target = (Component)getTarget();
+        Window window = SunToolkit.getContainingWindow(target);
+        if (window != null && !window.isOpaque()) {
+            // Non-opaque windows do not support heavyweight children.
+            // Redirect all painting to the Window's Graphics instead.
+            // The caller is responsible for calling the
+            // WindowPeer.updateWindow() after painting has finished.
+            int x = 0, y = 0;
+            for (Component c = target; c != window; c = c.getParent()) {
+                x += c.getX();
+                y += c.getY();
+            }
+
+            Graphics g =
+                ((WWindowPeer)window.getPeer()).getTranslucentGraphics();
+
+            g.translate(x, y);
+            g.clipRect(0, 0, target.getWidth(), target.getHeight());
+
+            return g;
+        }
+
         SurfaceData surfaceData = this.surfaceData;
-        if (!isDisposed() && surfaceData != null) {
+        if (surfaceData != null) {
             /* Fix for bug 4746122. Color and Font shouldn't be null */
             Color bgColor = background;
             if (bgColor == null) {

src/windows/classes/sun/awt/windows/WWindowPeer.java

@@ -578,11 +578,17 @@ public class WWindowPeer extends WPanelPeer implements WindowPeer,
         }
     }
 
+    public final Graphics getTranslucentGraphics() {
+        synchronized (getStateLock()) {
+            return isOpaque ? null : painter.getBackBuffer(false).getGraphics();
+        }
+    }
+
     @Override
     public Graphics getGraphics() {
         synchronized (getStateLock()) {
             if (!isOpaque) {
-                return painter.getBackBuffer(false).getGraphics();
+                return getTranslucentGraphics();
             }
         }
         return super.getGraphics();