83472

7 files changed, 43 insertions, 0 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/carbon/org/eclipse/swt/widgets/Control.java b/bundles/org.eclipse.swt/Eclipse SWT/carbon/org/eclipse/swt/widgets/Control.java
index 5518e5316b..4842554905 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/carbon/org/eclipse/swt/widgets/Control.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/carbon/org/eclipse/swt/widgets/Control.java
@@ -366,6 +366,10 @@ int colorProc (int inControl, int inMessage, int inDrawDepth, int inDrawInColor)
 	return OS.eventNotHandledErr;
 }
 
+void checkBuffered () {
+	style |= SWT.DOUBLE_BUFFERED;
+}
+
 /**
  * Returns the preferred size of the receiver.
  * <p>
@@ -474,6 +478,7 @@ Control computeTabRoot () {
 
 void createWidget () {
 	checkOrientation (parent);
+	checkBuffered ();
 	super.createWidget ();
 	setDefaultFont ();
 	setZOrder ();
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/SWT.java b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/SWT.java
index 2d96cadde9..60367bef00 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/SWT.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/SWT.java
@@ -844,6 +844,16 @@ public class SWT {
 	public static final int VIRTUAL = 1 << 28;
 
 	/**
+	 * Style constant to indicate double buffering (value is 1&lt;&lt;29).
+	 * <p><b>Used By:</b><ul>
+	 * <li><code>Control</code></li>
+	 * </ul></p>
+	 * 
+	 * @since 3.1
+	 */
+	public static final int DOUBLE_BUFFERED = 1 << 29;
+	
+	/**
 	 * Style constant for align up behavior (value is 1&lt;&lt;7,
 	 * since align UP and align TOP are considered the same).
 	 * <p><b>Used By:</b><ul>
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Composite.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Composite.java
index f76133fb8c..897baf253c 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Composite.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Composite.java
@@ -275,8 +275,17 @@ void createHandle (int index, boolean scrolled) {
 	if ((style & SWT.NO_REDRAW_RESIZE) != 0) {
 		OS.gtk_widget_set_redraw_on_allocate (handle, false);
 	}
+	/*
+	* Bug in GTK.  When a widget is double buffered and the back
+	* pixmap is null, the double buffer pixmap is filled with the
+	* background of the widget rather than the current contents of
+	* the screen.  If nothing is drawn during an expose event,
+	* the pixels are altered.  The fix is to clear double buffering
+	* and the DOUBLE_BUFFERED flag.
+	*/
 	if ((style & SWT.NO_BACKGROUND) != 0) {
 		OS.gtk_widget_set_double_buffered (handle, false);
+		style &= ~SWT.DOUBLE_BUFFERED;
 	}
 }
 
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java
index 12a6e7ee1b..9c5d7c5a50 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java
@@ -307,12 +307,17 @@ Control computeTabRoot () {
 	return parent.computeTabRoot ();
 }
 
+void checkBuffered () {
+	style |= SWT.DOUBLE_BUFFERED;
+}
+
 void checkBorder () {
 	if (getBorderWidth () == 0) style &= ~SWT.BORDER;
 }
 
 void createWidget (int index) {
 	checkOrientation (parent);
+	checkBuffered ();
 	super.createWidget (index);
 	showWidget ();
 	setInitialBounds ();
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/motif/org/eclipse/swt/widgets/Control.java b/bundles/org.eclipse.swt/Eclipse SWT/motif/org/eclipse/swt/widgets/Control.java
index ec2294a475..14967dc814 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/motif/org/eclipse/swt/widgets/Control.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/motif/org/eclipse/swt/widgets/Control.java
@@ -317,6 +317,9 @@ public void addTraverseListener (TraverseListener listener) {
 int borderHandle () {
 	return topHandle ();
 }
+void checkBuffered () {
+	style &= ~SWT.DOUBLE_BUFFERED;
+}
 /**
  * Returns the preferred size of the receiver.
  * <p>
@@ -424,6 +427,7 @@ Control [] computeTabList () {
 
 void createWidget (int index) {
 	checkOrientation (parent);
+	checkBuffered ();
 	super.createWidget (index);
 	setParentTraversal ();
 	overrideTranslations ();
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/photon/org/eclipse/swt/widgets/Control.java b/bundles/org.eclipse.swt/Eclipse SWT/photon/org/eclipse/swt/widgets/Control.java
index dc4aeec2db..9a4f8bd33f 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/photon/org/eclipse/swt/widgets/Control.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/photon/org/eclipse/swt/widgets/Control.java
@@ -352,6 +352,10 @@ public boolean forceFocus () {
 	return hasFocus ();
 }
 
+void checkBuffered () {
+	style &= ~SWT.DOUBLE_BUFFERED;
+}
+
 /**
  * Returns the preferred size of the receiver.
  * <p>
@@ -460,6 +464,7 @@ Control [] computeTabList () {
 
 void createWidget (int index) {
 	checkOrientation (parent);
+	checkBuffered ();
 	super.createWidget (index);
 	setZOrder ();
 	realizeWidget ();
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Control.java b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Control.java
index 00a1dabc98..b2a84da04c 100755
--- a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Control.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Control.java
@@ -346,6 +346,10 @@ void checkBorder () {
 	if (getBorderWidth () == 0) style &= ~SWT.BORDER;
 }
 
+void checkBuffered () {
+	style &= ~SWT.DOUBLE_BUFFERED;
+}
+
 boolean checkHandle (int hwnd) {
 	return hwnd == handle;
 }
@@ -490,6 +494,7 @@ void createHandle () {
 void createWidget () {
 	foreground = background = -1;
 	checkOrientation (parent);
+	checkBuffered ();
 	createHandle ();
 	register ();
 	subclass ();