Bug 483791: [GTK3] setBackground overrides GC drawing in PaintListener

This bug happens on GTK 3.9+, due to the fact that the GTK drawing
events are connected to the wrong widget. Changing the background color
on those widgets does not trigger the proper re-drawing. As far as I can
tell this has been a bug for awhile and is not a regression. Only Button
and Label are affected.

Solution: connect the paint signal/GTK drawing events to
the appropriate handles in Button and Label.

Change-Id: Ib6b513493cbb74680facd6ebc81569c3fa066379
Signed-off-by: Eric Williams <ericwill@redhat.com>

3 files changed, 50 insertions, 8 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Button.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Button.java
index f844454ccb..ad13b3ec5f 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Button.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Button.java
@@ -176,6 +176,25 @@ public void addSelectionListener (SelectionListener listener) {
 }
 
 @Override
+void connectPaint () {
+	/*
+	 * Feature in GTK3.10+: when attaching a paint listener to a Button
+	 * widget, re-drawing happens on GtkButton and not the GtkBox.
+	 * This causes issues when setting a background color, as whatever
+	 * is drawn on the Button is not re-drawn. See bug 483791.
+	 */
+	if (OS.GTK_VERSION >= OS.VERSION (3, 9, 0) && boxHandle != 0) {
+		int paintMask = OS.GDK_EXPOSURE_MASK;
+		OS.gtk_widget_add_events (boxHandle, paintMask);
+
+		OS.g_signal_connect_closure_by_id (boxHandle, display.signalIds [DRAW], 0, display.getClosure (EXPOSE_EVENT_INVERSE), false);
+		OS.g_signal_connect_closure_by_id (boxHandle, display.signalIds [DRAW], 0, display.getClosure (DRAW), true);
+	} else {
+		super.connectPaint();
+	}
+}
+
+@Override
 Point computeSizeInPixels (int wHint, int hHint, boolean changed) {
 	checkWidget ();
 	if (wHint != SWT.DEFAULT && wHint < 0) wHint = 0;
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 a217a5948e..430a4855ed 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
@@ -131,6 +131,16 @@ public Control (Composite parent, int style) {
 	createWidget (0);
 }
 
+void connectPaint () {
+	long /*int*/ paintHandle = paintHandle ();
+	int paintMask = OS.GDK_EXPOSURE_MASK;
+	OS.gtk_widget_add_events (paintHandle, paintMask);
+
+	OS.g_signal_connect_closure_by_id (paintHandle, display.signalIds [DRAW], 0, display.getClosure (EXPOSE_EVENT_INVERSE), false);
+
+	OS.g_signal_connect_closure_by_id (paintHandle, display.signalIds [DRAW], 0, display.getClosure (DRAW), true);
+}
+
 Font defaultFont () {
 	return display.getSystemFont ();
 }
@@ -381,13 +391,7 @@ void hookEvents () {
 	}
 
 	/* Connect the paint signal */
-	long /*int*/ paintHandle = paintHandle ();
-	int paintMask = OS.GDK_EXPOSURE_MASK;
-	OS.gtk_widget_add_events (paintHandle, paintMask);
-
-	OS.g_signal_connect_closure_by_id (paintHandle, display.signalIds [EXPOSE_EVENT], 0, display.getClosure (EXPOSE_EVENT_INVERSE), false);
-
-	OS.g_signal_connect_closure_by_id (paintHandle, display.signalIds [EXPOSE_EVENT], 0, display.getClosure (EXPOSE_EVENT), true);
+	connectPaint ();
 
 	/* Connect the Input Method signals */
 	OS.g_signal_connect_closure_by_id (handle, display.signalIds [REALIZE], 0, display.getClosure (REALIZE), true);
@@ -398,7 +402,7 @@ void hookEvents () {
 		OS.g_signal_connect_closure (imHandle, OS.preedit_changed, display.getClosure (PREEDIT_CHANGED), false);
 	}
 
-	OS.g_signal_connect_closure_by_id (paintHandle, display.signalIds [STYLE_SET], 0, display.getClosure (STYLE_SET), false);
+	OS.g_signal_connect_closure_by_id (paintHandle (), display.signalIds [STYLE_SET], 0, display.getClosure (STYLE_SET), false);
 
 	long /*int*/ topHandle = topHandle ();
 	OS.g_signal_connect_closure_by_id (topHandle, display.signalIds [MAP], 0, display.getClosure (MAP), true);
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Label.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Label.java
index 2d4109b8a8..9bdcbc8874 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Label.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Label.java
@@ -114,6 +114,25 @@ void addRelation (Control control) {
 }
 
 @Override
+void connectPaint () {
+	/*
+	 * Feature in GTK3.10+: when attaching a paint listener to a Label
+	 * widget, re-drawing happens on GtkEventBox and not the GtkLabel.
+	 * This causes issues when setting a background color, as whatever
+	 * is drawn on the Label is not re-drawn. See bug 483791.
+	 */
+	if (OS.GTK_VERSION >= OS.VERSION (3, 9, 0) && labelHandle != 0) {
+		int paintMask = OS.GDK_EXPOSURE_MASK;
+		OS.gtk_widget_add_events (labelHandle, paintMask);
+
+		OS.g_signal_connect_closure_by_id (labelHandle, display.signalIds [DRAW], 0, display.getClosure (EXPOSE_EVENT_INVERSE), false);
+		OS.g_signal_connect_closure_by_id (labelHandle, display.signalIds [DRAW], 0, display.getClosure (DRAW), true);
+	} else {
+		super.connectPaint();
+	}
+}
+
+@Override
 Point computeSizeInPixels (int wHint, int hHint, boolean changed) {
 	checkWidget ();
 	if (wHint != SWT.DEFAULT && wHint < 0) wHint = 0;