### Eclipse Workspace Patch 1.0
#P org.eclipse.ui.forms
Index: src/org/eclipse/ui/forms/widgets/Section.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.ui.forms/src/org/eclipse/ui/forms/widgets/Section.java,v
retrieving revision 1.43
diff -u -r1.43 Section.java
--- src/org/eclipse/ui/forms/widgets/Section.java	16 Mar 2007 20:24:01 -0000	1.43
+++ src/org/eclipse/ui/forms/widgets/Section.java	5 Sep 2007 18:39:23 -0000
@@ -27,6 +27,7 @@
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Text;
+import org.eclipse.ui.internal.forms.widgets.FormImages;
 import org.eclipse.ui.internal.forms.widgets.FormUtil;
 
 /**
@@ -89,8 +90,9 @@
 			Listener listener = new Listener() {
 				public void handleEvent(Event e) {
 					Image image = Section.super.getBackgroundImage();
-					if (image != null)
-						image.dispose();
+					if (image != null) {
+						FormImages.markFinished(image);
+					}
 					Section.super.setBackgroundImage(null);
 				}
 			};
@@ -457,15 +459,7 @@
 
 	private void updateHeaderImage(Color bg, Rectangle bounds, int theight,
 			int realtheight) {
-		Image image = new Image(getDisplay(), 1, realtheight);
-		image.setBackground(getBackground());
-		GC gc = new GC(image);
-		gc.setBackground(getBackground());
-		gc.fillRectangle(0, 0, 1, realtheight);
-		gc.setForeground(bg);
-		gc.setBackground(getBackground());
-		gc.fillGradientRectangle(0, marginHeight + 2, 1, theight - 2, true);
-		gc.dispose();
+		Image image = FormImages.getGradient(getDisplay(), getBackground(), bg, realtheight, theight, marginHeight);
 		super.setBackgroundImage(image);
 	}
 
Index: src/org/eclipse/ui/internal/forms/widgets/FormImages.java
===================================================================
RCS file: src/org/eclipse/ui/internal/forms/widgets/FormImages.java
diff -N src/org/eclipse/ui/internal/forms/widgets/FormImages.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/ui/internal/forms/widgets/FormImages.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,146 @@
+/*******************************************************************************
+ * Copyright (c) 2007 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.ui.internal.forms.widgets;
+
+import java.util.HashMap;
+
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.graphics.GC;
+import org.eclipse.swt.graphics.Image;
+import org.eclipse.swt.widgets.Display;
+
+public class FormImages {
+	private static HashMap images;
+	private static HashMap ids;
+	
+	private static class ImageIdentifier {
+		private Display fDisplay;
+		private Color fColor1;
+		private Color fColor2;
+		private int fRealtheight;
+		private int fTheight;
+		private int fMarginHeight;
+		
+		ImageIdentifier (Display display, Color color1, Color color2,
+				int realtheight, int theight, int marginHeight) {
+			fDisplay = display;
+			fColor1 = color1;
+			fColor2 = color2;
+			fRealtheight = realtheight;
+			fTheight = theight;
+			fMarginHeight = marginHeight;
+		}
+		
+		public boolean equals(Object obj) {
+			if (obj instanceof ImageIdentifier) {
+				ImageIdentifier id = (ImageIdentifier) obj;
+				if (id.fDisplay.equals(fDisplay) && id.fColor1.equals(fColor1) &&
+						id.fColor2.equals(fColor2) && id.fRealtheight == fRealtheight &&
+						id.fTheight == fTheight && id.fMarginHeight == fMarginHeight)
+					return true;
+			}
+			return false;
+		}
+		
+		public int hashCode() {
+			int hash = fDisplay.hashCode();
+			hash = hash * 7 + fColor1.hashCode();
+			hash = hash * 7 + fColor2.hashCode();
+			hash = hash * 7 + new Integer(fRealtheight).hashCode();
+			hash = hash * 7 + new Integer(fTheight).hashCode();
+			hash = hash * 7 + new Integer(fMarginHeight).hashCode();
+			return hash;
+		}
+	}
+	
+	private static class ImageReference {
+		private Image fImage;
+		private int fCount;
+		
+		public ImageReference(Image image) {
+			fImage = image;
+			fCount = 1;
+		}
+
+		public Image getImage() {
+			return fImage;
+		}
+		// returns a boolean indicating if all clients of this image are finished
+		// a true result indicates the underlying image should be disposed
+		public boolean decCount() {
+			return --fCount == 0;
+		}
+		public void incCount() {
+			fCount++;
+		}
+	}
+	
+	public static Image getGradient(Display display, Color color1, Color color2,
+			int realtheight, int theight, int marginHeight) {
+		checkHashMaps();
+		ImageIdentifier id = new ImageIdentifier(display, color1, color2, realtheight, theight, marginHeight);
+		ImageReference result = (ImageReference) images.get(id);
+		if (result != null && !result.getImage().isDisposed()) {
+			result.incCount();
+			return result.getImage();
+		}
+		Image image = createGradient(display, color1, color2, realtheight, theight, marginHeight);
+		images.put(id, new ImageReference(image));
+		ids.put(image, id);
+		return image;
+	}
+	
+	public static boolean markFinished(Image image) {
+		checkHashMaps();
+		ImageIdentifier id = (ImageIdentifier)ids.get(image);
+		if (id != null) {
+			ImageReference ref = (ImageReference) images.get(id);
+			if (ref != null) {
+				if (ref.decCount()) {
+					images.remove(id);
+					ids.remove(ref.getImage());
+					ref.getImage().dispose();
+					validateHashMaps();
+				}
+				return true;
+			}
+		}
+		return false;
+	}
+	
+	private static void validateHashMaps() {
+		if (images.size() == 0)
+			images = null;
+		if (ids.size() == 0)
+			ids = null;
+	}
+
+	private static void checkHashMaps() {
+		if (images == null)
+			images = new HashMap();
+		if (ids == null)
+			ids = new HashMap();
+	}
+	
+	private static Image createGradient(Display display, Color color1, Color color2,
+			int realtheight, int theight, int marginHeight) {
+		Image image = new Image(display, 1, realtheight);
+		image.setBackground(color1);
+		GC gc = new GC(image);
+		gc.setBackground(color1);
+		gc.fillRectangle(0, 0, 1, realtheight);
+		gc.setForeground(color2);
+		gc.setBackground(color1);
+		gc.fillGradientRectangle(0, marginHeight + 2, 1, theight - 2, true);
+		gc.dispose();
+		return image;
+	}
+}