Refactored demos to mostly subclass common Demo superclass providing

shutdown capabilities. Moved DemoListener to demos.common package.
Added ManipManager removal code to demos using manipulators or
ExaminerViewer to fix memory leak when run in JRefract harness. Added
workaround for another seeming memory leak when run under current JDK
1.6 due to java.awt.Component now being finalizable and keeping data
alive longer than previously. Made ManipManager.unregisterWindow more
lenient with respect to null or invalid arguments.


git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/../svn-server-sync/jogl-demos/branches/JSR-231@122 3298f667-5e0e-4b4a-8ed4-a3559d26a5f4

12 files changed, 186 insertions, 107 deletions

diff --git a/src/demos/common/Demo.java b/src/demos/common/Demo.java
new file mode 100755
index 0000000..00f5956
--- /dev/null
+++ b/src/demos/common/Demo.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * - Redistribution of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * 
+ * - Redistribution in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * 
+ * Neither the name of Sun Microsystems, Inc. or the names of
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * 
+ * This software is provided "AS IS," without a warranty of any kind. ALL
+ * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
+ * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
+ * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
+ * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
+ * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
+ * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
+ * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
+ * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
+ * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
+ * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
+ * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+ * 
+ * You acknowledge that this software is not designed or intended for use
+ * in the design, construction, operation or maintenance of any nuclear
+ * facility.
+ * 
+ * Sun gratefully acknowledges that this software was originally authored
+ * and developed by Kenneth Bradley Russell and Christopher John Kline.
+ */
+
+package demos.common;
+
+import javax.media.opengl.*;
+
+public abstract class Demo implements GLEventListener {
+  protected DemoListener demoListener;
+  private boolean doShutdown = true;
+
+  public void setDemoListener(DemoListener listener) {
+    this.demoListener = listener;
+  }
+
+  // Override this with any other cleanup actions
+  public void shutdownDemo() {
+    // Execute only once
+    boolean shouldDoShutdown = doShutdown;
+    doShutdown = false;
+    if (shouldDoShutdown) {
+      demoListener.shutdownDemo();
+    }
+  }
+}
diff --git a/src/demos/util/DemoListener.java b/src/demos/common/DemoListener.java
index ee343e7..95b5e9c 100755
--- a/src/demos/util/DemoListener.java
+++ b/src/demos/common/DemoListener.java
@@ -37,7 +37,7 @@
  * and developed by Kenneth Bradley Russell and Christopher John Kline.
  */
 
-package demos.util;
+package demos.common;
 
 /** Defines certain events demos can send. Different harnesses
     may respond differently to these events. */
diff --git a/src/demos/hdr/HDR.java b/src/demos/hdr/HDR.java
index b7467da..20122f4 100755
--- a/src/demos/hdr/HDR.java
+++ b/src/demos/hdr/HDR.java
@@ -11,6 +11,7 @@ import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
 import com.sun.opengl.cg.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.util.*;
 import gleem.*;
 import gleem.linalg.*;
@@ -20,7 +21,7 @@ import gleem.linalg.*;
     Ported to Java by Kenneth Russell
 */
 
-public class HDR implements GLEventListener {
+public class HDR extends Demo {
   private static String[] defaultArgs = {
     "demos/data/images/stpeters_cross.hdr",
     "512",
@@ -30,6 +31,7 @@ public class HDR implements GLEventListener {
     "3",
     "demos/data/models/teapot.obj"
   };
+  private GLAutoDrawable drawable;
   private boolean  useCg;
   private boolean  initComplete;
   private HDRTexture hdr;
@@ -217,15 +219,14 @@ public class HDR implements GLEventListener {
     return win_h;
   }
 
-  public void setDemoListener(DemoListener listener) {
-    demoListener = listener;
-  }
-
   //----------------------------------------------------------------------
   // Internals only below this point
   //
 
-  private DemoListener demoListener;
+  public void shutdownDemo() {
+    ManipManager.getManipManager().unregisterWindow(drawable);
+    super.shutdownDemo();
+  }
 
   //----------------------------------------------------------------------
   // Listener for main window
@@ -334,6 +335,7 @@ public class HDR implements GLEventListener {
     // Register the window with the ManipManager
     ManipManager manager = ManipManager.getManipManager();
     manager.registerWindow(drawable);
+    this.drawable = drawable;
 
     viewer = new ExaminerViewer(MouseButtonHelper.numMouseButtons());
     viewer.setAutoRedrawMode(false);
@@ -436,7 +438,7 @@ public class HDR implements GLEventListener {
 
   private void unavailableExtension(String message) {
     JOptionPane.showMessageDialog(null, message, "Unavailable extension", JOptionPane.ERROR_MESSAGE);
-    demoListener.shutdownDemo();
+    shutdownDemo();
     throw new GLException(message);
   }
 
@@ -447,7 +449,7 @@ public class HDR implements GLEventListener {
     switch (keyCode) {
     case KeyEvent.VK_ESCAPE:
     case KeyEvent.VK_Q:
-      demoListener.shutdownDemo();
+      shutdownDemo();
       break;
 
     case KeyEvent.VK_EQUALS:
@@ -1219,7 +1221,7 @@ public class HDR implements GLEventListener {
 
   private void usage() {
     System.err.println("usage: java demos.hdr.HDR [-cg] image.hdr pbuffer_w pbuffer_h window_scale blur_width blur_decimate [obj file]");
-    demoListener.shutdownDemo();
+    shutdownDemo();
   }
 
   private void printThreadName(String where) {
diff --git a/src/demos/hwShadowmapsSimple/HWShadowmapsSimple.java b/src/demos/hwShadowmapsSimple/HWShadowmapsSimple.java
index dcffc3a..ca2a8aa 100644
--- a/src/demos/hwShadowmapsSimple/HWShadowmapsSimple.java
+++ b/src/demos/hwShadowmapsSimple/HWShadowmapsSimple.java
@@ -45,6 +45,7 @@ import javax.swing.*;
 import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.util.*;
 import gleem.*;
 import gleem.linalg.*;
@@ -58,7 +59,7 @@ import gleem.linalg.*;
     Ported to Java by Kenneth Russell
 */
 
-public class HWShadowmapsSimple implements GLEventListener {
+public class HWShadowmapsSimple extends Demo {
   public static void main(String[] args) {
     final GLCanvas canvas = GLDrawableFactory.getFactory().createGLCanvas(new GLCapabilities());
     HWShadowmapsSimple demo = new HWShadowmapsSimple();
@@ -88,15 +89,15 @@ public class HWShadowmapsSimple implements GLEventListener {
       });
   }
 
-  public void setDemoListener(DemoListener listener) {
-    demoListener = listener;
-  }
-
   //----------------------------------------------------------------------
   // Internals only below this point
   //
 
-  private DemoListener demoListener;
+  public void shutdownDemo() {
+    ManipManager.getManipManager().unregisterWindow(drawable);
+    super.shutdownDemo();
+  }
+
   private GLPbuffer pbuffer;
 
   private GLUT glut;
@@ -152,6 +153,7 @@ public class HWShadowmapsSimple implements GLEventListener {
   private float lightshaper_zFar  = 5.0f;
 
   // Manipulators
+  private GLAutoDrawable drawable;
   private ExaminerViewer viewer;
   private boolean  doViewAll = true;
   //  private float    zNear = 0.5f;
@@ -257,6 +259,7 @@ public class HWShadowmapsSimple implements GLEventListener {
     // Register the window with the ManipManager
     ManipManager manager = ManipManager.getManipManager();
     manager.registerWindow(drawable);
+    this.drawable = drawable;
 
     object = new HandleBoxManip();
     object.setTranslation(new Vec3f(0, 0.7f, 1.8f));
@@ -370,7 +373,7 @@ public class HWShadowmapsSimple implements GLEventListener {
     switch (k) {
     case 27:
     case 'q':
-      demoListener.shutdownDemo();
+      shutdownDemo();
       break;
 
     case 'v':
diff --git a/src/demos/infiniteShadowVolumes/InfiniteShadowVolumes.java b/src/demos/infiniteShadowVolumes/InfiniteShadowVolumes.java
index eb90430..05594be 100644
--- a/src/demos/infiniteShadowVolumes/InfiniteShadowVolumes.java
+++ b/src/demos/infiniteShadowVolumes/InfiniteShadowVolumes.java
@@ -45,6 +45,7 @@ import javax.imageio.stream.*;
 import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.util.*;
 import gleem.*;
 import gleem.linalg.*;
@@ -66,7 +67,7 @@ import gleem.linalg.*;
   Ported to Java by Kenneth Russell
 */
 
-public class InfiniteShadowVolumes implements GLEventListener {
+public class InfiniteShadowVolumes extends Demo {
   public static void main(String[] args) {
     GLCapabilities caps = new GLCapabilities();
     caps.setStencilBits(16);
@@ -98,15 +99,14 @@ public class InfiniteShadowVolumes implements GLEventListener {
       });
   }
 
-  public void setDemoListener(DemoListener listener) {
-    demoListener = listener;
-  }
-
   //----------------------------------------------------------------------
   // Internals only below this point
   //
 
-  private DemoListener demoListener;
+  public void shutdownDemo() {
+    ManipManager.getManipManager().unregisterWindow(drawable);
+    super.shutdownDemo();
+  }
 
   static class Model {
     Model() {
@@ -148,6 +148,7 @@ public class InfiniteShadowVolumes implements GLEventListener {
 
   private GLUT glut = new GLUT();
 
+  private GLAutoDrawable drawable;
   private ExaminerViewer viewer;
   private HandleBoxManip objectManip;
   private HandleBoxManip lightManip;
@@ -228,6 +229,7 @@ public class InfiniteShadowVolumes implements GLEventListener {
     // Register the window with the ManipManager
     ManipManager manager = ManipManager.getManipManager();
     manager.registerWindow(drawable);
+    this.drawable = drawable;
 
     objectManip = new HandleBoxManip();
     manager.showManipInWindow(objectManip, drawable);
@@ -564,7 +566,7 @@ public class InfiniteShadowVolumes implements GLEventListener {
   private void dispatchKey(char k) {
     b[k] = ! b[k];
     if (k==27 || k=='q') {
-      demoListener.shutdownDemo();
+      shutdownDemo();
       return;
     }
 
diff --git a/src/demos/jrefract/JRefract.java b/src/demos/jrefract/JRefract.java
index d6c3e04..b3953b4 100755
--- a/src/demos/jrefract/JRefract.java
+++ b/src/demos/jrefract/JRefract.java
@@ -42,6 +42,7 @@ import javax.swing.event.*;
 import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.hdr.HDR;
 import demos.hwShadowmapsSimple.HWShadowmapsSimple;
 import demos.infiniteShadowVolumes.InfiniteShadowVolumes;
@@ -84,6 +85,17 @@ public class JRefract {
   private static final int WATER     = 8;
 
   private JInternalFrame addWindow(int which) {
+    // FIXME: workaround for problem in 1.6 where ALL Components,
+    // including Swing components, are Finalizable, requiring two full
+    // GC cycles (and running of finalizers) to reclaim
+    System.gc();
+    // Try to get finalizers run
+    try {
+      Thread.sleep(1);
+    } catch (InterruptedException e) {
+    }
+    System.gc();
+
     String str = "";
     switch (which) {
     case GEARS:     str = "Gears Demo"; break;
@@ -122,6 +134,7 @@ public class JRefract {
         }
       };
 
+    Demo demo = null;
     switch (which) {
       case GEARS: {
         // GLEventListener already added
@@ -129,46 +142,35 @@ public class JRefract {
       }
 
       case HDR: {
-        HDR demo = new HDR();
-        demo.setDemoListener(demoListener);
-        demo.setup(null);
-        inner.setSize(demo.getPreferredWidth(), demo.getPreferredHeight());
-        canvas.addGLEventListener(demo);
+        demo = new HDR();
+        ((HDR) demo).setup(null);
+        inner.setSize(((HDR) demo).getPreferredWidth(), ((HDR) demo).getPreferredHeight());
         break;
       }
 
       case HWSHADOWS: {
-        HWShadowmapsSimple demo = new HWShadowmapsSimple();
-        demo.setDemoListener(demoListener);
-        canvas.addGLEventListener(demo);
+        demo = new HWShadowmapsSimple();
         break;
       }
 
       case INFINITE: {
-        InfiniteShadowVolumes demo = new InfiniteShadowVolumes();
-        demo.setDemoListener(demoListener);
-        canvas.addGLEventListener(demo);
+        demo = new InfiniteShadowVolumes();
         break;
       }
 
       case REFRACT: {
-        VertexProgRefract demo = new VertexProgRefract();
-        demo.setDemoListener(demoListener);
-        canvas.addGLEventListener(demo);
+        demo = new VertexProgRefract();
         break;
       }
 
       case VBO: {
-        VertexBufferObject demo = new VertexBufferObject();
-        demo.setDemoListener(demoListener);
-        canvas.addGLEventListener(demo);
+        demo = new VertexBufferObject();
         break;
       }
 
       case WARP: {
-        VertexProgWarp demo = new VertexProgWarp();
-        demo.setDemoListener(demoListener);
-        demo.setTitleSetter(new VertexProgWarp.TitleSetter() {
+        demo = new VertexProgWarp();
+        ((VertexProgWarp) demo).setTitleSetter(new VertexProgWarp.TitleSetter() {
             public void setTitle(final String title) {
               SwingUtilities.invokeLater(new Runnable() {
                   public void run() {
@@ -177,17 +179,18 @@ public class JRefract {
                 });
             }
           });
-        canvas.addGLEventListener(demo);
         break;
       }
 
       case WATER: {
-        ProceduralTexturePhysics demo = new ProceduralTexturePhysics();
-        demo.setDemoListener(demoListener);
-        canvas.addGLEventListener(demo);
+        demo = new ProceduralTexturePhysics();
         break;
       }
     }
+    if (which != GEARS) {
+      demo.setDemoListener(demoListener);
+      canvas.addGLEventListener(demo);
+    }
     canvas.addMouseListener(new MouseAdapter() {
         public void mouseClicked(MouseEvent e) {
           canvas.requestFocus();
@@ -196,20 +199,23 @@ public class JRefract {
 
     addJPanel(canvas);
 
+    final Demo fDemo = demo;
+
     inner.addInternalFrameListener(new InternalFrameAdapter() {
         public void internalFrameClosed(InternalFrameEvent e) {
-          removeJPanel(canvas);
-          System.gc();
+          if (fDemo != null) {
+            fDemo.shutdownDemo();
+          }
         }
       });
 
     inner.getContentPane().setLayout(new BorderLayout());
     if (which == REFRACT) {
-      inner.getContentPane().add(canvas, BorderLayout.CENTER);
-      inner.getContentPane().add(new JButton("West"), BorderLayout.WEST);
-      inner.getContentPane().add(new JButton("East"), BorderLayout.EAST);
-      inner.getContentPane().add(new JButton("North"), BorderLayout.NORTH);
-      inner.getContentPane().add(new JButton("South"), BorderLayout.SOUTH);
+      // Testing scrolling
+      canvas.setSize(512, 512);
+      canvas.setPreferredSize(new Dimension(512, 512));
+      JScrollPane scroller = new JScrollPane(canvas);
+      inner.getContentPane().add(scroller);
     } else if (which == GEARS) {
       // Provide control over transparency of gears background
       canvas.setOpaque(false);
@@ -237,7 +243,6 @@ public class JRefract {
   }
 
   public void run(String[] args) {
-
     JFrame frame = new JFrame("JOGL and Swing Interoperability");
     desktop = new JDesktopPane();
     desktop.setSize(1024, 768);
@@ -350,7 +355,7 @@ public class JRefract {
     frame.setSize(desktop.getSize());
     frame.setVisible(true);
 
-    animator = new Animator();
+    animator = new FPSAnimator(60);
     animator.start();
   }
 
diff --git a/src/demos/proceduralTexturePhysics/ProceduralTexturePhysics.java b/src/demos/proceduralTexturePhysics/ProceduralTexturePhysics.java
index b1d52c5..6fbab29 100644
--- a/src/demos/proceduralTexturePhysics/ProceduralTexturePhysics.java
+++ b/src/demos/proceduralTexturePhysics/ProceduralTexturePhysics.java
@@ -39,6 +39,7 @@ import javax.swing.*;
 
 import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.util.*;
 import gleem.*;
 import gleem.linalg.*;
@@ -57,7 +58,7 @@ import gleem.linalg.*;
  *
  */
 
-public class ProceduralTexturePhysics implements GLEventListener {
+public class ProceduralTexturePhysics extends Demo {
   public static void main(String[] args) {
     GLCanvas canvas = GLDrawableFactory.getFactory().createGLCanvas(new GLCapabilities());
     ProceduralTexturePhysics demo = new ProceduralTexturePhysics();
@@ -88,19 +89,20 @@ public class ProceduralTexturePhysics implements GLEventListener {
     animator.start();
   }
 
-  public void setDemoListener(DemoListener listener) {
-    demoListener = listener;
-  }
-
   //----------------------------------------------------------------------
   // Internals only below this point
   //
 
-  private DemoListener demoListener;
+  public void shutdownDemo() {
+    ManipManager.getManipManager().unregisterWindow(drawable);
+    super.shutdownDemo();
+  }
+
   private volatile boolean drawing;
   private volatile int     mousePosX;
   private volatile int     mousePosY;
 
+  private GLAutoDrawable drawable;
   private Water    water = new Water();
   private volatile ExaminerViewer viewer;
   private boolean[] b = new boolean[256];
@@ -151,6 +153,7 @@ public class ProceduralTexturePhysics implements GLEventListener {
       // Register the window with the ManipManager
       ManipManager manager = ManipManager.getManipManager();
       manager.registerWindow(drawable);
+      this.drawable = drawable;
 
       viewer = new ExaminerViewer(MouseButtonHelper.numMouseButtons());
       viewer.setAutoRedrawMode(false);
@@ -248,7 +251,7 @@ public class ProceduralTexturePhysics implements GLEventListener {
     if (!gl.isExtensionAvailable(extensionName)) {
       String message = "Unable to initialize " + extensionName + " OpenGL extension";
       JOptionPane.showMessageDialog(null, message, "Unavailable extension", JOptionPane.ERROR_MESSAGE);
-      demoListener.shutdownDemo();
+      shutdownDemo();
     }
   }
 
@@ -258,7 +261,7 @@ public class ProceduralTexturePhysics implements GLEventListener {
     switch (k) {
     case 27:
     case 'q':
-      demoListener.shutdownDemo();
+      shutdownDemo();
       break;
     case 'w':
       water.enableWireframe(getFlag('w'));
diff --git a/src/demos/vertexArrayRange/VertexArrayRange.java b/src/demos/vertexArrayRange/VertexArrayRange.java
index 26d5512..7c4d1a5 100644
--- a/src/demos/vertexArrayRange/VertexArrayRange.java
+++ b/src/demos/vertexArrayRange/VertexArrayRange.java
@@ -42,6 +42,7 @@ import javax.swing.*;
 import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.util.*;
 
 /** <P> A port of NVidia's [tm] Vertex Array Range demonstration to
@@ -75,7 +76,7 @@ import demos.util.*;
     C++ speed with the HotSpot Client and Server compilers,
     respectively. </P> */
 
-public class VertexArrayRange implements GLEventListener {
+public class VertexArrayRange extends Demo {
   public static void main(String[] args) {
     boolean startSlow = false;
 
@@ -135,15 +136,10 @@ public class VertexArrayRange implements GLEventListener {
     setFlag('v', true);   // VAR on
   }
 
-  public void setDemoListener(DemoListener listener) {
-    demoListener = listener;
-  }
-
   //----------------------------------------------------------------------
   // Internals only below this point
   //
 
-  private DemoListener demoListener;
   private boolean[] b = new boolean[256];
   private static final int SIZEOF_FLOAT = 4;
   private static final int STRIP_SIZE  = 48;
@@ -264,7 +260,7 @@ public class VertexArrayRange implements GLEventListener {
       new Thread(new Runnable() {
           public void run() {
             JOptionPane.showMessageDialog(null, message, "Unavailable extension", JOptionPane.ERROR_MESSAGE);
-            demoListener.shutdownDemo();
+            shutdownDemo();
           }
         }).start();
       throw new RuntimeException(message);
@@ -289,7 +285,7 @@ public class VertexArrayRange implements GLEventListener {
       ensurePresent(gl, "glFinishFenceNV");
       ensurePresent(gl, "glAllocateMemoryNV");
     } catch (RuntimeException e) {
-      demoListener.shutdownDemo();
+      shutdownDemo();
       throw (e);
     }      
       
@@ -371,7 +367,7 @@ public class VertexArrayRange implements GLEventListener {
     setFlag(k, !getFlag(k));
     // Quit on escape or 'q'
     if ((k == (char) 27) || (k == 'q')) {
-      demoListener.shutdownDemo();
+      shutdownDemo();
       return;
     }
 
diff --git a/src/demos/vertexBufferObject/VertexBufferObject.java b/src/demos/vertexBufferObject/VertexBufferObject.java
index ee78499..97a5483 100644
--- a/src/demos/vertexBufferObject/VertexBufferObject.java
+++ b/src/demos/vertexBufferObject/VertexBufferObject.java
@@ -42,6 +42,7 @@ import javax.swing.*;
 import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.util.*;
 
 /** <P> A port of NVidia's [tm] Vertex Array Range demonstration to
@@ -67,7 +68,7 @@ import demos.util.*;
     same data in system memory allows. </P>
 */
 
-public class VertexBufferObject implements GLEventListener {
+public class VertexBufferObject extends Demo {
   public static void main(String[] args) {
     boolean vboEnabled = true;
 
@@ -124,15 +125,10 @@ public class VertexBufferObject implements GLEventListener {
     setFlag('i', true);   // infinite viewer and light
   }
 
-  public void setDemoListener(DemoListener listener) {
-    demoListener = listener;
-  }
-
   //----------------------------------------------------------------------
   // Internals only below this point
   //
 
-  private DemoListener demoListener;
   private boolean initComplete;
   private boolean[] b = new boolean[256];
   private static final int SIZEOF_FLOAT = 4;
@@ -266,7 +262,7 @@ public class VertexBufferObject implements GLEventListener {
       new Thread(new Runnable() {
           public void run() {
             JOptionPane.showMessageDialog(null, message, "Unavailable extension", JOptionPane.ERROR_MESSAGE);
-            demoListener.shutdownDemo();
+            shutdownDemo();
           }
         }).start();
       throw new RuntimeException(message);
@@ -366,7 +362,7 @@ public class VertexBufferObject implements GLEventListener {
     setFlag(k, !getFlag(k));
     // Quit on escape or 'q'
     if ((k == (char) 27) || (k == 'q')) {
-      demoListener.shutdownDemo();
+      shutdownDemo();
       return;
     }
 
diff --git a/src/demos/vertexProgRefract/VertexProgRefract.java b/src/demos/vertexProgRefract/VertexProgRefract.java
index 18dca1c..8c1e867 100644
--- a/src/demos/vertexProgRefract/VertexProgRefract.java
+++ b/src/demos/vertexProgRefract/VertexProgRefract.java
@@ -46,6 +46,7 @@ import javax.swing.*;
 import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.util.*;
 import gleem.*;
 import gleem.linalg.*;
@@ -62,7 +63,7 @@ import gleem.linalg.*;
   Ported to Java and ARB_fragment_program by Kenneth Russell
 */
 
-public class VertexProgRefract implements GLEventListener {
+public class VertexProgRefract extends Demo {
   public static void main(String[] args) {
     GLCanvas canvas = GLDrawableFactory.getFactory().createGLCanvas(new GLCapabilities());
     VertexProgRefract demo = new VertexProgRefract();
@@ -93,11 +94,6 @@ public class VertexProgRefract implements GLEventListener {
     animator.start();
   }
 
-  public void setDemoListener(DemoListener listener) {
-    demoListener = listener;
-  }
-
-  private DemoListener demoListener;
   private boolean useRegisterCombiners;
   private boolean initComplete;
   private boolean firstRender = true;
@@ -109,6 +105,7 @@ public class VertexProgRefract implements GLEventListener {
 
   private GLUT glut = new GLUT();
 
+  private GLAutoDrawable drawable;
   private ExaminerViewer viewer;
   private boolean doViewAll = true;
 
@@ -245,14 +242,14 @@ public class VertexProgRefract implements GLEventListener {
           new Thread(new Runnable() {
               public void run() {
                 JOptionPane.showMessageDialog(null, message, "Unavailable extension", JOptionPane.ERROR_MESSAGE);
-                demoListener.shutdownDemo();
+                shutdownDemo();
               }
             }).start();
           throw new RuntimeException(message);
         }
       }
     } catch (RuntimeException e) {
-      demoListener.shutdownDemo();
+      shutdownDemo();
       throw(e);
     }
 
@@ -282,7 +279,7 @@ public class VertexProgRefract implements GLEventListener {
     try {
       loadPNGCubemap(gl, glu, "demos/data/cubemaps/uffizi", true);
     } catch (IOException e) {
-      demoListener.shutdownDemo();
+      shutdownDemo();
       throw new RuntimeException(e);
     }
 
@@ -318,6 +315,7 @@ public class VertexProgRefract implements GLEventListener {
       // Register the window with the ManipManager
       ManipManager manager = ManipManager.getManipManager();
       manager.registerWindow(drawable);
+      this.drawable = drawable;
 
       viewer = new ExaminerViewer(MouseButtonHelper.numMouseButtons());
       viewer.setNoAltKeyMode(true);
@@ -454,13 +452,18 @@ public class VertexProgRefract implements GLEventListener {
   //----------------------------------------------------------------------
   // Internals only below this point
   //
+  public void shutdownDemo() {
+    ManipManager.getManipManager().unregisterWindow(drawable);
+    super.shutdownDemo();
+  }
+
   private boolean[] b = new boolean[256];
   private void dispatchKey(char k) {
     setFlag(k, !getFlag(k));
 
     // Quit on escape or 'q'
     if ((k == (char) 27) || (k == 'q')) {
-      demoListener.shutdownDemo();
+      shutdownDemo();
       return;
     }
 
@@ -562,7 +565,7 @@ public class VertexProgRefract implements GLEventListener {
       new Thread(new Runnable() {
           public void run() {
             JOptionPane.showMessageDialog(null, message, "Unavailable extension", JOptionPane.ERROR_MESSAGE);
-            demoListener.shutdownDemo();
+            shutdownDemo();
           }
         }).start();
       throw new RuntimeException(message);
diff --git a/src/demos/vertexProgWarp/VertexProgWarp.java b/src/demos/vertexProgWarp/VertexProgWarp.java
index c6e177a..e740a64 100644
--- a/src/demos/vertexProgWarp/VertexProgWarp.java
+++ b/src/demos/vertexProgWarp/VertexProgWarp.java
@@ -42,6 +42,7 @@ import javax.swing.*;
 
 import javax.media.opengl.*;
 import com.sun.opengl.utils.*;
+import demos.common.*;
 import demos.util.*;
 import gleem.*;
 import gleem.linalg.*;
@@ -55,11 +56,12 @@ import gleem.linalg.*;
         Ported to Java by Kenneth Russell
 */
 
-public class VertexProgWarp implements GLEventListener {
+public class VertexProgWarp extends Demo {
   private Frame    frame;
   private Animator animator;
   private volatile boolean quit;
 
+  private GLAutoDrawable drawable;
   private DurationTimer timer = new DurationTimer();
   private boolean  firstRender = true;
   private int      frameCount;
@@ -111,11 +113,6 @@ public class VertexProgWarp implements GLEventListener {
     titleSetter = setter;
   }
 
-  public void setDemoListener(DemoListener listener) {
-    demoListener = listener;
-  }
-
-  private DemoListener demoListener;
   private TitleSetter titleSetter;
   private boolean initComplete;
   
@@ -158,7 +155,7 @@ public class VertexProgWarp implements GLEventListener {
     try {
       initExtension(gl, "GL_ARB_vertex_program");
     } catch (RuntimeException e) {
-      demoListener.shutdownDemo();
+      shutdownDemo();
       throw(e);
     }
 
@@ -211,6 +208,7 @@ public class VertexProgWarp implements GLEventListener {
     // Register the window with the ManipManager
     ManipManager manager = ManipManager.getManipManager();
     manager.registerWindow(drawable);
+    this.drawable = drawable;
 
     viewer = new ExaminerViewer(MouseButtonHelper.numMouseButtons());
     viewer.setNoAltKeyMode(true);
@@ -301,13 +299,18 @@ public class VertexProgWarp implements GLEventListener {
   //----------------------------------------------------------------------
   // Internals only below this point
   //
+  public void shutdownDemo() {
+    ManipManager.getManipManager().unregisterWindow(drawable);
+    super.shutdownDemo();
+  }
+
   private void initExtension(GL gl, String glExtensionName) {
     if (!gl.isExtensionAvailable(glExtensionName)) {
       final String message = "OpenGL extension \"" + glExtensionName + "\" not available";
       new Thread(new Runnable() {
           public void run() {
             JOptionPane.showMessageDialog(null, message, "Unavailable extension", JOptionPane.ERROR_MESSAGE);
-            demoListener.shutdownDemo();
+            shutdownDemo();
           }
         }).start();
       throw new RuntimeException(message);
@@ -363,7 +366,7 @@ public class VertexProgWarp implements GLEventListener {
 
     case KeyEvent.VK_ESCAPE:
     case KeyEvent.VK_Q:
-      demoListener.shutdownDemo();
+      shutdownDemo();
       return;
 
     case KeyEvent.VK_W:
@@ -440,7 +443,7 @@ public class VertexProgWarp implements GLEventListener {
       try {
         Triceratops.drawObject(gl);
       } catch (IOException e) {
-        demoListener.shutdownDemo();
+        shutdownDemo();
         throw new RuntimeException(e);
       }
       break;
diff --git a/src/gleem/ManipManager.java b/src/gleem/ManipManager.java
index 767c8cd..85a3d80 100644
--- a/src/gleem/ManipManager.java
+++ b/src/gleem/ManipManager.java
@@ -117,12 +117,17 @@ public class ManipManager {
   /** Remove all references to a given window, including removing all
       manipulators from it. */
   public synchronized void unregisterWindow(GLAutoDrawable window) {
+    if (window == null) {
+      return;
+    }
     WindowInfo info = (WindowInfo) windowToInfoMap.get(window);
-    for (Iterator iter = info.manips.iterator(); iter.hasNext(); ) {
-      removeManipFromWindow((Manip) iter.next(), window);
+    if (info != null) {
+      for (Iterator iter = info.manips.iterator(); iter.hasNext(); ) {
+        removeManipFromWindow((Manip) iter.next(), window);
+      }
+      windowToInfoMap.remove(window);
+      removeMouseListeners(window);
     }
-    windowToInfoMap.remove(window);
-    removeMouseListeners(window);
   }
 
   /** Make a given manipulator visible and active in a given