1 files changed, 189 insertions, 0 deletions
diff --git a/src/demos/xtrans/OffscreenDesktopPane.java b/src/demos/xtrans/OffscreenDesktopPane.java
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+++ b/src/demos/xtrans/OffscreenDesktopPane.java
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+package demos.xtrans;
+
+import java.awt.*;
+import java.awt.geom.*;
+import java.util.*;
+import javax.swing.*;
+
+// Internal JOGL API references
+import com.sun.opengl.impl.Debug;
+
+/** A subclass of JDesktopPane which performs all of the rendering of
+    its child components into an off-screen buffer. Provides access to
+    this back buffer so subclasses can determine how to draw the
+    contents of the child windows to the screen. */
+
+public class OffscreenDesktopPane extends JDesktopPane {
+  //
+  // Debugging functionality only
+  //
+  private static final boolean DEBUG = Debug.debug("OffscreenDesktopPane");
+  private static final Color[] colors = {
+    Color.LIGHT_GRAY,
+    Color.CYAN,
+    Color.PINK,
+    Color.GRAY,
+    Color.MAGENTA,
+    Color.BLUE,
+    Color.ORANGE,
+    Color.DARK_GRAY,
+    Color.RED,
+    Color.YELLOW
+  };
+  private int colorIdx;
+
+  private Color getNextColor() {
+    Color c = colors[colorIdx];
+    colorIdx = (colorIdx + 1) % colors.length;
+    return c;
+  }
+
+  private Map/*<Component, Color>*/ componentColorMap;
+
+  /** Constructs a new OffscreenDesktopPane. */
+  public OffscreenDesktopPane() {
+    super();
+    if (DEBUG) {
+      componentColorMap = new WeakHashMap();
+    }
+    // Only use an OffscreenDesktopManager instance directly if we
+    // have not been subclassed
+    if (getClass() == OffscreenDesktopPane.class) {
+      setDesktopManager(new OffscreenDesktopManager());
+    }
+  }
+
+  /** Overrides superclass's addImpl to insert an
+      OffscreenComponentWrapper between the added component and this
+      one. The wrapper component produces Graphics objects used when
+      children repaint themselves directly. */
+  protected void addImpl(Component c, Object constraints, int index) {
+    if (c instanceof OffscreenComponentWrapper) {
+      throw new RuntimeException("Should not add OffscreenComponentWrappers directly");
+    }
+    OffscreenComponentWrapper wrapper = new OffscreenComponentWrapper(c);
+    // Note: this is essential in order to keep mouse events
+    // propagating correctly down the hierarchy
+    wrapper.setBounds(getBounds());
+    OffscreenDesktopManager.switchDoubleBuffering(wrapper, false);
+    super.addImpl(wrapper, constraints, index);
+    if (DEBUG) {
+      componentColorMap.put(c, getNextColor());
+    }
+    getOffscreenDesktopManager().setNeedsReLayout();
+    repaint();
+  }
+
+  // In order to hide the presence of the OffscreenComponentWrapper a
+  // little more, we override remove to make it look like we can
+  // simply pass in the JInternalFrames inside the
+  // OffscreenComponentWrappers. There are some situations where we
+  // can't hide the presence of the OffscreenComponentWrapper (such as
+  // when calling getParent() of the JInternalFrame) so to avoid
+  // incorrect behavior of the rest of the toolkit we don't override
+  // getComponent() to skip the OffscreenComponentWrappers.
+
+  /** Removes the component at the given index. */
+  public void remove(int index) {
+    Component c = getComponent(index);
+    super.remove(index);
+    OffscreenDesktopManager.switchDoubleBuffering(c, true);
+  }
+
+  /** Removes the specified component from this
+      OffscreenDesktopPane. This method accepts either the components
+      added by the application (which are not direct children of this
+      one) or the OffscreenComponentWrappers added implicitly by the
+      add() method. */
+  public void remove(Component comp) {
+    comp = getWrapper(comp);
+    if (comp == null) {
+      // This component must not be one of our children
+      return;
+    }
+    super.remove(comp);
+    OffscreenDesktopManager.switchDoubleBuffering(comp, true);
+  }
+
+  public void reshape(int x, int y, int w, int h) {
+    super.reshape(x, y, w, h);
+    Rectangle rect = new Rectangle(x, y, w, h);
+    Component[] cs = getComponents();
+    for (int i = 0; i < cs.length; i++) {
+      // Note: this is essential in order to keep mouse events
+      // propagating correctly down the hierarchy
+      ((OffscreenComponentWrapper) cs[i]).setBounds(rect);
+    }
+  }
+
+  /** Overridden from JLayeredPane for convenience when manipulating
+      child components. Accepts either the component added by the
+      application or the OffscreenComponentWrapper added implicitly by
+      the add() method. */
+  public void setPosition(Component c, int position) {
+    super.setPosition(getWrapper(c), position);
+  }
+
+  /** Paints all children of this OffscreenDesktopPane to the internal
+      off-screen buffer. Does no painting to the passed Graphics
+      object; this is the responsibility of subclasses. */
+  protected void paintChildren(Graphics g) {
+    // Update desktop manager's offscreen buffer if necessary
+    getOffscreenDesktopManager().updateOffscreenBuffer(this);
+
+    if (DEBUG) {
+      // Subclasses will need to override this behavior anyway, so
+      // only enable an on-screen representation if debugging is
+      // enabled. For now, simply paint colored rectangles indicating
+      // the on-screen locations of the windows.
+      final Component[] components = getRealChildComponents();
+      int compCount = components.length;
+      for (int i = compCount - 1; i >= 0; i--) {
+        Component c = components[i];
+        Rectangle r = c.getBounds();
+        Color col = (Color) componentColorMap.get(c);
+        g.setColor(col);
+        g.fillRect(r.x, r.y, r.width, r.height);
+      }
+    }
+  }
+
+  /** Fetches the real child components of this OffscreenDesktopPane,
+      skipping all OffscreenComponentWrappers implicitly added. */
+  protected Component[] getRealChildComponents() {
+    Component[] cs = getComponents();
+    for (int i = 0; i < cs.length; i++) {
+      cs[i] = ((OffscreenComponentWrapper) cs[i]).getChild();
+    }
+    return cs;
+  }
+
+  /** Returns the OffscreenDesktopManager associated with this
+      pane. */
+  public OffscreenDesktopManager getOffscreenDesktopManager() {
+    return (OffscreenDesktopManager) getDesktopManager();
+  }
+
+  /** Returns the real child component of this OffscreenDesktopPane,
+      skipping the OffscreenComponentWrapper implicitly added. */
+  protected static Component getRealComponent(Component c) {
+    if (c instanceof OffscreenComponentWrapper) {
+      return ((OffscreenComponentWrapper) c).getChild();
+    }    
+    return c;
+  }
+
+  /** Returns the OffscreenComponentWrapper corresponding to the given
+      child component, or the passed component if it is already the
+      wrapper. */
+  protected static Component getWrapper(Component c) {
+    if (c instanceof OffscreenComponentWrapper) {
+      return c;
+    }
+    Component parent = c.getParent();
+    if (parent instanceof OffscreenComponentWrapper) {
+      return parent;
+    }
+    return null;
+  }
+}