Fixed Issue 168: Add support for transparency in GLJPanel

Obey setOpaque() when selecting buffered image type. User must still
request alpha bits in the GLCapabilities. Not supported on all
back-end renderers; for example, Microsoft GDI renderer does not
implement alpha bits when rendering to DIB sections. Added examples of
use in JGears and JRefract demos.


git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/../svn-server-sync/jogl-demos/trunk@96 3298f667-5e0e-4b4a-8ed4-a3559d26a5f4

1 files changed, 35 insertions, 8 deletions

diff --git a/src/demos/jrefract/JRefract.java b/src/demos/jrefract/JRefract.java
index f47cfda..e842eba 100755
--- a/src/demos/jrefract/JRefract.java
+++ b/src/demos/jrefract/JRefract.java
@@ -83,13 +83,16 @@ public class JRefract {
     inner.setClosable(true);
     inner.setVisible(true);
 
-    final GLJPanel canvas = GLDrawableFactory.getFactory().createGLJPanel(new GLCapabilities());
+    GLCapabilities caps = new GLCapabilities();
+    if (!bunny) {
+      caps.setAlphaBits(8);
+    }
+    final GLJPanel canvas = GLDrawableFactory.getFactory().createGLJPanel(caps);
     if (bunny) {
       canvas.addGLEventListener(new Listener());
     } else {
       canvas.addGLEventListener(new GearRenderer());
     }
-    canvas.setSize(512, 512);
     canvas.addMouseListener(new MouseAdapter() {
         public void mouseClicked(MouseEvent e) {
           canvas.requestFocus();
@@ -106,12 +109,36 @@ public class JRefract {
       });
 
     inner.getContentPane().setLayout(new BorderLayout());
-    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);
-    inner.setSize(canvas.getSize());
+    if (bunny) {
+      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);
+    } else {
+      // Provide control over transparency of gears background
+      canvas.setOpaque(false);
+      JPanel gradientPanel = new JPanel() {
+          public void paintComponent(Graphics g) {
+            ((Graphics2D) g).setPaint(new GradientPaint(0, 0, Color.WHITE,
+                                                        getWidth(), getHeight(), Color.DARK_GRAY));
+            g.fillRect(0, 0, getWidth(), getHeight());
+          }
+        };
+      gradientPanel.setLayout(new BorderLayout());
+      inner.getContentPane().add(gradientPanel, BorderLayout.CENTER);
+      gradientPanel.add(canvas, BorderLayout.CENTER);
+
+      final JCheckBox checkBox = new JCheckBox("Transparent", true);
+      checkBox.addActionListener(new ActionListener() {
+          public void actionPerformed(ActionEvent e) {
+            canvas.setOpaque(!checkBox.isSelected());
+          }
+        });
+      inner.getContentPane().add(checkBox, BorderLayout.SOUTH);
+    }
+
+    inner.setSize(512, 512);
     desktop.add(inner);
 
     return inner;