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, 27 insertions, 4 deletions

diff --git a/src/demos/jgears/JGears.java b/src/demos/jgears/JGears.java
index ee0690c..59e6c79 100644
--- a/src/demos/jgears/JGears.java
+++ b/src/demos/jgears/JGears.java
@@ -2,6 +2,7 @@ package demos.jgears;
 
 import java.awt.*;
 import java.awt.event.*;
+import javax.swing.*;
 
 import net.java.games.jogl.*;
 
@@ -14,11 +15,33 @@ import net.java.games.jogl.*;
 
 public class JGears {
   public static void main(String[] args) {
-    Frame frame = new Frame("Gear Demo");
-    GLJPanel drawable = GLDrawableFactory.getFactory().createGLJPanel(new GLCapabilities());
-
+    JFrame frame = new JFrame("Gear Demo");
+    frame.getContentPane().setLayout(new BorderLayout());
+    GLCapabilities caps = new GLCapabilities();
+    caps.setAlphaBits(8);
+    final GLJPanel drawable = GLDrawableFactory.getFactory().createGLJPanel(caps);
+    drawable.setOpaque(false);
     drawable.addGLEventListener(new GearRenderer());
-    frame.add(drawable);
+
+    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());
+    frame.getContentPane().add(gradientPanel, BorderLayout.CENTER);
+    gradientPanel.add(drawable, BorderLayout.CENTER);
+
+    final JCheckBox checkBox = new JCheckBox("Transparent", true);
+    checkBox.addActionListener(new ActionListener() {
+        public void actionPerformed(ActionEvent e) {
+          drawable.setOpaque(!checkBox.isSelected());
+        }
+      });
+    frame.getContentPane().add(checkBox, BorderLayout.SOUTH);
+
     frame.setSize(300, 300);
     final Animator animator = new Animator(drawable);
     frame.addWindowListener(new WindowAdapter() {