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

2 files changed, 62 insertions, 12 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() {
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;