GLCanvas: Fix disableBackgroundErase/X11, make drawable creation more robust, doc Java2D/AWT properties.

On X11 disableBackgroundErase() must happen before native peer creation,
this patch issues it before and after super.addNotify().

Make drawable creation more robust, ie only create a drawable in case the size is > 0x0
and do this check/create at display/paint in case size it not yet determined.

Add documentation about Java2D/AWT properties impact on GLCanvas.

Make JUnit tests on AWT/GLProfile's more robust, while adding frame validate()
ensuring 1st paint will have a size, hence will create the drawable.
This is necessary for eg. AMD GPU's and GL context > 3.

2 files changed, 11 insertions, 0 deletions

diff --git a/src/junit/com/jogamp/test/junit/jogl/awt/TestAWT01GLn.java b/src/junit/com/jogamp/test/junit/jogl/awt/TestAWT01GLn.java
index 88551bdb4..0fef76c7d 100644
--- a/src/junit/com/jogamp/test/junit/jogl/awt/TestAWT01GLn.java
+++ b/src/junit/com/jogamp/test/junit/jogl/awt/TestAWT01GLn.java
@@ -85,7 +85,12 @@ public class TestAWT01GLn extends UITestCase {
         glCanvas = new GLCanvas(caps);
         Assert.assertNotNull(glCanvas);
         frame.add(glCanvas);
+
+        // Revalidate size/layout.
+        // Always validate if component added/removed.
+        // Ensure 1st paint of GLCanvas will have a valid size, hence drawable gets created.
         frame.setSize(512, 512);
+        frame.validate();
 
         glCanvas.addGLEventListener(new Gears());
 
diff --git a/src/junit/com/jogamp/test/junit/jogl/awt/TestSwingAWT01GLn.java b/src/junit/com/jogamp/test/junit/jogl/awt/TestSwingAWT01GLn.java
index 661f61d37..74ca0a3e7 100644
--- a/src/junit/com/jogamp/test/junit/jogl/awt/TestSwingAWT01GLn.java
+++ b/src/junit/com/jogamp/test/junit/jogl/awt/TestSwingAWT01GLn.java
@@ -85,7 +85,13 @@ public class TestSwingAWT01GLn extends UITestCase {
                     glCanvas[0] = new GLCanvas(caps);
                     glCanvas[0].addGLEventListener(new Gears());
                     window.add(glCanvas[0]);
+
+                    // Revalidate size/layout.
+                    // Always validate if component added/removed.
+                    // Ensure 1st paint of GLCanvas will have a valid size, hence drawable gets created.
                     window.setSize(512, 512);
+                    window.validate();
+
                     window.setVisible(true);
                     glCanvas[0].display();
                 }