Bug 1430 - Fix Background erase not disabled with AWT GLCanvas and NewtCanvasAWT

Commit c5431f46b7bf64f109315ec78461859dd88f202a
reduced the disableBackgroundErase(..) to SunToolkit's variation which doesn't work on Windows
as it does not act upon the java.awt.Canvas peer post addNotify().

This re-introduces the java.awt.Canvas method via class JAWTUtil.BackgroundEraseControl
and its called only after addNotify() on Windows and ASAP for everyone else.
Method also calles the SunTookit variation just to be sure.

1 files changed, 95 insertions, 8 deletions

diff --git a/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java b/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
index 86de6e30d..f3c3da286 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
@@ -109,7 +109,7 @@ public class JAWTUtil {
     // default initialization to null, false
     Method awtLockMID;
     Method awtUnlockMID;
-    Method disableBackgroundEraseMID;
+    Method stkDisableBackgroundEraseMID;
     boolean ok;
   }
   private static class GraphicsDeviceData {
@@ -117,7 +117,6 @@ public class JAWTUtil {
     // default initialization to null, false
     Method getScaleFactorMID;
     Method getCGDisplayIDMIDOnOSX;
-    boolean ok;
   }
 
   /**
@@ -381,8 +380,8 @@ public class JAWTUtil {
                                 d.awtLockMID.setAccessible(true);
                                 d.awtUnlockMID = sunToolkitClass.getDeclaredMethod("awtUnlock");
                                 d.awtUnlockMID.setAccessible(true);
-                                d.disableBackgroundEraseMID = sunToolkitClass.getDeclaredMethod("disableBackgroundErase", java.awt.Component.class);
-                                d.disableBackgroundEraseMID.setAccessible(true);
+                                d.stkDisableBackgroundEraseMID = sunToolkitClass.getDeclaredMethod("disableBackgroundErase", java.awt.Component.class);
+                                d.stkDisableBackgroundEraseMID.setAccessible(true);
                                 d.ok=true;
                             } catch (final Exception e) {
                                 // Either not a Sun JDK or the interfaces have changed since [Java 1.4.2 / 1.5 -> Java 11]
@@ -394,7 +393,7 @@ public class JAWTUtil {
                         }}); }});
             stkAWTLockMID = std.awtLockMID;
             stkAWTUnlockMID = std.awtUnlockMID;
-            stkDisableBackgroundEraseMID = std.disableBackgroundEraseMID;
+            stkDisableBackgroundEraseMID = std.stkDisableBackgroundEraseMID;
             boolean _hasSunToolkitAWTLock = false;
             if ( std.ok ) {
                 try {
@@ -489,7 +488,7 @@ public class JAWTUtil {
     }
 
     if (DEBUG) {
-        System.err.println("JAWTUtil: Has sun.awt.SunToolkit: awtLock/awtUnlock " + hasSTKAWTLock + ", disableBackgroundErase "+(null!=stkDisableBackgroundEraseMID));
+        System.err.println("JAWTUtil: Has sun.awt.SunToolkit: awtLock/awtUnlock " + hasSTKAWTLock + ", stkDisableBackgroundErase "+(null!=stkDisableBackgroundEraseMID));
         System.err.println("JAWTUtil: Has Java2D " + j2dExist);
         System.err.println("JAWTUtil: Is headless " + headlessMode);
         final int hints = ( null != desktophints ) ? desktophints.size() : 0 ;
@@ -604,19 +603,27 @@ public class JAWTUtil {
    * @param component
    * @return {@code true} if available and successful, otherwise {@code false}
    */
-  public static boolean disableBackgroundErase(final java.awt.Component component) {
+  public static boolean disableBackgroundEraseSTK(final java.awt.Component component) {
       if( null != stkDisableBackgroundEraseMID ) {
           try {
               stkDisableBackgroundEraseMID.invoke(component.getToolkit(), component);
+              if( DEBUG ) {
+                  System.err.println(getThreadName()+dbe_msg+" OK");
+              }
               return true;
           } catch (final Exception e) {
               if( DEBUG ) {
-                  ExceptionUtils.dumpThrowable("JAWTUtil", e);
+                  System.err.println(getThreadName()+dbe_msg+" failed, error "+e);
+                  ExceptionUtils.dumpThrowable(dbe_msg, e);
               }
           }
       }
+      if( DEBUG ) {
+          System.err.println(getThreadName()+dbe_msg+" failed, no method");
+      }
       return false;
   }
+  private static final String dbe_msg = ": java.awt.Component: STK disableBackgroundErase";
 
   /**
    * Queries the Monitor's display ID of the given device
@@ -800,5 +807,85 @@ public class JAWTUtil {
       return NativeWindowFactory.createScreen(adevice, AWTGraphicsScreen.findScreenIndex(awtComp.getGraphicsConfiguration().getDevice()));
   }
 
+
+  /**
+   * Disables the AWT's erasing of this Canvas's background on Windows in Java SE 6.
+   * <p>
+   * Utilize this class as a static instance within your AWT Canvas override.
+   * </p>
+   * <p>
+   * Implementation also calls {@link JAWTUtil#disableBackgroundEraseSTK(java.awt.Component)} just in case.
+   * </p>
+   * <p>
+   * This internal API is not available in previous releases,
+   * but the system property {@code -Dsun.awt.noerasebackground=true}
+   * can be specified to get similar results globally in previous releases.
+   * </p>
+   */
+  public static class BackgroundEraseControl {
+      private boolean disableBackgroundEraseInitialized = false;
+      private Method  disableBackgroundEraseMethod = null;
+      private static final String msg = ": java.awt.Canvas: TK disableBackgroundErase";
+
+      /**
+       * Disables the AWT's erasing of this Canvas's background on Windows in Java SE 6.
+       * <p>
+       * Method also calls {@link JAWTUtil#disableBackgroundEraseSTK(java.awt.Component)} just in case.
+       * </p>
+       */
+      public boolean disable(final java.awt.Canvas canvas) {
+          if (!disableBackgroundEraseInitialized) {
+              try {
+                  SecurityUtil.doPrivileged(new PrivilegedAction<Object>() {
+                      @Override
+                      public Object run() {
+                          try {
+                              Class<?> clazz = canvas.getToolkit().getClass();
+                              while (clazz != null && disableBackgroundEraseMethod == null) {
+                                  try {
+                                      disableBackgroundEraseMethod =
+                                              clazz.getDeclaredMethod("disableBackgroundErase",
+                                                      new Class[] { java.awt.Canvas.class });
+                                      disableBackgroundEraseMethod.setAccessible(true);
+                                  } catch (final Exception e) {
+                                      clazz = clazz.getSuperclass();
+                                  }
+                              }
+                          } catch (final Exception e) {
+                          }
+                          return null;
+                      }
+                  });
+              } catch (final Exception e) {
+              }
+              disableBackgroundEraseInitialized = true;
+              if(DEBUG) {
+                  System.err.println(getThreadName()+msg+" method found: "+
+                          (null!=disableBackgroundEraseMethod));
+              }
+          }
+          boolean res = false;
+          if (disableBackgroundEraseMethod != null) {
+              Throwable t=null;
+              try {
+                  disableBackgroundEraseMethod.invoke(canvas.getToolkit(), new Object[] { canvas });
+                  res = true;
+              } catch (final Exception e) {
+                  t = e;
+              }
+              if(DEBUG) {
+                  System.err.println(getThreadName()+msg+" res "+res+", error: "+t);
+                  if( null != t ) {
+                      ExceptionUtils.dumpThrowable(msg, t);
+                  }
+              }
+          } else if(DEBUG) {
+              System.err.println(getThreadName()+msg+" failed, no method");
+          }
+          JAWTUtil.disableBackgroundEraseSTK(canvas);
+          return res;
+      }
+  }
+
 }