Bug 1363: Java 11: Resolve unsupported JAWTUtil.getMonitorDisplayID(..)

Previous commits removed access to OSX's GraphicsDevice.getCGDisplayID()
on Java9+, avoiding illegal reflective access.

Here we JAWTUtil.getMonitorDisplayID(..) simply returns null
if Java9 or !OSX, so the sole NewtFactory caller falls back
to the alternative working solution.

Orig patch Wade Walker:
    This was used on Mac OS only to create a MonitorDevice in
    NewtFactoryAWT. But there was a fallback method for creating
    MonitorDevice, and testing with TestGearsES2GLJPanelAWT shows that the
    fallback method seems to give identical results on Mac, so changed to
    just use the fallback method (which is now the only method) everywhere.
    This gets rid of an illegal reflective access.

1 files changed, 11 insertions, 5 deletions

diff --git a/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java b/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
index 3eb5328bd..d2dc8f91b 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
@@ -557,19 +557,25 @@ public class JAWTUtil {
     return jawtToolkitLock;
   }
 
-  public static final int getMonitorDisplayID(final GraphicsDevice device) {
-      int displayID = 0;
+  /**
+   * Queries the Monitor's display ID of the given device
+   * <p>
+   * Currently only supported for OSX on Java<9
+   * </p>
+   * @param device for which the display id is being queried
+   * @return {@code null} if not supported (Java9+ or !OSX), otherwise the monitor displayID
+   */
+  public static final Integer getMonitorDisplayID(final GraphicsDevice device) {
       if( null != getCGDisplayIDMethodOnOSX ) {
           // OSX specific for Java<9
           try {
               final Object res = getCGDisplayIDMethodOnOSX.invoke(device);
               if (res instanceof Integer) {
-                  displayID = ((Integer)res).intValue();
+                  return (Integer)res;
               }
           } catch (final Throwable t) {}
       }
-      // TODO: Needs non-reflective Java9+ solution for all platforms
-      return displayID;
+      return null;
   }
 
   /**