modules/javafx.graphics/src/main/java/com/sun/glass/ui/gtk/GtkApplication.java

*** 43,52 ****
--- 43,53 ----
  import java.nio.IntBuffer;
  import java.security.AccessController;
  import java.security.PrivilegedAction;
  import java.util.Map;
  import java.util.concurrent.CountDownLatch;
+ import java.lang.annotation.Native;
  
  final class GtkApplication extends Application implements InvokeLaterDispatcher.InvokeLaterSubmitter {
  
      static {
          AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
*** 86,106 ****
          return val;
      }
  
      GtkApplication() {
  
-         // Check whether the Display is valid and throw an exception if not.
-         // We use UnsupportedOperationException rather than HeadlessException
-         // so as not to introduce a dependency on AWT.
-         if (!isDisplayValid()) {
-             throw new UnsupportedOperationException("Unable to open DISPLAY");
-         }
- 
          int gtkVersion =
                  AccessController.doPrivileged((PrivilegedAction<Integer>) () -> {
              String v = System.getProperty("jdk.gtk.version","2");
!             int ret = 0;
              if ("3".equals(v) || v.startsWith("3.")) {
                  ret = 3;
              } else if ("2".equals(v) || v.startsWith("2.")) {
                  ret = 2;
              }
--- 87,100 ----
          return val;
      }
  
      GtkApplication() {
  
          int gtkVersion =
                  AccessController.doPrivileged((PrivilegedAction<Integer>) () -> {
              String v = System.getProperty("jdk.gtk.version","2");
!             int ret = 0; // start with "no preference
              if ("3".equals(v) || v.startsWith("3.")) {
                  ret = 3;
              } else if ("2".equals(v) || v.startsWith("2.")) {
                  ret = 2;
              }
*** 114,123 ****
--- 108,137 ----
              overrideUIScale = AccessController.doPrivileged((PrivilegedAction<Float>) () ->
                      getFloat("glass.gtk.uiScale", -1.0f, "Forcing UI scaling factor: "));
          } else {
              overrideUIScale = -1.0f;
          }
+ 
+         int libraryToLoad = _queryLibrary(gtkVersion, gtkVersionVerbose);
+ 
+         if (libraryToLoad ==  QUERY_NO_DISPLAY) {
+             throw new UnsupportedOperationException("Unable to open DISPLAY");
+         } else if (libraryToLoad == QUERY_USE_CURRENT) {
+             if (gtkVersionVerbose)
+                 System.out.println("Glass GTK library to load is already loaded");
+         } else if (libraryToLoad == QUERY_LOAD_GTK2) {
+             if (gtkVersionVerbose)
+                 System.out.println("Glass GTK library to load is glassgtk2");
+             com.sun.glass.utils.NativeLibLoader.loadLibrary("glassgtk2");
+         } else if (libraryToLoad == QUERY_LOAD_GTK3) {
+             if (gtkVersionVerbose)
+                 System.out.println("Glass GTK library to load is glassgtk3");
+             com.sun.glass.utils.NativeLibLoader.loadLibrary("glassgtk3");
+         } else {
+             throw new UnsupportedOperationException("Internal Error");
+         }
+ 
          int version = _initGTK(gtkVersion, gtkVersionVerbose, overrideUIScale);
  
          if (version == -1) {
              throw new RuntimeException("Error loading GTK libraries");
          }
*** 131,145 ****
          } else {
              invokeLaterDispatcher = null;
          }
      }
  
!     private static native int _initGTK(int version, boolean verbose, float overrideUIScale);
  
!     private static boolean isDisplayValid() {
!         return _isDisplayValid();
!     }
  
      private void initDisplay() {
          Map ds = getDeviceDetails();
          if (ds != null) {
              Object value;
--- 145,166 ----
          } else {
              invokeLaterDispatcher = null;
          }
      }
  
!     @Native private static final int QUERY_ERROR = -2;
!     @Native private static final int QUERY_NO_DISPLAY = -1;
!     @Native private static final int QUERY_USE_CURRENT = 1;
!     @Native private static final int QUERY_LOAD_GTK2 = 2;
!     @Native private static final int QUERY_LOAD_GTK3 = 3;
!     /*
!      * check the system and return an indication of which library to load
!      *  return values are the QUERY_ constants
!      */
!     private static native int _queryLibrary(int version, boolean verbose);
  
!     private static native int _initGTK(int version, boolean verbose, float overrideUIScale);
  
      private void initDisplay() {
          Map ds = getDeviceDetails();
          if (ds != null) {
              Object value;
*** 210,221 ****
  
      @Override public boolean shouldUpdateWindow() {
          return true;
      }
  
-     private static native boolean _isDisplayValid();
- 
      private native void _terminateLoop();
  
      private native void _init(long eventProc, boolean disableGrab);
  
      private native void _runLoop(Runnable launchable, boolean noErrorTrap);
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