Bug 1358: 'Honor' SWT's projection of High-DPI Scaling (Reading hidden pixel dimensions)

Christian reported this bug and described multiple pathways.

This change usese the following:
- access to getClientAreaInPixels w/ fallback of
- DPIUtil.autoScaleUp(getClientArea())

I hardly have tested this on Linux/GTK, even though I use a High DPI monitor,
maybe just because of it and Eclipse _poor_ state of proper UI presentation.

Christian: Please test this .. if buggy, reopen quick for release 2.4.0

SWT/GTK High-DPI is a PIA:
- GDK_SCALE renders offscreen and scales the image (wow & ugly)
- GDK_DPI_SCALE works at least on the fonts properly
- swt.autoScale is pretty much like: What will be scaled?
  It scales some icons in Eclipse, not fonts and result in Eclipse
  looks horrible.

Maybe I just made this patch to vent about this poor state of things.

Notable: KDE looks great and uses DPI, firefox some GDK_DPI_SCALE equivalent (OK)

One also wonders why there is only a single scale dimension, where DPI differs x/y!
But enough of my rant :)

4 files changed, 105 insertions, 65 deletions

diff --git a/make/scripts/tests.sh b/make/scripts/tests.sh
index 47daa91e5..bad31647a 100644
--- a/make/scripts/tests.sh
+++ b/make/scripts/tests.sh
@@ -118,6 +118,7 @@ function jrun() {
     #D_ARGS="-Djogamp.debug.ProcAddressHelper -Djogamp.debug.NativeLibrary -Djogamp.debug.NativeLibrary.Lookup -Djogamp.debug.JNILibLoader -Djogamp.debug.TempJarCache -Djogamp.debug.JarUtil -Djogl.glu.nojava=true"
 
     #D_ARGS="-Dnativewindow.debug=all -Djogl.debug=all -Dnewt.debug=all"
+    #D_ARGS="-Dnativewindow.debug.SWT"
     #D_ARGS="-Dnativewindow.debug.SWT -Dnativewindow.debug.X11Util -Dnewt.debug.Window"
     #D_ARGS="-Dnativewindow.debug=all -Dnewt.debug.Window"
     #D_ARGS="-Djogl.debug=all -Dnativewindow.debug=all -Dnewt.debug=all -Djogamp.debug.Lock"
@@ -761,7 +762,7 @@ function testawtswt() {
 #testswt com.jogamp.opengl.test.junit.jogl.swt.TestSWTAccessor02NewtGLWindow $*
 #testswt com.jogamp.opengl.test.junit.jogl.swt.TestNewtCanvasSWTGLn $*
 #testswt com.jogamp.opengl.test.junit.jogl.swt.TestSWTJOGLGLCanvas01GLn $*
-#testswt com.jogamp.opengl.test.junit.jogl.demos.es2.newt.TestGearsES2NewtCanvasSWT $*
+testswt com.jogamp.opengl.test.junit.jogl.demos.es2.newt.TestGearsES2NewtCanvasSWT $*
 #testswt com.jogamp.opengl.test.junit.jogl.demos.es2.swt.TestGearsES2SWT $*
 #testswt com.jogamp.opengl.test.junit.jogl.swt.TestSWTEclipseGLCanvas01GLn $*
 #testswt com.jogamp.opengl.test.junit.jogl.swt.TestBug672NewtCanvasSWTSashForm $*
@@ -814,7 +815,7 @@ function testawtswt() {
 #testawt com.jogamp.opengl.test.junit.newt.DemoCreateAndDisposeOnCloseNEWT $*
 #testawt com.jogamp.opengl.test.junit.newt.TestCloseNewtAWT
 #testawt com.jogamp.opengl.test.junit.newt.TestWindowClosingProtocol01AWT $*
-testnoawt com.jogamp.opengl.test.junit.newt.TestWindowClosingProtocol02NEWT $*
+#testnoawt com.jogamp.opengl.test.junit.newt.TestWindowClosingProtocol02NEWT $*
 #testawt com.jogamp.opengl.test.junit.newt.TestWindowClosingProtocol03NewtAWT $*
 #testawt com.jogamp.opengl.test.junit.newt.TestMultipleNewtCanvasAWT $*
 
diff --git a/src/jogl/classes/com/jogamp/opengl/swt/GLCanvas.java b/src/jogl/classes/com/jogamp/opengl/swt/GLCanvas.java
index a34c8648a..5e90c4035 100644
--- a/src/jogl/classes/com/jogamp/opengl/swt/GLCanvas.java
+++ b/src/jogl/classes/com/jogamp/opengl/swt/GLCanvas.java
@@ -114,13 +114,12 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
    private final GLCapabilitiesImmutable capsRequested;
    private final GLCapabilitiesChooser capsChooser;
 
-   private volatile Rectangle clientArea;
+   private volatile Rectangle clientAreaPixels, clientAreaWindow;
    private volatile GLDrawableImpl drawable; // volatile: avoid locking for read-only access
    private volatile GLContextImpl context; // volatile: avoid locking for read-only access
 
    /* Native window surface */
    private final boolean useX11GTK;
-   private volatile long gdkWindow; // either GDK child window ..
    private volatile long x11Window; // .. or X11 child window (for GL rendering)
    private final AbstractGraphicsScreen screen;
 
@@ -154,7 +153,7 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
       @Override
       public void run() {
          if (sendReshape) {
-            helper.reshape(GLCanvas.this, 0, 0, clientArea.width, clientArea.height);
+            helper.reshape(GLCanvas.this, 0, 0, clientAreaPixels.width, clientAreaPixels.height);
             sendReshape = false;
          }
          helper.display(GLCanvas.this);
@@ -243,9 +242,6 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
                  if( 0 != x11Window) {
                      SWTAccessor.destroyX11Window(screen.getDevice(), x11Window);
                      x11Window = 0;
-                 } else if( 0 != gdkWindow) {
-                     SWTAccessor.destroyGDKWindow(gdkWindow);
-                     gdkWindow = 0;
                  }
                  screen.getDevice().close();
              } catch (final Throwable re) {
@@ -349,7 +345,8 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
 
       SWTAccessor.setRealized(this, true);
 
-      clientArea = GLCanvas.this.getClientArea();
+      clientAreaPixels = SWTAccessor.getClientAreaInPixels(this);
+      clientAreaWindow = getClientArea();
 
       /* Get the nativewindow-Graphics Device associated with this control (which is determined by the parent Composite).
        * Note: SWT is owner of the native handle, hence closing operation will be a NOP. */
@@ -377,7 +374,6 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
       this.capsChooser = capsChooser;
 
       // post create .. when ready
-      gdkWindow = 0;
       x11Window = 0;
       drawable = null;
       context = null;
@@ -426,17 +422,17 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
 
        @Override
        public final int getSurfaceWidth(final ProxySurface s) {
-           return clientArea.width;
+           return clientAreaPixels.width;
        }
 
        @Override
        public final int getSurfaceHeight(final ProxySurface s) {
-           return clientArea.height;
+           return clientAreaPixels.height;
        }
 
        @Override
        public String toString() {
-           return "SWTCanvasUpstreamSurfaceHook[upstream: "+GLCanvas.this.toString()+", "+clientArea.width+"x"+clientArea.height+"]";
+           return "SWTCanvasUpstreamSurfaceHook[upstream: "+GLCanvas.this.toString()+", "+clientAreaPixels.width+"x"+clientAreaPixels.height+" [pixel], "+clientAreaWindow.width+"x"+clientAreaWindow.height+" [win]]";
        }
 
        /**
@@ -452,25 +448,27 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
    };
 
    protected final void updateSizeCheck() {
-      final Rectangle oClientArea = clientArea;
-      final Rectangle nClientArea = GLCanvas.this.getClientArea();
-      if ( nClientArea != null &&
-           ( nClientArea.width != oClientArea.width || nClientArea.height != oClientArea.height )
+      final Rectangle oClientAreaPixels = clientAreaPixels;
+      final Rectangle nClientAreaPixels = SWTAccessor.getClientAreaInPixels(this);
+
+      if ( nClientAreaPixels != null &&
+           ( nClientAreaPixels.width != oClientAreaPixels.width || nClientAreaPixels.height != oClientAreaPixels.height )
          ) {
-          clientArea = nClientArea; // write back new value
+          clientAreaPixels = nClientAreaPixels; // write back new value
+          clientAreaWindow = getClientArea();
 
           final GLDrawableImpl _drawable = drawable;
           final boolean drawableOK = null != _drawable && _drawable.isRealized();
           if(DEBUG) {
               final long dh = drawableOK ? _drawable.getHandle() : 0;
-              System.err.println(getThreadName()+": GLCanvas.sizeChanged: ("+Thread.currentThread().getName()+"): "+nClientArea.x+"/"+nClientArea.y+" "+nClientArea.width+"x"+nClientArea.height+" - drawableHandle "+toHexString(dh));
+              System.err.println(getThreadName()+": GLCanvas.sizeChanged: ("+Thread.currentThread().getName()+"): "+nClientAreaPixels.x+"/"+nClientAreaPixels.y+" "+nClientAreaPixels.width+"x"+nClientAreaPixels.height+" - drawableHandle "+toHexString(dh));
           }
           if( drawableOK ) {
               if( ! _drawable.getChosenGLCapabilities().isOnscreen() ) {
                   final RecursiveLock _lock = lock;
                   _lock.lock();
                   try {
-                      final GLDrawableImpl _drawableNew = GLDrawableHelper.resizeOffscreenDrawable(_drawable, context, nClientArea.width, nClientArea.height);
+                      final GLDrawableImpl _drawableNew = GLDrawableHelper.resizeOffscreenDrawable(_drawable, context, nClientAreaPixels.width, nClientAreaPixels.height);
                       if(_drawable != _drawableNew) {
                           // write back
                           drawable = _drawableNew;
@@ -481,9 +479,7 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
               }
           }
           if(0 != x11Window) {
-              SWTAccessor.resizeX11Window(screen.getDevice(), clientArea, x11Window);
-          } else if(0 != gdkWindow) {
-              SWTAccessor.resizeGDKWindow(clientArea, gdkWindow);
+              SWTAccessor.resizeX11Window(screen.getDevice(), clientAreaPixels, x11Window);
           }
           sendReshape = true; // async if display() doesn't get called below, but avoiding deadlock
       }
@@ -553,7 +549,7 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
       return res;
    }
    private final void createDrawableImpl() {
-       final Rectangle nClientArea = clientArea;
+       final Rectangle nClientArea = clientAreaPixels;
        if(0 >= nClientArea.width || 0 >= nClientArea.height) {
           if(DEBUG) {
               System.err.println(getThreadName()+": SWT.GLCanvas.validate.X "+toHexString(hashCode())+": drawable could not be created: size < 0x0");
@@ -578,7 +574,7 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
            if( VisualIDHolder.VID_UNDEFINED != visualID ) {
                // gdkWindow = SWTAccessor.createCompatibleGDKChildWindow(this, visualID, clientArea.width, clientArea.height);
                // nativeWindowHandle = SWTAccessor.gdk_window_get_xwindow(gdkWindow);
-               x11Window = SWTAccessor.createCompatibleX11ChildWindow(screen, this, visualID, clientArea.width, clientArea.height);
+               x11Window = SWTAccessor.createCompatibleX11ChildWindow(screen, this, visualID, clientAreaPixels.width, clientAreaPixels.height);
                nativeWindowHandle = x11Window;
            } else {
               throw new GLException("Could not choose valid visualID: "+toHexString(visualID)+", "+this);
@@ -674,12 +670,12 @@ public class GLCanvas extends Canvas implements GLAutoDrawable, GLSharedContextS
 
    @Override
    public int getSurfaceWidth() {
-      return clientArea.width;
+      return clientAreaPixels.width;
    }
 
    @Override
    public int getSurfaceHeight() {
-      return clientArea.height;
+      return clientAreaPixels.height;
    }
 
    @Override
diff --git a/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java b/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
index 48661170c..d99519878 100644
--- a/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
+++ b/src/nativewindow/classes/com/jogamp/nativewindow/swt/SWTAccessor.java
@@ -35,7 +35,9 @@ import java.security.PrivilegedAction;
 
 import org.eclipse.swt.graphics.GCData;
 import org.eclipse.swt.graphics.Rectangle;
+import org.eclipse.swt.internal.DPIUtil;
 import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Scrollable;
 
 import com.jogamp.nativewindow.AbstractGraphicsScreen;
 import com.jogamp.nativewindow.NativeWindowException;
@@ -56,6 +58,8 @@ import jogamp.nativewindow.Debug;
 public class SWTAccessor {
     private static final boolean DEBUG = Debug.debug("SWT");
 
+    private static final Method swt_scrollable_clientAreaInPixels;
+
     private static final Field swt_control_handle;
     private static final boolean swt_uses_long_handles;
 
@@ -139,6 +143,18 @@ public class SWTAccessor {
         isWindows = NativeWindowFactory.TYPE_WINDOWS == nwt;
         isX11 = NativeWindowFactory.TYPE_X11 == nwt;
 
+        Method m = null;
+        try {
+            m = Scrollable.class.getDeclaredMethod("getClientAreaInPixels");
+            m.setAccessible(true);
+        } catch (final Exception ex) {
+            m = null;
+            if( DEBUG ) {
+                System.err.println("getClientAreaInPixels not implemented: "+ex.getMessage());
+            }
+        }
+        swt_scrollable_clientAreaInPixels = m;
+
         Field f = null;
         if( !isOSX ) {
             try {
@@ -159,7 +175,7 @@ public class SWTAccessor {
         // System.err.println("SWT long handles: " + swt_uses_long_handles);
         // System.err.println("Platform 64bit: "+Platform.is64Bit());
 
-        Method m=null;
+        m=null;
         try {
             m = ReflectionUtil.getMethod(Control.class, str_internal_new_GC, new Class[] { GCData.class });
         } catch (final Exception ex) {
@@ -167,6 +183,7 @@ public class SWTAccessor {
         }
         swt_control_internal_new_GC = m;
 
+        m=null;
         try {
             if(swt_uses_long_handles) {
                 m = Control.class.getDeclaredMethod(str_internal_dispose_GC, new Class[] { long.class, GCData.class });
@@ -350,6 +367,43 @@ public class SWTAccessor {
     //
 
     /**
+     * Returns the unscaled {@link Scrollable#getClientArea()} in pixels.
+     * <p>
+     * If the package restricted method {@link Scrollable#getClientAreaInPixels()}
+     * is implemented, we return its result.
+     * </p>
+     * <p>
+     * Fallback is to return {@link DPIUtil#autoScaleUp(Rectangle) DPIUtil#autoScaleUp}({@link Scrollable#getClientArea()}),
+     * reverting  {@link Scrollable#getClientArea()}'s {@link DPIUtil#autoScaleDown(Rectangle)}.
+     * </p>
+     * <p>
+     * Note to SWT's API spec writers: You need to allow access to the unscaled value, scale properties and define what is being scaled (fonts, images, ..).
+     * Further more the scale should be separate for x/y coordinates, as DPI differs here.
+     * </p>
+     * <p>
+     * Note to Eclipse authors: Scaling up the fonts and images hardly works on GTK/SWT/Eclipse.
+     * GDK_SCALE, GDK_DPI_SCALE and swt.autoScale produce inconsistent results with Eclipse.
+     * Broken High-DPI for .. some years now.
+     * </p>
+     *
+     * Requires SWT >= 3.105 (DPIUtil)
+     *
+     * @param s the {@link Scrollable} instance
+     * @return unscaled client area in pixels, see above
+     * @throws NativeWindowException during invocation of the method, if any
+     */
+    public static Rectangle getClientAreaInPixels(final Scrollable s) throws NativeWindowException {
+        if( null == swt_scrollable_clientAreaInPixels ) {
+            return DPIUtil.autoScaleUp(s.getClientArea());
+        }
+        try {
+            return (Rectangle) swt_scrollable_clientAreaInPixels.invoke(s);
+        } catch (final Throwable e) {
+            throw new NativeWindowException(e);
+        }
+    }
+
+    /**
      * @param swtControl the SWT Control to retrieve the native widget-handle from
      * @return the native widget-handle
      * @throws NativeWindowException if the widget handle is null
diff --git a/src/newt/classes/com/jogamp/newt/swt/NewtCanvasSWT.java b/src/newt/classes/com/jogamp/newt/swt/NewtCanvasSWT.java
index d30dbe6dc..bd5c43d6c 100644
--- a/src/newt/classes/com/jogamp/newt/swt/NewtCanvasSWT.java
+++ b/src/newt/classes/com/jogamp/newt/swt/NewtCanvasSWT.java
@@ -79,7 +79,7 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
 
     private WindowClosingMode newtChildClosingMode = WindowClosingMode.DISPOSE_ON_CLOSE;
     private final WindowClosingMode closingMode = WindowClosingMode.DISPOSE_ON_CLOSE;
-    private volatile Rectangle clientArea;
+    private volatile Rectangle clientAreaPixels, clientAreaWindow;
 
     private volatile SWTNativeWindow nativeWindow;
     private volatile Window newtChild = null;
@@ -129,7 +129,8 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
 
         SWTAccessor.setRealized(this, true);
 
-        clientArea = getClientArea();
+        clientAreaPixels = SWTAccessor.getClientAreaInPixels(this);
+        clientAreaWindow = getClientArea();
 
         final AbstractGraphicsDevice device = SWTAccessor.getDevice(this);
         screen = SWTAccessor.getScreen(device, -1 /* default */);
@@ -154,14 +155,14 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
                     if( null != nativeWindow || validateNative() ) {
                         if( newtChildReady ) {
                             if( postSetSize ) {
-                                newtChild.setSize(clientArea.width, clientArea.height);
+                                newtChild.setSize(clientAreaPixels.width, clientAreaPixels.height);
                                 postSetSize = false;
                             }
                             if( postSetPos ) {
-                                newtChild.setPosition(clientArea.x, clientArea.y);
+                                newtChild.setPosition(clientAreaPixels.x, clientAreaPixels.y);
                                 postSetPos = false;
                             }
-                            newtChild.windowRepaint(0, 0, clientArea.width, clientArea.height);
+                            newtChild.windowRepaint(0, 0, clientAreaPixels.width, clientAreaPixels.height);
                         }
                     }
                     break;
@@ -175,7 +176,7 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
                     if( DEBUG ) {
                         System.err.println("NewtCanvasSWT.Event.RESIZE, "+event);
                     }
-                    updateSizeCheck();
+                    updatePosSizeCheck(false);
                     break;
                 case SWT.Dispose:
                     if( DEBUG ) {
@@ -204,14 +205,14 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
     	}
     	if( SWTAccessor.isOSX ) {
             // Force newtChild to update its size and position (OSX only)
-    	    updatePosSizeCheck(x, y, width, height, true /* updatePos */);
+    	    updatePosSizeCheck(true /* updatePos */);
     	}
     }
 
     /** assumes nativeWindow == null ! */
     protected final boolean validateNative() {
-        updateSizeCheck();
-        final Rectangle nClientArea = clientArea;
+        updatePosSizeCheck(false);
+        final Rectangle nClientArea = clientAreaPixels;
         if(0 >= nClientArea.width || 0 >= nClientArea.height) {
             return false;
         }
@@ -249,46 +250,34 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
         return null != nativeWindow;
     }
 
-    protected final void updateSizeCheck() {
-        final Rectangle nClientArea = getClientArea();
-        if( null != nClientArea ) {
-            updatePosSizeCheck(nClientArea.x, nClientArea.y, nClientArea.width, nClientArea.height, false /* updatePos */);
-        }
-    }
-    protected final void updatePosSizeCheck() {
-        final Rectangle nClientArea = getClientArea();
-        if( null != nClientArea ) {
-            updatePosSizeCheck(nClientArea.x, nClientArea.y, nClientArea.width, nClientArea.height, true /* updatePos */);
-        }
-    }
-    protected final void updatePosSizeCheck(final int newX, final int newY, final int newWidth, final int newHeight, final boolean updatePos) {
+    protected final void updatePosSizeCheck(final boolean updatePos) {
         final boolean sizeChanged, posChanged;
-        final Rectangle nClientArea;
+        Rectangle nClientAreaPixels = SWTAccessor.getClientAreaInPixels(this);
         {
-            final Rectangle oClientArea = clientArea;
-            sizeChanged = newWidth != oClientArea.width || newHeight != oClientArea.height;
-            posChanged = newX != oClientArea.x || newY != oClientArea.y;
+            final Rectangle oClientAreaPixels = clientAreaPixels;
+            sizeChanged = nClientAreaPixels.width != oClientAreaPixels.width || nClientAreaPixels.height != oClientAreaPixels.height;
+            posChanged = nClientAreaPixels.x != oClientAreaPixels.x || nClientAreaPixels.y != oClientAreaPixels.y;
             if( sizeChanged || posChanged ) {
-                nClientArea = new Rectangle(updatePos ? newX : oClientArea.x, updatePos ? newY : oClientArea.y, newWidth, newHeight);
-                clientArea = nClientArea;
+                clientAreaPixels = nClientAreaPixels;
+                clientAreaWindow = getClientArea();
             } else {
-                nClientArea = clientArea;
+                nClientAreaPixels = clientAreaPixels;
             }
         }
         if(DEBUG) {
             final long nsh = newtChildReady ? newtChild.getSurfaceHandle() : 0;
-            System.err.println("NewtCanvasSWT.updatePosSizeCheck: sizeChanged "+sizeChanged+", posChanged "+posChanged+", updatePos "+updatePos+", ("+Thread.currentThread().getName()+"): newtChildReady "+newtChildReady+", "+nClientArea.x+"/"+nClientArea.y+" "+nClientArea.width+"x"+nClientArea.height+" - surfaceHandle 0x"+Long.toHexString(nsh));
+            System.err.println("NewtCanvasSWT.updatePosSizeCheck: sizeChanged "+sizeChanged+", posChanged "+posChanged+", updatePos "+updatePos+", ("+Thread.currentThread().getName()+"): newtChildReady "+newtChildReady+", "+nClientAreaPixels.x+"/"+nClientAreaPixels.y+" "+nClientAreaPixels.width+"x"+nClientAreaPixels.height+" - surfaceHandle 0x"+Long.toHexString(nsh));
         }
         if( sizeChanged ) {
             if( newtChildReady ) {
-                newtChild.setSize(nClientArea.width, nClientArea.height);
+                newtChild.setSize(nClientAreaPixels.width, nClientAreaPixels.height);
             } else {
                 postSetSize = true;
             }
         }
         if( updatePos && posChanged ) {
             if( newtChildReady ) {
-                newtChild.setPosition(nClientArea.x, nClientArea.y);
+                newtChild.setPosition(nClientAreaPixels.x, nClientAreaPixels.y);
             } else {
                 postSetPos = true;
             }
@@ -437,9 +426,9 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
 
         newtChild.setFocusAction(null); // no AWT focus traversal ..
         if(add) {
-            updateSizeCheck();
-            final int w = clientArea.width;
-            final int h = clientArea.height;
+            updatePosSizeCheck(false);
+            final int w = clientAreaPixels.width;
+            final int h = clientAreaPixels.height;
 
             // set SWT EDT and start it
             {
@@ -557,12 +546,12 @@ public class NewtCanvasSWT extends Canvas implements NativeWindowHolder, WindowC
 
         @Override
         public int getSurfaceWidth() {
-            return clientArea.width;
+            return clientAreaPixels.width;
         }
 
         @Override
         public int getSurfaceHeight() {
-            return clientArea.height;
+            return clientAreaPixels.height;
         }
 
         @Override