iOS / MacOS: PixelScale Update

- IOSUtil/OSXUtil: Return float value and refine name to GetScreenPixelScale*

- WindowDriver's updateMaxScreenPixelScaleByDisplayID(..) and updateMaxScreenPixelScaleByWindowHandle(..)
will only update the maxPixelScale, as actual user pixelSize change should not be triggered here.

A user pixelSize adaption to the changed underlying scale capabilities (e.g. switch monitor)
should be supported by the implemented WindowDriver's: updatePixelScale(..) called by native code.

10 files changed, 118 insertions, 110 deletions

diff --git a/src/nativewindow/classes/jogamp/nativewindow/ios/IOSUtil.java b/src/nativewindow/classes/jogamp/nativewindow/ios/IOSUtil.java
index bd4b36239..7100cb0b5 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/ios/IOSUtil.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/ios/IOSUtil.java
@@ -115,18 +115,18 @@ public class IOSUtil implements ToolkitProperties {
       return (Insets) GetInsets0(windowOrView);
     }
 
-    public static double GetPixelScaleByDisplayID(final int displayID) {
-      if( 0 != displayID ) {
-          return GetPixelScale1(displayID);
+    public static float GetScreenPixelScaleByScreenIdx(final int screenIdx) {
+      if( 0 <= screenIdx ) {
+          return GetScreenPixelScale1(screenIdx);
       } else {
-          return 1.0; // default
+          return 1.0f; // default
       }
     }
-    public static double GetPixelScale(final long windowOrView) {
+    public static float GetScreenPixelScale(final long windowOrView) {
       if( 0 != windowOrView ) {
-          return GetPixelScale2(windowOrView);
+          return GetScreenPixelScale2(windowOrView);
       } else {
-          return 1.0; // default
+          return 1.0f; // default
       }
     }
 
@@ -310,8 +310,8 @@ public class IOSUtil implements ToolkitProperties {
     private static native boolean isUIWindow0(long object);
     private static native Object GetLocationOnScreen0(long windowOrView, int src_x, int src_y);
     private static native Object GetInsets0(long windowOrView);
-    private static native double GetPixelScale1(int displayID);
-    private static native double GetPixelScale2(long windowOrView);
+    private static native float GetScreenPixelScale1(int screenIdx);
+    private static native float GetScreenPixelScale2(long windowOrView);
     private static native long CreateUIWindow0(int x, int y, int width, int height);
     private static native void DestroyUIWindow0(long uiWindow);
     private static native long GetCALayer0(long uiView);
diff --git a/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java b/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
index 3b824cfe4..0f4a70ddc 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/jawt/JAWTUtil.java
@@ -592,7 +592,7 @@ public class JAWTUtil {
                   final Object res = getCGDisplayIDMethodOnOSX.invoke(device);
                   if (res instanceof Integer) {
                       final int displayID = ((Integer)res).intValue();
-                      sx = (float) OSXUtil.GetPixelScaleByDisplayID(displayID);
+                      sx = OSXUtil.GetScreenPixelScaleByDisplayID(displayID);
                       sy = sx;
                   }
               } catch (final Throwable t) {}
diff --git a/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java b/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
index b1bf248ce..e93c9574f 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/macosx/OSXUtil.java
@@ -107,18 +107,18 @@ public class OSXUtil implements ToolkitProperties {
       return (Insets) GetInsets0(windowOrView);
     }
 
-    public static double GetPixelScaleByDisplayID(final int displayID) {
+    public static float GetScreenPixelScaleByDisplayID(final int displayID) {
       if( 0 != displayID ) {
-          return GetPixelScale1(displayID);
+          return GetScreenPixelScale1(displayID);
       } else {
-          return 1.0; // default
+          return 1.0f; // default
       }
     }
-    public static double GetPixelScale(final long windowOrView) {
+    public static float GetScreenPixelScale(final long windowOrView) {
       if( 0 != windowOrView ) {
-          return GetPixelScale2(windowOrView);
+          return GetScreenPixelScale2(windowOrView);
       } else {
-          return 1.0; // default
+          return 1.0f; // default
       }
     }
 
@@ -404,8 +404,8 @@ public class OSXUtil implements ToolkitProperties {
     private static native boolean isNSWindow0(long object);
     private static native Object GetLocationOnScreen0(long windowOrView, int src_x, int src_y);
     private static native Object GetInsets0(long windowOrView);
-    private static native double GetPixelScale1(int displayID);
-    private static native double GetPixelScale2(long windowOrView);
+    private static native float GetScreenPixelScale1(int displayID);
+    private static native float GetScreenPixelScale2(long windowOrView);
     private static native long CreateNSWindow0(int x, int y, int width, int height);
     private static native void DestroyNSWindow0(long nsWindow);
     private static native long GetNSView0(long nsWindow);
diff --git a/src/nativewindow/native/ios/IOSmisc.m b/src/nativewindow/native/ios/IOSmisc.m
index 49fe8325e..70cff4c06 100644
--- a/src/nativewindow/native/ios/IOSmisc.m
+++ b/src/nativewindow/native/ios/IOSmisc.m
@@ -252,35 +252,35 @@ JNIEXPORT jobject JNICALL Java_jogamp_nativewindow_ios_IOSUtil_GetInsets0
 
 /*
  * Class:     Java_jogamp_nativewindow_ios_IOSUtil
- * Method:    GetPixelScale1
- * Signature: (I)D
+ * Method:    GetScreenPixelScale1
+ * Signature: (I)F
  */
-JNIEXPORT jdouble JNICALL Java_jogamp_nativewindow_ios_IOSUtil_GetPixelScale1
-  (JNIEnv *env, jclass unused, jint displayID)
+JNIEXPORT jfloat JNICALL Java_jogamp_nativewindow_ios_IOSUtil_GetScreenPixelScale1
+  (JNIEnv *env, jclass unused, jint screenIdx)
 {
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
 
     CGFloat pixelScale = 1.0; // default
-    // UIScreen *screen =  IOSUtil_getUIScreenByCGDirectDisplayID((CGDirectDisplayID)displayID);
-    UIScreen *screen =  [UIScreen mainScreen];
-    if( NULL != screen ) {
-NS_DURING
-        // Available >= 10.7
-        pixelScale = [screen scale]; // HiDPI scaling
-NS_HANDLER
-NS_ENDHANDLER
+
+    NSArray *screens = [UIScreen screens];
+    int count = [screens count];
+    if( 0 <= screenIdx && screenIdx < count ) {
+        UIScreen * screen = (UIScreen *) [screens objectAtIndex: screenIdx];
+        if( NULL != screen ) {
+            pixelScale = [screen scale];
+        }
     }
     [pool release];
 
-    return (jdouble)pixelScale;
+    return (jfloat)pixelScale;
 }
 
 /*
  * Class:     Java_jogamp_nativewindow_ios_IOSUtil
- * Method:    GetPixelScale1
- * Signature: (J)D
+ * Method:    GetScreenPixelScale1
+ * Signature: (J)F
  */
-JNIEXPORT jdouble JNICALL Java_jogamp_nativewindow_ios_IOSUtil_GetPixelScale2
+JNIEXPORT jfloat JNICALL Java_jogamp_nativewindow_ios_IOSUtil_GetScreenPixelScale2
   (JNIEnv *env, jclass unused, jlong winOrView)
 {
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
@@ -302,16 +302,11 @@ JNIEXPORT jdouble JNICALL Java_jogamp_nativewindow_ios_IOSUtil_GetPixelScale2
         NativewindowCommon_throwNewRuntimeException(env, "neither win nor view %p\n", nsObj);
     }
 
-    CGFloat pixelScale = 1.0; // default
-NS_DURING
-    // Available >= 10.7
-    pixelScale = [screen scale]; // HiDPI scaling
-NS_HANDLER
-NS_ENDHANDLER
+    CGFloat pixelScale = [screen scale];
 
     [pool release];
 
-    return (jdouble)pixelScale;
+    return (jfloat)pixelScale;
 }
 
 /*
diff --git a/src/nativewindow/native/macosx/OSXmisc.m b/src/nativewindow/native/macosx/OSXmisc.m
index fb15c43b9..1135c5fb2 100644
--- a/src/nativewindow/native/macosx/OSXmisc.m
+++ b/src/nativewindow/native/macosx/OSXmisc.m
@@ -266,10 +266,10 @@ JNIEXPORT jobject JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_GetInsets0
 
 /*
  * Class:     Java_jogamp_nativewindow_macosx_OSXUtil
- * Method:    GetPixelScale1
- * Signature: (I)D
+ * Method:    GetScreenPixelScale1
+ * Signature: (I)F
  */
-JNIEXPORT jdouble JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_GetPixelScale1
+JNIEXPORT jfloat JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_GetScreenPixelScale1
   (JNIEnv *env, jclass unused, jint displayID)
 {
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
@@ -285,15 +285,15 @@ NS_ENDHANDLER
     }
     [pool release];
 
-    return (jdouble)pixelScale;
+    return (jfloat)pixelScale;
 }
 
 /*
  * Class:     Java_jogamp_nativewindow_macosx_OSXUtil
- * Method:    GetPixelScale1
- * Signature: (J)D
+ * Method:    GetScreenPixelScale1
+ * Signature: (J)F
  */
-JNIEXPORT jdouble JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_GetPixelScale2
+JNIEXPORT jfloat JNICALL Java_jogamp_nativewindow_macosx_OSXUtil_GetScreenPixelScale2
   (JNIEnv *env, jclass unused, jlong winOrView)
 {
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
@@ -324,7 +324,7 @@ NS_ENDHANDLER
 
     [pool release];
 
-    return (jdouble)pixelScale;
+    return (jfloat)pixelScale;
 }
 
 /*
diff --git a/src/newt/classes/jogamp/newt/driver/ios/ScreenDriver.java b/src/newt/classes/jogamp/newt/driver/ios/ScreenDriver.java
index 47280865d..daa033edb 100644
--- a/src/newt/classes/jogamp/newt/driver/ios/ScreenDriver.java
+++ b/src/newt/classes/jogamp/newt/driver/ios/ScreenDriver.java
@@ -82,7 +82,7 @@ public class ScreenDriver extends ScreenImpl {
             //
             for(int crtIdx=0; crtIdx<count; crtIdx++) {
                 final int crt_id = crtIDs[crtIdx];
-                final float pixelScaleRaw = (float)IOSUtil.GetPixelScaleByDisplayID(crt_id);
+                final float pixelScaleRaw = IOSUtil.GetScreenPixelScaleByScreenIdx(crt_id);
                 pixelScaleArray[crtIdx] = FloatUtil.isZero(pixelScaleRaw, FloatUtil.EPSILON) ? 1.0f : pixelScaleRaw;
                 propsOrigArray[crtIdx] = getMonitorProps0(crt_id);
                 if ( null == propsOrigArray[crtIdx] ) {
diff --git a/src/newt/classes/jogamp/newt/driver/ios/WindowDriver.java b/src/newt/classes/jogamp/newt/driver/ios/WindowDriver.java
index 2a257436a..79c35c310 100644
--- a/src/newt/classes/jogamp/newt/driver/ios/WindowDriver.java
+++ b/src/newt/classes/jogamp/newt/driver/ios/WindowDriver.java
@@ -49,6 +49,7 @@ import jogamp.newt.driver.DriverUpdatePosition;
 import com.jogamp.newt.event.InputEvent;
 import com.jogamp.newt.event.KeyEvent;
 import com.jogamp.newt.event.MonitorEvent;
+import com.jogamp.newt.event.MouseEvent;
 import com.jogamp.opengl.math.FloatUtil;
 
 public class WindowDriver extends WindowImpl implements MutableSurface, DriverClearFocus, DriverUpdatePosition {
@@ -75,7 +76,7 @@ public class WindowDriver extends WindowImpl implements MutableSurface, DriverCl
 
         if( SurfaceScaleUtils.setNewPixelScale(hasPixelScale, hasPixelScale, newPixelScale, minPixelScale, maxPixelScale, DEBUG_IMPLEMENTATION ? getClass().getName() : null) ) {
             if( sendEvent ) {
-                if( deferOffThread ) {
+                if( defer && deferOffThread ) {
                     superSizeChangedOffThread(defer, getWidth(), getHeight(), true);
                 } else {
                     super.sizeChanged(defer, getWidth(), getHeight(), true);
@@ -89,51 +90,55 @@ public class WindowDriver extends WindowImpl implements MutableSurface, DriverCl
         }
     }
 
-    private boolean updatePixelScaleByDisplayID(final boolean sendEvent) {
-        final float maxPixelScaleRaw = (float) IOSUtil.GetPixelScaleByDisplayID(getDisplayID());
+    /**
+     * Essentially updates {@code maxPixelScale} ..
+     */
+    private boolean updateMaxScreenPixelScaleByDisplayID(final boolean sendEvent) {
+        final float maxPixelScaleRaw = IOSUtil.GetScreenPixelScaleByScreenIdx(getDisplayID());
         if( DEBUG_IMPLEMENTATION ) {
-            System.err.println("WindowDriver.updatePixelScale.1: "+hasPixelScale[0]+", "+maxPixelScaleRaw+" (max)");
+            System.err.println("WindowDriver.updatePixelScale.1: req "+reqPixelScale[0]+", has "+hasPixelScale[0]+", max "+maxPixelScaleRaw);
         }
-        return updatePixelScale(sendEvent, true /* defer */, false /*offthread */, maxPixelScaleRaw, maxPixelScaleRaw);
+        return updatePixelScale(sendEvent, true /* defer */, false /*offthread */, hasPixelScale[0], maxPixelScaleRaw);
     }
 
-    private boolean updatePixelScaleByWindowHandle(final boolean sendEvent) {
+    /**
+     * Essentially updates {@code maxPixelScale} ..
+     */
+    private boolean updateMaxScreenPixelScaleByWindowHandle(final boolean sendEvent) {
         final long handle = getWindowHandle();
         if( 0 != handle ) {
-            final float maxPixelScaleRaw = (float)IOSUtil.GetPixelScale(handle);
+            final float maxPixelScaleRaw = IOSUtil.GetScreenPixelScale(handle);
             if( DEBUG_IMPLEMENTATION ) {
-                System.err.println("WindowDriver.updatePixelScale.2: "+hasPixelScale[0]+", "+maxPixelScaleRaw+" (max)");
+                System.err.println("WindowDriver.updatePixelScale.2: req "+reqPixelScale[0]+", has "+hasPixelScale[0]+", max "+maxPixelScaleRaw);
             }
-            return updatePixelScale(sendEvent, true /* defer */, false /*offthread */, maxPixelScaleRaw, maxPixelScaleRaw);
+            return updatePixelScale(sendEvent, true /* defer */, false /*offthread */, hasPixelScale[0], maxPixelScaleRaw);
         } else {
             return false;
         }
     }
 
     /** Called from native code */
-    protected void updatePixelScale(final boolean defer, final float newPixelScaleRaw, final float maxPixelScaleRaw) {
+    protected void updatePixelScale(final boolean defer, final float oldPixelScaleRaw, final float newPixelScaleRaw, final float maxPixelScaleRaw, final boolean changed) {
         if( DEBUG_IMPLEMENTATION ) {
-            System.err.println("WindowDriver.updatePixelScale.3: "+hasPixelScale[0]+" (has) -> "+newPixelScaleRaw+" (new), "+maxPixelScaleRaw+" (max), drop "+!isNativeValid());
-        }
-        if( isNativeValid() ) {
-            updatePixelScale(true /* sendEvent*/, defer, true /*offthread */, newPixelScaleRaw, maxPixelScaleRaw);
+            System.err.println("WindowDriver.updatePixelScale.3: req "+reqPixelScale[0]+", has "+hasPixelScale[0]+", old "+oldPixelScaleRaw+", new "+newPixelScaleRaw+", max "+maxPixelScaleRaw+", changed "+changed);
         }
+        updatePixelScale(true /* sendEvent*/, defer, true /*offthread */, newPixelScaleRaw, maxPixelScaleRaw);
     }
 
     @Override
     protected final void instantiationFinishedImpl() {
-        updatePixelScaleByDisplayID(false /* sendEvent*/);
+        updateMaxScreenPixelScaleByDisplayID(false /* sendEvent*/);
     }
 
     @Override
     protected void setScreen(final ScreenImpl newScreen) { // never null !
         super.setScreen(newScreen);
-        updatePixelScaleByDisplayID(false /* sendEvent*/);  // caller (reparent, ..) will send reshape event
+        updateMaxScreenPixelScaleByDisplayID(false /* sendEvent*/);  // caller (reparent, ..) will send reshape event
     }
 
     @Override
     protected void monitorModeChanged(final MonitorEvent me, final boolean success) {
-        updatePixelScaleByWindowHandle(false /* sendEvent*/); // send reshape event itself
+        updateMaxScreenPixelScaleByWindowHandle(false /* sendEvent*/); // send reshape event itself
     }
 
     @Override
@@ -441,7 +446,7 @@ public class WindowDriver extends WindowImpl implements MutableSurface, DriverCl
                 createWindow(false, 0 != oldWindowHandle, pClientLevelOnSreen, width, height, flags);
             }
             // no native event (fullscreen, some reparenting)
-            updatePixelScaleByWindowHandle(false /* sendEvent */);
+            updateMaxScreenPixelScaleByWindowHandle(false /* sendEvent */);
             if( isOffscreenInstance) {
                 super.sizeChanged(false, width, height, true);
                 positionChanged(false,  x, y);
diff --git a/src/newt/classes/jogamp/newt/driver/macosx/ScreenDriver.java b/src/newt/classes/jogamp/newt/driver/macosx/ScreenDriver.java
index ddeea265a..590f706df 100644
--- a/src/newt/classes/jogamp/newt/driver/macosx/ScreenDriver.java
+++ b/src/newt/classes/jogamp/newt/driver/macosx/ScreenDriver.java
@@ -88,7 +88,7 @@ public class ScreenDriver extends ScreenImpl {
             //
             for(int crtIdx=0; crtIdx<count; crtIdx++) {
                 final int crt_id = crtIDs[crtIdx];
-                final float pixelScaleRaw = (float)OSXUtil.GetPixelScaleByDisplayID(crt_id);
+                final float pixelScaleRaw = OSXUtil.GetScreenPixelScaleByDisplayID(crt_id);
                 pixelScaleArray[crtIdx] = FloatUtil.isZero(pixelScaleRaw, FloatUtil.EPSILON) ? 1.0f : pixelScaleRaw;
                 propsOrigArray[crtIdx] = getMonitorProps0(crt_id);
                 if ( null == propsOrigArray[crtIdx] ) {
diff --git a/src/newt/classes/jogamp/newt/driver/macosx/WindowDriver.java b/src/newt/classes/jogamp/newt/driver/macosx/WindowDriver.java
index e6ae7719c..1c6102f88 100644
--- a/src/newt/classes/jogamp/newt/driver/macosx/WindowDriver.java
+++ b/src/newt/classes/jogamp/newt/driver/macosx/WindowDriver.java
@@ -82,7 +82,7 @@ public class WindowDriver extends WindowImpl implements MutableSurface, DriverCl
 
         if( SurfaceScaleUtils.setNewPixelScale(hasPixelScale, hasPixelScale, newPixelScale, minPixelScale, maxPixelScale, DEBUG_IMPLEMENTATION ? getClass().getName() : null) ) {
             if( sendEvent ) {
-                if( deferOffThread ) {
+                if( defer && deferOffThread ) {
                     superSizeChangedOffThread(defer, getWidth(), getHeight(), true);
                 } else {
                     super.sizeChanged(defer, getWidth(), getHeight(), true);
@@ -96,51 +96,55 @@ public class WindowDriver extends WindowImpl implements MutableSurface, DriverCl
         }
     }
 
-    private boolean updatePixelScaleByDisplayID(final boolean sendEvent) {
-        final float maxPixelScaleRaw = (float) OSXUtil.GetPixelScaleByDisplayID(getDisplayID());
+    /**
+     * Essentially updates {@code maxPixelScale} ..
+     */
+    private boolean updateMaxScreenPixelScaleByDisplayID(final boolean sendEvent) {
+        final float maxPixelScaleRaw = OSXUtil.GetScreenPixelScaleByDisplayID(getDisplayID());
         if( DEBUG_IMPLEMENTATION ) {
-            System.err.println("WindowDriver.updatePixelScale.1: "+hasPixelScale[0]+", "+maxPixelScaleRaw+" (max)");
+            System.err.println("WindowDriver.updatePixelScale.1: req "+reqPixelScale[0]+", has "+hasPixelScale[0]+", max "+maxPixelScaleRaw);
         }
-        return updatePixelScale(sendEvent, true /* defer */, false /*offthread */, maxPixelScaleRaw, maxPixelScaleRaw);
+        return updatePixelScale(sendEvent, true /* defer */, false /*offthread */, hasPixelScale[0], maxPixelScaleRaw);
     }
 
-    private boolean updatePixelScaleByWindowHandle(final boolean sendEvent) {
+    /**
+     * Essentially updates {@code maxPixelScale} ..
+     */
+    private boolean updateMaxScreenPixelScaleByWindowHandle(final boolean sendEvent) {
         final long handle = getWindowHandle();
         if( 0 != handle ) {
-            final float maxPixelScaleRaw = (float)OSXUtil.GetPixelScale(handle);
+            final float maxPixelScaleRaw = OSXUtil.GetScreenPixelScale(handle);
             if( DEBUG_IMPLEMENTATION ) {
-                System.err.println("WindowDriver.updatePixelScale.2: "+hasPixelScale[0]+", "+maxPixelScaleRaw+" (max)");
+                System.err.println("WindowDriver.updatePixelScale.2: req "+reqPixelScale[0]+", has "+hasPixelScale[0]+", max "+maxPixelScaleRaw);
             }
-            return updatePixelScale(sendEvent, true /* defer */, false /*offthread */, maxPixelScaleRaw, maxPixelScaleRaw);
+            return updatePixelScale(sendEvent, true /* defer */, false /*offthread */, hasPixelScale[0], maxPixelScaleRaw);
         } else {
             return false;
         }
     }
 
     /** Called from native code */
-    protected void updatePixelScale(final boolean defer, final float newPixelScaleRaw, final float maxPixelScaleRaw) {
+    protected void updatePixelScale(final boolean defer, final float oldPixelScaleRaw, final float newPixelScaleRaw, final float maxPixelScaleRaw, final boolean changed) {
         if( DEBUG_IMPLEMENTATION ) {
-            System.err.println("WindowDriver.updatePixelScale.3: "+hasPixelScale[0]+" (has) -> "+newPixelScaleRaw+" (new), "+maxPixelScaleRaw+" (max), drop "+!isNativeValid());
-        }
-        if( isNativeValid() ) {
-            updatePixelScale(true /* sendEvent*/, defer, true /*offthread */, newPixelScaleRaw, maxPixelScaleRaw);
+            System.err.println("WindowDriver.updatePixelScale.3: req "+reqPixelScale[0]+", has "+hasPixelScale[0]+", old "+oldPixelScaleRaw+", new "+newPixelScaleRaw+", max "+maxPixelScaleRaw+", changed "+changed);
         }
+        updatePixelScale(true /* sendEvent*/, defer, true /*offthread */, newPixelScaleRaw, maxPixelScaleRaw);
     }
 
     @Override
     protected final void instantiationFinishedImpl() {
-        updatePixelScaleByDisplayID(false /* sendEvent*/);
+        updateMaxScreenPixelScaleByDisplayID(false /* sendEvent*/);
     }
 
     @Override
     protected void setScreen(final ScreenImpl newScreen) { // never null !
         super.setScreen(newScreen);
-        updatePixelScaleByDisplayID(false /* sendEvent*/);  // caller (reparent, ..) will send reshape event
+        updateMaxScreenPixelScaleByDisplayID(false /* sendEvent*/);  // caller (reparent, ..) will send reshape event
     }
 
     @Override
     protected void monitorModeChanged(final MonitorEvent me, final boolean success) {
-        updatePixelScaleByWindowHandle(false /* sendEvent*/); // send reshape event itself
+        updateMaxScreenPixelScaleByWindowHandle(false /* sendEvent*/); // send reshape event itself
     }
 
     @Override
@@ -448,7 +452,7 @@ public class WindowDriver extends WindowImpl implements MutableSurface, DriverCl
                 createWindow(false, 0 != oldWindowHandle, pClientLevelOnSreen, width, height, flags);
             }
             // no native event (fullscreen, some reparenting)
-            updatePixelScaleByWindowHandle(false /* sendEvent */);
+            updateMaxScreenPixelScaleByWindowHandle(false /* sendEvent */);
             if( isOffscreenInstance) {
                 super.sizeChanged(false, width, height, true);
                 positionChanged(false,  x, y);
diff --git a/src/newt/native/MacNewtNSWindow.m b/src/newt/native/MacNewtNSWindow.m
index 31d7863d3..96dff76f6 100644
--- a/src/newt/native/MacNewtNSWindow.m
+++ b/src/newt/native/MacNewtNSWindow.m
@@ -272,21 +272,20 @@ static jmethodID windowRepaintID = NULL;
 
 - (BOOL) softLock
 {
-    // DBG_PRINT("*************** softLock.0: %p\n", (void*)pthread_self());
     int err;
     if( 0 != ( err = pthread_mutex_lock(&softLockSync) ) ) {
         NSLog(@"NewtNSView::softLock failed: errCode %d - %@", err, [NSThread callStackSymbols]);
         return NO;
     }
     softLockCount++;
-    // DBG_PRINT("*************** softLock.X: %p\n", (void*)pthread_self());
+    // DBG_PRINT("*************** softLock: %p count %d\n", (void*)pthread_self(), softLockCount);
     return 0 < softLockCount;
 }
 
 - (BOOL) softUnlock
 {
-    // DBG_PRINT("*************** softUnlock: %p\n", (void*)pthread_self());
     softLockCount--;
+    // DBG_PRINT("*************** softUnlock: %p count %d\n", (void*)pthread_self(), softLockCount);
     int err;
     if( 0 != ( err = pthread_mutex_unlock(&softLockSync) ) ) {
         softLockCount++;
@@ -321,7 +320,7 @@ static jmethodID windowRepaintID = NULL;
 
 - (void) drawRect:(NSRect)dirtyRect
 {
-    DBG_PRINT("*************** dirtyRect: %p %lf/%lf %lfx%lf\n", 
+    DBG_PRINT("*************** drawRect: dirtyRect: %p %lf/%lf %lfx%lf\n", 
         javaWindowObject, dirtyRect.origin.x, dirtyRect.origin.y, dirtyRect.size.width, dirtyRect.size.height);
 
     if(NULL==javaWindowObject) {
@@ -789,20 +788,24 @@ static jmethodID windowRepaintID = NULL;
     // HiDPI scaling
     BOOL useHiDPI = false;
     CGFloat maxPixelScale = 1.0;
-    CGFloat winPixelScale = 1.0;
+    CGFloat pixelScale = 1.0;
     NSWindow* window = [self window];
     NSScreen* screen = [window screen];
+    CGFloat oldPixelScale = [[self layer] contentsScale];
 NS_DURING
     maxPixelScale = [screen backingScaleFactor];
     useHiDPI = [self wantsBestResolutionOpenGLSurface];
     if( useHiDPI ) {
-        winPixelScale = [window backingScaleFactor];
+        pixelScale = [window backingScaleFactor];
     }
 NS_HANDLER
 NS_ENDHANDLER
-    DBG_PRINT("viewDidChangeBackingProperties: PixelScale: HiDPI %d, max %f, window %f\n", useHiDPI, (float)maxPixelScale, (float)winPixelScale);
-    [[self layer] setContentsScale: winPixelScale];
-
+    BOOL changeScale = oldPixelScale != pixelScale;
+    DBG_PRINT("viewDidChangeBackingProperties: PixelScale: useHiDPI %d, max %f, old %f -> %f (change %d)\n", 
+        useHiDPI, (float)maxPixelScale, (float)oldPixelScale, (float)pixelScale, changeScale);
+    if( changeScale ) {
+        [[self layer] setContentsScale: pixelScale];
+    }
     if (javaWindowObject == NULL) {
         DBG_PRINT("viewDidChangeBackingProperties: null javaWindowObject\n");
         return;
@@ -813,8 +816,8 @@ NS_ENDHANDLER
         DBG_PRINT("viewDidChangeBackingProperties: null JNIEnv\n");
         return;
     }
-
-    (*env)->CallVoidMethod(env, javaWindowObject, updatePixelScaleID, JNI_TRUE, (jfloat)winPixelScale, (jfloat)maxPixelScale); // defer 
+    (*env)->CallVoidMethod(env, javaWindowObject, updatePixelScaleID, JNI_TRUE /* defer */, 
+                          (jfloat)oldPixelScale, (jfloat)pixelScale, (jfloat)maxPixelScale, (jboolean)changeScale);
 
     // detaching thread not required - daemon
     // NewtCommon_ReleaseJNIEnv(shallBeDetached);
@@ -830,7 +833,7 @@ NS_ENDHANDLER
     enqueueMouseEventID = (*env)->GetMethodID(env, clazz, "enqueueMouseEvent", "(ZSIIISF)V");
     enqueueKeyEventID = (*env)->GetMethodID(env, clazz, "enqueueKeyEvent", "(ZSISCC)V");
     sizeChangedID = (*env)->GetMethodID(env, clazz, "sizeChanged", "(ZIIZ)V");
-    updatePixelScaleID = (*env)->GetMethodID(env, clazz, "updatePixelScale", "(ZFF)V");
+    updatePixelScaleID = (*env)->GetMethodID(env, clazz, "updatePixelScale", "(ZFFFZ)V");
     visibleChangedID = (*env)->GetMethodID(env, clazz, "visibleChanged", "(ZZ)V");
     insetsChangedID = (*env)->GetMethodID(env, clazz, "insetsChanged", "(ZIIII)V");
     sizeScreenPosInsetsChangedID = (*env)->GetMethodID(env, clazz, "sizeScreenPosInsetsChanged", "(ZIIIIIIIIZZ)V");
@@ -1125,7 +1128,7 @@ NS_ENDHANDLER
         return;
     }
     jobject javaWindowObject = [newtView getJavaWindowObject];
-    if (javaWindowObject == NULL) {
+    if ( NULL == javaWindowObject ) {
         DBG_PRINT("focusChanged: null javaWindowObject\n");
         return;
     }
@@ -1254,21 +1257,22 @@ NS_ENDHANDLER
 
 - (void) sendResizeEvent
 {
-    jobject javaWindowObject = NULL;
+    NewtNSView* newtView = (NewtNSView *) [self contentView];
+    if( ! [newtView isKindOfClass:[NewtNSView class]] ) {
+        return;
+    }
+    jobject javaWindowObject = [newtView getJavaWindowObject];
+    if ( NULL == javaWindowObject ) {
+        DBG_PRINT("sendResizeEvent: null javaWindowObject\n");
+        return;
+    }
     int shallBeDetached = 0;
     JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
-
     if( NULL == env ) {
         DBG_PRINT("windowDidResize: null JNIEnv\n");
         return;
     }
-    NewtNSView* newtView = (NewtNSView *) [self contentView];
-    if( [newtView isKindOfClass:[NewtNSView class]] ) {
-        javaWindowObject = [newtView getJavaWindowObject];
-    }
-    if( NULL != javaWindowObject ) {
-        [self updateSizePosInsets: env jwin: javaWindowObject defer:JNI_TRUE];
-    }
+    [self updateSizePosInsets: env jwin: javaWindowObject defer:JNI_TRUE];
     // detaching thread not required - daemon
     // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 }
@@ -1280,7 +1284,7 @@ NS_ENDHANDLER
         return;
     }
     jobject javaWindowObject = [newtView getJavaWindowObject];
-    if (javaWindowObject == NULL) {
+    if ( NULL == javaWindowObject ) {
         DBG_PRINT("windowDidMove: null javaWindowObject\n");
         return;
     }