Android/NEWT MouseEvent: Fix Detection/Processing of 2-Finger-Scroll Gesture - Part 2

Multiple tests on different devices disclosed that:
  - 1 of 2 pointers get disconnected every now and then ..
    -> Shall tolerate this case

  - dist-delta within gesture may shrink below doubleTouchSlope
    -> Remove constraint after gesture detection

- Always validate pointer-id

GearsES2
  - Works quite stable on several devices now
  - Moved soft-keyboad show to 4-pointer pressed >= 0.7f pressure

4 files changed, 154 insertions, 88 deletions

diff --git a/src/newt/classes/jogamp/newt/driver/android/event/AndroidNewtEventFactory.java b/src/newt/classes/jogamp/newt/driver/android/event/AndroidNewtEventFactory.java
index 21f552fdb..4c2ed06e8 100644
--- a/src/newt/classes/jogamp/newt/driver/android/event/AndroidNewtEventFactory.java
+++ b/src/newt/classes/jogamp/newt/driver/android/event/AndroidNewtEventFactory.java
@@ -244,12 +244,11 @@ public class AndroidNewtEventFactory {
         return maxPressure;
     }
     
-    private final int touchSlop, touchSlop2x, touchSlopSquare, doubleTapSlop, doubleTapSlopSquare;
+    private final int touchSlop, touchSlopSquare, doubleTapSlop, doubleTapSlopSquare;
     
     public AndroidNewtEventFactory(android.content.Context context, android.os.Handler handler) {
         final android.view.ViewConfiguration configuration = android.view.ViewConfiguration.get(context);
         touchSlop = configuration.getScaledTouchSlop();
-        touchSlop2x = 2*touchSlop;
         touchSlopSquare = touchSlop * touchSlop;         
         doubleTapSlop = configuration.getScaledDoubleTapSlop();
         doubleTapSlopSquare = doubleTapSlop * doubleTapSlop;  
@@ -294,32 +293,31 @@ public class AndroidNewtEventFactory {
         {
             final int aType0 = event.getActionMasked();
             if( isOnTouchEvent ) {
-                boolean action = false;
                 switch ( aType0 ) {
                     case MotionEvent.ACTION_DOWN:
-                        action = true;
-                        // fall through intended
                     case MotionEvent.ACTION_POINTER_DOWN:
-                        gesture2FingerScrl.onDown(event, action);
+                        gesture2FingerScrl.onDown(event);
                         break;
                     case MotionEvent.ACTION_UP:
-                        action = true;
-                        // fall through intended
                     case MotionEvent.ACTION_POINTER_UP:
-                        gesture2FingerScrl.onUp(event, action);
+                        gesture2FingerScrl.onUp(event);
                         break;
                     case MotionEvent.ACTION_MOVE:
-                        gesture2FingerScrl.onActionMove(event);
+                        gesture2FingerScrl.onMove(event);
                         break;
                 }
             }
                         
-            if( gesture2FingerScrl.isWithinGesture() ) {
-                final float[] rot = gesture2FingerScrl.getScrollDistanceXY();            
-                rotationXYZ[0] = rot[0] / rotationScale;
-                rotationXYZ[1] = rot[1] / rotationScale;
-                aType = ACTION_SCROLL; // 8
-                rotationSource = 1;
+            if( gesture2FingerScrl.gestureStarted() ) {
+                if( gesture2FingerScrl.hasGesture(true) ) {
+                    final float[] rot = gesture2FingerScrl.getScrollDistanceXY();            
+                    rotationXYZ[0] = rot[0] / rotationScale;
+                    rotationXYZ[1] = rot[1] / rotationScale;
+                    aType = ACTION_SCROLL; // 8
+                    rotationSource = 1;
+                } else {
+                    return new com.jogamp.newt.event.MouseEvent[0]; // skip, but cont. sending events
+                }
             } else {
                 aType = aType0;
             }
@@ -342,7 +340,7 @@ public class AndroidNewtEventFactory {
                     modifiers |= com.jogamp.newt.event.InputEvent.SHIFT_MASK;
                 }
                 if(DEBUG_MOUSE_EVENT) {
-                    System.err.println("createMouseEvent: Scroll "+rotationXYZ[0]+"/"+rotationXYZ[1]+", "+rotationScale+", mods "+modifiers+", source "+rotationSource);
+                    System.err.println("createMouseEvent: Gesture2FingerScrl Scroll "+rotationXYZ[0]+"/"+rotationXYZ[1]+", "+rotationScale+", mods "+modifiers+", source "+rotationSource);
                 }      
             }
             
@@ -423,38 +421,59 @@ public class AndroidNewtEventFactory {
     }
         
     static interface GestureHandler {
-        /** Returns true if within the gesture */ 
-        public boolean isWithinGesture();
+        /** 
+         * Returns true if last on* command produced a gesture, otherwise false. 
+         * @param clear if true, method clears the gesture flag. 
+         */ 
+        public boolean hasGesture(boolean clear);
+        /** Returns true if the gesture has started */ 
+        public boolean gestureStarted();
         /** Returns distance of the last consecutive double-tab scrolling. */ 
         public float[] getScrollDistanceXY();
-        
-        public void onUp(android.view.MotionEvent e, boolean action);
-        public void onDown(android.view.MotionEvent e, boolean action);
-        public void onActionMove(android.view.MotionEvent e);
+        public void onDown(android.view.MotionEvent e);
+        public void onUp(android.view.MotionEvent e);
+        public void onMove(android.view.MotionEvent e);
     }
     
     /**
      * Criteria related to Android parameter:
      *    - ScaledDoubleTapSlop:
-     *       - Max 2 finger distance
+     *       - Max 2 finger distance to start 'scroll' mode
      *
      *    - ScaledTouchSlop:
      *       - Min. movement w/ 2 pointer withing ScaledDoubleTapSlop starting 'scroll' mode
-     *       - Max. change of finger distance in respect to initiating 2-finger distance (2x ScaledTouchSlop)
-     *       - Max. distance growth in respect to initiating 2-finger distance.
+     *       - Max. distance growth in respect to initiated 2-finger distance.
+     *       
+     *    - Tolerate temporary lift of 1/2 pointer
+     *    
+     *     - Always validate pointer-id
      */
     private final GestureHandler gesture2FingerScrl = new GestureHandler() {
         private final float[] scrollDistance = new float[] { 0f, 0f };
-        private int dStartDist = 0;
-        private float dDownY = 0;
-        private float dDownX = 0;
-        private float dLastY = 0;
-        private float dLastX = 0;
+        private int[] pIds = new int[] { -1, -1 };
+        private int startDist = -1;
+        private float downY = 0;
+        private float downX = 0;
+        private float lastY = 0;
+        private float lastX = 0;
         private int pointerDownCount = 0;
-        private boolean dDownScroll = false;
+        private boolean withinGesture = false;
+        private boolean hasGesture = false;
         
         public String toString() {
-            return "Gesture2FingerScrl[in "+dDownScroll+", pc "+pointerDownCount+"]";
+            return "Gesture2FingerScrl[in "+withinGesture+", has "+hasGesture+", pc "+pointerDownCount+"]";
+        }
+        
+        private void clear() {
+            downX = 0f;
+            downY = 0f;
+            lastX = 0f;
+            lastY = 0f;
+            startDist = -1;
+            withinGesture = false;
+            hasGesture = false;
+            pIds[0] = -1;
+            pIds[1] = -1;
         }
         
         private final int getSquareDistance(float x1, float y1, float x2, float y2) {
@@ -463,76 +482,119 @@ public class AndroidNewtEventFactory {
             return deltaX * deltaX + deltaY * deltaY;
         }
         
-        public boolean isWithinGesture() {
-            return dDownScroll;
+        private int gesturePointers(final android.view.MotionEvent e, final int excludeIndex) {
+            int j = 0;       
+            for(int i=e.getPointerCount()-1; i>=0; i--) {
+                if( excludeIndex != i ) {
+                    final int id = e.getPointerId(i); 
+                    if( pIds[0] == id || pIds[1] == id ) {
+                        j++;
+                    }
+                }
+            }
+            return j;
         }
+        
+        @Override
+        public boolean gestureStarted() {
+            return 0 <= startDist && withinGesture;
+        }
+        
+        @Override
+        public boolean hasGesture(boolean clear) {
+            final boolean r = hasGesture;
+            if( clear ) {
+                hasGesture = false;
+            }
+            return r;
+        }
+        
         @Override
         public final float[] getScrollDistanceXY() {
             return scrollDistance;
         }
         
         @Override
-        public void onDown(android.view.MotionEvent e, boolean action) {
+        public void onDown(android.view.MotionEvent e) {
             pointerDownCount = e.getPointerCount();
-            if( 2 == pointerDownCount ) {
-                final int sqDist = getSquareDistance(e.getX(0), e.getY(0), e.getX(1), e.getY(1));
-                final boolean isDistWithinDoubleTapSlop = sqDist < doubleTapSlopSquare;
-                if(DEBUG_MOUSE_EVENT) {
-                    System.err.println(this+".onDown: action "+action+", dist "+Math.sqrt(sqDist)+", distWithin2DTSlop "+isDistWithinDoubleTapSlop+", "+e);
-                }
-                if( isDistWithinDoubleTapSlop ) {
-                    dDownX = e.getX();
-                    dDownY = e.getY();
-                    dLastX = dDownX;
-                    dLastY = dDownY;
-                    dStartDist = (int)Math.sqrt(sqDist);
-                }
+            final int gPtr = gesturePointers(e, -1);
+            if( 2 <= gPtr ) { // pick-up dLast coordinate to cont. gesture after temp loosing 1/2 pointers
+                lastX = e.getX(0);
+                lastY = e.getY(0);
+            }
+            if(DEBUG_MOUSE_EVENT) {
+                System.err.println(this+".onDown: gPtr "+gPtr+", "+e);
             }
         }
         
         @Override
-        public void onUp(android.view.MotionEvent e, boolean action) {
+        public void onUp(android.view.MotionEvent e) {
             pointerDownCount = e.getPointerCount();
-            if(DEBUG_MOUSE_EVENT) {
-                System.err.println(this+".onrUp: action "+action+", "+e);
-            }
-            if( 2 >= pointerDownCount ) {
-                dDownScroll = false;
+            final int gPtr = gesturePointers(e, e.getActionIndex()); // w/o lifted pointer
+            if( 1 > gPtr ) { // tolerate lifting 1/2 gesture pointers temporary
+                clear();
             }
             pointerDownCount--; // lifted now!
-            if(!dDownScroll) {
-                dDownY = 0f;
-                dDownX = 0f;
-                dLastY = 0f;
-                dLastX = 0f;
+            if(DEBUG_MOUSE_EVENT) {
+                System.err.println(this+".onUp: gPtr "+gPtr+", "+e);
             }
         }
-     
+        
         @Override
-        public void onActionMove(android.view.MotionEvent e) {
+        public void onMove(android.view.MotionEvent e) {
             pointerDownCount = e.getPointerCount();
             if( 2 <= pointerDownCount ) {
-                final int sqDist = getSquareDistance(e.getX(0), e.getY(0), e.getX(1), e.getY(1));
-                final int dist = (int)Math.sqrt(sqDist);
-                final float x = e.getX();
-                final float y = e.getY();
+                final float x0 = e.getX(0);
+                final float y0 = e.getY(0);
+                final int sqDist = getSquareDistance(x0, y0, e.getX(1), e.getY(1));
                 final boolean isDistWithinDoubleTapSlop = sqDist < doubleTapSlopSquare;
-                final boolean isDistDeltaWithinTouchSlop = Math.abs( dStartDist - dist ) <= touchSlop2x &&
-                                                                       dist - dStartDist <= touchSlop; 
-                if( !isDistWithinDoubleTapSlop || !isDistDeltaWithinTouchSlop ) {
-                    dDownScroll = false;
-                } else  if( !dDownScroll ) {  
-                    final int dX = (int) (x - dDownX);
-                    final int dY = (int) (y - dDownY);
-                    final int d = (dX * dX) + (dY * dY);
-                    dDownScroll = d > touchSlopSquare;
+                final int dist = (int)Math.sqrt(sqDist);
+                if( !withinGesture ) {
+                    int gPtr = 0;
+                    if( isDistWithinDoubleTapSlop ) {
+                        if( 0 > startDist ) {
+                            gPtr = 2;
+                            pIds[0] = e.getPointerId(0);
+                            pIds[1] = e.getPointerId(1);
+                            downX = x0;
+                            downY = y0;
+                            lastX = x0;
+                            lastY = y0;
+                            startDist = dist;
+                        } else {
+                            gPtr = gesturePointers(e, -1);
+                            if( 2 <= gPtr ) {
+                                final int dX = (int) (x0 - downX);
+                                final int dY = (int) (y0 - downY);
+                                final int d = (dX * dX) + (dY * dY);
+                                withinGesture = d > touchSlopSquare;                            
+                            }
+                        }
+                    }
+                    if(DEBUG_MOUSE_EVENT) {
+                        final double dX = x0 - downX;
+                        final double dY = y0 - downY;
+                        final double d = Math.sqrt( (dX * dX) + (dY * dY) );
+                        System.err.println(this+".onMove.0: mDist "+d+", pStartDist "+dist+", gPtr "+gPtr+", distWithin2DTSlop "+isDistWithinDoubleTapSlop+", dLast "+lastX+"/"+lastY+", "+e);
+                    }
                 }
-                scrollDistance[0] = dLastX - x;
-                scrollDistance[1] = dLastY - y;
-                dLastX = x;
-                dLastY = y;
-                if(DEBUG_MOUSE_EVENT) {
-                    System.err.println(this+".onActionMove: startDist "+dStartDist+", dist "+dist+", distWithin2DTSlop "+isDistWithinDoubleTapSlop+", distDeltaWithinTSlop "+isDistDeltaWithinTouchSlop+", d "+scrollDistance[0]+"/"+scrollDistance[1]+", "+e);
+                if( withinGesture ) {
+                    final int gPtr = gesturePointers(e, -1);
+                    final boolean isDistGrowthWithinTouchSlop = dist - startDist <= touchSlop; 
+                    if( 2 > gPtr || !isDistGrowthWithinTouchSlop ) {
+                        clear();
+                    } else {
+                        scrollDistance[0] = lastX - x0;
+                        scrollDistance[1] = lastY - y0;
+                        lastX = x0;
+                        lastY = y0;
+                        hasGesture = true;
+                    }
+                    if(DEBUG_MOUSE_EVENT) {
+                        System.err.println(this+".onMove.1: pStartDist "+startDist+", pDist "+dist+", gPtr "+gPtr+" ["+pIds[0]+", "+pIds[1]+"]"+
+                                           ", distWithin2DTSlop "+isDistWithinDoubleTapSlop+", distGrowthWithinTSlop "+isDistGrowthWithinTouchSlop+
+                                           ", dLast "+lastX+"/"+lastY+", d "+scrollDistance[0]+"/"+scrollDistance[1]+", "+e);
+                    }
                 }
             }
         }
diff --git a/src/test/com/jogamp/opengl/test/android/MovieCubeActivity0.java b/src/test/com/jogamp/opengl/test/android/MovieCubeActivity0.java
index 6aa2a045e..3e61e509c 100644
--- a/src/test/com/jogamp/opengl/test/android/MovieCubeActivity0.java
+++ b/src/test/com/jogamp/opengl/test/android/MovieCubeActivity0.java
@@ -54,7 +54,7 @@ public class MovieCubeActivity0 extends NewtBaseActivity {
    MouseAdapter showKeyboardMouseListener = new MouseAdapter() {
         @Override
         public void mousePressed(MouseEvent e) {
-           if(e.getPressure(true)>0.8f) {
+           if( e.getPointerCount() == 4 && e.getPressure(true) > 0.7f ) {
                ((com.jogamp.newt.Window) e.getSource()).setKeyboardVisible(true);
            }
         }
diff --git a/src/test/com/jogamp/opengl/test/android/NEWTGearsES2ActivityLauncher.java b/src/test/com/jogamp/opengl/test/android/NEWTGearsES2ActivityLauncher.java
index 35cf9e7dd..af5b70776 100644
--- a/src/test/com/jogamp/opengl/test/android/NEWTGearsES2ActivityLauncher.java
+++ b/src/test/com/jogamp/opengl/test/android/NEWTGearsES2ActivityLauncher.java
@@ -60,6 +60,7 @@ public class NEWTGearsES2ActivityLauncher extends LauncherUtil.BaseActivityLaunc
        props.setProperty("newt.debug.Window", "true");
        props.setProperty("newt.debug.Window.MouseEvent", "true");
        props.setProperty("newt.debug.Window.KeyEvent", "true");
+       // props.setProperty("newt.debug.Android.MouseEvent", "true");       
     }
     
     @Override
diff --git a/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/GearsES2.java b/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/GearsES2.java
index 06635f2d5..49f1940dc 100644
--- a/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/GearsES2.java
+++ b/src/test/com/jogamp/opengl/test/junit/jogl/demos/es2/GearsES2.java
@@ -434,12 +434,15 @@ public class GearsES2 implements GLEventListener {
         }
         
         public void mousePressed(MouseEvent e) {
-            if( !gesture2PtrZoom.isWithinGesture() && e.getPointerCount()==1 ) {
-                prevMouseX = e.getX();
-                prevMouseY = e.getY();
-                Object src = e.getSource();
-                if(e.getPressure(true)>0.8f && src instanceof Window) { // show Keyboard
-                   ((Window) src).setKeyboardVisible(true);
+            if( !gesture2PtrZoom.isWithinGesture() ) {
+                if( e.getPointerCount()==1 ) {
+                    prevMouseX = e.getX();
+                    prevMouseY = e.getY();
+                } else if( e.getPointerCount() == 4 ) {
+                    final Object src = e.getSource();
+                    if( e.getPressure(true) > 0.7f && src instanceof Window) { // show Keyboard
+                       ((Window) src).setKeyboardVisible(true);
+                    }
                 }
             }
         }