android: PanZoomControler updates from Fennec

Change-Id: Ic338221ced6133771af8f46ae4a257e043a1709f

6 files changed, 119 insertions, 128 deletions

diff --git a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerController.java b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerController.java
index 59fc1fea2573..8a39b82c259f 100644
--- a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerController.java
+++ b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerController.java
@@ -80,6 +80,10 @@ public class LayerController {
         layerClient.setLayerController(this);
     }
 
+    public void destroy() {
+        mPanZoomController.destroy();
+    }
+
     public void setForceRedraw() {
         mForceRedraw = true;
     }
@@ -93,26 +97,10 @@ public class LayerController {
         return mViewportMetrics.getViewport();
     }
 
-    public RectF getCssViewport() {
-        return mViewportMetrics.getCssViewport();
-    }
-
     public FloatSize getViewportSize() {
         return mViewportMetrics.getSize();
     }
 
-    public RectF getPageRect() {
-        return mViewportMetrics.getPageRect();
-    }
-
-    public RectF getCssPageRect() {
-        return mViewportMetrics.getCssPageRect();
-    }
-
-    public PointF getOrigin() {
-        return mViewportMetrics.getOrigin();
-    }
-
     public float getZoomFactor() {
         return mViewportMetrics.zoomFactor;
     }
@@ -321,11 +309,6 @@ public class LayerController {
 
     public void setAllowZoom(final boolean aValue) {
         mAllowZoom = aValue;
-        mView.post(new Runnable() {
-            public void run() {
-                mView.getTouchEventHandler().setDoubleTapEnabled(aValue);
-            }
-        });
     }
 
     public boolean getAllowZoom() {
diff --git a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerRenderer.java b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerRenderer.java
index f7d8c4efe8d3..c6f11f4ba089 100644
--- a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerRenderer.java
+++ b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerRenderer.java
@@ -188,11 +188,9 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
     @Override
     protected void finalize() throws Throwable {
         try {
-            if (mCoordByteBuffer != null) {
-                DirectBufferAllocator.free(mCoordByteBuffer);
-                mCoordByteBuffer = null;
-                mCoordBuffer = null;
-            }
+            DirectBufferAllocator.free(mCoordByteBuffer);
+            mCoordByteBuffer = null;
+            mCoordBuffer = null;
         } finally {
             super.finalize();
         }
@@ -333,14 +331,6 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
             moveFrameRateLayer(width, height);
         }
 
-        // updating the state in the view/controller/client should be
-        // done on the main UI thread, not the GL renderer thread
-        mView.post(new Runnable() {
-            public void run() {
-                mView.setViewportSize(new IntSize(width, height));
-            }
-        });
-
         /* TODO: Throw away tile images? */
     }
 
diff --git a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerView.java b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerView.java
index 9c6a61698926..18f6328d55d7 100644
--- a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerView.java
+++ b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerView.java
@@ -74,6 +74,13 @@ public class LayerView extends SurfaceView implements SurfaceHolder.Callback {
 
     @Override
     public boolean onTouchEvent(MotionEvent event) {
+        if (event.getActionMasked() == MotionEvent.ACTION_DOWN)
+            requestFocus();
+        return mTouchEventHandler.handleEvent(event);
+    }
+
+    @Override
+    public boolean onHoverEvent(MotionEvent event) {
         return mTouchEventHandler.handleEvent(event);
     }
 
diff --git a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/TouchEventHandler.java b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/TouchEventHandler.java
index 78a141ee0343..b93b5f0a1ff6 100644
--- a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/TouchEventHandler.java
+++ b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/TouchEventHandler.java
@@ -7,6 +7,7 @@ package org.mozilla.gecko.gfx;
 
 import android.content.Context;
 import android.os.SystemClock;
+import android.util.Log;
 import android.view.GestureDetector;
 import android.view.MotionEvent;
 import android.view.View.OnTouchListener;
@@ -58,7 +59,6 @@ public final class TouchEventHandler {
     private final GestureDetector mGestureDetector;
     private final SimpleScaleGestureDetector mScaleGestureDetector;
     private final PanZoomController mPanZoomController;
-    private final GestureDetector.OnDoubleTapListener mDoubleTapListener;
 
     // the queue of events that we are holding on to while waiting for a preventDefault
     // notification
@@ -133,8 +133,7 @@ public final class TouchEventHandler {
         mListenerTimeoutProcessor = new ListenerTimeoutProcessor();
         mDispatchEvents = true;
 
-        mDoubleTapListener = controller.getDoubleTapListener();
-        setDoubleTapEnabled(true);
+        mGestureDetector.setOnDoubleTapListener(controller.getDoubleTapListener());
     }
 
     /* This function MUST be called on the UI thread */
@@ -146,6 +145,12 @@ public final class TouchEventHandler {
             return true;
         }
 
+        // if this is a hover event just notify gecko, we don't have any interest in the java layer.
+        if (isHoverEvent(event)) {
+            mOnTouchListener.onTouch(mView, event);
+            return true;
+        }
+
         if (isDownEvent(event)) {
             // this is the start of a new block of events! whee!
             mHoldInQueue = mWaitForTouchListeners;
@@ -159,18 +164,20 @@ public final class TouchEventHandler {
                 // other blocks waiting in the queue, then we should let the pan/zoom controller
                 // know we are waiting for the touch listeners to run
                 if (mEventQueue.isEmpty()) {
-                    mPanZoomController.waitingForTouchListeners(event);
+                    mPanZoomController.startingNewEventBlock(event, true);
                 }
-                // if we're holding the events in the queue, set the timeout so that
-                // we dispatch these events if we don't get a default-prevented notification
-                mView.postDelayed(mListenerTimeoutProcessor, EVENT_LISTENER_TIMEOUT);
             } else {
-                // if we're not holding these events, then we still need to pretend like
-                // we did and had a ListenerTimeoutProcessor fire so that when we get
-                // the default-prevented notification for this block, it doesn't accidentally
-                // act upon some other block
-                mProcessingBalance++;
+                // we're not going to be holding this block of events in the queue, but we need
+                // a marker of some sort so that the processEventBlock loop deals with the blocks
+                // in the right order as notifications come in. we use a single null event in
+                // the queue as a placeholder for a block of events that has already been dispatched.
+                mEventQueue.add(null);
+                mPanZoomController.startingNewEventBlock(event, false);
             }
+
+            // set the timeout so that we dispatch these events and update mProcessingBalance
+            // if we don't get a default-prevented notification
+            mView.postDelayed(mListenerTimeoutProcessor, EVENT_LISTENER_TIMEOUT);
         }
 
         // if we need to hold the events, add it to the queue. if we need to dispatch
@@ -213,11 +220,6 @@ public final class TouchEventHandler {
     }
 
     /* This function MUST be called on the UI thread. */
-    public void setDoubleTapEnabled(boolean aValue) {
-        mGestureDetector.setOnDoubleTapListener(aValue ? mDoubleTapListener : null);
-    }
-
-    /* This function MUST be called on the UI thread. */
     public void setWaitForTouchListeners(boolean aValue) {
         mWaitForTouchListeners = aValue;
     }
@@ -227,6 +229,11 @@ public final class TouchEventHandler {
         mOnTouchListener = onTouchListener;
     }
 
+    private boolean isHoverEvent(MotionEvent event) {
+        int action = (event.getAction() & MotionEvent.ACTION_MASK);
+        return (action == MotionEvent.ACTION_HOVER_ENTER || action == MotionEvent.ACTION_HOVER_MOVE || action == MotionEvent.ACTION_HOVER_EXIT);
+    }
+
     private boolean isDownEvent(MotionEvent event) {
         int action = (event.getAction() & MotionEvent.ACTION_MASK);
         return (action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_POINTER_DOWN);
@@ -242,16 +249,7 @@ public final class TouchEventHandler {
      */
     private void dispatchEvent(MotionEvent event) {
         if (mGestureDetector.onTouchEvent(event)) {
-            // An up/cancel event should get passed to both detectors, in
-            // case it comes from a pointer the scale detector is tracking.
-            switch (event.getAction() & MotionEvent.ACTION_MASK) {
-                case MotionEvent.ACTION_POINTER_UP:
-                case MotionEvent.ACTION_UP:
-                case MotionEvent.ACTION_CANCEL:
-                    break;
-                default:
-                    return;
-            }
+            return;
         }
         mScaleGestureDetector.onTouchEvent(event);
         if (mScaleGestureDetector.isInProgress()) {
@@ -272,6 +270,11 @@ public final class TouchEventHandler {
             dispatchEvent(MotionEvent.obtain(now, now, MotionEvent.ACTION_CANCEL, 0, 0, 0));
         }
 
+        if (mEventQueue.isEmpty()) {
+            Log.e(LOGTAG, "Unexpected empty event queue in processEventBlock!", new Exception());
+            return;
+        }
+
         // the odd loop condition is because the first event in the queue will
         // always be a DOWN or POINTER_DOWN event, and we want to process all
         // the events in the queue starting at that one, up to but not including
@@ -279,15 +282,19 @@ public final class TouchEventHandler {
 
         MotionEvent event = mEventQueue.poll();
         while (true) {
-            // for each event we process, only dispatch it if the block hasn't been
-            // default-prevented.
-            if (allowDefaultAction) {
-                dispatchEvent(event);
-            } else if (touchFinished(event)) {
-                mPanZoomController.preventedTouchFinished();
+            // event being null here is valid and represents a block of events
+            // that has already been dispatched.
+
+            if (event != null) {
+                // for each event we process, only dispatch it if the block hasn't been
+                // default-prevented.
+                if (allowDefaultAction) {
+                    dispatchEvent(event);
+                } else if (touchFinished(event)) {
+                    mPanZoomController.preventedTouchFinished();
+                }
             }
-            event = mEventQueue.peek();
-            if (event == null) {
+            if (mEventQueue.isEmpty()) {
                 // we have processed the backlog of events, and are all caught up.
                 // now we can set clear the hold flag and set the dispatch flag so
                 // that the handleEvent() function can do the right thing for all
@@ -297,10 +304,13 @@ public final class TouchEventHandler {
                 mDispatchEvents = allowDefaultAction;
                 break;
             }
-            if (isDownEvent(event)) {
+            event = mEventQueue.peek();
+            if (event == null || isDownEvent(event)) {
                 // we have finished processing the block we were interested in.
                 // now we wait for the next call to processEventBlock
-                mPanZoomController.waitingForTouchListeners(event);
+                if (event != null) {
+                    mPanZoomController.startingNewEventBlock(event, true);
+                }
                 break;
             }
             // pop the event we peeked above, as it is still part of the block and
diff --git a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/PanZoomController.java b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/PanZoomController.java
index 0cb83ef79d8c..243fa75d2129 100644
--- a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/PanZoomController.java
+++ b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/PanZoomController.java
@@ -14,6 +14,7 @@ import android.view.MotionEvent;
 
 import org.libreoffice.LOKitShell;
 import org.libreoffice.LibreOfficeMainActivity;
+import org.mozilla.gecko.gfx.ImmutableViewportMetrics;
 import org.mozilla.gecko.gfx.LayerController;
 import org.mozilla.gecko.gfx.ViewportMetrics;
 import org.mozilla.gecko.util.FloatUtils;
@@ -117,7 +118,19 @@ public class PanZoomController
         mMainThread = LibreOfficeMainActivity.mAppContext.getMainLooper().getThread();
         checkMainThread();
 
-        mState = PanZoomState.NOTHING;
+        setState(PanZoomState.NOTHING);
+    }
+
+    public void destroy() {
+        mSubscroller.destroy();
+    }
+
+    private void setState(PanZoomState state) {
+        mState = state;
+    }
+
+    private ImmutableViewportMetrics getMetrics() {
+        return mController.getViewportMetrics();
     }
 
     // for debugging bug 713011; it can be taken out once that is resolved.
@@ -171,7 +184,7 @@ public class PanZoomController
         case ANIMATED_ZOOM:
             // the zoom that's in progress likely makes no sense any more (such as if
             // the screen orientation changed) so abort it
-            mState = PanZoomState.NOTHING;
+            setState(PanZoomState.NOTHING);
             // fall through
         case NOTHING:
             // Don't do animations here; they're distracting and can cause flashes on page
@@ -185,14 +198,14 @@ public class PanZoomController
     }
 
     /** This function must be called on the UI thread. */
-    public void waitingForTouchListeners(MotionEvent event) {
+    public void startingNewEventBlock(MotionEvent event, boolean waitingForTouchListeners) {
         checkMainThread();
-        if ((event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
+        mSubscroller.cancel();
+        if (waitingForTouchListeners && (event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
             // this is the first touch point going down, so we enter the pending state
-            mSubscroller.cancel();
             // seting the state will kill any animations in progress, possibly leaving
             // the page in overscroll
-            mState = PanZoomState.WAITING_LISTENERS;
+            setState(PanZoomState.WAITING_LISTENERS);
         }
     }
 
@@ -203,7 +216,6 @@ public class PanZoomController
             // if we enter here, we just finished a block of events whose default actions
             // were prevented by touch listeners. Now there are no touch points left, so
             // we need to reset our state and re-bounce because we might be in overscroll
-            mState = PanZoomState.NOTHING;
             bounce();
         }
     }
@@ -213,7 +225,7 @@ public class PanZoomController
         if (mState == PanZoomState.NOTHING) {
             synchronized (mController) {
                 ViewportMetrics validated = getValidViewportMetrics();
-                if (! (new ViewportMetrics(mController.getViewportMetrics())).fuzzyEquals(validated)) {
+                if (! (new ViewportMetrics(getMetrics())).fuzzyEquals(validated)) {
                     // page size changed such that we are now in overscroll. snap to the
                     // the nearest valid viewport
                     mController.setViewportMetrics(validated);
@@ -231,7 +243,6 @@ public class PanZoomController
         // user is taking control of movement, so stop
         // any auto-movement we have going
         stopAnimationTimer();
-        mSubscroller.cancel();
 
         switch (mState) {
         case ANIMATED_ZOOM:
@@ -285,14 +296,14 @@ public class PanZoomController
             return true;
 
         case PANNING_HOLD_LOCKED:
-            mState = PanZoomState.PANNING_LOCKED;
+            setState(PanZoomState.PANNING_LOCKED);
             // fall through
         case PANNING_LOCKED:
             track(event);
             return true;
 
         case PANNING_HOLD:
-            mState = PanZoomState.PANNING;
+            setState(PanZoomState.PANNING);
             // fall through
         case PANNING:
             track(event);
@@ -322,7 +333,6 @@ public class PanZoomController
             return false;
 
         case TOUCHING:
-            mState = PanZoomState.NOTHING;
             // the switch into TOUCHING might have happened while the page was
             // snapping back after overscroll. we need to finish the snap if that
             // was the case
@@ -333,12 +343,12 @@ public class PanZoomController
         case PANNING_LOCKED:
         case PANNING_HOLD:
         case PANNING_HOLD_LOCKED:
-            mState = PanZoomState.FLING;
+            setState(PanZoomState.FLING);
             fling();
             return true;
 
         case PINCHING:
-            mState = PanZoomState.NOTHING;
+            setState(PanZoomState.NOTHING);
             return true;
         }
         Log.e(LOGTAG, "Unhandled case " + mState + " in onTouchEnd");
@@ -357,7 +367,6 @@ public class PanZoomController
         }
 
         cancelTouch();
-        mState = PanZoomState.NOTHING;
         // ensure we snap back if we're overscrolled
         bounce();
         return false;
@@ -366,7 +375,7 @@ public class PanZoomController
     private void startTouch(float x, float y, long time) {
         mX.startTouch(x);
         mY.startTouch(y);
-        mState = PanZoomState.TOUCHING;
+        setState(PanZoomState.TOUCHING);
         mLastEventTime = time;
     }
 
@@ -384,12 +393,12 @@ public class PanZoomController
 
         if (angle < AXIS_LOCK_ANGLE || angle > (Math.PI - AXIS_LOCK_ANGLE)) {
             mY.setScrollingDisabled(true);
-            mState = PanZoomState.PANNING_LOCKED;
+            setState(PanZoomState.PANNING_LOCKED);
         } else if (Math.abs(angle - (Math.PI / 2)) < AXIS_LOCK_ANGLE) {
             mX.setScrollingDisabled(true);
-            mState = PanZoomState.PANNING_LOCKED;
+            setState(PanZoomState.PANNING_LOCKED);
         } else {
-            mState = PanZoomState.PANNING;
+            setState(PanZoomState.PANNING);
         }
     }
 
@@ -425,13 +434,13 @@ public class PanZoomController
 
         if (stopped()) {
             if (mState == PanZoomState.PANNING) {
-                mState = PanZoomState.PANNING_HOLD;
+                setState(PanZoomState.PANNING_HOLD);
             } else if (mState == PanZoomState.PANNING_LOCKED) {
-                mState = PanZoomState.PANNING_HOLD_LOCKED;
+                setState(PanZoomState.PANNING_HOLD_LOCKED);
             } else {
                 // should never happen, but handle anyway for robustness
                 Log.e(LOGTAG, "Impossible case " + mState + " when stopped in track");
-                mState = PanZoomState.PANNING_HOLD_LOCKED;
+                setState(PanZoomState.PANNING_HOLD_LOCKED);
             }
         }
 
@@ -456,9 +465,9 @@ public class PanZoomController
     private void bounce(ViewportMetrics metrics) {
         stopAnimationTimer();
 
-        ViewportMetrics bounceStartMetrics = new ViewportMetrics(mController.getViewportMetrics());
+        ViewportMetrics bounceStartMetrics = new ViewportMetrics(getMetrics());
         if (bounceStartMetrics.fuzzyEquals(metrics)) {
-            mState = PanZoomState.NOTHING;
+            setState(PanZoomState.NOTHING);
             return;
         }
 
@@ -472,7 +481,7 @@ public class PanZoomController
 
     /* Performs a bounce-back animation to the nearest valid viewport metrics. */
     private void bounce() {
-        mState = PanZoomState.BOUNCE;
+        setState(PanZoomState.BOUNCE);
         bounce(getValidViewportMetrics());
     }
 
@@ -596,7 +605,7 @@ public class PanZoomController
             /* Finally, if there's nothing else to do, complete the animation and go to sleep. */
             finishBounce();
             finishAnimation();
-            mState = PanZoomState.NOTHING;
+            setState(PanZoomState.NOTHING);
         }
 
         /* Performs one frame of a bounce animation. */
@@ -664,7 +673,7 @@ public class PanZoomController
                 bounce();
             } else {
                 finishAnimation();
-                mState = PanZoomState.NOTHING;
+                setState(PanZoomState.NOTHING);
             }
         }
     }
@@ -672,7 +681,6 @@ public class PanZoomController
     private void finishAnimation() {
         checkMainThread();
 
-        Log.d(LOGTAG, "Finishing animation at " + mController.getViewportMetrics());
         stopAnimationTimer();
 
         // Force a viewport synchronisation
@@ -682,12 +690,10 @@ public class PanZoomController
 
     /* Returns the nearest viewport metrics with no overscroll visible. */
     private ViewportMetrics getValidViewportMetrics() {
-        return getValidViewportMetrics(new ViewportMetrics(mController.getViewportMetrics()));
+        return getValidViewportMetrics(new ViewportMetrics(getMetrics()));
     }
 
     private ViewportMetrics getValidViewportMetrics(ViewportMetrics viewportMetrics) {
-        Log.d(LOGTAG, "generating valid viewport using " + viewportMetrics);
-
         /* First, we adjust the zoom factor so that we can make no overscrolled area visible. */
         float zoomFactor = viewportMetrics.getZoomFactor();
         RectF pageRect = viewportMetrics.getPageRect();
@@ -740,7 +746,6 @@ public class PanZoomController
 
         /* Now we pan to the right origin. */
         viewportMetrics.setViewport(viewportMetrics.getClampedViewport());
-        Log.d(LOGTAG, "generated valid viewport as " + viewportMetrics);
 
         return viewportMetrics;
     }
@@ -748,25 +753,25 @@ public class PanZoomController
     private class AxisX extends Axis {
         AxisX(SubdocumentScrollHelper subscroller) { super(subscroller); }
         @Override
-        public float getOrigin() { return mController.getOrigin().x; }
+        public float getOrigin() { return getMetrics().viewportRectLeft; }
         @Override
-        protected float getViewportLength() { return mController.getViewportSize().width; }
+        protected float getViewportLength() { return getMetrics().getWidth(); }
         @Override
-        protected float getPageStart() { return mController.getPageRect().left; }
+        protected float getPageStart() { return getMetrics().pageRectLeft; }
         @Override
-        protected float getPageLength() { return mController.getPageRect().width(); }
+        protected float getPageLength() { return getMetrics().getPageWidth(); }
     }
 
     private class AxisY extends Axis {
         AxisY(SubdocumentScrollHelper subscroller) { super(subscroller); }
         @Override
-        public float getOrigin() { return mController.getOrigin().y; }
+        public float getOrigin() { return getMetrics().viewportRectTop; }
         @Override
-        protected float getViewportLength() { return mController.getViewportSize().height; }
+        protected float getViewportLength() { return getMetrics().getHeight(); }
         @Override
-        protected float getPageStart() { return mController.getPageRect().top; }
+        protected float getPageStart() { return getMetrics().pageRectTop; }
         @Override
-        protected float getPageLength() { return mController.getPageRect().height(); }
+        protected float getPageLength() { return getMetrics().getPageHeight(); }
     }
 
     /*
@@ -774,15 +779,13 @@ public class PanZoomController
      */
     @Override
     public boolean onScaleBegin(SimpleScaleGestureDetector detector) {
-        Log.d(LOGTAG, "onScaleBegin in " + mState);
-
         if (mState == PanZoomState.ANIMATED_ZOOM)
             return false;
 
         if (!mController.getAllowZoom())
             return false;
 
-        mState = PanZoomState.PINCHING;
+        setState(PanZoomState.PINCHING);
         mLastZoomFocus = new PointF(detector.getFocusX(), detector.getFocusY());
         cancelTouch();
 
@@ -791,9 +794,6 @@ public class PanZoomController
 
     @Override
     public boolean onScale(SimpleScaleGestureDetector detector) {
-        Log.d(LOGTAG, "onScale in state " + mState);
-
-
         if (mState != PanZoomState.PINCHING)
             return false;
 
@@ -857,8 +857,6 @@ public class PanZoomController
 
     @Override
     public void onScaleEnd(SimpleScaleGestureDetector detector) {
-        Log.d(LOGTAG, "onScaleEnd in " + mState);
-
         if (mState == PanZoomState.ANIMATED_ZOOM)
             return;
 
@@ -892,23 +890,17 @@ public class PanZoomController
     @Override
     public boolean onSingleTapUp(MotionEvent motionEvent) {
         // When zooming is enabled, wait to see if there's a double-tap.
-        if (mController.getAllowZoom())
-            return false;
-        return true;
+        return false;
     }
 
     @Override
     public boolean onSingleTapConfirmed(MotionEvent motionEvent) {
         // When zooming is disabled, we handle this in onSingleTapUp.
-        if (!mController.getAllowZoom())
-            return false;
         return true;
     }
 
     @Override
     public boolean onDoubleTap(MotionEvent motionEvent) {
-        if (!mController.getAllowZoom())
-            return false;
         return true;
     }
 
@@ -922,7 +914,7 @@ public class PanZoomController
      * pixels.
      */
     private boolean animatedZoomTo(RectF zoomToRect) {
-        mState = PanZoomState.ANIMATED_ZOOM;
+        setState(PanZoomState.ANIMATED_ZOOM);
         final float startZoom = mController.getZoomFactor();
 
         RectF viewport = mController.getViewport();
@@ -948,7 +940,7 @@ public class PanZoomController
 
         float finalZoom = viewport.width() / zoomToRect.width();
 
-        ViewportMetrics finalMetrics = new ViewportMetrics(mController.getViewportMetrics());
+        ViewportMetrics finalMetrics = new ViewportMetrics(getMetrics());
         finalMetrics.setOrigin(new PointF(zoomToRect.left * finalMetrics.getZoomFactor(),
                                           zoomToRect.top * finalMetrics.getZoomFactor()));
         finalMetrics.scaleTo(finalZoom, new PointF(0.0f, 0.0f));
@@ -960,4 +952,10 @@ public class PanZoomController
         bounce(finalMetrics);
         return true;
     }
+
+    /** This function must be called from the UI thread. */
+    public void abortPanning() {
+        checkMainThread();
+        bounce();
+    }
 }
diff --git a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/SubdocumentScrollHelper.java b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/SubdocumentScrollHelper.java
index 8e7de558e18d..0e74456896ec 100644
--- a/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/SubdocumentScrollHelper.java
+++ b/android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/SubdocumentScrollHelper.java
@@ -45,6 +45,9 @@ class SubdocumentScrollHelper {
         mPendingDisplacement = new PointF();
     }
 
+    void destroy() {
+    }
+
     boolean scrollBy(PointF displacement) {
         if (! mOverridePanning) {
             return false;