Bug 1180295 - Ensure we don't scroll past the end of the page. r=rbarker

--HG--
extra : commitid : 1y6f6Li4Zl4

mobile/android/base/gfx/Axis.java

@@ -206,6 +206,7 @@ abstract class Axis {
     protected abstract float getViewportLength();
     protected abstract float getPageStart();
     protected abstract float getPageLength();
+    protected abstract float getVisibleEndOfLayerView();
 
     Axis(SubdocumentScrollHelper subscroller) {
         mSubscroller = subscroller;
@@ -499,8 +500,8 @@ abstract class Axis {
 
             if (mDisplacement + getOrigin() < getPageStart()) {
                 mDisplacement = getPageStart() - getOrigin();
-            } else if (mDisplacement + getViewportEnd() > getPageEnd()) {
-                mDisplacement = getPageEnd() - getViewportEnd();
+            } else if (mDisplacement + getOrigin() + getVisibleEndOfLayerView() > getPageEnd()) {
+                mDisplacement = getPageEnd() - getOrigin() - getVisibleEndOfLayerView();
             }
 
             // Return the amount of overscroll so that the overscroll controller can draw it for us

mobile/android/base/gfx/DynamicToolbarAnimator.java

@@ -331,6 +331,11 @@ public class DynamicToolbarAnimator {
         return true;
     }
 
+    public PointF getVisibleEndOfLayerView() {
+        return new PointF(mTarget.getView().getWidth(),
+            mTarget.getView().getHeight() - mMaxTranslation + mLayerViewTranslation);
+    }
+
     private float bottomOfCssViewport(ImmutableViewportMetrics aMetrics) {
         return aMetrics.getHeight() + mMaxTranslation - mLayerViewTranslation;
     }

mobile/android/base/gfx/GeckoLayerClient.java

@@ -746,6 +746,12 @@ class GeckoLayerClient implements LayerView.Listener, PanZoomTarget
         return mView.getFullScreenState();
     }
 
+    /** Implementation of PanZoomTarget */
+    @Override
+    public PointF getVisibleEndOfLayerView() {
+        return mToolbarAnimator.getVisibleEndOfLayerView();
+    }
+
     /** Implementation of PanZoomTarget */
     @Override
     public void setAnimationTarget(ImmutableViewportMetrics metrics) {

mobile/android/base/gfx/JavaPanZoomController.java

@@ -1103,6 +1103,10 @@ class JavaPanZoomController
         @Override
         protected float getPageLength() { return getMetrics().getPageWidthWithMargins(); }
         @Override
+        protected float getVisibleEndOfLayerView() {
+            return mTarget.getVisibleEndOfLayerView().x;
+        }
+        @Override
         protected void overscrollFling(final float velocity) {
             if (mOverscroll != null) {
                 mOverscroll.setVelocity(velocity, Overscroll.Axis.X);
@@ -1127,6 +1131,10 @@ class JavaPanZoomController
         @Override
         protected float getPageLength() { return getMetrics().getPageHeightWithMargins(); }
         @Override
+        protected float getVisibleEndOfLayerView() {
+            return mTarget.getVisibleEndOfLayerView().y;
+        }
+        @Override
         protected void overscrollFling(final float velocity) {
             if (mOverscroll != null) {
                 mOverscroll.setVelocity(velocity, Overscroll.Axis.Y);

mobile/android/base/gfx/PanZoomTarget.java

@@ -14,6 +14,7 @@ public interface PanZoomTarget {
     public ImmutableViewportMetrics getViewportMetrics();
     public ZoomConstraints getZoomConstraints();
     public FullScreenState getFullScreenState();
+    public PointF getVisibleEndOfLayerView();
 
     public void setAnimationTarget(ImmutableViewportMetrics viewport);
     public void setViewportMetrics(ImmutableViewportMetrics viewport);