Bug 1515774 - Pass current GeckoView position with touch events to APZC. r=geckoview-reviewers,snorp

Differential Revision: https://phabricator.services.mozilla.com/D17044

--HG--
extra : moz-landing-system : lando

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/PanZoomController.java

@@ -39,7 +39,7 @@ public class PanZoomController extends JNIObject {
 
     @WrapForJNI(calledFrom = "ui")
     private native boolean handleMotionEvent(
-            int action, int actionIndex, long time, int metaState,
+            int action, int actionIndex, long time, int metaState,  float screenX, float screenY,
             int pointerId[], float x[], float y[], float orientation[], float pressure[],
             float toolMajor[], float toolMinor[]);
 
@@ -94,8 +94,15 @@ public class PanZoomController extends JNIObject {
             toolMinor[i] = coords.toolMinor;
         }
 
+        final float screenX = event.getRawX() - event.getX();
+        final float screenY = event.getRawY() - event.getY();
+
+        // Take this opportunity to update screen origin of session. This gets
+        // dispatched to the gecko thread, so we also pass the new screen x/y directly to apz.
+        mSession.onScreenOriginChanged((int)screenX, (int)screenY);
+
         return handleMotionEvent(action, event.getActionIndex(), event.getEventTime(),
-                event.getMetaState(), pointerId, x, y, orientation, pressure,
+                event.getMetaState(), screenX, screenY, pointerId, x, y, orientation, pressure,
                 toolMajor, toolMinor);
     }
 

widget/android/nsWindow.cpp

@@ -647,7 +647,8 @@ class nsWindow::NPZCSupport final
 
   bool HandleMotionEvent(const PanZoomController::LocalRef& aInstance,
                          int32_t aAction, int32_t aActionIndex, int64_t aTime,
-                         int32_t aMetaState, jni::IntArray::Param aPointerId,
+                         int32_t aMetaState, float aScreenX, float aScreenY,
+                         jni::IntArray::Param aPointerId,
                          jni::FloatArray::Param aX, jni::FloatArray::Param aY,
                          jni::FloatArray::Param aOrientation,
                          jni::FloatArray::Param aPressure,
@@ -697,6 +698,8 @@ class nsWindow::NPZCSupport final
     MultiTouchInput input(type, aTime, GetEventTimeStamp(aTime), 0);
     input.modifiers = GetModifiers(aMetaState);
     input.mTouches.SetCapacity(endIndex - startIndex);
+    input.mScreenOffset =
+        ExternalIntPoint(int32_t(floorf(aScreenX)), int32_t(floorf(aScreenY)));
 
     nsTArray<float> x(aX->GetElements());
     nsTArray<float> y(aY->GetElements());