Bug 1233056 - Long tapping on a link will select a different link from the page r=tnikkel

Long tapping would fail when Java Pan-Zoom was enabled in Fennec.

dom/base/nsContentUtils.cpp

@@ -7659,7 +7659,7 @@ nsContentUtils::ToWidgetPoint(const CSSPoint& aPoint,
 {
   return LayoutDeviceIntPoint::FromAppUnitsRounded(
     (CSSPoint::ToAppUnits(aPoint) +
-    aOffset).ApplyResolution(aPresContext->PresShell()->GetCumulativeNonRootScaleResolution()),
+    aOffset).ApplyResolution(nsLayoutUtils::GetCurrentAPZResolutionScale(aPresContext->PresShell())),
     aPresContext->AppUnitsPerDevPixel());
 }
 

dom/events/Event.cpp

@@ -933,7 +933,7 @@ Event::GetScreenCoords(nsPresContext* aPresContext,
     LayoutDevicePixel::ToAppUnits(aPoint, aPresContext->DeviceContext()->AppUnitsPerDevPixelAtUnitFullZoom());
 
   if (aPresContext->PresShell()) {
-    pt = pt.RemoveResolution(aPresContext->PresShell()->GetCumulativeNonRootScaleResolution());
+    pt = pt.RemoveResolution(nsLayoutUtils::GetCurrentAPZResolutionScale(aPresContext->PresShell()));
   }
 
   pt += LayoutDevicePixel::ToAppUnits(guiEvent->widget->WidgetToScreenOffset(),

layout/base/nsLayoutUtils.cpp

@@ -809,6 +809,15 @@ nsLayoutUtils::AsyncPanZoomEnabled(nsIFrame* aFrame)
   return widget->AsyncPanZoomEnabled();
 }
 
+float
+nsLayoutUtils::GetCurrentAPZResolutionScale(nsIPresShell* aShell) {
+#if !defined(MOZ_WIDGET_ANDROID) || defined(MOZ_ANDROID_APZ)
+  return aShell ? aShell->GetCumulativeNonRootScaleResolution() : 1.0;
+#else
+  return 1.0f;
+#endif
+}
+
 // Return the maximum displayport size, based on the LayerManager's maximum
 // supported texture size. The result is in app units.
 static nscoord
@@ -2063,7 +2072,7 @@ nsLayoutUtils::GetEventCoordinatesRelativeTo(nsIWidget* aWidget,
       nsPoint pt(presContext->DevPixelsToAppUnits(aPoint.x),
                  presContext->DevPixelsToAppUnits(aPoint.y));
       pt = pt - view->ViewToWidgetOffset();
-      pt = pt.RemoveResolution(presContext->PresShell()->GetCumulativeNonRootScaleResolution());
+      pt = pt.RemoveResolution(GetCurrentAPZResolutionScale(presContext->PresShell()));
       return pt;
     }
   }
@@ -2102,7 +2111,7 @@ nsLayoutUtils::GetEventCoordinatesRelativeTo(nsIWidget* aWidget,
   nsIPresShell* shell = aFrame->PresContext()->PresShell();
 
   // XXX Bug 1224748 - Update nsLayoutUtils functions to correctly handle nsPresShell resolution
-  widgetToView = widgetToView.RemoveResolution(shell->GetCumulativeNonRootScaleResolution());
+  widgetToView = widgetToView.RemoveResolution(GetCurrentAPZResolutionScale(shell));
 
   /* If we encountered a transform, we can't do simple arithmetic to figure
    * out how to convert back to aFrame's coordinates and must use the CTM.
@@ -2851,7 +2860,7 @@ nsLayoutUtils::TranslateViewToWidget(nsPresContext* aPresContext,
   }
 
   nsPoint pt = (aPt +
-  viewOffset).ApplyResolution(aPresContext->PresShell()->GetCumulativeNonRootScaleResolution());
+  viewOffset).ApplyResolution(GetCurrentAPZResolutionScale(aPresContext->PresShell()));
   LayoutDeviceIntPoint relativeToViewWidget(aPresContext->AppUnitsToDevPixels(pt.x),
                                             aPresContext->AppUnitsToDevPixels(pt.y));
   return relativeToViewWidget + WidgetToWidgetOffset(viewWidget, aWidget);

layout/base/nsLayoutUtils.h

@@ -2660,6 +2660,12 @@ public:
    */
   static bool AsyncPanZoomEnabled(nsIFrame* aFrame);
 
+  /**
+   * Returns the current APZ Resolution Scale. When Java Pan/Zoom is
+   * enabled in Fennec it will always return 1.0.
+   */
+  static float GetCurrentAPZResolutionScale(nsIPresShell* aShell);
+
   /**
    * Log a key/value pair for APZ testing during a paint.
    * @param aManager   The data will be written to the APZTestData associated