From 1460000399897d529f925928737669cd3712474f Mon Sep 17 00:00:00 2001
From: Chris Lord <chrislord.net@gmail.com>
Date: Fri, 16 Jan 2015 16:42:46 +0000
Subject: [PATCH] Bug 1042103 - Don't ignore events during overscroll. r=botond

---
 gfx/layers/apz/src/APZCTreeManager.cpp        | 26 -------------------
 gfx/layers/apz/src/APZUtils.h                 |  1 -
 gfx/layers/apz/src/AsyncPanZoomController.cpp | 11 ++++----
 3 files changed, 6 insertions(+), 32 deletions(-)

diff --git a/gfx/layers/apz/src/APZCTreeManager.cpp b/gfx/layers/apz/src/APZCTreeManager.cpp
index 43f0ca869494..edf67fb6b44c 100644
--- a/gfx/layers/apz/src/APZCTreeManager.cpp
+++ b/gfx/layers/apz/src/APZCTreeManager.cpp
@@ -649,9 +649,6 @@ APZCTreeManager::ReceiveInputEvent(InputData& aEvent,
       break;
     }
   }
-  if (hitResult == HitOverscrolledApzc) {
-    result = nsEventStatus_eConsumeNoDefault;
-  }
   return result;
 }
 
@@ -772,9 +769,6 @@ APZCTreeManager::ProcessTouchInput(MultiTouchInput& aInput,
           outTransform, touchData.mScreenPoint);
     }
   }
-  if (mHitResultForInputBlock == HitOverscrolledApzc) {
-    result = nsEventStatus_eConsumeNoDefault;
-  }
 
   if (aInput.mType == MultiTouchInput::MULTITOUCH_END) {
     if (mTouchCount >= aInput.mTouches.Length()) {
@@ -834,9 +828,6 @@ APZCTreeManager::ProcessEvent(WidgetInputEvent& aEvent,
     Matrix4x4 outTransform = transformToApzc * transformToGecko;
     aEvent.refPoint = TransformTo<LayoutDevicePixel>(outTransform, aEvent.refPoint);
   }
-  if (hitResult == HitOverscrolledApzc) {
-    result = nsEventStatus_eConsumeNoDefault;
-  }
   return result;
 }
 
@@ -1195,8 +1186,6 @@ APZCTreeManager::GetTargetAPZC(const ScreenPoint& aPoint, HitTestResult* aOutHit
     PixelCastJustification::ScreenIsParentLayerForRoot);
   nsRefPtr<AsyncPanZoomController> target = GetAPZCAtPoint(mRootNode, point, &hitResult);
 
-  // If we are in an overscrolled APZC, we should be returning nullptr.
-  MOZ_ASSERT(!(target && (hitResult == HitOverscrolledApzc)));
   if (aOutHitResult) {
     *aOutHitResult = hitResult;
   }
@@ -1322,8 +1311,6 @@ APZCTreeManager::GetAPZCAtPoint(HitTestingTreeNode* aNode,
   // This walks the tree in depth-first, reverse order, so that it encounters
   // APZCs front-to-back on the screen.
   for (HitTestingTreeNode* node = aNode; node; node = node->GetPrevSibling()) {
-    AsyncPanZoomController* apzc = node->GetApzc();
-
     if (node->IsOutsideClip(aHitTestPoint)) {
       // If the point being tested is outside the clip region for this node
       // then we don't need to test against this node or any of its children.
@@ -1342,10 +1329,6 @@ APZCTreeManager::GetAPZCAtPoint(HitTestingTreeNode* aNode,
       ParentLayerPoint childPoint = ViewAs<ParentLayerPixel>(hitTestPointForChildLayers.ref(),
         PixelCastJustification::MovingDownToChildren);
       result = GetAPZCAtPoint(node->GetLastChild(), childPoint, aOutHitResult);
-      if (*aOutHitResult == HitOverscrolledApzc) {
-        // We matched an overscrolled APZC, abort.
-        return nullptr;
-      }
     }
 
     // If we didn't match anything in the subtree, check |node|.
@@ -1365,15 +1348,6 @@ APZCTreeManager::GetAPZCAtPoint(HitTestingTreeNode* aNode,
       }
     }
 
-    // If we are overscrolled, and the point matches us or one of our children,
-    // the result is inside an overscrolled APZC, inform our caller of this
-    // (callers typically ignore events targeted at overscrolled APZCs).
-    if (*aOutHitResult != HitNothing && apzc && apzc->IsOverscrolled()) {
-      APZCTM_LOG("Result is inside overscrolled APZC %p\n", apzc);
-      *aOutHitResult = HitOverscrolledApzc;
-      return nullptr;
-    }
-
     if (*aOutHitResult != HitNothing) {
       if (result && !gfxPrefs::LayoutEventRegionsEnabled()) {
         // When event-regions are disabled, we treat scrollinfo layers as
diff --git a/gfx/layers/apz/src/APZUtils.h b/gfx/layers/apz/src/APZUtils.h
index b60347d549c6..8742589cab17 100644
--- a/gfx/layers/apz/src/APZUtils.h
+++ b/gfx/layers/apz/src/APZUtils.h
@@ -14,7 +14,6 @@ enum HitTestResult {
   HitNothing,
   HitLayer,
   HitDispatchToContentRegion,
-  HitOverscrolledApzc,
 };
 
 }
diff --git a/gfx/layers/apz/src/AsyncPanZoomController.cpp b/gfx/layers/apz/src/AsyncPanZoomController.cpp
index fb28129b4cfa..588d66d64362 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -1146,6 +1146,7 @@ nsEventStatus AsyncPanZoomController::OnTouchStart(const MultiTouchInput& aEvent
     case FLING:
     case ANIMATING_ZOOM:
     case SMOOTH_SCROLL:
+    case OVERSCROLL_ANIMATION:
       CurrentTouchBlock()->GetOverscrollHandoffChain()->CancelAnimations();
       // Fall through.
     case NOTHING: {
@@ -1226,8 +1227,8 @@ nsEventStatus AsyncPanZoomController::OnTouchMove(const MultiTouchInput& aEvent)
 
     case OVERSCROLL_ANIMATION:
       // Should not receive a touch-move in the OVERSCROLL_ANIMATION state
-      // as touch blocks that begin in an overscrolled state
-      // are ignored.
+      // as touch blocks that begin in an overscrolled state cancel the
+      // animation.
       NS_WARNING("Received impossible touch in OnTouchMove");
       break;
   }
@@ -1310,9 +1311,9 @@ nsEventStatus AsyncPanZoomController::OnTouchEnd(const MultiTouchInput& aEvent)
     return nsEventStatus_eIgnore;
 
   case OVERSCROLL_ANIMATION:
-    // Should not receive a touch-move in the OVERSCROLL_ANIMATION state
-    // as touch blocks that begin in an overscrolled state
-    // are ignored.
+    // Should not receive a touch-end in the OVERSCROLL_ANIMATION state
+    // as touch blocks that begin in an overscrolled state cancel the
+    // animation.
     NS_WARNING("Received impossible touch in OnTouchEnd");
     break;
   }