Bug 976605 - Turn GeckoCC::NotifyTransform[Begin|End] into an extensible APZ state change notification mechanism. r=kats

--HG--
extra : source : 5353e86dcfe8b2ff6f02e577a4c69a1de6808d9b

dom/ipc/PBrowser.ipdl

@@ -50,6 +50,7 @@ using struct mozilla::layers::TextureFactoryIdentifier from "mozilla/layers/Comp
 using mozilla::CSSPoint from "Units.h";
 using mozilla::CSSToScreenScale from "Units.h";
 using mozilla::CommandInt from "mozilla/EventForwards.h";
+using mozilla::layers::GeckoContentController::APZStateChange from "mozilla/layers/GeckoContentController.h";
 
 namespace mozilla {
 namespace dom {
@@ -410,11 +411,10 @@ child:
     HandleLongTapUp(CSSPoint point, ScrollableLayerGuid aGuid);
 
     /**
-     * Notifies the child that the parent has begun or finished transforming
-     * the visible child content area. Useful for showing/hiding scrollbars.
+     * Notifies the child about various APZ state changes.
+     * See GeckoContentController::NotifyAPZStateChange() for details.
      */
-    NotifyTransformBegin(ViewID aViewId);
-    NotifyTransformEnd(ViewID aViewId);
+    NotifyAPZStateChange(ViewID aViewId, APZStateChange aChange, int aArg);
 
     /**
      * Sending an activate message moves focus to the child.

dom/ipc/TabChild.cpp

@@ -1730,23 +1730,34 @@ TabChild::RecvHandleLongTapUp(const CSSPoint& aPoint, const ScrollableLayerGuid&
 }
 
 bool
-TabChild::RecvNotifyTransformBegin(const ViewID& aViewId)
+TabChild::RecvNotifyAPZStateChange(const ViewID& aViewId,
+                                   const APZStateChange& aChange,
+                                   const int& aArg)
 {
-  nsIScrollableFrame* sf = nsLayoutUtils::FindScrollableFrameFor(aViewId);
-  nsIScrollbarOwner* scrollbarOwner = do_QueryFrame(sf);
-  if (scrollbarOwner) {
-    scrollbarOwner->ScrollbarActivityStarted();
+  switch (aChange)
+  {
+  case APZStateChange::TransformBegin:
+  {
+    nsIScrollableFrame* sf = nsLayoutUtils::FindScrollableFrameFor(aViewId);
+    nsIScrollbarOwner* scrollbarOwner = do_QueryFrame(sf);
+    if (scrollbarOwner) {
+      scrollbarOwner->ScrollbarActivityStarted();
+    }
+    break;
   }
-  return true;
-}
-
-bool
-TabChild::RecvNotifyTransformEnd(const ViewID& aViewId)
-{
-  nsIScrollableFrame* sf = nsLayoutUtils::FindScrollableFrameFor(aViewId);
-  nsIScrollbarOwner* scrollbarOwner = do_QueryFrame(sf);
-  if (scrollbarOwner) {
-    scrollbarOwner->ScrollbarActivityStopped();
+  case APZStateChange::TransformEnd:
+  {
+    nsIScrollableFrame* sf = nsLayoutUtils::FindScrollableFrameFor(aViewId);
+    nsIScrollbarOwner* scrollbarOwner = do_QueryFrame(sf);
+    if (scrollbarOwner) {
+      scrollbarOwner->ScrollbarActivityStopped();
+    }
+    break;
+  }
+  default:
+    // APZStateChange has a 'sentinel' value, and the compiler complains
+    // if an enumerator is not handled and there is no 'default' case.
+    break;
   }
   return true;
 }

dom/ipc/TabChild.h

@@ -296,8 +296,9 @@ public:
                                    const mozilla::layers::ScrollableLayerGuid& aGuid) MOZ_OVERRIDE;
     virtual bool RecvHandleLongTapUp(const CSSPoint& aPoint,
                                      const mozilla::layers::ScrollableLayerGuid& aGuid) MOZ_OVERRIDE;
-    virtual bool RecvNotifyTransformBegin(const ViewID& aViewId) MOZ_OVERRIDE;
-    virtual bool RecvNotifyTransformEnd(const ViewID& aViewId) MOZ_OVERRIDE;
+    virtual bool RecvNotifyAPZStateChange(const ViewID& aViewId,
+                                          const APZStateChange& aChange,
+                                          const int& aArg) MOZ_OVERRIDE;
     virtual bool RecvActivate() MOZ_OVERRIDE;
     virtual bool RecvDeactivate() MOZ_OVERRIDE;
     virtual bool RecvMouseEvent(const nsString& aType,

dom/ipc/TabParent.cpp

@@ -554,17 +554,12 @@ void TabParent::HandleLongTapUp(const CSSPoint& aPoint,
   }
 }
 
-void TabParent::NotifyTransformBegin(ViewID aViewId)
+void TabParent::NotifyAPZStateChange(ViewID aViewId,
+                                     APZStateChange aChange,
+                                     int aArg)
 {
   if (!mIsDestroyed) {
-    unused << SendNotifyTransformBegin(aViewId);
-  }
-}
-
-void TabParent::NotifyTransformEnd(ViewID aViewId)
-{
-  if (!mIsDestroyed) {
-    unused << SendNotifyTransformEnd(aViewId);
+    unused << SendNotifyAPZStateChange(aViewId, aChange, aArg);
   }
 }
 

dom/ipc/TabParent.h

@@ -212,8 +212,9 @@ public:
     void HandleLongTapUp(const CSSPoint& aPoint,
                          int32_t aModifiers,
                          const ScrollableLayerGuid& aGuid);
-    void NotifyTransformBegin(ViewID aViewId);
-    void NotifyTransformEnd(ViewID aViewId);
+    void NotifyAPZStateChange(ViewID aViewId,
+                              APZStateChange aChange,
+                              int aArg);
     void Activate();
     void Deactivate();
 

gfx/ipc/GfxMessageUtils.h

@@ -26,6 +26,7 @@
 #include "mozilla/layers/CompositorTypes.h"
 #include "FrameMetrics.h"
 #include "FilterSupport.h"
+#include "mozilla/layers/GeckoContentController.h"
 
 #ifdef _MSC_VER
 #pragma warning( disable : 4800 )
@@ -1069,6 +1070,16 @@ struct ParamTraits<mozilla::gfx::FilterDescription>
   }
 };
 
+typedef mozilla::layers::GeckoContentController::APZStateChange APZStateChange;
+
+template <>
+struct ParamTraits<APZStateChange>
+  : public ContiguousTypedEnumSerializer<
+             APZStateChange,
+             APZStateChange::TransformBegin,
+             APZStateChange::APZStateChangeSentinel>
+{};
+
 } /* namespace IPC */
 
 #endif /* __GFXMESSAGEUTILS_H__ */

gfx/layers/ipc/AsyncPanZoomController.cpp

@@ -132,6 +132,7 @@ namespace mozilla {
 namespace layers {
 
 typedef mozilla::layers::AllowedTouchBehavior AllowedTouchBehavior;
+typedef GeckoContentController::APZStateChange APZStateChange;
 
 /*
  * The following prefs are used to control the behaviour of the APZC.
@@ -1992,11 +1993,11 @@ void AsyncPanZoomController::SetState(PanZoomState aNewState) {
 
   if (mGeckoContentController) {
     if (!IsTransformingState(oldState) && IsTransformingState(aNewState)) {
-      mGeckoContentController->NotifyTransformBegin(
-        ScrollableLayerGuid(mLayersId, mFrameMetrics.mPresShellId, mFrameMetrics.GetScrollId()));
+      mGeckoContentController->NotifyAPZStateChange(
+        GetGuid(), APZStateChange::TransformBegin);
     } else if (IsTransformingState(oldState) && !IsTransformingState(aNewState)) {
-      mGeckoContentController->NotifyTransformEnd(
-        ScrollableLayerGuid(mLayersId, mFrameMetrics.mPresShellId, mFrameMetrics.GetScrollId()));
+      mGeckoContentController->NotifyAPZStateChange(
+        GetGuid(), APZStateChange::TransformEnd);
     }
   }
 }

gfx/layers/ipc/GeckoContentController.h

@@ -113,13 +113,28 @@ public:
     return false;
   }
 
+  MOZ_BEGIN_NESTED_ENUM_CLASS(APZStateChange, int8_t)
+    /**
+     * APZ started modifying the view (including panning, zooming, and fling).
+     */
+    TransformBegin,
+    /**
+     * APZ finished modifying the view.
+     */
+    TransformEnd,
+    APZStateChangeSentinel
+  MOZ_END_NESTED_ENUM_CLASS(APZStateChange)
+
   /**
-   * General tranformation notices for consumers. These fire any time
-   * the apzc is modifying the view, including panning, zooming, and
-   * fling.
+   * General notices of APZ state changes for consumers.
+   * |aGuid| identifies the APZC originating the state change.
+   * |aChange| identifies the type of state change
+   * |aArg| is used by some state changes to pass extra information (see
+   *        the documentation for each state change above)
    */
-  virtual void NotifyTransformBegin(const ScrollableLayerGuid& aGuid) {}
-  virtual void NotifyTransformEnd(const ScrollableLayerGuid& aGuid) {}
+  virtual void NotifyAPZStateChange(const ScrollableLayerGuid& aGuid,
+                                    APZStateChange aChange,
+                                    int aArg = 0) {}
 
   GeckoContentController() {}
 
@@ -128,6 +143,8 @@ protected:
   virtual ~GeckoContentController() {}
 };
 
+MOZ_FINISH_NESTED_ENUM_CLASS(GeckoContentController::APZStateChange)
+
 }
 }
 

layout/ipc/RenderFrameParent.cpp

@@ -658,33 +658,20 @@ public:
     return true;
   }
 
-  virtual void NotifyTransformBegin(const ScrollableLayerGuid& aGuid)
+  virtual void NotifyAPZStateChange(const ScrollableLayerGuid& aGuid,
+                                    APZStateChange aChange,
+                                    int aArg)
   {
     if (MessageLoop::current() != mUILoop) {
       mUILoop->PostTask(
         FROM_HERE,
-        NewRunnableMethod(this, &RemoteContentController::NotifyTransformBegin,
-                          aGuid));
+        NewRunnableMethod(this, &RemoteContentController::NotifyAPZStateChange,
+                          aGuid, aChange, aArg));
       return;
     }
     if (mRenderFrame) {
       TabParent* browser = static_cast<TabParent*>(mRenderFrame->Manager());
-      browser->NotifyTransformBegin(aGuid.mScrollId);
-    }
-  }
-
-  virtual void NotifyTransformEnd(const ScrollableLayerGuid& aGuid)
-  {
-    if (MessageLoop::current() != mUILoop) {
-      mUILoop->PostTask(
-        FROM_HERE,
-        NewRunnableMethod(this, &RemoteContentController::NotifyTransformEnd,
-                          aGuid));
-      return;
-    }
-    if (mRenderFrame) {
-      TabParent* browser = static_cast<TabParent*>(mRenderFrame->Manager());
-      browser->NotifyTransformEnd(aGuid.mScrollId);
+      browser->NotifyAPZStateChange(aGuid.mScrollId, aChange, aArg);
     }
   }
 

widget/windows/winrt/APZController.cpp

@@ -303,25 +303,37 @@ class TransformedEndEvent : public nsRunnable
 };
 
 void
-APZController::NotifyTransformBegin(const ScrollableLayerGuid& aGuid)
+APZController::NotifyAPZStateChange(const ScrollableLayerGuid& aGuid,
+                                    APZStateChange aChange,
+                                    int aArg)
 {
-  if (NS_IsMainThread()) {
-    MetroUtils::FireObserver("apzc-transform-begin", L"");
-    return;
+  switch (aChange) {
+    case APZStateChange::TransformBegin:
+    {
+      if (NS_IsMainThread()) {
+        MetroUtils::FireObserver("apzc-transform-begin", L"");
+        return;
+      }
+      nsCOMPtr<nsIRunnable> runnable = new TransformedStartEvent();
+      NS_DispatchToMainThread(runnable);
+      break;
+    }
+    case APZStateChange::TransformEnd:
+    {
+      if (NS_IsMainThread()) {
+        MetroUtils::FireObserver("apzc-transform-end", L"");
+        return;
+      }
+      nsCOMPtr<nsIRunnable> runnable = new TransformedEndEvent();
+      NS_DispatchToMainThread(runnable);
+      break;
+    }
+    default:
+    {
+      // We don't currently care about other state changes.
+      break;
+    }
   }
-  nsCOMPtr<nsIRunnable> runnable = new TransformedStartEvent();
-  NS_DispatchToMainThread(runnable);
-}
-
-void
-APZController::NotifyTransformEnd(const ScrollableLayerGuid& aGuid)
-{
-  if (NS_IsMainThread()) {
-    MetroUtils::FireObserver("apzc-transform-end", L"");
-    return;
-  }
-  nsCOMPtr<nsIRunnable> runnable = new TransformedEndEvent();
-  NS_DispatchToMainThread(runnable);
 }
 
 } } }

widget/windows/winrt/APZController.h

@@ -49,8 +49,9 @@ public:
   virtual void SendAsyncScrollDOMEvent(bool aIsRoot, const mozilla::CSSRect &aContentRect, const mozilla::CSSSize &aScrollableSize);
   virtual void PostDelayedTask(Task* aTask, int aDelayMs);
   virtual bool GetRootZoomConstraints(ZoomConstraints* aOutConstraints);
-  virtual void NotifyTransformBegin(const ScrollableLayerGuid& aGuid);
-  virtual void NotifyTransformEnd(const ScrollableLayerGuid& aGuid);
+  virtual void NotifyAPZStateChange(const ScrollableLayerGuid& aGuid,
+                                    APZStateChange aChange,
+                                    int aArg);
   
   void SetWidgetListener(nsIWidgetListener* aWidgetListener);