Bug 1290823 - Factor out the code for dispatching a single tap event to observers into its own function. r=rbarker

This is not just a refactoring. It ensures that the early return in the
factored-out code only skips the dispatch to observers, *not* the
additional processing by ChromeProcessController.

MozReview-Commit-ID: F7xCoORKRlG

--HG--
extra : rebase_source : f9ef57d25a54442dd083560029437fcad885149c

widget/android/AndroidContentController.cpp

@@ -43,6 +43,44 @@ AndroidContentController::NotifyDefaultPrevented(IAPZCTreeManager* aManager,
     aManager->ContentReceivedInputBlock(aInputBlockId, aDefaultPrevented);
 }
 
+void
+AndroidContentController::DispatchSingleTapToObservers(const LayoutDevicePoint& aPoint,
+                                                       const ScrollableLayerGuid& aGuid) const
+{
+    nsIContent* content = nsLayoutUtils::FindContentFor(aGuid.mScrollId);
+    nsIPresShell* shell = content
+        ? mozilla::layers::APZCCallbackHelper::GetRootContentDocumentPresShellForContent(content)
+        : nullptr;
+
+    if (!shell || !shell->GetPresContext()) {
+        return;
+    }
+
+    CSSPoint point = mozilla::layers::APZCCallbackHelper::ApplyCallbackTransform(
+        aPoint / shell->GetPresContext()->CSSToDevPixelScale(), aGuid);
+
+    if (shell->ScaleToResolution()) {
+        // We need to convert from the root document to the root content document,
+        // by unapplying the resolution that's on the content document.
+        const float resolution = shell->GetResolution();
+        point.x /= resolution;
+        point.y /= resolution;
+    }
+
+    CSSIntPoint rounded = RoundedToInt(point);
+    nsAppShell::PostEvent([rounded] {
+        nsCOMPtr<nsIObserverService> obsServ =
+            mozilla::services::GetObserverService();
+        if (!obsServ) {
+            return;
+        }
+
+        nsPrintfCString data("{\"x\":%d,\"y\":%d}", rounded.x, rounded.y);
+        obsServ->NotifyObservers(nullptr, "Gesture:SingleTap",
+                                 NS_ConvertASCIItoUTF16(data).get());
+    });
+}
+
 void
 AndroidContentController::HandleTap(TapType aType, const LayoutDevicePoint& aPoint,
                                     Modifiers aModifiers,
@@ -55,38 +93,7 @@ AndroidContentController::HandleTap(TapType aType, const LayoutDevicePoint& aPoi
     // done from either thread but we need access to the callback transform
     // so we do it from the main thread.
     if (NS_IsMainThread() && aType == TapType::eSingleTap) {
-        nsIContent* content = nsLayoutUtils::FindContentFor(aGuid.mScrollId);
+        DispatchSingleTapToObservers(aPoint, aGuid);
-        nsIPresShell* shell = content
-            ? mozilla::layers::APZCCallbackHelper::GetRootContentDocumentPresShellForContent(content)
-            : nullptr;
-
-        if (!shell || !shell->GetPresContext()) {
-            return;
-        }
-
-        CSSPoint point = mozilla::layers::APZCCallbackHelper::ApplyCallbackTransform(
-            aPoint / shell->GetPresContext()->CSSToDevPixelScale(), aGuid);
-
-        if (shell->ScaleToResolution()) {
-            // We need to convert from the root document to the root content document,
-            // by unapplying the resolution that's on the content document.
-            const float resolution = shell->GetResolution();
-            point.x /= resolution;
-            point.y /= resolution;
-        }
-
-        CSSIntPoint rounded = RoundedToInt(point);
-        nsAppShell::PostEvent([rounded] {
-            nsCOMPtr<nsIObserverService> obsServ =
-                mozilla::services::GetObserverService();
-            if (!obsServ) {
-                return;
-            }
-
-            nsPrintfCString data("{\"x\":%d,\"y\":%d}", rounded.x, rounded.y);
-            obsServ->NotifyObservers(nullptr, "Gesture:SingleTap",
-                                     NS_ConvertASCIItoUTF16(data).get());
-        });
     }
 
     ChromeProcessController::HandleTap(aType, aPoint, aModifiers, aGuid, aInputBlockId);

widget/android/AndroidContentController.h

@@ -48,6 +48,9 @@ public:
                                        uint64_t aInputBlockId, bool aDefaultPrevented);
 private:
     nsWindow* mAndroidWindow;
+
+    void DispatchSingleTapToObservers(const LayoutDevicePoint& aPoint,
+                                      const ScrollableLayerGuid& aGuid) const;
 };
 
 } // namespace widget