[Chromecast] Chromecast support for tap down gestures

- TAP_DOWN is added to CastContentWindow::GestureType
- The gesture detection is attached to the root window and handles
  tap down events. A new JS binding API: onTapDownHandler will be hosted on
  platform
- HandleTapGesture: finger is released after pressed within tap timeout window
  HandleTapDownGesture: finger is pressed

Bug: internal b/75979846
Test: build manually and test whether both tap and tap down handler callback works
Change-Id: Iaefa6df9c7a5284ba27964083fc056bf36cf480a
Reviewed-on: https://chromium-review.googlesource.com/1115418Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Jiawei Li <lijiawei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574373}

chromecast/browser/cast_content_window.h

@@ -64,7 +64,7 @@ enum class VisibilityPriority {
   HIDDEN = 5,
 };
 
-enum class GestureType { NO_GESTURE = 0, GO_BACK = 1, TAP = 2 };
+enum class GestureType { NO_GESTURE = 0, GO_BACK = 1, TAP = 2, TAP_DOWN = 3 };
 
 // Class that represents the "window" a WebContents is displayed in cast_shell.
 // For Linux, this represents an Aura window. For Android, this is a Activity.

chromecast/browser/cast_content_window_aura.cc

@@ -144,15 +144,20 @@ void CastContentWindowAura::HandleSideSwipeContinue(
   gesture_dispatcher_->HandleSideSwipeContinue(swipe_origin, touch_location);
 }
 
-void CastContentWindowAura::HandleTapGesture(const gfx::Point& touch_location) {
-  gesture_dispatcher_->HandleTapGesture(touch_location);
-}
-
 void CastContentWindowAura::HandleSideSwipeEnd(
     CastSideSwipeOrigin swipe_origin,
     const gfx::Point& touch_location) {
   gesture_dispatcher_->HandleSideSwipeEnd(swipe_origin, touch_location);
 }
 
+void CastContentWindowAura::HandleTapDownGesture(
+    const gfx::Point& touch_location) {
+  gesture_dispatcher_->HandleTapDownGesture(touch_location);
+}
+
+void CastContentWindowAura::HandleTapGesture(const gfx::Point& touch_location) {
+  gesture_dispatcher_->HandleTapGesture(touch_location);
+}
+
 }  // namespace shell
 }  // namespace chromecast

chromecast/browser/cast_content_window_aura.h

@@ -44,6 +44,7 @@ class CastContentWindowAura : public CastContentWindow,
                                const gfx::Point& touch_location) override;
   void HandleSideSwipeEnd(CastSideSwipeOrigin swipe_origin,
                           const gfx::Point& touch_location) override;
+  void HandleTapDownGesture(const gfx::Point& touch_location) override;
   void HandleTapGesture(const gfx::Point& touch_location) override;
 
  private:

chromecast/browser/cast_gesture_dispatcher.cc

@@ -77,6 +77,14 @@ void CastGestureDispatcher::HandleSideSwipeEnd(
   }
 }
 
+void CastGestureDispatcher::HandleTapDownGesture(
+    const gfx::Point& touch_location) {
+  if (!delegate_->CanHandleGesture(GestureType::TAP_DOWN)) {
+    return;
+  }
+  delegate_->ConsumeGesture(GestureType::TAP_DOWN);
+}
+
 void CastGestureDispatcher::HandleTapGesture(const gfx::Point& touch_location) {
   if (!delegate_->CanHandleGesture(GestureType::TAP)) {
     return;

chromecast/browser/cast_gesture_dispatcher.h

@@ -28,6 +28,7 @@ class CastGestureDispatcher : public CastGestureHandler {
                                const gfx::Point& touch_location) override;
   void HandleSideSwipeEnd(CastSideSwipeOrigin swipe_origin,
                           const gfx::Point& touch_location) override;
+  void HandleTapDownGesture(const gfx::Point& touch_location) override;
   void HandleTapGesture(const gfx::Point& touch_location) override;
 
  private:

chromecast/graphics/cast_gesture_handler.h

@@ -37,7 +37,12 @@ class CastGestureHandler {
   virtual void HandleSideSwipeEnd(CastSideSwipeOrigin swipe_origin,
                                   const gfx::Point& touch_location) {}
 
-  // Triggered on the completion of a tap event.
+  // Triggered on the completion of a tap down event, fired when the
+  // finger is pressed.
+  virtual void HandleTapDownGesture(const gfx::Point& touch_location) {}
+
+  // Triggered on the completion of a tap event, fire after a press
+  // followed by a release, within the tap timeout window
   virtual void HandleTapGesture(const gfx::Point& touch_location) {}
 
  private:

chromecast/graphics/cast_system_gesture_event_handler.cc

@@ -149,8 +149,7 @@ void CastSystemGestureEventHandler::OnTouchEvent(ui::TouchEvent* event) {
 
 void CastSystemGestureEventHandler::OnGestureEvent(ui::GestureEvent* event) {
   if (event->type() == ui::ET_GESTURE_TAP ||
-      event->type() == ui::ET_GESTURE_TAP_DOWN ||
-      event->type() == ui::ET_GESTURE_LONG_PRESS) {
+      event->type() == ui::ET_GESTURE_TAP_DOWN) {
     ProcessPressedEvent(event);
   }
 }
@@ -161,9 +160,21 @@ void CastSystemGestureEventHandler::ProcessPressedEvent(
     return;
   }
   gfx::Point touch_location(event->location());
-  for (auto* gesture_handler : gesture_handlers_) {
-    // Let the subscriber know about the gesture begin.
-    gesture_handler->HandleTapGesture(touch_location);
+  // Let the subscriber know about the gesture begin.
+  switch (event->type()) {
+    case ui::ET_GESTURE_TAP_DOWN: {
+      for (auto* gesture_handler : gesture_handlers_) {
+        gesture_handler->HandleTapDownGesture(touch_location);
+      }
+      break;
+    }
+    case ui::ET_GESTURE_TAP: {
+      for (auto* gesture_handler : gesture_handlers_) {
+        gesture_handler->HandleTapGesture(touch_location);
+      }
+      break;
+    }
+    default: { return; }
   }
 }