Reland: Fix touchpad gesture routing to renderers

content/browser/renderer_host/render_widget_host_input_event_router.cc

Index: content/browser/renderer_host/render_widget_host_input_event_router.cc
diff --git a/content/browser/renderer_host/render_widget_host_input_event_router.cc b/content/browser/renderer_host/render_widget_host_input_event_router.cc
index e1d4f1c539ddf18143c28aba58ba97f8180f04c3..f660843f295560a04373cd070c38b2896f907678 100644
--- a/content/browser/renderer_host/render_widget_host_input_event_router.cc
+++ b/content/browser/renderer_host/render_widget_host_input_event_router.cc
@@ -48,14 +48,19 @@ void RenderWidgetHostInputEventRouter::OnRenderWidgetHostViewBaseDestroyed(
   // If the target that's being destroyed is in the gesture target queue, we
   // replace it with nullptr so that we maintain the 1:1 correspondence between
   // queue entries and the touch sequences that underly them.
-  for (size_t i = 0; i < gesture_target_queue_.size(); ++i) {
-    if (gesture_target_queue_[i].target == view)
-      gesture_target_queue_[i].target = nullptr;
+  for (size_t i = 0; i < touchscreen_gesture_target_queue_.size(); ++i) {
+    if (touchscreen_gesture_target_queue_[i].target == view)
+      touchscreen_gesture_target_queue_[i].target = nullptr;
   }
 
-  if (view == gesture_target_) {
-    gesture_target_ = nullptr;
-    gesture_delta_ = gfx::Vector2d();
+  if (view == touchscreen_gesture_target_) {

[tdresser, 2016/06/08 17:41:12]

We should be able to clean this up once we switch to storing this data in a
struct.

[mohsen, 2016/06/08 23:32:26]

What sort of cleanup do you have in mind? I opted for just setting |target| to
nullptr and leaving |delta| as is since |delta| is always initialized whenever
|target| is initialized and its usages are guarded by |target| not being
nullptr.

Or, do you want a full-blown class implementation for TargetData with
getter/setters and a reset() function?

+    touchscreen_gesture_target_ = nullptr;
+    touchscreen_gesture_delta_ = gfx::Vector2d();
+  }
+
+  if (view == touchpad_gesture_target_) {
+    touchpad_gesture_target_ = nullptr;
+    touchpad_gesture_delta_ = gfx::Vector2d();
   }
 }
 
@@ -90,7 +95,8 @@ bool RenderWidgetHostInputEventRouter::HittestDelegate::AcceptHitTarget(
 
 RenderWidgetHostInputEventRouter::RenderWidgetHostInputEventRouter()
     : touch_target_(nullptr),
-      gesture_target_(nullptr),
+      touchscreen_gesture_target_(nullptr),
+      touchpad_gesture_target_(nullptr),
       active_touches_(0) {}
 
 RenderWidgetHostInputEventRouter::~RenderWidgetHostInputEventRouter() {
@@ -165,34 +171,17 @@ void RenderWidgetHostInputEventRouter::RouteGestureEvent(
     RenderWidgetHostViewBase* root_view,
     blink::WebGestureEvent* event,
     const ui::LatencyInfo& latency) {
-  // We use GestureTapDown to detect the start of a gesture sequence since there
-  // is no WebGestureEvent equivalent for ET_GESTURE_BEGIN. Note that this
-  // means the GestureFlingCancel that always comes between ET_GESTURE_BEGIN and
-  // GestureTapDown is sent to the previous target, in case it is still in a
-  // fling.
-  if (event->type == blink::WebInputEvent::GestureTapDown) {
-    if (gesture_target_queue_.empty()) {
-      LOG(ERROR) << "Gesture sequence start detected with no target available.";
-      // Ignore this gesture sequence as no target is available.
-      // TODO(wjmaclean): this only happens on Windows, and should not happen.
-      // https://crbug.com/595422
-      gesture_target_ = nullptr;
-      base::debug::DumpWithoutCrashing();
-      return;
-    }
-
-    const GestureTargetData& data = gesture_target_queue_.front();
-    gesture_target_ = data.target;
-    gesture_delta_ = data.delta;
-    gesture_target_queue_.pop_front();
-  }
-
-  if (!gesture_target_)
-    return;
-
-  event->x += gesture_delta_.x();
-  event->y += gesture_delta_.y();
-  gesture_target_->ProcessGestureEvent(*event, latency);
+  switch (event->sourceDevice) {
+    case blink::WebGestureDeviceUninitialized:
+      NOTREACHED() << "Uninitialized device type is not allowed";
+      break;
+    case blink::WebGestureDeviceTouchpad:
+      RouteTouchpadGestureEvent(root_view, event, latency);
+      break;
+    case blink::WebGestureDeviceTouchscreen:
+      RouteTouchscreenGestureEvent(root_view, event, latency);
+      break;
+  };
 }
 
 void RenderWidgetHostInputEventRouter::RouteTouchEvent(
@@ -217,7 +206,8 @@ void RenderWidgetHostInputEventRouter::RouteTouchEvent(
         // might be to always transform each point to the touch_target_
         // for the duration of the sequence.
         touch_delta_ = transformed_point - original_point;
-        gesture_target_queue_.emplace_back(touch_target_, touch_delta_);
+        touchscreen_gesture_target_queue_.emplace_back(touch_target_,
+                                                       touch_delta_);
 
         if (!touch_target_)
           return;
@@ -290,4 +280,66 @@ void RenderWidgetHostInputEventRouter::OnHittestData(
   hittest_data_[params.surface_id] = data;
 }
 
+void RenderWidgetHostInputEventRouter::RouteTouchscreenGestureEvent(
+    RenderWidgetHostViewBase* root_view,
+    blink::WebGestureEvent* event,
+    const ui::LatencyInfo& latency) {
+  DCHECK_EQ(blink::WebGestureDeviceTouchscreen, event->sourceDevice);
+
+  // We use GestureTapDown to detect the start of a gesture sequence since there
+  // is no WebGestureEvent equivalent for ET_GESTURE_BEGIN. Note that this
+  // means the GestureFlingCancel that always comes between ET_GESTURE_BEGIN and
+  // GestureTapDown is sent to the previous target, in case it is still in a
+  // fling.
+  if (event->type == blink::WebInputEvent::GestureTapDown) {
+    if (touchscreen_gesture_target_queue_.empty()) {
+      LOG(ERROR) << "Gesture sequence start detected with no target available.";
+      // Ignore this gesture sequence as no target is available.
+      // TODO(wjmaclean): this only happens on Windows, and should not happen.
+      // https://crbug.com/595422
+      touchscreen_gesture_target_ = nullptr;
+      base::debug::DumpWithoutCrashing();
+      return;
+    }
+
+    const TouchscreenGestureTargetData& data =
+        touchscreen_gesture_target_queue_.front();
+    touchscreen_gesture_target_ = data.target;
+    touchscreen_gesture_delta_ = data.delta;
+    touchscreen_gesture_target_queue_.pop_front();
+  }
+
+  if (!touchscreen_gesture_target_)
+    return;
+
+  event->x += touchscreen_gesture_delta_.x();
+  event->y += touchscreen_gesture_delta_.y();
+  touchscreen_gesture_target_->ProcessGestureEvent(*event, latency);
+}
+
+void RenderWidgetHostInputEventRouter::RouteTouchpadGestureEvent(
+    RenderWidgetHostViewBase* root_view,
+    blink::WebGestureEvent* event,
+    const ui::LatencyInfo& latency) {
+  DCHECK_EQ(blink::WebGestureDeviceTouchpad, event->sourceDevice);
+  DCHECK(event->type == blink::WebInputEvent::GesturePinchBegin ||
+         event->type == blink::WebInputEvent::GesturePinchUpdate ||
+         event->type == blink::WebInputEvent::GesturePinchEnd);
+
+  if (event->type == blink::WebInputEvent::GesturePinchBegin) {
+    gfx::Point transformed_point;
+    gfx::Point original_point(event->x, event->y);
+    touchpad_gesture_target_ =
+        FindEventTarget(root_view, original_point, &transformed_point);
+    touchpad_gesture_delta_ = transformed_point - original_point;

[sadrul, 2016/06/08 15:56:30]

Add a TODO here like above for TouchStart that computing just the delta isn't
going to be sufficient in some cases.

[mohsen, 2016/06/08 23:32:26]

Done.

+  }
+
+  if (!touchpad_gesture_target_)
+    return;
+
+  event->x += touchpad_gesture_delta_.x();
+  event->y += touchpad_gesture_delta_.y();
+  touchpad_gesture_target_->ProcessGestureEvent(*event, latency);
+}
+
 }  // namespace content