Prepare for Unified Gesture Recognizer landing in Aura

ui/events/gesture_detection/gesture_provider.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/events/gesture_detection/gesture_provider.h"
 
 #include <cmath>
 
 #include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
@@ skipping 340 matching lines @@
                                     e1.GetX(),
                                     e1.GetY(),
                                     e2.GetPointerCount(),
                                     GetBoundingBox(e2),
                                     scroll_details));
     }
 
     if (distance_x || distance_y) {
       GestureEventDetails scroll_details(
           ET_GESTURE_SCROLL_UPDATE, -distance_x, -distance_y);
-      provider_->Send(
-          CreateGesture(ET_GESTURE_SCROLL_UPDATE, e2, scroll_details));
+      provider_->Send(CreateGesture(ET_GESTURE_SCROLL_UPDATE,

[jdduke (slow), 2014/05/28 16:26:00]

Please cache GetBoundingBox(e2) before using.

[tdresser, 2014/05/29 14:26:21]

Done.

+                                    e2.GetId(),
+                                    e2.GetEventTime(),
+                                    GetBoundingBox(e2).CenterPoint().x(),

[jdduke (slow), 2014/05/28 16:26:00]

Just curious, why was this change necessary? Does the Aura UI not lock to a
specific layer when scrolling?

[tdresser, 2014/05/29 14:26:21]

Multi-finger window dragging uses the scroll update location delta to determine
how far to drag the window. This lets us use the same drag logic as is used for
mouse
(https://code.google.com/p/chromium/codesearch#chromium/src/ash/wm/toplevel_wi...).

[jdduke (slow), 2014/05/29 16:25:40]

sgtm.

+                                    GetBoundingBox(e2).CenterPoint().y(),
+                                    e2.GetPointerCount(),
+                                    GetBoundingBox(e2),
+                                    scroll_details));
     }
 
     return true;
   }
 
   virtual bool OnFling(const MotionEvent& e1,
                        const MotionEvent& e2,
                        float velocity_x,
                        float velocity_y) OVERRIDE {
     if (snap_scroll_controller_.IsSnappingScrolls()) {
@@ skipping 270 matching lines @@
   }
   EndTouchScrollIfNecessary(event, false);
 
   GestureEventDetails fling_details(
       ET_SCROLL_FLING_START, velocity_x, velocity_y);
   Send(CreateGesture(
       ET_SCROLL_FLING_START, event, fling_details));
 }
 
 void GestureProvider::Send(const GestureEventData& gesture) {
-  DCHECK(!gesture.time.is_null());

[jdduke (slow), 2014/05/28 16:26:00]

Why was this removed?

[tdresser, 2014/05/29 14:26:21]

There are a whole pile of tests which synthesize gesture events without
assigning them a time. In theory I could go through and update all the tests,
but I don't think it's worth it.

[jdduke (slow), 2014/05/29 16:25:40]

My only worry here is that gesture detection is *very* timestamp sensitive. If
any of those tests are actually testing generated gestures, a stream of zeroed
timestamps may not yield what we want? If we don't care about the output
gestures, even a base::TimeTicks::Now() would be better so that we can at least
verify runtime behavior for Chrome builds. 

[tdresser, 2014/05/30 14:05:37]

Done.

   // The only valid events that should be sent without an active touch sequence
   // are SHOW_PRESS and TAP, potentially triggered by the double-tap
   // delay timing out.
   DCHECK(current_down_event_ || gesture.type == ET_GESTURE_TAP ||
          gesture.type == ET_GESTURE_SHOW_PRESS);
 
   switch (gesture.type) {
     case ET_GESTURE_LONG_PRESS:
       DCHECK(!scale_gesture_listener_->IsScaleGestureDetectionInProgress());
       current_longpress_time_ = gesture.time;
@@ skipping 70 matching lines @@
   switch (event.GetAction()) {
     case MotionEvent::ACTION_DOWN:
       current_down_event_ = event.Clone();
       touch_scroll_in_progress_ = false;
       pinch_in_progress_ = false;
       current_longpress_time_ = base::TimeTicks();
       if (gesture_begin_end_types_enabled_)
         Send(CreateGesture(ET_GESTURE_BEGIN, event));
       break;
     case MotionEvent::ACTION_POINTER_DOWN:
-      if (gesture_begin_end_types_enabled_)
-        Send(CreateGesture(ET_GESTURE_BEGIN, event));
+      if (gesture_begin_end_types_enabled_) {
+        Send(CreateGesture(ET_GESTURE_BEGIN,
+                           event.GetId(),
+                           event.GetEventTime(),
+                           event.GetX(event.GetActionIndex()),
+                           event.GetY(event.GetActionIndex()),
+                           event.GetPointerCount(),
+                           GetBoundingBox(event)));
+      }
       break;
     case MotionEvent::ACTION_POINTER_UP:
     case MotionEvent::ACTION_UP:
     case MotionEvent::ACTION_CANCEL:
     case MotionEvent::ACTION_MOVE:
       break;
   }
 }
 
 void GestureProvider::OnTouchEventHandlingEnd(const MotionEvent& event) {
   switch (event.GetAction()) {
     case MotionEvent::ACTION_UP:
     case MotionEvent::ACTION_CANCEL:
       // Note: This call will have no effect if a fling was just generated, as
       // |Fling()| will have already signalled an end to touch-scrolling.
       EndTouchScrollIfNecessary(event, true);
 
-      if (gesture_begin_end_types_enabled_)
-        Send(CreateGesture(ET_GESTURE_END, event));
+      if (gesture_begin_end_types_enabled_) {
+        for (size_t i = 0; i < event.GetPointerCount(); ++i) {
+          Send(CreateGesture(ET_GESTURE_END,
+                             event.GetId(),
+                             event.GetEventTime(),
+                             event.GetX(i),
+                             event.GetY(i),
+                             event.GetPointerCount() - i,
+                             GetBoundingBox(event)));

[jdduke (slow), 2014/05/28 16:26:00]

Cache GetBoundingBox?

[tdresser, 2014/05/29 14:26:21]

Done.

+        }
+      }
 
       current_down_event_.reset();
 
       UpdateDoubleTapDetectionSupport();
       break;
     case MotionEvent::ACTION_POINTER_UP:
       if (gesture_begin_end_types_enabled_)
         Send(CreateGesture(ET_GESTURE_END, event));
       break;
     case MotionEvent::ACTION_DOWN:
@@ skipping 10 matching lines @@
   if (current_down_event_)
     return;
 
   const bool double_tap_enabled = double_tap_support_for_page_ &&
                                   double_tap_support_for_platform_;
   gesture_listener_->SetDoubleTapEnabled(double_tap_enabled);
   scale_gesture_listener_->SetDoubleTapEnabled(double_tap_enabled);
 }
 
 }  //  namespace ui