Support GestureBegin and GestureEnd in ui::GestureProvider

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 54 matching lines @@
   GestureEventDetails tap_details(type, 1, 0);
   tap_details.set_bounding_box(
       gfx::RectF(event.GetTouchMajor(), event.GetTouchMajor()));
   return tap_details;
 }
 
 }  // namespace
 
 // GestureProvider:::Config
 
-GestureProvider::Config::Config() : disable_click_delay(false) {}
+GestureProvider::Config::Config()
+    : disable_click_delay(false), gesture_begin_end_types_enabled(false) {}
 
 GestureProvider::Config::~Config() {}
 
 // GestureProvider::ScaleGestureListener
 
 class GestureProvider::ScaleGestureListenerImpl
     : public ScaleGestureDetector::ScaleGestureListener {
  public:
   ScaleGestureListenerImpl(const ScaleGestureDetector::Config& config,
                            float device_scale_factor,
@@ skipping 427 matching lines @@
 // GestureProvider
 
 GestureProvider::GestureProvider(const Config& config,
                                  GestureProviderClient* client)
     : client_(client),
       needs_show_press_event_(false),
       needs_tap_ending_event_(false),
       touch_scroll_in_progress_(false),
       pinch_in_progress_(false),
       double_tap_support_for_page_(true),
-      double_tap_support_for_platform_(true) {
+      double_tap_support_for_platform_(true),
+      gesture_begin_end_types_enabled_(config.gesture_begin_end_types_enabled) {
   DCHECK(client);
   InitGestureDetectors(config);
 }
 
 GestureProvider::~GestureProvider() {}
 
 bool GestureProvider::OnTouchEvent(const MotionEvent& event) {
   TRACE_EVENT1("input", "GestureProvider::OnTouchEvent",
                "action", GetMotionEventActionName(event.GetAction()));
   if (!CanHandle(event))
     return false;
 
   const bool in_scale_gesture =
       scale_gesture_listener_->IsScaleGestureDetectionInProgress();
 
-  if (event.GetAction() == MotionEvent::ACTION_DOWN) {
-    current_down_event_ = event.Clone();
-    touch_scroll_in_progress_ = false;
-    needs_show_press_event_ = true;
-    current_longpress_time_ = base::TimeTicks();
-    SendTapCancelIfNecessary(event);
-  }
+  OnTouchEventHandlingBegin(event);
 
-  bool handled = gesture_listener_->OnTouchEvent(event, in_scale_gesture);
-  handled |= scale_gesture_listener_->OnTouchEvent(event);
+  gesture_listener_->OnTouchEvent(event, in_scale_gesture);
+  scale_gesture_listener_->OnTouchEvent(event);
 
-  if (event.GetAction() == MotionEvent::ACTION_UP ||
-      event.GetAction() == 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.GetEventTime(), true);
-
-    // We shouldn't necessarily cancel a tap on ACTION_UP, as the double-tap
-    // timeout may yet trigger a SINGLE_TAP.
-    if (event.GetAction() == MotionEvent::ACTION_CANCEL)
-      SendTapCancelIfNecessary(event);
-
-    UpdateDoubleTapDetectionSupport();
-
-    current_down_event_.reset();
-  }
+  OnTouchEventHandlingEnd(event);
 
   return true;
 }
 
 void GestureProvider::ResetGestureDetectors() {
   if (!current_down_event_)
     return;
   scoped_ptr<MotionEvent> cancel_event = current_down_event_->Cancel();
   gesture_listener_->OnTouchEvent(*cancel_event, false);
   scale_gesture_listener_->OnTouchEvent(*cancel_event);
@@ skipping 84 matching lines @@
   DCHECK(!gesture.time.is_null());
   // 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_TAP_DOWN:
       needs_tap_ending_event_ = true;
+      needs_show_press_event_ = true;
       break;
     case ET_GESTURE_TAP_UNCONFIRMED:
       needs_show_press_event_ = false;
       break;
     case ET_GESTURE_TAP:
       if (needs_show_press_event_)
         Send(CreateGesture(
             ET_GESTURE_SHOW_PRESS, gesture.time, gesture.x, gesture.y));
       needs_tap_ending_event_ = false;
       break;
@@ skipping 71 matching lines @@
 
 void GestureProvider::UpdateDoubleTapDetectionSupport() {
   if (IsDoubleTapInProgress())
     return;
 
   const bool supports_double_tap = IsDoubleTapSupported();
   gesture_listener_->SetDoubleTapEnabled(supports_double_tap);
   scale_gesture_listener_->SetDoubleTapEnabled(supports_double_tap);
 }
 
+void GestureProvider::OnTouchEventHandlingBegin(const MotionEvent& event) {
+  switch (event.GetAction()) {
+    case MotionEvent::ACTION_DOWN:
+      current_down_event_ = event.Clone();
+      touch_scroll_in_progress_ = false;
+      needs_show_press_event_ = false;
+      current_longpress_time_ = base::TimeTicks();
+      SendTapCancelIfNecessary(event);
+      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));
+      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.GetEventTime(), true);
+      // We shouldn't necessarily cancel a tap on ACTION_UP, as the double-tap

[jdduke (slow), 2014/04/04 19:08:36]

Let's add a line break before "// We shouldn't".

[tdresser, 2014/04/07 13:42:55]

Done.

+      // timeout may yet trigger a SINGLE_TAP.
+      if (event.GetAction() == MotionEvent::ACTION_CANCEL)
+        SendTapCancelIfNecessary(event);
+      UpdateDoubleTapDetectionSupport();

[jdduke (slow), 2014/04/04 19:08:36]

Also line break before |UpdateDouble...|.

[tdresser, 2014/04/07 13:42:55]

Done.

+
+      if (gesture_begin_end_types_enabled_)
+        Send(CreateGesture(ET_GESTURE_END, event));
+
+      current_down_event_.reset();
+      break;
+    case MotionEvent::ACTION_POINTER_UP:
+      if (gesture_begin_end_types_enabled_)
+        Send(CreateGesture(ET_GESTURE_END, event));
+      break;
+    case MotionEvent::ACTION_DOWN:
+    case MotionEvent::ACTION_POINTER_DOWN:
+    case MotionEvent::ACTION_MOVE:
+      break;
+  }
+}
+
 }  //  namespace ui