content/browser/renderer_host/input/synthetic_gesture_controller.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/renderer_host/input/synthetic_gesture_controller.h"
   6
   7 #include "base/trace_event/trace_event.h"
   8 #include "content/browser/renderer_host/input/synthetic_gesture_target.h"
   9 #include "content/common/input/synthetic_smooth_scroll_gesture_params.h"
  10 #include "content/common/input_messages.h"
  11 #include "content/public/browser/render_widget_host.h"
  12
  13 namespace content {
  14
  15 SyntheticGestureController::SyntheticGestureController(
  16     scoped_ptr<SyntheticGestureTarget> gesture_target)
  17     : gesture_target_(gesture_target.Pass()) {}
  18
  19 SyntheticGestureController::~SyntheticGestureController() {}
  20
  21 void SyntheticGestureController::QueueSyntheticGesture(
  22     scoped_ptr<SyntheticGesture> synthetic_gesture,
  23     const OnGestureCompleteCallback& completion_callback) {
  24   DCHECK(synthetic_gesture);
  25
  26   bool was_empty = pending_gesture_queue_.IsEmpty();
  27
  28   pending_gesture_queue_.Push(synthetic_gesture.Pass(), completion_callback);
  29
  30   if (was_empty)
  31     StartGesture(*pending_gesture_queue_.FrontGesture());
  32 }
  33
  34 void SyntheticGestureController::Flush(base::TimeTicks timestamp) {
  35   TRACE_EVENT0("input", "SyntheticGestureController::Flush");
  36   if (pending_gesture_queue_.IsEmpty())
  37     return;
  38
  39   if (pending_gesture_result_)
  40     return;
  41
  42   SyntheticGesture* gesture = pending_gesture_queue_.FrontGesture();
  43   SyntheticGesture::Result result =
  44       gesture->ForwardInputEvents(timestamp, gesture_target_.get());
  45
  46   if (result == SyntheticGesture::GESTURE_RUNNING) {
  47     gesture_target_->SetNeedsFlush();
  48     return;
  49   }
  50
  51   // It's possible that all events generated by the gesture have been fully
  52   // dispatched at this point, in which case |OnDidFlushInput()| was called
  53   // before |pending_gesture_result_| was initialized. Requesting another flush
  54   // will trigger the necessary gesture-ending call to |OnDidFlushInput()|.
  55   pending_gesture_result_.reset(new SyntheticGesture::Result(result));
  56   gesture_target_->SetNeedsFlush();
  57 }
  58
  59 void SyntheticGestureController::OnDidFlushInput() {
  60   if (!pending_gesture_result_)
  61     return;
  62
  63   DCHECK(!pending_gesture_queue_.IsEmpty());
  64   auto pending_gesture_result = pending_gesture_result_.Pass();
  65   StopGesture(*pending_gesture_queue_.FrontGesture(),
  66               pending_gesture_queue_.FrontCallback(),
  67               *pending_gesture_result);
  68   pending_gesture_queue_.Pop();
  69
  70   if (!pending_gesture_queue_.IsEmpty())
  71     StartGesture(*pending_gesture_queue_.FrontGesture());
  72 }
  73
  74 void SyntheticGestureController::StartGesture(const SyntheticGesture& gesture) {
  75   TRACE_EVENT_ASYNC_BEGIN0("input,benchmark",
  76                            "SyntheticGestureController::running",
  77                            &gesture);
  78   gesture_target_->SetNeedsFlush();
  79 }
  80
  81 void SyntheticGestureController::StopGesture(
  82     const SyntheticGesture& gesture,
  83     const OnGestureCompleteCallback& completion_callback,
  84     SyntheticGesture::Result result) {
  85   DCHECK_NE(result, SyntheticGesture::GESTURE_RUNNING);
  86   TRACE_EVENT_ASYNC_END0("input,benchmark",
  87                          "SyntheticGestureController::running",
  88                          &gesture);
  89
  90   completion_callback.Run(result);
  91 }
  92
  93 SyntheticGestureController::GestureAndCallbackQueue::GestureAndCallbackQueue() {
  94 }
  95
  96 SyntheticGestureController::GestureAndCallbackQueue::
  97     ~GestureAndCallbackQueue() {
  98 }
  99
 100 }  // namespace content