src/content/browser/renderer_host/input/synthetic_gesture_controller.h

   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 #ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_GESTURE_CONTROLLER_H_
   6 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_GESTURE_CONTROLLER_H_
   7
   8 #include <queue>
   9 #include <utility>
  10
  11 #include "base/callback.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/memory/scoped_vector.h"
  14 #include "base/time/time.h"
  15 #include "content/browser/renderer_host/input/synthetic_gesture.h"
  16 #include "content/common/content_export.h"
  17 #include "content/common/input/synthetic_gesture_params.h"
  18
  19 namespace content {
  20
  21 class SyntheticGestureTarget;
  22
  23 // Controls a synthetic gesture.
  24 // Repeatedly invokes the gesture object's ForwardInputEvent method to send
  25 // input events to the platform until the gesture has finished.
  26 class CONTENT_EXPORT SyntheticGestureController {
  27  public:
  28   explicit SyntheticGestureController(
  29       scoped_ptr<SyntheticGestureTarget> gesture_target);
  30   virtual ~SyntheticGestureController();
  31
  32   typedef base::Callback<void(SyntheticGesture::Result)>
  33       OnGestureCompleteCallback;
  34   void QueueSyntheticGesture(
  35       scoped_ptr<SyntheticGesture> synthetic_gesture,
  36       const OnGestureCompleteCallback& completion_callback);
  37
  38   // Forward input events of the currently processed gesture.
  39   void Flush(base::TimeTicks timestamp);
  40
  41   // To be called when all events generated from the current gesture have been
  42   // fully flushed from the input pipeline (i.e., sent, processed and ack'ed).
  43   void OnDidFlushInput();
  44
  45  private:
  46   void StartGesture(const SyntheticGesture& gesture);
  47   void StopGesture(const SyntheticGesture& gesture,
  48                    const OnGestureCompleteCallback& completion_callback,
  49                    SyntheticGesture::Result result);
  50
  51   scoped_ptr<SyntheticGestureTarget> gesture_target_;
  52   scoped_ptr<SyntheticGesture::Result> pending_gesture_result_;
  53
  54   // A queue of gesture/callback pairs.  Implemented as two queues to
  55   // simplify the ownership of SyntheticGesture pointers.
  56   class GestureAndCallbackQueue {
  57   public:
  58     GestureAndCallbackQueue();
  59     ~GestureAndCallbackQueue();
  60     void Push(scoped_ptr<SyntheticGesture> gesture,
  61         const OnGestureCompleteCallback& callback) {
  62       gestures_.push_back(gesture.release());
  63       callbacks_.push(callback);
  64     }
  65     void Pop() {
  66       gestures_.erase(gestures_.begin());
  67       callbacks_.pop();
  68     }
  69     SyntheticGesture* FrontGesture() {
  70       return gestures_.front();
  71     }
  72     OnGestureCompleteCallback& FrontCallback() {
  73       return callbacks_.front();
  74     }
  75     bool IsEmpty() {
  76       CHECK(gestures_.empty() == callbacks_.empty());
  77       return gestures_.empty();
  78     }
  79    private:
  80     ScopedVector<SyntheticGesture> gestures_;
  81     std::queue<OnGestureCompleteCallback> callbacks_;
  82   } pending_gesture_queue_;
  83
  84   DISALLOW_COPY_AND_ASSIGN(SyntheticGestureController);
  85 };
  86
  87 }  // namespace content
  88
  89 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_GESTURE_CONTROLLER_H_