content/browser/renderer_host/input/synthetic_gesture.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_H_
   6 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_GESTURE_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "base/time/time.h"
  10 #include "content/common/content_export.h"
  11 #include "content/common/input/synthetic_gesture_params.h"
  12
  13 namespace content {
  14
  15 class SyntheticGestureTarget;
  16
  17 // Base class for synthetic gesture implementations. A synthetic gesture class
  18 // is responsible for forwaring InputEvents, simulating the gesture, to a
  19 // SyntheticGestureTarget.
  20 //
  21 // Adding new gesture types involved the following steps:
  22 //   1) Create a sub-type of SyntheticGesture that implements the gesture.
  23 //   2) Extend SyntheticGesture::Create with the new class.
  24 //   3) Add at least one unit test per supported input source type (touch,
  25 //      mouse, etc) to SyntheticGestureController unit tests. The unit tests
  26 //      only checks basic functionality and termination. If the gesture is
  27 //      hooked up to Telemetry its correctness can additionally be tested there.
  28 class CONTENT_EXPORT SyntheticGesture {
  29  public:
  30   SyntheticGesture();
  31   virtual ~SyntheticGesture();
  32
  33   static scoped_ptr<SyntheticGesture> Create(
  34       const SyntheticGestureParams& gesture_params);
  35
  36   enum Result {
  37     GESTURE_RUNNING,
  38     GESTURE_FINISHED,
  39     GESTURE_SOURCE_TYPE_NOT_IMPLEMENTED,
  40     GESTURE_RESULT_MAX = GESTURE_SOURCE_TYPE_NOT_IMPLEMENTED
  41   };
  42
  43   // Update the state of the gesture and forward the appropriate events to the
  44   // platform. This function is called repeatedly by the synthetic gesture
  45   // controller until it stops returning GESTURE_RUNNING.
  46   virtual Result ForwardInputEvents(
  47       const base::TimeTicks& timestamp, SyntheticGestureTarget* target) = 0;
  48
  49  protected:
  50   static double ConvertTimestampToSeconds(const base::TimeTicks& timestamp);
  51
  52   DISALLOW_COPY_AND_ASSIGN(SyntheticGesture);
  53 };
  54
  55 }  // namespace content
  56
  57 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_GESTURE_H_