Home | History | Annotate | Download | only in input 
      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_COMMON_INPUT_SYNTHETIC_GESTURE_PARAMS_H_
      6 #define CONTENT_COMMON_INPUT_SYNTHETIC_GESTURE_PARAMS_H_
      7 
      8 #include "base/memory/scoped_ptr.h"
      9 #include "content/common/content_export.h"
     10 
     11 namespace content {
     12 
     13 // Base class for storing parameters of synthetic gestures. Sending an object
     14 // over IPC is handled by encapsulating it in a SyntheticGesturePacket object.
     15 //
     16 // The subclasses of this class only store data on synthetic gestures.
     17 // The logic for dispatching input events that implement the gesture lives
     18 // in separate classes in content/browser/renderer_host/input/.
     19 //
     20 // Adding new gesture types involves the following steps:
     21 //   1) Create a new sub-type of SyntheticGestureParams with the parameters
     22 //      needed for the new gesture.
     23 //   2) Use IPC macros to create serialization methods for the new type in
     24 //      content/common/input_messages.h.
     25 //   3) Extend ParamTraits<content::SyntheticGesturePacket>::Write/Read/Log in
     26 //      content/common/input/input_param_traits.cc.
     27 //   4) Add a new unit test to make sure that sending the type over IPC works
     28 //      correctly.
     29 // The details of each step should become clear when looking at other types.
     30 struct CONTENT_EXPORT SyntheticGestureParams {
     31   SyntheticGestureParams();
     32   SyntheticGestureParams(const SyntheticGestureParams& other);
     33   virtual ~SyntheticGestureParams();
     34 
     35   // Describes which type of input events synthetic gesture objects should
     36   // generate. When specifying DEFAULT_INPUT the platform will be queried for
     37   // the preferred input event type.
     38   enum GestureSourceType {
     39     DEFAULT_INPUT,
     40     TOUCH_INPUT,
     41     MOUSE_INPUT,
     42     GESTURE_SOURCE_TYPE_MAX = MOUSE_INPUT
     43   };
     44   GestureSourceType gesture_source_type;
     45 
     46   enum GestureType {
     47     SMOOTH_SCROLL_GESTURE,
     48     PINCH_GESTURE,
     49     TAP_GESTURE,
     50     SYNTHETIC_GESTURE_TYPE_MAX = TAP_GESTURE
     51   };
     52   virtual GestureType GetGestureType() const = 0;
     53 
     54   // Returns true if the specific gesture source type is supported on this
     55   // platform.
     56   static bool IsGestureSourceTypeSupported(
     57       GestureSourceType gesture_source_type);
     58 };
     59 
     60 }  // namespace content
     61 
     62 #endif  // CONTENT_COMMON_INPUT_SYNTHETIC_GESTURE_PARAMS_H_
     63