components/html_viewer/touch_handler.h

   1 // Copyright 2015 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 COMPONENTS_HTML_VIEWER_TOUCH_HANDLER_H_
   6 #define COMPONENTS_HTML_VIEWER_TOUCH_HANDLER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "ui/events/gesture_detection/filtered_gesture_provider.h"
  10
  11 namespace blink {
  12 class WebView;
  13 }
  14
  15 namespace mojo {
  16 class Event;
  17 }
  18
  19 namespace ui {
  20 class MotionEventGeneric;
  21 }
  22
  23 namespace html_viewer {
  24
  25 // TouchHandler is responsible for converting touch events into gesture events.
  26 // It does this by converting mojo::Events into a MotionEventGeneric and using
  27 // FilteredGestureProvider.
  28 class TouchHandler : public ui::GestureProviderClient {
  29  public:
  30   explicit TouchHandler(blink::WebView* web_view);
  31   ~TouchHandler() override;
  32
  33   void OnTouchEvent(const mojo::Event& event);
  34
  35   // ui::GestureProviderClient implementation.
  36   void OnGestureEvent(const ui::GestureEventData& gesture) override;
  37
  38  private:
  39   // Updates |current_motion_event_| from |event|. Returns true on success.
  40   bool UpdateMotionEvent(const mojo::Event& event);
  41
  42   // Sends |current_motion_event_| to the GestureProvider and WebView.
  43   void SendMotionEventToGestureProvider();
  44
  45   // Does post processing after sending |current_motion_event_| to the
  46   // GestureProvider.
  47   void PostProcessMotionEvent(const mojo::Event& event);
  48
  49   blink::WebView* web_view_;
  50
  51   ui::FilteredGestureProvider gesture_provider_;
  52
  53   // As touch events are received they are converted to this event. If null no
  54   // touch events are in progress.
  55   scoped_ptr<ui::MotionEventGeneric> current_motion_event_;
  56
  57   DISALLOW_COPY_AND_ASSIGN(TouchHandler);
  58 };
  59
  60 }  // namespace html_viewer
  61
  62 #endif  // COMPONENTS_HTML_VIEWER_TOUCH_HANDLER_H_