content/browser/renderer_host/input/touch_emulator.h

   1 // Copyright 2014 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_TOUCH_EMULATOR_H_
   6 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_
   7
   8 #include "content/browser/renderer_host/input/touch_emulator_client.h"
   9 #include "content/common/cursors/webcursor.h"
  10 #include "content/common/input/input_event_ack_state.h"
  11 #include "third_party/WebKit/public/web/WebInputEvent.h"
  12 #include "ui/events/gesture_detection/filtered_gesture_provider.h"
  13 #include "ui/gfx/size_f.h"
  14
  15 namespace content {
  16
  17 // Emulates touch input with mouse and keyboard.
  18 class CONTENT_EXPORT TouchEmulator : public ui::GestureProviderClient {
  19  public:
  20   explicit TouchEmulator(TouchEmulatorClient* client);
  21   virtual ~TouchEmulator();
  22
  23   void Enable();
  24   void Disable();
  25
  26   // Note that TouchEmulator should always listen to touch events and their acks
  27   // (even in disabled state) to track native stream presence.
  28   bool enabled() const { return enabled_; }
  29
  30   // Returns |true| if the event was consumed. Consumed event should not
  31   // propagate any further.
  32   // TODO(dgozman): maybe pass latency info together with events.
  33   bool HandleMouseEvent(const blink::WebMouseEvent& event);
  34   bool HandleMouseWheelEvent(const blink::WebMouseWheelEvent& event);
  35   bool HandleKeyboardEvent(const blink::WebKeyboardEvent& event);
  36   bool HandleTouchEvent(const blink::WebTouchEvent& event);
  37
  38   // Returns |true| if the event ack was consumed. Consumed ack should not
  39   // propagate any further.
  40   bool HandleTouchEventAck(const blink::WebTouchEvent& event,
  41                            InputEventAckState ack_result);
  42
  43   // Cancel any touches, for example, when focus is lost.
  44   void CancelTouch();
  45
  46  private:
  47   // ui::GestureProviderClient implementation.
  48   virtual void OnGestureEvent(const ui::GestureEventData& gesture) OVERRIDE;
  49
  50   // Returns cursor size in DIP.
  51   gfx::SizeF InitCursorFromResource(
  52       WebCursor* cursor, float scale, int resource_id);
  53   void ResetState();
  54   void UpdateCursor();
  55   bool UpdateShiftPressed(bool shift_pressed);
  56
  57   // Whether we should convert scrolls into pinches.
  58   bool InPinchGestureMode() const;
  59
  60   bool FillTouchEventAndPoint(const blink::WebMouseEvent& mouse_event);
  61   void FillPinchEvent(const blink::WebInputEvent& event);
  62
  63   // The following methods generate and pass gesture events to the renderer.
  64   void PinchBegin(const blink::WebGestureEvent& event);
  65   void PinchUpdate(const blink::WebGestureEvent& event);
  66   void PinchEnd(const blink::WebGestureEvent& event);
  67   void ScrollEnd(const blink::WebGestureEvent& event);
  68
  69   void ForwardTouchEventToClient();
  70
  71   TouchEmulatorClient* const client_;
  72   ui::FilteredGestureProvider gesture_provider_;
  73
  74   // Disabled emulator does only process touch acks left from previous
  75   // emulation. It does not intercept any events.
  76   bool enabled_;
  77
  78   // While emulation is on, default cursor is touch. Pressing shift changes
  79   // cursor to the pinch one.
  80   WebCursor pointer_cursor_;
  81   WebCursor touch_cursor_;
  82   WebCursor pinch_cursor_;
  83   gfx::SizeF cursor_size_;
  84
  85   // These are used to drop extra mouse move events coming too quickly, so
  86   // we don't handle too much touches in gesture provider.
  87   bool last_mouse_event_was_move_;
  88   double last_mouse_move_timestamp_;
  89
  90   bool mouse_pressed_;
  91   bool shift_pressed_;
  92
  93   blink::WebTouchEvent touch_event_;
  94   int emulated_stream_active_sequence_count_;
  95   int native_stream_active_sequence_count_;
  96
  97   // Whether we should suppress next fling cancel. This may happen when we
  98   // did not send fling start in pinch mode.
  99   bool suppress_next_fling_cancel_;
 100
 101   blink::WebGestureEvent pinch_event_;
 102   // Point which does not move while pinch-zooming.
 103   gfx::Point pinch_anchor_;
 104   // The cumulative scale change from the start of pinch gesture.
 105   float pinch_scale_;
 106   bool pinch_gesture_active_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(TouchEmulator);
 109 };
 110
 111 }  // namespace content
 112
 113 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_