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