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/events/gesture_detection/gesture_provider_config_helper.h"
  14 #include "ui/gfx/geometry/size_f.h"
  15
  16 namespace content {
  17
  18 // Emulates touch input with mouse and keyboard.
  19 class CONTENT_EXPORT TouchEmulator : public ui::GestureProviderClient {
  20  public:
  21   TouchEmulator(TouchEmulatorClient* client, float device_scale_factor);
  22   ~TouchEmulator() override;
  23
  24   void Enable(ui::GestureProviderConfigType config_type);
  25   void Disable();
  26
  27   // See GestureProvider::SetDoubleTapSupportForPageEnabled.
  28   void SetDoubleTapSupportForPageEnabled(bool enabled);
  29
  30   // Note that TouchEmulator should always listen to touch events and their acks
  31   // (even in disabled state) to track native stream presence.
  32   bool enabled() const { return gesture_provider_; }
  33
  34   // Returns |true| if the event was consumed. Consumed event should not
  35   // propagate any further.
  36   // TODO(dgozman): maybe pass latency info together with events.
  37   bool HandleMouseEvent(const blink::WebMouseEvent& event);
  38   bool HandleMouseWheelEvent(const blink::WebMouseWheelEvent& event);
  39   bool HandleKeyboardEvent(const blink::WebKeyboardEvent& event);
  40   bool HandleTouchEvent(const blink::WebTouchEvent& event);
  41
  42   // Returns |true| if the event ack was consumed. Consumed ack should not
  43   // propagate any further.
  44   bool HandleTouchEventAck(const blink::WebTouchEvent& event,
  45                            InputEventAckState ack_result);
  46
  47   // Cancel any touches, for example, when focus is lost.
  48   void CancelTouch();
  49
  50  private:
  51   // ui::GestureProviderClient implementation.
  52   void OnGestureEvent(const ui::GestureEventData& gesture) override;
  53
  54   // Returns cursor size in DIP.
  55   gfx::SizeF InitCursorFromResource(
  56       WebCursor* cursor, float scale, int resource_id);
  57   void ResetState();
  58   void UpdateCursor();
  59   bool UpdateShiftPressed(bool shift_pressed);
  60
  61   // Whether we should convert scrolls into pinches.
  62   bool InPinchGestureMode() const;
  63
  64   void FillTouchEventAndPoint(const blink::WebMouseEvent& mouse_event);
  65   void FillPinchEvent(const blink::WebInputEvent& event);
  66
  67   // The following methods generate and pass gesture events to the renderer.
  68   void PinchBegin(const blink::WebGestureEvent& event);
  69   void PinchUpdate(const blink::WebGestureEvent& event);
  70   void PinchEnd(const blink::WebGestureEvent& event);
  71   void ScrollEnd(const blink::WebGestureEvent& event);
  72
  73   // Offers the emulated event to |gesture_provider_|, conditionally forwarding
  74   // it to the client if appropriate.
  75   void HandleEmulatedTouchEvent(blink::WebTouchEvent event);
  76
  77   TouchEmulatorClient* const client_;
  78
  79   // Emulator is enabled iff gesture provider is created.
  80   // Disabled emulator does only process touch acks left from previous
  81   // emulation. It does not intercept any events.
  82   scoped_ptr<ui::FilteredGestureProvider> gesture_provider_;
  83   ui::GestureProviderConfigType gesture_provider_config_type_;
  84   bool double_tap_enabled_;
  85
  86   // While emulation is on, default cursor is touch. Pressing shift changes
  87   // cursor to the pinch one.
  88   WebCursor pointer_cursor_;
  89   WebCursor touch_cursor_;
  90   WebCursor pinch_cursor_;
  91   gfx::SizeF cursor_size_;
  92
  93   // These are used to drop extra mouse move events coming too quickly, so
  94   // we don't handle too much touches in gesture provider.
  95   bool last_mouse_event_was_move_;
  96   double last_mouse_move_timestamp_;
  97
  98   bool mouse_pressed_;
  99   bool shift_pressed_;
 100
 101   blink::WebTouchEvent touch_event_;
 102   int emulated_stream_active_sequence_count_;
 103   int native_stream_active_sequence_count_;
 104
 105   // Whether we should suppress next fling cancel. This may happen when we
 106   // did not send fling start in pinch mode.
 107   bool suppress_next_fling_cancel_;
 108
 109   blink::WebGestureEvent pinch_event_;
 110   // Point which does not move while pinch-zooming.
 111   gfx::Point pinch_anchor_;
 112   // The cumulative scale change from the start of pinch gesture.
 113   float pinch_scale_;
 114   bool pinch_gesture_active_;
 115
 116   DISALLOW_COPY_AND_ASSIGN(TouchEmulator);
 117 };
 118
 119 }  // namespace content
 120
 121 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_