[DevTools] Touch emulation in content.

content/browser/renderer_host/input/touch_emulator.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_
+#define CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_
+
+#include "content/browser/renderer_host/input/touch_emulator_client.h"
+#include "content/common/cursors/webcursor.h"
+#include "content/port/common/input_event_ack_state.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+#include "ui/events/gesture_detection/filtered_gesture_provider.h"
+
+namespace content {
+
+// Emulates touch input with mouse and keyboard.
+class CONTENT_EXPORT TouchEmulator : public ui::GestureProviderClient {
+ public:
+  explicit TouchEmulator(TouchEmulatorClient* client);
+  virtual ~TouchEmulator();
+
+  void Enable(bool allow_pinch);
+  void Disable();
+
+  // Returns |true| if the event was consumed.
+  // TODO(dgozman): maybe pass latency info together with events.
+  bool HandleMouseEvent(const blink::WebMouseEvent& event);
+  bool HandleMouseWheelEvent(const blink::WebMouseWheelEvent& event);
+  bool HandleKeyboardEvent(const blink::WebKeyboardEvent& event);
+
+  // Returns |true| if the event ack was consumed. Consumed ack should not
+  // propagate any further.
+  bool HandleTouchEventAck(InputEventAckState ack_result);
+
+  // Cancel any touches, for example, when focus is lost.
+  void CancelTouch();
+
+ private:
+  // ui::GestureProviderClient implementation.
+  virtual void OnGestureEvent(const ui::GestureEventData& gesture) OVERRIDE;
+
+  void InitCursorFromResource(WebCursor* cursor, int resource_id);
+  void ResetState();
+  void UpdateCursor();
+  bool UpdateShiftPressed(bool shift_pressed);
+
+  // Whether we should convert scrolls into pinches.
+  bool InPinchGestureMode() const;
+
+  bool FillTouchEventAndPoint(const blink::WebMouseEvent& mouse_event);
+  void FillPinchEvent(const blink::WebInputEvent& event);
+
+  // The following methods generate and pass gesture events to the renderer.
+  void PinchBegin(const blink::WebGestureEvent& event);
+  void PinchUpdate(const blink::WebGestureEvent& event);
+  void PinchEnd(const blink::WebGestureEvent& event);
+  void ScrollEnd(const blink::WebGestureEvent& event);
+
+  TouchEmulatorClient* const client_;
+  ui::FilteredGestureProvider gesture_provider_;
+
+  // Disabled emulator does only process touch acks left from previous
+  // emulation. It does not intercept any events.
+  bool enabled_;
+  bool allow_pinch_;
+
+  // While emulation is on, default cursor is touch. Pressing shift changes
+  // cursor to the pinch one.
+  WebCursor pointer_cursor_;
+  WebCursor touch_cursor_;
+  WebCursor pinch_cursor_;
+
+  // These are used to drop extra mouse move events coming too quickly, so
+  // we don't handle too much touches in gesture provider.
+  bool last_mouse_event_was_move_;
+  double last_mouse_move_timestamp_;
+
+  bool mouse_pressed_;
+  bool shift_pressed_;
+
+  blink::WebTouchEvent touch_event_;
+  bool touch_active_;
+
+  // Whether we should suppress next fling cancel. This may happen when we
+  // did not send fling start in pinch mode.
+  bool suppress_next_fling_cancel_;
+
+  blink::WebGestureEvent pinch_event_;
+  // Point which does not move while pinch-zooming.
+  gfx::Point pinch_anchor_;
+  // The cumulative scale change from the start of pinch gesture.
+  float pinch_scale_;
+  bool pinch_gesture_active_;
+
+  DISALLOW_COPY_AND_ASSIGN(TouchEmulator);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_EMULATOR_H_