[Android] Support double-tap selection

ui/touch_selection/touch_selection_controller.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 UI_TOUCH_SELECTION_TOUCH_SELECTION_CONTROLLER_H_
 #define UI_TOUCH_SELECTION_TOUCH_SELECTION_CONTROLLER_H_
 
 #include "base/time/time.h"
 #include "ui/base/touch/selection_bound.h"
 #include "ui/gfx/geometry/point_f.h"
@@ skipping 64 matching lines @@
   void OnSelectionBoundsChanged(const SelectionBound& start,
                                 const SelectionBound& end);
 
   // Allows touch-dragging of the handle.
   // Returns true iff the event was consumed, in which case the caller should
   // cease further handling of the event.
   bool WillHandleTouchEvent(const MotionEvent& event);
 
   // To be called before forwarding a tap event. This allows automatically
   // showing the insertion handle from subsequent bounds changes.
-  bool WillHandleTapEvent(const gfx::PointF& location);
+  // |tap_count| is tap index in a repeated sequence, i.e., 1 for the first
+  // tap, 2 for the second tap, etc...
+  bool WillHandleTapEvent(const gfx::PointF& location, int tap_count);
 
   // To be called before forwarding a longpress event. This allows automatically
   // showing the selection or insertion handles from subsequent bounds changes.
   bool WillHandleLongPressEvent(base::TimeTicks event_time,
                                 const gfx::PointF& location);
 
   // Allow showing the selection handles from the most recent selection bounds
   // update (if valid), or a future valid bounds update.
   void AllowShowingFromCurrentSelection();
 
@@ skipping 30 matching lines @@
   const gfx::PointF& GetEndPosition() const;
 
   const SelectionBound& start() const { return start_; }
   const SelectionBound& end() const { return end_; }
 
   ActiveStatus active_status() const { return active_status_; }
 
  private:
   friend class TouchSelectionControllerTestApi;
 
-  enum InputEventType { TAP, LONG_PRESS, INPUT_EVENT_TYPE_NONE };
+  enum InputEventType { TAP, REPEATED_TAP, LONG_PRESS, INPUT_EVENT_TYPE_NONE };
 
   // TouchHandleClient implementation.
   void OnDragBegin(const TouchSelectionDraggable& draggable,
                    const gfx::PointF& drag_position) override;
   void OnDragUpdate(const TouchSelectionDraggable& draggable,
                     const gfx::PointF& drag_position) override;
   void OnDragEnd(const TouchSelectionDraggable& draggable) override;
   bool IsWithinTapSlop(const gfx::Vector2dF& delta) const override;
   void OnHandleTapped(const TouchHandle& handle) override;
   void SetNeedsAnimate() override;
@@ skipping 73 matching lines @@
   // Whether a selection handle was dragged during the current 'selection
   // session' - i.e. since the current selection has been activated.
   bool selection_handle_dragged_;
 
   DISALLOW_COPY_AND_ASSIGN(TouchSelectionController);
 };
 
 }  // namespace ui
 
 #endif  // UI_TOUCH_SELECTION_TOUCH_SELECTION_CONTROLLER_H_