ui/touch_selection/longpress_drag_selector.h

   1 // Copyright 2015 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 UI_TOUCH_SELECTION_LONGPRESS_DRAG_SELECTOR_H_
   6 #define UI_TOUCH_SELECTION_LONGPRESS_DRAG_SELECTOR_H_
   7
   8 #include "base/time/time.h"
   9 #include "ui/gfx/geometry/point_f.h"
  10 #include "ui/gfx/geometry/vector2d_f.h"
  11 #include "ui/touch_selection/touch_selection_draggable.h"
  12 #include "ui/touch_selection/ui_touch_selection_export.h"
  13
  14 namespace ui {
  15
  16 class MotionEvent;
  17
  18 class UI_TOUCH_SELECTION_EXPORT LongPressDragSelectorClient
  19     : public TouchSelectionDraggableClient {
  20  public:
  21   ~LongPressDragSelectorClient() override {}
  22   virtual void OnLongPressDragActiveStateChanged() = 0;
  23   virtual gfx::PointF GetSelectionStart() const = 0;
  24   virtual gfx::PointF GetSelectionEnd() const = 0;
  25 };
  26
  27 // Supports text selection via touch dragging after a longpress-initiated
  28 // selection.
  29 class UI_TOUCH_SELECTION_EXPORT LongPressDragSelector
  30     : public TouchSelectionDraggable {
  31  public:
  32   explicit LongPressDragSelector(LongPressDragSelectorClient* client);
  33   ~LongPressDragSelector() override;
  34
  35   // TouchSelectionDraggable implementation.
  36   bool WillHandleTouchEvent(const MotionEvent& event) override;
  37   bool IsActive() const override;
  38
  39   // Called just prior to a longpress event being handled.
  40   void OnLongPressEvent(base::TimeTicks event_time,
  41                         const gfx::PointF& position);
  42
  43   // Called when the active selection changes.
  44   void OnSelectionActivated();
  45   void OnSelectionDeactivated();
  46
  47  private:
  48   enum SelectionState {
  49     INACTIVE,
  50     LONGPRESS_PENDING,
  51     SELECTION_PENDING,
  52     DRAG_PENDING,
  53     DRAGGING
  54   };
  55
  56   void SetState(SelectionState state);
  57
  58   LongPressDragSelectorClient* const client_;
  59
  60   SelectionState state_;
  61
  62   base::TimeTicks touch_down_time_;
  63   gfx::PointF touch_down_position_;
  64
  65   gfx::Vector2dF longpress_drag_selection_offset_;
  66   gfx::PointF longpress_drag_start_anchor_;
  67   bool has_longpress_drag_start_anchor_;
  68 };
  69
  70 }  // namespace ui
  71
  72 #endif  // UI_TOUCH_SELECTION_LONGPRESS_DRAG_SELECTOR_H_