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      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_HANDLE_H_
      6 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_HANDLE_H_
      7 
      8 #include "base/logging.h"
      9 #include "base/memory/scoped_ptr.h"
     10 #include "base/time/time.h"
     11 #include "content/common/content_export.h"
     12 #include "ui/events/gesture_detection/motion_event.h"
     13 #include "ui/gfx/geometry/point_f.h"
     14 #include "ui/gfx/geometry/rect_f.h"
     15 #include "ui/gfx/geometry/vector2d_f.h"
     16 
     17 namespace content {
     18 
     19 class TouchHandle;
     20 
     21 enum TouchHandleOrientation {
     22   TOUCH_HANDLE_LEFT,
     23   TOUCH_HANDLE_CENTER,
     24   TOUCH_HANDLE_RIGHT,
     25   TOUCH_HANDLE_ORIENTATION_UNDEFINED,
     26 };
     27 
     28 // Interface through which |TouchHandle| delegates rendering-specific duties.
     29 class CONTENT_EXPORT TouchHandleDrawable {
     30  public:
     31   virtual ~TouchHandleDrawable() {}
     32   virtual void SetEnabled(bool enabled) = 0;
     33   virtual void SetOrientation(TouchHandleOrientation orientation) = 0;
     34   virtual void SetAlpha(float alpha) = 0;
     35   virtual void SetFocus(const gfx::PointF& position) = 0;
     36   virtual void SetVisible(bool visible) = 0;
     37   virtual bool IntersectsWith(const gfx::RectF& rect) const = 0;
     38 };
     39 
     40 // Interface through which |TouchHandle| communicates handle manipulation and
     41 // requests concrete drawable instances.
     42 class CONTENT_EXPORT TouchHandleClient {
     43  public:
     44   virtual ~TouchHandleClient() {}
     45   virtual void OnHandleDragBegin(const TouchHandle& handle) = 0;
     46   virtual void OnHandleDragUpdate(const TouchHandle& handle,
     47                                   const gfx::PointF& new_position) = 0;
     48   virtual void OnHandleDragEnd(const TouchHandle& handle) = 0;
     49   virtual void OnHandleTapped(const TouchHandle& handle) = 0;
     50   virtual void SetNeedsAnimate() = 0;
     51   virtual scoped_ptr<TouchHandleDrawable> CreateDrawable() = 0;
     52   virtual base::TimeDelta GetTapTimeout() const = 0;
     53   virtual float GetTapSlop() const = 0;
     54 };
     55 
     56 // Responsible for displaying a selection or insertion handle for text
     57 // interaction.
     58 class CONTENT_EXPORT TouchHandle {
     59  public:
     60   // The drawable will be enabled but invisible until otherwise specified.
     61   TouchHandle(TouchHandleClient* client, TouchHandleOrientation orientation);
     62   ~TouchHandle();
     63 
     64   // Sets whether the handle is active, allowing resource cleanup if necessary.
     65   // If false, active animations or touch drag sequences will be cancelled.
     66   // While disabled, manipulation is *explicitly not supported*, and may lead to
     67   // undesirable and/or unstable side-effects. The handle can be safely
     68   // re-enabled to allow continued operation.
     69   void SetEnabled(bool enabled);
     70 
     71   enum AnimationStyle { ANIMATION_NONE, ANIMATION_SMOOTH };
     72   // Update the handle visibility, fading in/out according to |animation_style|.
     73   // If an animation is in-progress, it will be overriden appropriately.
     74   void SetVisible(bool visible, AnimationStyle animation_style);
     75 
     76   // Update the handle placement to |position|.
     77   // Note: If a fade out animation is active or the handle is invisible, the
     78   // handle position will not be updated until the handle regains visibility.
     79   void SetPosition(const gfx::PointF& position);
     80 
     81   // Update the handle visuals to |orientation|.
     82   // Note: If the handle is being dragged, the orientation change will be
     83   // deferred until the drag has ceased.
     84   void SetOrientation(TouchHandleOrientation orientation);
     85 
     86   // Allows touch-dragging of the handle. Returns true if the event was
     87   // consumed, in which case the caller should cease further handling.
     88   bool WillHandleTouchEvent(const ui::MotionEvent& event);
     89 
     90   // Ticks an active animation, as requested to the client by |SetNeedsAnimate|.
     91   // Returns true if an animation is active and requires further ticking.
     92   bool Animate(base::TimeTicks frame_time);
     93 
     94   bool is_dragging() const { return is_dragging_; }
     95   const gfx::PointF& position() const { return position_; }
     96   TouchHandleOrientation orientation() const { return orientation_; }
     97 
     98  private:
     99   void BeginDrag();
    100   void EndDrag();
    101   void BeginFade();
    102   void EndFade();
    103   void SetAlpha(float alpha);
    104 
    105   scoped_ptr<TouchHandleDrawable> drawable_;
    106 
    107   TouchHandleClient* const client_;
    108 
    109   gfx::PointF position_;
    110   TouchHandleOrientation orientation_;
    111   TouchHandleOrientation deferred_orientation_;
    112 
    113   gfx::PointF touch_down_position_;
    114   gfx::Vector2dF touch_to_focus_offset_;
    115   base::TimeTicks touch_down_time_;
    116 
    117   // Note that when a fade animation is active, |is_visible_| and |position_|
    118   // may not reflect the actual visibilty and position of the drawable. This
    119   // discrepancy is resolved either upon fade completion or cancellation.
    120   base::TimeTicks fade_end_time_;
    121   gfx::PointF fade_start_position_;
    122   float alpha_;
    123   bool animate_deferred_fade_;
    124 
    125   bool enabled_;
    126   bool is_visible_;
    127   bool is_dragging_;
    128   bool is_drag_within_tap_region_;
    129 
    130   DISALLOW_COPY_AND_ASSIGN(TouchHandle);
    131 };
    132 
    133 }  // namespace content
    134 
    135 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_TOUCH_HANDLE_H_
    136