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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_MOTION_EVENT_ANDROID_H_
      6 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_MOTION_EVENT_ANDROID_H_
      7 
      8 #include <jni.h>
      9 
     10 #include "base/android/scoped_java_ref.h"
     11 #include "base/memory/scoped_ptr.h"
     12 #include "base/time/time.h"
     13 #include "content/common/content_export.h"
     14 #include "ui/events/gesture_detection/motion_event.h"
     15 #include "ui/gfx/geometry/point_f.h"
     16 
     17 namespace content {
     18 
     19 // Implementation of ui::MotionEvent wrapping a native Android MotionEvent.
     20 // All *input* coordinates are in device pixels (as with Android MotionEvent),
     21 // while all *output* coordinates are in DIPs (as with WebTouchEvent).
     22 class CONTENT_EXPORT MotionEventAndroid : public ui::MotionEvent {
     23  public:
     24   // Forcing the caller to provide all cached values upon construction
     25   // eliminates the need to perform a JNI call to retrieve values individually.
     26   MotionEventAndroid(float pix_to_dip,
     27                      JNIEnv* env,
     28                      jobject event,
     29                      jlong time_ms,
     30                      jint android_action,
     31                      jint pointer_count,
     32                      jint history_size,
     33                      jint action_index,
     34                      jfloat pos_x_0_pixels,
     35                      jfloat pos_y_0_pixels,
     36                      jfloat pos_x_1_pixels,
     37                      jfloat pos_y_1_pixels,
     38                      jint pointer_id_0,
     39                      jint pointer_id_1,
     40                      jfloat touch_major_0_pixels,
     41                      jfloat touch_major_1_pixels,
     42                      jfloat touch_minor_0_pixels,
     43                      jfloat touch_minor_1_pixels,
     44                      jfloat orientation_0_rad,
     45                      jfloat orientation_1_rad,
     46                      jfloat raw_pos_x_pixels,
     47                      jfloat raw_pos_y_pixels,
     48                      jint android_tool_type_0,
     49                      jint android_tool_type_1,
     50                      jint android_button_state,
     51                      jint meta_state);
     52   virtual ~MotionEventAndroid();
     53 
     54   // ui::MotionEvent methods.
     55   virtual int GetId() const OVERRIDE;
     56   virtual Action GetAction() const OVERRIDE;
     57   virtual int GetActionIndex() const OVERRIDE;
     58   virtual size_t GetPointerCount() const OVERRIDE;
     59   virtual int GetPointerId(size_t pointer_index) const OVERRIDE;
     60   virtual float GetX(size_t pointer_index) const OVERRIDE;
     61   virtual float GetY(size_t pointer_index) const OVERRIDE;
     62   virtual float GetRawX(size_t pointer_index) const OVERRIDE;
     63   virtual float GetRawY(size_t pointer_index) const OVERRIDE;
     64   virtual float GetTouchMajor(size_t pointer_index) const OVERRIDE;
     65   virtual float GetTouchMinor(size_t pointer_index) const OVERRIDE;
     66   virtual float GetOrientation(size_t pointer_index) const OVERRIDE;
     67   virtual float GetPressure(size_t pointer_index) const OVERRIDE;
     68   virtual base::TimeTicks GetEventTime() const OVERRIDE;
     69   virtual size_t GetHistorySize() const OVERRIDE;
     70   virtual base::TimeTicks GetHistoricalEventTime(
     71       size_t historical_index) const OVERRIDE;
     72   virtual float GetHistoricalTouchMajor(size_t pointer_index,
     73                                         size_t historical_index) const OVERRIDE;
     74   virtual float GetHistoricalX(size_t pointer_index,
     75                                size_t historical_index) const OVERRIDE;
     76   virtual float GetHistoricalY(size_t pointer_index,
     77                                size_t historical_index) const OVERRIDE;
     78   virtual ToolType GetToolType(size_t pointer_index) const OVERRIDE;
     79   virtual int GetButtonState() const OVERRIDE;
     80   virtual int GetFlags() const OVERRIDE;
     81   virtual scoped_ptr<MotionEvent> Clone() const OVERRIDE;
     82   virtual scoped_ptr<MotionEvent> Cancel() const OVERRIDE;
     83 
     84   // Additional Android MotionEvent methods.
     85   base::TimeTicks GetDownTime() const;
     86 
     87   static bool RegisterMotionEventAndroid(JNIEnv* env);
     88 
     89   static base::android::ScopedJavaLocalRef<jobject> Obtain(
     90       const MotionEventAndroid& event);
     91   static base::android::ScopedJavaLocalRef<jobject> Obtain(
     92       base::TimeTicks down_time,
     93       base::TimeTicks event_time,
     94       Action action,
     95       float x_pixels,
     96       float y_pixels);
     97 
     98  private:
     99   MotionEventAndroid();
    100   MotionEventAndroid(float pix_to_dip, JNIEnv* env, jobject event);
    101   MotionEventAndroid(const MotionEventAndroid&);
    102   MotionEventAndroid& operator=(const MotionEventAndroid&);
    103 
    104   float ToDips(float pixels) const;
    105   gfx::PointF ToDips(const gfx::PointF& pixels) const;
    106 
    107   // Cache pointer coords, id's and major lengths for the most common
    108   // touch-related scenarios, i.e., scrolling and pinching.  This prevents
    109   // redundant JNI fetches for the same bits.
    110   enum { MAX_POINTERS_TO_CACHE = 2 };
    111 
    112   // The Java reference to the underlying MotionEvent.
    113   base::android::ScopedJavaGlobalRef<jobject> event_;
    114 
    115   base::TimeTicks cached_time_;
    116   Action cached_action_;
    117   size_t cached_pointer_count_;
    118   size_t cached_history_size_;
    119   int cached_action_index_;
    120   gfx::PointF cached_positions_[MAX_POINTERS_TO_CACHE];
    121   int cached_pointer_ids_[MAX_POINTERS_TO_CACHE];
    122   float cached_touch_majors_[MAX_POINTERS_TO_CACHE];
    123   float cached_touch_minors_[MAX_POINTERS_TO_CACHE];
    124   float cached_orientations_[MAX_POINTERS_TO_CACHE];
    125   gfx::Vector2dF cached_raw_position_offset_;
    126   ToolType cached_tool_types_[MAX_POINTERS_TO_CACHE];
    127   int cached_button_state_;
    128   int cached_flags_;
    129 
    130   // Used to convert pixel coordinates from the Java-backed MotionEvent to
    131   // DIP coordinates cached/returned by the MotionEventAndroid.
    132   const float pix_to_dip_;
    133 
    134   // Whether |event_| should be recycled on destruction. This will only be true
    135   // for those events generated via |Obtain(...)|.
    136   bool should_recycle_;
    137 };
    138 
    139 }  // namespace content
    140 
    141 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_MOTION_EVENT_ANDROID_H_
    142