content/browser/renderer_host/input/motion_event_android.h

   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 raw_pos_x_pixels,
  43                      jfloat raw_pos_y_pixels,
  44                      jint android_tool_type_0,
  45                      jint android_tool_type_1,
  46                      jint android_button_state);
  47   virtual ~MotionEventAndroid();
  48
  49   // ui::MotionEvent methods.
  50   virtual int GetId() const OVERRIDE;
  51   virtual Action GetAction() const OVERRIDE;
  52   virtual int GetActionIndex() const OVERRIDE;
  53   virtual size_t GetPointerCount() const OVERRIDE;
  54   virtual int GetPointerId(size_t pointer_index) const OVERRIDE;
  55   virtual float GetX(size_t pointer_index) const OVERRIDE;
  56   virtual float GetY(size_t pointer_index) const OVERRIDE;
  57   virtual float GetRawX(size_t pointer_index) const OVERRIDE;
  58   virtual float GetRawY(size_t pointer_index) const OVERRIDE;
  59   virtual float GetTouchMajor(size_t pointer_index) const OVERRIDE;
  60   virtual float GetPressure(size_t pointer_index) const OVERRIDE;
  61   virtual base::TimeTicks GetEventTime() const OVERRIDE;
  62   virtual size_t GetHistorySize() const OVERRIDE;
  63   virtual base::TimeTicks GetHistoricalEventTime(
  64       size_t historical_index) const OVERRIDE;
  65   virtual float GetHistoricalTouchMajor(size_t pointer_index,
  66                                         size_t historical_index) const OVERRIDE;
  67   virtual float GetHistoricalX(size_t pointer_index,
  68                                size_t historical_index) const OVERRIDE;
  69   virtual float GetHistoricalY(size_t pointer_index,
  70                                size_t historical_index) const OVERRIDE;
  71   virtual ToolType GetToolType(size_t pointer_index) const OVERRIDE;
  72   virtual int GetButtonState() const OVERRIDE;
  73   virtual scoped_ptr<MotionEvent> Clone() const OVERRIDE;
  74   virtual scoped_ptr<MotionEvent> Cancel() const OVERRIDE;
  75
  76   // Additional Android MotionEvent methods.
  77   float GetTouchMinor() const { return GetTouchMinor(0); }
  78   float GetTouchMinor(size_t pointer_index) const;
  79   float GetOrientation() const;
  80   base::TimeTicks GetDownTime() const;
  81
  82   static bool RegisterMotionEventAndroid(JNIEnv* env);
  83
  84   static base::android::ScopedJavaLocalRef<jobject> Obtain(
  85       const MotionEventAndroid& event);
  86   static base::android::ScopedJavaLocalRef<jobject> Obtain(
  87       base::TimeTicks down_time,
  88       base::TimeTicks event_time,
  89       Action action,
  90       float x_pixels,
  91       float y_pixels);
  92
  93  private:
  94   MotionEventAndroid();
  95   MotionEventAndroid(float pix_to_dip, JNIEnv* env, jobject event);
  96   MotionEventAndroid(const MotionEventAndroid&);
  97   MotionEventAndroid& operator=(const MotionEventAndroid&);
  98
  99   float ToDips(float pixels) const;
 100   gfx::PointF ToDips(const gfx::PointF& pixels) const;
 101
 102   // Cache pointer coords, id's and major lengths for the most common
 103   // touch-related scenarios, i.e., scrolling and pinching.  This prevents
 104   // redundant JNI fetches for the same bits.
 105   enum { MAX_POINTERS_TO_CACHE = 2 };
 106
 107   // The Java reference to the underlying MotionEvent.
 108   base::android::ScopedJavaGlobalRef<jobject> event_;
 109
 110   base::TimeTicks cached_time_;
 111   Action cached_action_;
 112   size_t cached_pointer_count_;
 113   size_t cached_history_size_;
 114   int cached_action_index_;
 115   gfx::PointF cached_positions_[MAX_POINTERS_TO_CACHE];
 116   int cached_pointer_ids_[MAX_POINTERS_TO_CACHE];
 117   float cached_touch_majors_[MAX_POINTERS_TO_CACHE];
 118   gfx::Vector2dF cached_raw_position_offset_;
 119   ToolType cached_tool_types_[MAX_POINTERS_TO_CACHE];
 120   int cached_button_state_;
 121
 122   // Used to convert pixel coordinates from the Java-backed MotionEvent to
 123   // DIP coordinates cached/returned by the MotionEventAndroid.
 124   const float pix_to_dip_;
 125
 126   // Whether |event_| should be recycled on destruction. This will only be true
 127   // for those events generated via |Obtain(...)|.
 128   bool should_recycle_;
 129 };
 130
 131 }  // namespace content
 132
 133 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_MOTION_EVENT_ANDROID_H_