content/browser/renderer_host/input/motion_event_android.h

   1
   2 // Copyright 2014 The Chromium Authors. All rights reserved.
   3 // Use of this source code is governed by a BSD-style license that can be
   4 // found in the LICENSE file.
   5
   6 #ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_MOTION_EVENT_ANDROID_H_
   7 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_MOTION_EVENT_ANDROID_H_
   8
   9 #include <jni.h>
  10
  11 #include "base/android/scoped_java_ref.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/time/time.h"
  14 #include "content/common/content_export.h"
  15 #include "ui/events/gesture_detection/motion_event.h"
  16 #include "ui/gfx/geometry/point_f.h"
  17
  18 namespace content {
  19
  20 // Implementation of ui::MotionEvent wrapping a native Android MotionEvent.
  21 // All *input* coordinates are in device pixels (as with Android MotionEvent),
  22 // while all *output* coordinates are in DIPs (as with WebTouchEvent).
  23 class CONTENT_EXPORT MotionEventAndroid : public ui::MotionEvent {
  24  public:
  25   struct Pointer {
  26     Pointer(jint id,
  27             jfloat pos_x_pixels,
  28             jfloat pos_y_pixels,
  29             jfloat touch_major_pixels,
  30             jfloat touch_minor_pixels,
  31             jfloat orientation_rad,
  32             jint tool_type);
  33     jint id;
  34     jfloat pos_x_pixels;
  35     jfloat pos_y_pixels;
  36     jfloat touch_major_pixels;
  37     jfloat touch_minor_pixels;
  38     jfloat orientation_rad;
  39     jint tool_type;
  40   };
  41
  42   // Forcing the caller to provide all cached values upon construction
  43   // eliminates the need to perform a JNI call to retrieve values individually.
  44   MotionEventAndroid(float pix_to_dip,
  45                      JNIEnv* env,
  46                      jobject event,
  47                      jlong time_ms,
  48                      jint android_action,
  49                      jint pointer_count,
  50                      jint history_size,
  51                      jint action_index,
  52                      jint android_button_state,
  53                      jint meta_state,
  54                      jfloat raw_offset_x_pixels,
  55                      jfloat raw_offset_y_pixels,
  56                      const Pointer& pointer0,
  57                      const Pointer& pointer1);
  58   ~MotionEventAndroid() override;
  59
  60   // ui::MotionEvent methods.
  61   uint32 GetUniqueEventId() const override;
  62   Action GetAction() const override;
  63   int GetActionIndex() const override;
  64   size_t GetPointerCount() const override;
  65   int GetPointerId(size_t pointer_index) const override;
  66   float GetX(size_t pointer_index) const override;
  67   float GetY(size_t pointer_index) const override;
  68   float GetRawX(size_t pointer_index) const override;
  69   float GetRawY(size_t pointer_index) const override;
  70   float GetTouchMajor(size_t pointer_index) const override;
  71   float GetTouchMinor(size_t pointer_index) const override;
  72   float GetOrientation(size_t pointer_index) const override;
  73   float GetPressure(size_t pointer_index) const override;
  74   base::TimeTicks GetEventTime() const override;
  75   size_t GetHistorySize() const override;
  76   base::TimeTicks GetHistoricalEventTime(
  77       size_t historical_index) const override;
  78   float GetHistoricalTouchMajor(size_t pointer_index,
  79                                 size_t historical_index) const override;
  80   float GetHistoricalX(size_t pointer_index,
  81                        size_t historical_index) const override;
  82   float GetHistoricalY(size_t pointer_index,
  83                        size_t historical_index) const override;
  84   ToolType GetToolType(size_t pointer_index) const override;
  85   int GetButtonState() const override;
  86   int GetFlags() const override;
  87
  88   static bool RegisterMotionEventAndroid(JNIEnv* env);
  89
  90  private:
  91   struct CachedPointer;
  92
  93   float ToDips(float pixels) const;
  94   CachedPointer FromAndroidPointer(const Pointer& pointer) const;
  95
  96   // Cache pointer coords, id's and major lengths for the most common
  97   // touch-related scenarios, i.e., scrolling and pinching.  This prevents
  98   // redundant JNI fetches for the same bits.
  99   enum { MAX_POINTERS_TO_CACHE = 2 };
 100
 101   // The Java reference to the underlying MotionEvent.
 102   base::android::ScopedJavaGlobalRef<jobject> event_;
 103
 104   // Used to convert pixel coordinates from the Java-backed MotionEvent to
 105   // DIP coordinates cached/returned by the MotionEventAndroid.
 106   const float pix_to_dip_;
 107
 108   const base::TimeTicks cached_time_;
 109   const Action cached_action_;
 110   const size_t cached_pointer_count_;
 111   const size_t cached_history_size_;
 112   const int cached_action_index_;
 113   const int cached_button_state_;
 114   const int cached_flags_;
 115   const gfx::Vector2dF cached_raw_position_offset_;
 116   struct CachedPointer {
 117     CachedPointer();
 118     int id;
 119     gfx::PointF position;
 120     float touch_major;
 121     float touch_minor;
 122     float orientation;
 123     ToolType tool_type;
 124   } cached_pointers_[MAX_POINTERS_TO_CACHE];
 125
 126   // A unique identifier for the Android motion event.
 127   const uint32 unique_event_id_;
 128
 129   DISALLOW_COPY_AND_ASSIGN(MotionEventAndroid);
 130 };
 131
 132 }  // namespace content
 133
 134 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_MOTION_EVENT_ANDROID_H_