Add EventForwarder for routing touch events

ui/events/android/motion_event_android.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_EVENTS_ANDROID_MOTION_EVENT_ANDROID_H_
 #define UI_EVENTS_ANDROID_MOTION_EVENT_ANDROID_H_
 
 #include <jni.h>
 #include <stddef.h>
 #include <stdint.h>
@@ skipping 36 matching lines @@
   // Forcing the caller to provide all cached values upon construction
   // eliminates the need to perform a JNI call to retrieve values individually.
   MotionEventAndroid(float pix_to_dip,
                      JNIEnv* env,
                      jobject event,
                      jlong time_ms,
                      jint android_action,
                      jint pointer_count,
                      jint history_size,
                      jint action_index,
+                     jint android_action_button,
                      jint android_button_state,
                      jint meta_state,
                      jfloat raw_offset_x_pixels,
                      jfloat raw_offset_y_pixels,
                      const Pointer* const pointer0,
                      const Pointer* const pointer1);
   ~MotionEventAndroid() override;
 
+  MotionEventAndroid(const MotionEventAndroid& e, float x, float y);

[boliu, 2017/03/03 22:01:32]

can we just have an offset(x,y) method that returns a new instance?

[Jinsuk Kim, 2017/03/06 04:07:34]

Done this way since copy/Assign is disallowed. See my old reply to aelias@'
command.

[boliu, 2017/03/06 22:08:04]

oh is it because the return by value is a copy? Parent class has
std::unique_ptr<MotionEvent> MotionEvent::Clone. so I guess you can return a
unique_ptr from offset too?


Anyway, this is a really odd subclass.. Calling Clone on this class will return
a MotionEventGeneric right now afaict o_O

[Jinsuk Kim, 2017/03/07 05:02:23]

Added |Offset| that returns std::unique_ptr, and also added the private copy ctr
for that, since it's hard to make use of the existing ctr to create a new
instance from another one (most params are translated to something else at
construction).

+
   // ui::MotionEvent methods.
   uint32_t GetUniqueEventId() const override;
   Action GetAction() const override;
   int GetActionIndex() const override;
   size_t GetPointerCount() const override;
   int GetPointerId(size_t pointer_index) const override;
   float GetX(size_t pointer_index) const override;
   float GetY(size_t pointer_index) const override;
   float GetRawX(size_t pointer_index) const override;
   float GetRawY(size_t pointer_index) const override;
   float GetTouchMajor(size_t pointer_index) const override;
   float GetTouchMinor(size_t pointer_index) const override;
   float GetOrientation(size_t pointer_index) const override;
   float GetPressure(size_t pointer_index) const override;
   float GetTilt(size_t pointer_index) const override;
   base::TimeTicks GetEventTime() const override;
   size_t GetHistorySize() const override;
   base::TimeTicks GetHistoricalEventTime(
       size_t historical_index) const override;
   float GetHistoricalTouchMajor(size_t pointer_index,
                                 size_t historical_index) const override;
   float GetHistoricalX(size_t pointer_index,
                        size_t historical_index) const override;
   float GetHistoricalY(size_t pointer_index,
                        size_t historical_index) const override;
   ToolType GetToolType(size_t pointer_index) const override;
   int GetButtonState() const override;
   int GetFlags() const override;
 
+  int GetActionButton() const;
+  base::android::ScopedJavaLocalRef<jobject> GetJavaObject() const;
+
  private:
   struct CachedPointer;
 
   float ToDips(float pixels) const;
   CachedPointer FromAndroidPointer(const Pointer& pointer) const;
+  CachedPointer FromCachedPointer(const CachedPointer& pointer,
+                                  float x,
+                                  float y) const;
 
   // Cache pointer coords, id's and major lengths for the most common
   // touch-related scenarios, i.e., scrolling and pinching.  This prevents
   // redundant JNI fetches for the same bits.
   enum { MAX_POINTERS_TO_CACHE = 2 };
 
   // The Java reference to the underlying MotionEvent.
   base::android::ScopedJavaGlobalRef<jobject> event_;
 
   // Used to convert pixel coordinates from the Java-backed MotionEvent to
   // DIP coordinates cached/returned by the MotionEventAndroid.
   const float pix_to_dip_;
 
   const base::TimeTicks cached_time_;
   const Action cached_action_;
   const size_t cached_pointer_count_;
   const size_t cached_history_size_;
   const int cached_action_index_;
+  const int cached_action_button_;
   const int cached_button_state_;
   const int cached_flags_;
   const gfx::Vector2dF cached_raw_position_offset_;
   struct CachedPointer {
     CachedPointer();
     int id;
     gfx::PointF position;
     float touch_major;
     float touch_minor;
     float orientation;
     float tilt;
     ToolType tool_type;
   } cached_pointers_[MAX_POINTERS_TO_CACHE];
 
   // A unique identifier for the Android motion event.
   const uint32_t unique_event_id_;
 
   DISALLOW_COPY_AND_ASSIGN(MotionEventAndroid);
 };
 
 }  // namespace content
 
 #endif  // UI_EVENTS_ANDROID_MOTION_EVENT_ANDROID_H_