android4.0鼠标右键返回功能

1. 鼠标右键返回功能。
   
2. 在\frameworks\base\services\input\InputReader.cpp文件下修改
   
3. 
   
4. uint32_t CursorButtonAccumulator::getButtonState() const {
   
5. uint32_t result = 0;
   
6. if (mBtnLeft) {
   
7. result |= AMOTION_EVENT_BUTTON_PRIMARY;
   
8. }
   
9. if (mBtnRight) {
   
10. result |= AMOTION_EVENT_BUTTON_BACK;
    
11. }
    
12. if (mBtnMiddle) {
    
13. result |= AMOTION_EVENT_BUTTON_TERTIARY;
    
14. }
    
15. if (mBtnBack || mBtnSide) {
    
16. result |= AMOTION_EVENT_BUTTON_BACK;
    
17. }
    
18. if (mBtnForward || mBtnExtra) {
    
19. result |= AMOTION_EVENT_BUTTON_FORWARD;
    
20. }
    
21. return result;