android 通过onTouchEvent判断是否为双击事件

通过onTouchEvent判断是否为双击事件，通过前面一次up 跟本次down之间的时间差，并且点击的点的坐标偏移来确定是否为双击事件DOUBLE_TAP_TIMEOUT

boolean isMove = false;private final int DOUBLE_TAP_TIMEOUT = 200;private MotionEvent mCurrentDownEvent;private boolean mDoubleTapEnabled = false;private MotionEvent mPreviousUpEvent;@Overridepublic void onTouchEvent(MotionEvent event) {    Log.e(LOG_TAG, "MotionEvent="+ event.getAction()+",isMove="+isMove);    Log.e(LOG_TAG, "mPreviousUpEvent="+ mPreviousUpEvent+",mCurrentDownEvent="+mCurrentDownEvent);    if (event.getAction() == MotionEvent.ACTION_MOVE) {        isMove = true;}    else if (event.getAction() == MotionEvent.ACTION_DOWN) {if (mPreviousUpEvent != null && mCurrentDownEvent != null && isConsideredDoubleTap(mCurrentDownEvent, mPreviousUpEvent, event)) {if (mDoubleTapEnabled && Environment.getExternalStorageState().equals("mounted")) {Toast.makeText(getApplicationContext(), getResources().getString(R.string.double_click), Toast.LENGTH_LONG).show();}}mCurrentDownEvent = MotionEvent.obtain(event);}else if (event.getAction() == MotionEvent.ACTION_UP){mPreviousUpEvent = MotionEvent.obtain(event);isMove = false;}}private boolean isConsideredDoubleTap(MotionEvent firstDown, MotionEvent firstUp, MotionEvent secondDown){if (secondDown.getEventTime() - firstUp.getEventTime() > DOUBLE_TAP_TIMEOUT) {return false;}int deltaX =(int) firstUp.getX() - (int)secondDown.getX();int deltaY =(int) firstUp.getY()- (int)secondDown.getY(); return deltaX * deltaX + deltaY * deltaY < 10000;}