public boolean onTouchEvent(MotionEvent event) {//获取基本信息(没考虑多点，仅考虑单点) 坐标&action final float x = event.getX();final float y = event.getY();final int viewFlags = mViewFlags;final int action = event.getAction();//判断是否可点击，长按和上下文点击（上下文菜单，鼠标右键）final boolean clickable = ((viewFlags & CLICKABLE) == CLICKABLE|| (viewFlags & LONG_CLICKABLE) == LONG_CLICKABLE)|| (viewFlags & CONTEXT_CLICKABLE) == CONTEXT_CLICKABLE;//如果是不可用的，直接把事件消费掉，不再向下传递if ((viewFlags & ENABLED_MASK) == DISABLED) {if (action == MotionEvent.ACTION_UP && (mPrivateFlags & PFLAG_PRESSED) != 0) {setPressed(false);}mPrivateFlags3 &= ~PFLAG3_FINGER_DOWN;// A disabled view that is clickable still consumes the touch// events, it just doesn't respond to them.return clickable;}//是否有TouchDelegate，有就消费 -TouchDelegate：点击代理if (mTouchDelegate != null) {if (mTouchDelegate.onTouchEvent(event)) {return true;}}//TOOLTIP：解释文本if (clickable || (viewFlags & TOOLTIP) == TOOLTIP) {switch (action) {case MotionEvent.ACTION_UP://手触摸到屏幕标记置空mPrivateFlags3 &= ~PFLAG3_FINGER_DOWN;//抬手后 tooltip延迟一会消失if ((viewFlags & TOOLTIP) == TOOLTIP) {handleTooltipUp();}//不可点 各种清空还原if (!clickable) {removeTapCallback();removeLongPressCallback();mInContextButtonPress = false;mHasPerformedLongPress = false;mIgnoreNextUpEvent = false;break;}//是否是点下 &预按下boolean prepressed = (mPrivateFlags & PFLAG_PREPRESSED) != 0;if ((mPrivateFlags & PFLAG_PRESSED) != 0 || prepressed) {// take focus if we don't have it already and we should in// touch mode.boolean focusTaken = false;//如果可以获取焦点 可在实体按键中获取焦点 && 当前没有焦点 if (isFocusable() && isFocusableInTouchMode() && !isFocused()) {focusTaken = requestFocus(); //请求焦点}//如果是预按下 up时设置按下if (prepressed) {// The button is being released before we actually// showed it as pressed. Make it show the pressed// state now (before scheduling the click) to ensure// the user sees it.setPressed(true, x, y);}//回调点击if (!mHasPerformedLongPress && !mIgnoreNextUpEvent) {// This is a tap, so remove the longpress checkremoveLongPressCallback();// Only perform take click actions if we were in the pressed stateif (!focusTaken) {// Use a Runnable and post this rather than calling// performClick directly. This lets other visual state// of the view update before click actions start.if (mPerformClick == null) {mPerformClick = new PerformClick();}if (!post(mPerformClick)) {performClickInternal();}}}if (mUnsetPressedState == null) {mUnsetPressedState = new UnsetPressedState();}//如果是预按下 抬起 效果等4帧if (prepressed) {postDelayed(mUnsetPressedState,ViewConfiguration.getPressedStateDuration());} else if (!post(mUnsetPressedState)) {// If the post failed, unpress right nowmUnsetPressedState.run();}removeTapCallback();}mIgnoreNextUpEvent = false;break;case MotionEvent.ACTION_DOWN://判断是否触摸到屏幕：存在实体按键->标记为手指按下if (event.getSource() == InputDevice.SOURCE_TOUCHSCREEN) {mPrivateFlags3 |= PFLAG3_FINGER_DOWN;}mHasPerformedLongPress = false;//不可点的话，设置长按等待器：为了TOOLTIP，显示提示文字if (!clickable) {checkForLongClick(0, x, y); //break;}//是否是鼠标右键点击，是就显示上下文菜单if (performButtonActionOnTouchDown(event)) {break;}//是否存在在滑动控件中 如果在滑动控件中就 存在触摸延迟// Walk up the hierarchy to determine if we're inside a scrolling container.boolean isInScrollingContainer = isInScrollingContainer();// For views inside a scrolling container, delay the pressed feedback for// a short period in case this is a scroll.if (isInScrollingContainer) { //在滑动控件中mPrivateFlags |= PFLAG_PREPRESSED; //设置预按下状态 在滑动控件中，第一时间判断不了是按下还是滑动if (mPendingCheckForTap == null) {mPendingCheckForTap = new CheckForTap(); //CheckForTap run:还原预按下状态，设置为按下状态，设置一个长按等待器}mPendingCheckForTap.x = event.getX();mPendingCheckForTap.y = event.getY();postDelayed(mPendingCheckForTap, ViewConfiguration.getTapTimeout());} else { //不在滑动控件中 置为按下状态，设置一个长按等待器// Not inside a scrolling container, so show the feedback right awaysetPressed(true, x, y);checkForLongClick(0, x, y); //0减去已等待}break;case MotionEvent.ACTION_CANCEL: //纯粹各种清空还原if (clickable) {setPressed(false);}removeTapCallback();removeLongPressCallback();mInContextButtonPress = false;mHasPerformedLongPress = false;mIgnoreNextUpEvent = false;mPrivateFlags3 &= ~PFLAG3_FINGER_DOWN;break;case MotionEvent.ACTION_MOVE:if (clickable) {//热点改变：如水波纹中心 drawableHotspotChanged(x, y);}// Be lenient about moving outside of buttons//手指移出了控件区域if (!pointInView(x, y, mTouchSlop)) { //mTouchSlop：溢出宽容距离// Outside button// Remove any future long press/tap checks//监听移除和flag清除removeTapCallback();removeLongPressCallback();if ((mPrivateFlags & PFLAG_PRESSED) != 0) {setPressed(false);}mPrivateFlags3 &= ~PFLAG3_FINGER_DOWN;}break;}return true;}return false;
}