View的dispatchTouchEvent总结

View的dispatchTouchEvent派发比较简单，不需要经过打断这一环。
而是直接去调用onTouchEvent方法，注意View如果存在TouchListener，则TouchListener优先。
看源码：

public boolean dispatchTouchEvent(MotionEvent event) {        // If the event should be handled by accessibility focus first.        if (event.isTargetAccessibilityFocus()) {            // We don't have focus or no virtual descendant has it, do not handle the event.            if (!isAccessibilityFocusedViewOrHost()) {                return false;            }            // We have focus and got the event, then use normal event dispatch.            event.setTargetAccessibilityFocus(false);        }        boolean result = false;        if (mInputEventConsistencyVerifier != null) {            mInputEventConsistencyVerifier.onTouchEvent(event, 0);        }        final int actionMasked = event.getActionMasked();        if (actionMasked == MotionEvent.ACTION_DOWN) {            // Defensive cleanup for new gesture            stopNestedScroll();        }        if (onFilterTouchEventForSecurity(event)) {            //noinspection SimplifiableIfStatement            ListenerInfo li = mListenerInfo;            //如果存在onTouchListener则优先处理，否则去执行onTouchEvent            if (li != null && li.mOnTouchListener != null                    && (mViewFlags & ENABLED_MASK) == ENABLED                    && li.mOnTouchListener.onTouch(this, event)) {                result = true;            }            if (!result && onTouchEvent(event)) {                result = true;            }        }        if (!result && mInputEventConsistencyVerifier != null) {            mInputEventConsistencyVerifier.onUnhandledEvent(event, 0);        }        // Clean up after nested scrolls if this is the end of a gesture;        // also cancel it if we tried an ACTION_DOWN but we didn't want the rest        // of the gesture.        if (actionMasked == MotionEvent.ACTION_UP ||                actionMasked == MotionEvent.ACTION_CANCEL ||                (actionMasked == MotionEvent.ACTION_DOWN && !result)) {            stopNestedScroll();        }        return result;    }

再看看onTouchEvent，如果View是CLICKABLE，LONG_CLICKABLE可点击，返回的是true，处理掉
否则 返回false，不处理。

解释一下为什么ListView中的onInterceptTouchEvent只执行了一次。
ListView重写了onInterceptTouchEvent和onTouchEvent，事件分发使用基类ViewGroup的分发，Item的View是ListView的子View，在Item中放一个TextView，发现只在Down的时候onInterceptTouchEvent执行了一次，为什么呢？因为TextView没有CLICKABLE，Down时是不拦截的，而TextView并没有消化事件，所以Down事件被ListView重写的onTouchEvent本身处理了，所以拦截函数就不会执行啦。
如果有给TextView加上onClickListener，则onTouchEvent处理了Down事件，后续的move还是要判断拦截的，到滑动程度就会拦截。

总结：由dispatchTouchEvent派发给TouchListener或onTouchevent