另外还有一种情况是disallowIntercept为true时，intercepted直接赋值false不进行拦截。FLAG_DISALLOW_INTERCEPT是通过requestDisallowInterceptTouchEvent方法来设置的，用于在子View中设置，设置后ViewGroup只能拦截down事件，无法拦截其他move、up、cancel事件。为什么ViewGroup还能拦截down事件呢？因为ViewGroup在down事件时进行了重置，看看以下代码

// Handle an initial down.
if (actionMasked == MotionEvent.ACTION_DOWN) {
    // Throw away all previous state when starting a new touch gesture.
    // The framework may have dropped the up or cancel event for the previous gesture
    // due to an app switch, ANR, or some other state change.
    cancelAndClearTouchTargets(ev);
    resetTouchState();
}

private void resetTouchState() {
    clearTouchTargets();
    resetCancelNextUpFlag(this);
    mGroupFlags &= ~FLAG_DISALLOW_INTERCEPT;
    mNestedScrollAxes = SCROLL_AXIS_NONE;
}

通过源码可以了解到，ViewGroup拦截事件后，不再调用onInterceptTouchEvent，而是直接交给mFirstTouchTarget的onTouchEvent处理,如果该onTouchEvent不处理最终会交给Activity的onTouchEvent。

3.2 ViewGroup不拦截事件的情况

ViewGroup不拦截事件时，会遍历子View，使事件分发到子View进行处理。

final View[] children = mChildren;
for (int i = childrenCount - 1; i >= 0; i--) {
    final int childIndex = getAndVerifyPreorderedIndex(
            childrenCount, i, customOrder);
    final View child = getAndVerifyPreorderedView(
            preorderedList, children, childIndex);

    // If there is a view that has accessibility focus we want it
    // to get the event first and if not handled we will perform a
    // normal dispatch. We may do a double iteration but this is
    // safer given the timeframe.
    if (childWithAccessibilityFocus != null) {
        if (childWithAccessibilityFocus != child) {
            continue;
        }
        childWithAccessibilityFocus = null;
        i = childrenCount - 1;
    }

    if (!canViewReceivePointerEvents(child)
            || !isTransformedTouchPointInView(x, y, child, null)) {
        ev.setTargetAccessibilityFocus(false);
        continue;
    }

    newTouchTarget = getTouchTarget(child);
    if (newTouchTarget != null) {
        // Child is already receiving touch within its bounds.
        // Give it the new pointer in addition to the ones it is handling.
        newTouchTarget.pointerIdBits |= idBitsToAssign;
        break;
    }

    resetCancelNextUpFlag(child);
    if (dispatchTransformedTouchEvent(ev, false, child, idBitsToAssign)) {
        // Child wants to receive touch within its bounds.
        mLastTouchDownTime = ev.getDownTime();
        if (preorderedList != null) {
            // childIndex points into presorted list, find original index
            for (int j = 0; j < childrenCount; j++) {
                if (children[childIndex] == mChildren[j]) {
                    mLastTouchDownIndex = j;
                    break;
                }
            }
        } else {
            mLastTouchDownIndex = childIndex;
        }
        mLastTouchDownX = ev.getX();
        mLastTouchDownY = ev.getY();
        newTouchTarget = addTouchTarget(child, idBitsToAssign);
        alreadyDispatchedToNewTouchTarget = true;
        break;
    }
}

3.2.1 寻找可接收事件的子View

通过canViewReceivePointerEvents判断子View是否能够接收到点击事件。必须符合2种情况，缺一不可：1、点击事件的坐标落在在子View的区域内；2、子View没有正在播放动画。满足条件后，调用dispatchTransformedTouchEvent，其实也是调用子View的dispatchTouchEvent。