android - android 5 onInterceptTouchEvent 模块中的 SwipeRefreshLayout.java 没有中断

Question

我注意到该函数在 Action_down 之后没有中断，然后代码可以运行到 ACTION_MOVE，对吗？

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    ensureTarget();

    final int action = MotionEventCompat.getActionMasked(ev);

    if (mReturningToStart && action == MotionEvent.ACTION_DOWN) {
        mReturningToStart = false;
    }

    if (!isEnabled() || mReturningToStart || canChildScrollUp() || mRefreshing) {
        // Fail fast if we're not in a state where a swipe is possible
        return false;
    }

    switch (action) {
        case MotionEvent.ACTION_DOWN:
            setTargetOffsetTopAndBottom(mOriginalOffsetTop - mCircleView.getTop(), true);
            mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
            mIsBeingDragged = false;
            final float initialMotionY = getMotionEventY(ev, mActivePointerId);
            if (initialMotionY == -1) {
                return false;
            }
            mInitialMotionY = initialMotionY;
           //-------NO Break here, why? It will run down to ACTION_MOVE
        case MotionEvent.ACTION_MOVE:
            if (mActivePointerId == INVALID_POINTER) {
                Log.e(LOG_TAG, "Got ACTION_MOVE event but don't have an active pointer id.");
                return false;
            }
            final float y = getMotionEventY(ev, mActivePointerId);
            if (y == -1) {
                return false;
            }
            final float yDiff = y - mInitialMotionY;
            if (yDiff > mTouchSlop && !mIsBeingDragged) {
                mIsBeingDragged = true;
                mProgress.setAlpha(STARTING_PROGRESS_ALPHA);
            }
            break;

        case MotionEventCompat.ACTION_POINTER_UP:
            onSecondaryPointerUp(ev);
            break;

        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_CANCEL:
            mIsBeingDragged = false;
            mActivePointerId = INVALID_POINTER;
            break;
    }

    return mIsBeingDragged;
}

我不知道为什么对待ACTION_DOWN然后直接对待ACTION_MOVE，这样对吗？提前致谢。

Answer 1

最后我在 google code 上发布了一个错误报告，它被接受到 future 的版本。 No break in SwipeRefreshLayout.java in android 5 onInterceptTouchEvent module