SwipeRefreshLayout 内的 Horizo​​ntalScrollView

Question

我在我的应用程序中实现了新的SwipeRefreshLayout 组件，它适用于任何垂直视图，例如ListView、GridView 和ScrollView。

它在水平视图中表现得非常糟糕，例如HorizontalScrollView。 当向右或向左滚动时，SwipeRefreshLayout 视图缓存触摸，阻止 HorizontalScrollView 接收并开始垂直滚动以执行刷新。

我尝试解决这个问题，因为我之前使用requestDisallowInterceptTouchEvent 解决了垂直ScrollView 和ViewPager 内部的问题，但它不起作用。我还注意到这个方法在原始的SwipeRefreshLayout 类中被覆盖，而没有返回超值。谷歌的开发者留下了评论“//Nope.”:)

因为SwipeRefreshLayout 组件相对较新，我找不到解决水平滚动问题同时仍允许滑动刷新视图以跟踪和处理垂直滚动的解决方案，所以我想我会带着希望分享我的解决方案它会节省某人一两个小时。

Answer 1

这是我所做的：

class HorizontalScrollViewWithDragListener
    @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null) : HorizontalScrollView(context, attrs) {
    var draggingState: Boolean = false
        set(value) {
            if (field != value) {
                field = value
                listener?.invoke(value)
            }
        }

    var listener: ((draggingState: Boolean) -> Unit)? = null

    override fun onInterceptTouchEvent(ev: MotionEvent) =
        super.onInterceptTouchEvent(ev)
            .also { draggingState = it }


    @SuppressLint("ClickableViewAccessibility")
    override fun onTouchEvent(ev: MotionEvent) =
        super.onTouchEvent(ev)
            .also {
                if(ev.action == MotionEvent.ACTION_UP) {
                    draggingState = false
                }
            }
}

然后我只是在设置代码中执行此操作：

   myScrollView.listener = { refreshView.isEnabled = !it }

Answer 2

Lior Iluz 提出的覆盖 onInterceptTouchEvent() 的解决方案存在严重问题。 如果内容可滚动容器未完全向上滚动，则可能无法在相同的向上滚动手势中激活滑动刷新。 实际上，当您开始滚动内部容器并无意中将手指水平移动到 mTouchSlop 时（默认为 8dp）， 建议的 CustomSwipeToRefresh 拒绝此手势。因此，用户必须再次尝试开始刷新。这对用户来说可能看起来很奇怪。

我从支持库中提取了原始 SwipeRefreshLayout 的源代码到我的项目中，并重新编写了 onInterceptTouchEvent()。新的类名为 TouchSafeSwipeRefreshLayout

private boolean mPendingActionDown;
private float mInitialDownY;
private float mInitialDownX;
private boolean mGestureDeclined;

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    ensureTarget();
    final int action = ev.getActionMasked();
    int pointerIndex;

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

    if (!isEnabled() || mReturningToStart || mRefreshing ) {
        // Fail fast if we're not in a state where a swipe is possible
        if (D) Log.e(LOG_TAG, "Fail because of not enabled OR refreshing OR returning to start. "+motionEventToShortText(ev));
        return false;
    }

    switch (action) {
        case MotionEvent.ACTION_DOWN:
            setTargetOffsetTopAndBottom(mOriginalOffsetTop - mCircleView.getTop());
            mActivePointerId = ev.getPointerId(0);

            if ((pointerIndex = ev.findPointerIndex(mActivePointerId)) >= 0) {

                if (mNestedScrollInProgress || canChildScrollUp()) {
                    if (D) Log.e(LOG_TAG, "Fail because of nested content is Scrolling. Set pending DOWN=true. "+motionEventToShortText(ev));
                    mPendingActionDown = true;
                } else {
                    mInitialDownX = ev.getX(pointerIndex);
                    mInitialDownY = ev.getY(pointerIndex);
                }
            }
            return false;

        case MotionEvent.ACTION_MOVE:
            if (mActivePointerId == INVALID_POINTER) {
                if (D) Log.e(LOG_TAG, "Got ACTION_MOVE event but don't have an active pointer id.");
                return false;
            } else if (mGestureDeclined) {
                if (D) Log.e(LOG_TAG, "Gesture was declined previously because of horizontal swipe");
                return false;
            } else if ((pointerIndex = ev.findPointerIndex(mActivePointerId)) < 0) {
                return false;
            } else if (mNestedScrollInProgress || canChildScrollUp()) {
                if (D) Log.e(LOG_TAG, "Fail because of nested content is Scrolling. "+motionEventToShortText(ev));
                return false;
            } else if (mPendingActionDown) {
                // This is the 1-st Move after content stops scrolling.
                // Consider this Move as Down (a start of new gesture)
                if (D) Log.e(LOG_TAG, "Consider this move as down - setup initial X/Y."+motionEventToShortText(ev));
                mPendingActionDown = false;
                mInitialDownX = ev.getX(pointerIndex);
                mInitialDownY = ev.getY(pointerIndex);
                return false;
            } else if (Math.abs(ev.getX(pointerIndex) - mInitialDownX) > mTouchSlop) {
                mGestureDeclined = true;
                if (D) Log.e(LOG_TAG, "Decline gesture because of horizontal swipe");
                return false;
            }

            final float y = ev.getY(pointerIndex);
            startDragging(y);
            if (!mIsBeingDragged) {
                if (D) Log.d(LOG_TAG, "Waiting for dY to start dragging. "+motionEventToShortText(ev));
            } else {
                if (D) Log.d(LOG_TAG, "Dragging started! "+motionEventToShortText(ev));
            }
            break;

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

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

    return mIsBeingDragged;
}

在Github 上查看我的示例项目。

Answer 3

我通过扩展SwipeRefreshLayout 并覆盖它的onInterceptTouchEvent 解决了这个问题。在里面，我计算用户游走的 X 距离是否大于触摸斜率。如果是这样，则意味着用户正在水平滑动，因此我返回false，它让子视图（在本例中为HorizontalScrollView）获取触摸事件。

public class CustomSwipeToRefresh extends SwipeRefreshLayout {

    private int mTouchSlop;
    private float mPrevX;

    public CustomSwipeToRefresh(Context context, AttributeSet attrs) {
        super(context, attrs);

        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mPrevX = MotionEvent.obtain(event).getX();
                break;

            case MotionEvent.ACTION_MOVE:
                final float eventX = event.getX();
                float xDiff = Math.abs(eventX - mPrevX);

                if (xDiff > mTouchSlop) {
                    return false;
                }
        }

        return super.onInterceptTouchEvent(event);
    }
}

Answer 4

如果你使用 Tim Roes EnhancedListView

看到这个issues。我对我很有用，因为他们添加了一个功能，可以检测何时开始滑动以及何时结束。

当滑动开始时，我禁用 SwipeRefreshLayout，当滑动完成时，我启用 swipeRefreshLayout。

Answer 5

如果您没有记住您已经拒绝 ACTION_MOVE 事件的事实，那么如果用户回到您最初的 mPrevX 附近，您最终会接受它。

只需添加一个布尔值即可记住它。

public class CustomSwipeToRefresh extends SwipeRefreshLayout {

    private int mTouchSlop;
    private float mPrevX;
    // Indicate if we've already declined the move event
    private boolean mDeclined;

    public CustomSwipeToRefresh(Context context, AttributeSet attrs) {
        super(context, attrs);

        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mPrevX = MotionEvent.obtain(event).getX();
                mDeclined = false; // New action
                break;

            case MotionEvent.ACTION_MOVE:
                final float eventX = event.getX();
                float xDiff = Math.abs(eventX - mPrevX);

                if (mDeclined || xDiff > mTouchSlop) {
                    mDeclined = true; // Memorize
                    return false;
                }
        }

        return super.onInterceptTouchEvent(event);
    }
}