问题
I implemented the new SwipeRefreshLayout component in my application and it works well with any vertical views, like ListView, GridView and ScrollView.
It behaves very bad with horizontal views, like HorizontalScrollView.
When scrolling to the right or left, the SwipeRefreshLayout view caches the touch, prevents the HorizontalScrollView from receiving it and starts scrolling vertically to perform the refresh.
I tried solving this issue as I previously solved issues with vertical ScrollView with ViewPager inside, using requestDisallowInterceptTouchEvent but it didn't work. I also noticed that this method is overridden in the original SwipeRefreshLayout class without returning the super. Google's developer left a comment instead "//Nope." :)
Because SwipeRefreshLayout component is relatively new, I couldn't find a solution that fixes the horizontal scroll issue while still allowing the swipe to refresh view to track and handle vertical scrolling so I thought I'll share my solution with hopes it will spare someone an hour or two.
回答1:
I solved it by extending SwipeRefreshLayout and overriding its onInterceptTouchEvent. Inside, I calculate if the X distance the user has wandered is bigger than the touch slop. If it does, it means the user is swiping horizontally, therefor I return false which lets the child view (the HorizontalScrollView in this case) to get the touch event.
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);
}
}
回答2:
If you do not memorize the fact that you already declined the ACTION_MOVE event, you will eventually take it later if the user go back near your initial mPrevX.
Just add a boolean to memorize it.
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);
}
}
回答3:
The solution proposed by Lior Iluz with overriding onInterceptTouchEvent() has a serious issue. If the content scrollable container is not fully scrolled-up, then it may be not possible to activate swipe-to-refresh in the same scroll-up gesture. Indeed, when you start scrolling the inner container and move finger horizontally more then mTouchSlop unintentionally (which is 8dp by default), the proposed CustomSwipeToRefresh declines this gesture. So a user has to try once more to start refreshing. This may look odd for the user.
I extracted the source code of the original SwipeRefreshLayout from the support library to my project and re-wrote the onInterceptTouchEvent(). The new class name is 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;
}
See my example project on Github.
回答4:
If you use the Tim Roes EnhancedListView
See this issues. I was very usefull for me because they add a fonction who detect when the swipe begin and when the swipe finish.
When swipe begin, i disable the SwipeRefreshLayout and when swipe finish, i enble the swipeRefreshLayout.
来源：https://stackoverflow.com/questions/23989910/horizontalscrollview-inside-swiperefreshlayout