[ViewPagerTabListViewFragment] The view pager changes the sliding bar selected location with onTouch event.

[AabidMulani]

I am facing the following issue:

• Using ActionBar-Tab-ViewPager activity and ViewPagerTabListViewFragment
• The first child fragment works perfect
• But when you swipe to the second fragment and touch any where on the fragment the Sliding Tab flickers and most of the time shifts to the next child.
• Swiping reverse works fine, but while swiping forward, many times it catches the onTouch event instead of the swipe event and hence the flickring /next child selection.

Check this link for the code: http://stackoverflow.com/questions/29991358/android-observablescrollview-unexpected-touch-changes-the-child-fragment-while

And here is the video of the exact issue: https://youtu.be/0katNDIWcmg

[ksoichiro]

Hi, thank you for your feedback.
I've confirmed the issue and answered in Stack Overflow just now,
I'll also write it here, just for tracking the issue.

It seems it's a problem inside the ObservableListView, sorry.
To intercept touch events, ObservableListView is designed to call its parent's onInterceptTouchEvent() and the parent -- in this case, the parent is ViewPager -- accidentally handles the touch event, which causes this behavior.

Anyway, I found a workaround for this.
Could you try this in your app?

1. Add an ID like to the root ViewGroup
   in your MainActivity-Layout.xml, like android:id="@+id/root":

   <FrameLayout
           android:id="@+id/root"
           android:layout_width="match_parent"
           android:layout_height="match_parent">
   
           <!--
           Padding for ViewPager must be set outside the ViewPager itself
           because with padding, EdgeEffect of ViewPager become strange.
           -->

2. Then set this FrameLayout as TouchInterceptionViewGroup
   to the ObservableListView in ViewPagerTabListViewFragment.java.
   Maybe around listView.setScrollViewCallbacks() is good.

   listView.setTouchInterceptionViewGroup((ViewGroup) parentActivity.findViewById(R.id.root));
   listView.setScrollViewCallbacks((ObservableScrollViewCallbacks) parentActivity);

With this workaround, you can avoid the ViewPager handles the ACTION_MOVE event.

[michaelbarlow7]

Thanks for posting the workaround, this same issue occurs with ObservableScrollView as well.

[ksoichiro]

@AabidMulani @michaelbarlow7
Thanks for checking! I added this workaround for both examples.

[radikan]

Thank you for your workaround! Everything works like a charm now.