CODEWITHSUNDEEP
androidandroid-viewpager2
brisdeveloper
brisdeveloper

Reputation: 45

ViewPager2 setCurrentItem bug workaround?

This reported bug is causing me problems; https://issuetracker.google.com/issues/183847283

When combined with FragmentStateAdapter, ViewPager2.setCurrentItem doesn't always work. The TabLayout correctly changes (if you have one), but the ViewPager2 itself doesn't show the correct page.

Has anyone found a workaround?

Upvotes: 3

Views: 3023

Answers (2)

Mohit Der
Mohit Der

Reputation: 11

I solved it like this:

viewPager.setCurrentItem(tab.getPosition());
                if (tab.getPosition()==0||tab.getPosition()==1||tab.getPosition()==2||tab.getPosition()==3){
                    pagerAdapter.notifyDataSetChanged();
                }

Upvotes: 0

avalerio
avalerio

Reputation: 2335

I had a similar problem, if not the same. The solution was to change fragments/tabs/pages in a specific order.

  1. The FragmentStateAdapter should be notified first of the change to the fragment.
  2. The TabLayout should then call selectTab under a post
  3. The ViewPager should then call setCurrentItem under a post, inside the TabLayouts post to selectTab.

This may be overkill but it worked for me.

Example

//or some other notify depending on your use case.
fragmentStateAdapter.notifyItemInserted(position);

tabLayout.post(()->{
     tabLayout.selectTab(tabLayout.getTabAt(position));
     viewPager2.post(()->{
          viewPager2.setCurrentItem(position);
          //I noticed on older devices like API 19
          //the viewPager wouldn't complete transformations
          //so we call this.
          viewPager2.requestTransform();
     });
});

Upvotes: 6

Related Questions