IssueTracker

Component used: ViewPager2

Version used: 1.0.0

Devices/Android versions reproduced on: Multiple/Emulator (Android TV) API 29

Context

Dpad navigation on Android TV.

The ViewPager2 is expected to change currentItem only on programmatic events.

Summary

A ViewPager2 with isUserInputEnabled = false, focusable="false" and focusableInTouchMode="false" does not stop dpad navigation from focusing items in other pages/fragments that are off-screen. This causes dpad navigation within a page displayed in a ViewPager2 to misbehave, e.g. on Android TV.

Steps to reproduce

(See also attached example project)

1. Set up a ViewPager2 with multiple pages of focusable content
2. Focus an item on a visible page.
3. Use dpad navigation to move focus (e.g. up or down in a vertical ViewPager2)

Expected

Pages outside the screen should not be focusable. The last focused item in the current page should remain focused (navigation to focusables outside the viewpager itself should be supported!).

Actual

Focus moves to a focusable View in a page off-screen. Sometimes this causes dpad navigation to stop working completely inside the app.

Workaround

Override onBindViewHolder in your FragmentStateAdapter and explicitly set isFocusable = false and descendantFocusability = ViewGroup.FOCUS_BLOCK_DESCENDANTS on the FragmentViewHolder.itemView. Then, when ViewPager2.currentItem is modified, reset these values for the FragmentViewHolder.itemView at position currentItem.

Note that still causes the ViewPager2 to load more pages in the pressed direction until all pages in that direction has been loaded (this happens in the background and is invisible to the user).