Widget stops updating, displays wrong bitmap for item on Android 16

[UweTrottmann]

Update: also discussed on the forum.

A few users, all using Pixel devices, have reported that the widget stops updating (for example after marking an episode watched) or displays wrong information (like image not matching the description). Edit: for another user, it turns completely white.

One user has attributed this to the Android 16 update, but other users and research online suggest that this may be related to the Pixel launcher home screen app or the use of a third-party home screen app. Update: all users are using the stock Pixel launcher.

I have failed to reproduce this issue on an official Android 16 emulator. Edit: could finally reproduce.

Also the user attributing it to Android 16 has sent a debug log that indicates the widget update is triggered every few minutes by SeriesGuide as expected.

[UweTrottmann]

Asked the users to contact Google about this. I don't have a Pixel device, so I'm not sure how exactly to do this.

[UweTrottmann]

Finally could reproduce thanks to another report: with widget set to "Recent" (not sure if relevant), when marking an episode watched images do not update with the item.

The item data is correct, the loaded bitmap is not null.

Things to check:

• is the bitmap the correct one
  • try to set the bitmap null first?
• try to reproduce the update issue with a large list of items (up to the limit, use the infinite calendar option)
• is this only broken on Android 16

This might be resolved by using the new RemoteCollectionItems widget APIs (or maybe a Compose based approach using Jetpack Glance, but it looks early and only available on Android 12+). However, those will restrict the list widget to a fixed number of items.

See also https://github.com/android/platform-samples/tree/main/samples/user-interface/appwidgets

[UweTrottmann]

There is a similar issue reported at nextcloud/android#14998

Related: https://issuetracker.google.com/issues/398066578

[UweTrottmann]

Some observations: the code that displays widgets, AppWidgetServiceImpl, has significant different behavior in Android 16.

For the worse, for a list widget it now calls ListWidgetRemoteViewsFactory#getViewAt for all items, regardless of how many are actually visible. That would explain slower update times as poster bitmaps worst case have to be created for each item. (Luckily SeriesGuide already limits upcoming/recent for widgets to 100 items, only shows are uncapped.)

Logcat widget updates

// Android 15

07:34:50.558 ListWidgetProvider             com.battlelancer.seriesguide         D  onReceive: widget DATA_CHANGED action.
07:34:50.559 AppWidgetServiceImpl           system_server                        I  getAppWidgetIds() 0
07:34:50.562 AppWidgetServiceImpl           system_server                        I  notifyAppWidgetViewDataChanged() 0
07:34:50.562 AppWidgetServiceImpl           system_server                        D  Trying to notify widget view data changed
07:34:50.569 ListWidgetProvider             com.battlelancer.seriesguide         D  scheduled widget UPDATE alarm.

// once returning to home screen
07:34:53.286 ListWidgetRemoteViewsFactory   com.battlelancer.seriesguide         D  onQueryForData for appWidgetId=2

// Then calls com.battlelancer.seriesguide.appwidget.ListWidgetRemoteViewsFactory#getViewAt for **visible** items


// Android 16

07:45:05.988 ListWidgetProvider             com.battlelancer.seriesguide         D  onReceive: widget DATA_CHANGED action.
07:45:05.989 AppWidgetServiceImpl           system_server                        I  getAppWidgetIds() 0
07:45:05.991 AppWidgetServiceImpl           system_server                        I  getAppWidgetViews() 0
07:45:05.993 ListWidgetProvider             com.battlelancer.seriesguide         D  scheduled widget UPDATE alarm.
07:45:06.003 ListWidgetRemoteViewsFactory   com.battlelancer.seriesguide         D  onQueryForData for appWidgetId=2

// Then calls com.battlelancer.seriesguide.appwidget.ListWidgetRemoteViewsFactory#getViewAt for **all** items

07:45:06.093 AppWidgetServiceImpl           system_server                        I  updateAppWidgetIds() 0
07:45:06.094 AppWidgetServiceImpl           system_server                        D  Trying to notify widget update deferred for id: 2
07:45:06.095 AppWidgetServiceImpl           system_server                        I  getAppWidgetViews() 0

For a still unknown reason, when the bitmap of a single item has changed (here a show poster) it is not updated. The previous bitmap set for that ImageView is reused. It does not appear to be a caching issue as this is also observed when using a randomized bitmap.

The correct bitmap is used once re-configuring the widget or waiting for the widget to self-update. So apparently there is a difference between calling appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.list_view) and letting it self-update.

[UweTrottmann]

A workaround is to rebuild the whole collection widget with appWidgetManager.updateAppWidget(appWidgetId, rv) instead of just the collection items with appWidgetManager.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.list_view). Due to the changed behavior this will also rebuild RemoveViews for all collection items (which previously required to call the second method). There should be no difference in usability as the scroll state is preserved. The collection items will just be updated twice then.

[UweTrottmann]

One user has reported that the widget now doesn't update after marking an episode watched on a Samsung device (SM-F766B) with Android 16. Looks like Samsung continues to use their own implementation of the widget update code (or a more recent version of Android 16 that has fixed this issue).

This then might require reverting to calling notifyAppWidgetViewDataChanged right after updateAppWidget.

But continuing to observe for now. Edit: asked the Samsung user for a debug log.

[UweTrottmann]

Debug log confirms the widget now being broken on Samsung's version of Android 16.

Also, on Google's Android 16 QPR2 (still in preview though), when first adding the widget no items are displayed. As of course, in that case appWidgetManager.updateAppWidget doesn't also populate items. As should always be the case.

Just calling both appWidgetManager.updateAppWidget and appWidgetManager.notifyAppWidgetViewDataChanged regardless if adding or updating the widget on Google's version has the bitmap not updating issue. So hopefully this is fixed before QPR2 is released.

Oh my.