IssueTracker

Component used: Fragment

Version used: 1.7.1

Given that two Fragments have enter transitions defined, trying to show both of those Fragments in two separate transactions executed synchronously will result in the second Fragment never entering the resumed state despite being visible and interactable.

I have attached a sample project demonstrating this issue - simply click the "next" button and you'll see that the text indicating whether the second fragment's state is resumed will never transition.

A little more detail without opening the project-

We have a Fragment with transitions defined like so:

class SecondFragment : Fragment() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    enterTransition = Slide(Gravity.RIGHT)
    exitTransition = Fade()
  }
}

When a button is pressed elsewhere in the app, we perform two Fragment transactions with two instances of this Fragment:

requireActivity().supportFragmentManager.beginTransaction()
  .replace(R.id.container, SecondFragment.newInstance("two"))
  .commitNow()

requireActivity().supportFragmentManager.beginTransaction()
  .replace(R.id.container, SecondFragment.newInstance("three"))
  .commitNow()

This latter instance will never transition to resumed.

A few things I've tried that are able to work around this bug:

• Using setReorderingAllowed() and commit() instead of commitNow() (note that just switching to commit() doesn't fix this issue, you also need to allow reordering)
• Removing the transitions on either the first or second instance of this Fragment also fixes the issue

I suspect that the transition on the intermediate transaction is simply never finishing because that screen is immediately replaced and that transition not finishing or being cancelled is the root cause here.

Unfortunately the first workaround isn't viable in our application - the way our navigation is currently structured we have two transactions executed serially and synchronously and without performing deeper changes to our navigation there isn't a clear path to asynchronous transactions here. We would like to keep the animations, but could remove them for one of the two screens. This also doesn't seem like expected behavior though.