[BUG]: App got stuck during a student playthrough

[seanlip]

Describe the bug

We received a report from a UXR study that the app hung in the middle of a lesson and the student wasn't able to go ahead. See screenshot below:

The learner spent some time retrying again and again, and was able to go ahead. (It's not stated what they actually did, but I assume they might have picked other options).

Steps To Reproduce

Not sure. This information was not provided in the report, but the question in the screenshot is from Fractions.

Expected Behavior

If a response is selected, the submit button should not be disabled.

Screenshots/Videos

What device/emulator are you using?

Not known

Which Android version is your device/emulator running?

Not known

Which version of the Oppia Android app are you using?

0.13-beta-dcde7b359e

Additional Context

No response

[agallop]

Hey @seanlip, I want to contribute to Oppia android and I started trying to reproduce this (with no success), but I compile what I've looked at myself. Maybe it'll be helpful if it gets reproduced. I've only been able to disabled the button when it is expected to be disabled.

It looks like the submit button is enabled by default and only gets disabled when an error is shown.

StateFragmentPresenter.kt:455

  /** Updates submit button UI as active if pendingAnswerError null else inactive. */
  fun updateSubmitButton(pendingAnswerError: String?, inputAnswerAvailable: Boolean) {
    if (inputAnswerAvailable) {
      stateViewModel.setCanSubmitAnswer(pendingAnswerError == null)
    } else {
      stateViewModel.setCanSubmitAnswer(canSubmitAnswer = false)
    }
  }

inputAnswerAvailable looks to set to true in the callsites I looked at.

I noticed the code above gets called twice when selecting an answer when the button is disabled. I would expect it to only update once, but i don't know if that's important

Stack trace 1

at org.oppia.android.app.player.state.StateFragmentPresenter.updateSubmitButton(StateFragmentPresenter.kt:463)
at org.oppia.android.app.player.state.StateFragment.onPendingAnswerErrorOrAvailabilityCheck(StateFragment.kt:143)
at org.oppia.android.app.player.state.itemviewmodel.SelectionInteractionViewModel$callback$1.onPropertyChanged(SelectionInteractionViewModel.kt:101)
at androidx.databinding.PropertyChangeRegistry$1.onNotifyCallback(PropertyChangeRegistry.java:30)
at androidx.databinding.PropertyChangeRegistry$1.onNotifyCallback(PropertyChangeRegistry.java:26)
at androidx.databinding.CallbackRegistry.notifyCallbacks(CallbackRegistry.java:201)
at androidx.databinding.CallbackRegistry.notifyFirst64(CallbackRegistry.java:122)
at androidx.databinding.CallbackRegistry.notifyRemainder(CallbackRegistry.java:169)
at androidx.databinding.CallbackRegistry.notifyRecurse(CallbackRegistry.java:145)
at androidx.databinding.CallbackRegistry.notifyCallbacks(CallbackRegistry.java:91)
at androidx.databinding.BaseObservable.notifyChange(BaseObservable.java:60)
at androidx.databinding.ObservableField.set(ObservableField.java:92)
at org.oppia.android.app.player.state.itemviewmodel.SelectionInteractionViewModel.checkPendingAnswerError(SelectionInteractionViewModel.kt:180)
at org.oppia.android.app.player.state.itemviewmodel.SelectionInteractionViewModel.updateSelection(SelectionInteractionViewModel.kt:206)
at org.oppia.android.app.player.state.itemviewmodel.SelectionInteractionContentViewModel.handleItemClicked(SelectionInteractionContentViewModel.kt:20)
at org.oppia.android.databinding.MultipleChoiceInteractionItemsBindingImpl._internalCallbackOnClick(MultipleChoiceInteractionItemsBindingImpl.java:234)
at org.oppia.android.generated.callback.OnClickListener.onClick(OnClickListener.java:11)
at android.view.View.performClick(View.java:7931)
at android.view.View.performClickInternal(View.java:7908)
at android.view.View.-$$Nest$mperformClickInternal(Unknown Source:0)
at android.view.View$PerformClick.run(View.java:30990)
at android.os.Handler.handleCallback(Handler.java:959)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loopOnce(Looper.java:232)
at android.os.Looper.loop(Looper.java:317)
at android.app.ActivityThread.main(ActivityThread.java:8592)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:878)

Stack trace 2

at org.oppia.android.app.player.state.StateFragmentPresenter.updateSubmitButton(StateFragmentPresenter.kt:463)
at org.oppia.android.app.player.state.StateFragment.onPendingAnswerErrorOrAvailabilityCheck(StateFragment.kt:143)
at org.oppia.android.app.player.state.itemviewmodel.SelectionInteractionViewModel$callback$1.onPropertyChanged(SelectionInteractionViewModel.kt:101)
at androidx.databinding.PropertyChangeRegistry$1.onNotifyCallback(PropertyChangeRegistry.java:30)
at androidx.databinding.PropertyChangeRegistry$1.onNotifyCallback(PropertyChangeRegistry.java:26)
at androidx.databinding.CallbackRegistry.notifyCallbacks(CallbackRegistry.java:201)
at androidx.databinding.CallbackRegistry.notifyFirst64(CallbackRegistry.java:122)
at androidx.databinding.CallbackRegistry.notifyRemainder(CallbackRegistry.java:169)
at androidx.databinding.CallbackRegistry.notifyRecurse(CallbackRegistry.java:145)
at androidx.databinding.CallbackRegistry.notifyCallbacks(CallbackRegistry.java:91)
at androidx.databinding.BaseObservable.notifyChange(BaseObservable.java:60)
at androidx.databinding.ObservableField.set(ObservableField.java:92)
at org.oppia.android.app.player.state.itemviewmodel.SelectionInteractionViewModel.updateIsAnswerAvailable(SelectionInteractionViewModel.kt:276)
at org.oppia.android.app.player.state.itemviewmodel.SelectionInteractionViewModel.updateSelection(SelectionInteractionViewModel.kt:220)
at org.oppia.android.app.player.state.itemviewmodel.SelectionInteractionContentViewModel.handleItemClicked(SelectionInteractionContentViewModel.kt:20)
at org.oppia.android.databinding.MultipleChoiceInteractionItemsBindingImpl._internalCallbackOnClick(MultipleChoiceInteractionItemsBindingImpl.java:234)
at org.oppia.android.generated.callback.OnClickListener.onClick(OnClickListener.java:11)
at android.view.View.performClick(View.java:7931)
at android.view.View.performClickInternal(View.java:7908)
at android.view.View.-$$Nest$mperformClickInternal(Unknown Source:0)
at android.view.View$PerformClick.run(View.java:30990)
at android.os.Handler.handleCallback(Handler.java:959)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loopOnce(Looper.java:232)
at android.os.Looper.loop(Looper.java:317)
at android.app.ActivityThread.main(ActivityThread.java:8592)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:878)

Some of the ways (not exhaustive) i tried to break it are:

• Rotate the phone screen to make the activity reload from state
• Minimizing the app and reopen
• interact with the hint popup (since it's in the screenshot) while the button is disabled.
• Get to this part in lesson, switch users, and go back to the lesson.

Side note, I noticed whie trying to break it is that the radio buttons are able to go from one selected to no selected, which is odd for a radio button. The radio buttons on the web app seem to function as expected.
https://github.com/user-attachments/assets/ae5f1c23-217c-4a0d-8da7-00422731224d

[BenHenning]

This needs investigation before it can be fixed, and we need to release 0.14 in the next few days. Bumping to the next release milestone.