Improve logic to trigger LockScreenViewEvents

vector/src/main/java/im/vector/app/features/pin/lockscreen/ui/LockScreenAction.kt

@@ -22,4 +22,5 @@ import im.vector.app.core.platform.VectorViewModelAction
 sealed class LockScreenAction : VectorViewModelAction {
     data class PinCodeEntered(val value: String) : LockScreenAction()
     data class ShowBiometricPrompt(val callingActivity: FragmentActivity) : LockScreenAction()
+    object OnUIReady : LockScreenAction()
 }

vector/src/main/java/im/vector/app/features/pin/lockscreen/ui/LockScreenFragment.kt

@@ -23,7 +23,6 @@ import android.view.ViewGroup
 import android.view.animation.AnimationUtils
 import android.widget.TextView
 import androidx.core.view.isVisible
-import androidx.lifecycle.lifecycleScope
 import com.airbnb.mvrx.fragmentViewModel
 import com.airbnb.mvrx.withState
 import dagger.hilt.android.AndroidEntryPoint
@@ -34,10 +33,6 @@ import im.vector.app.databinding.FragmentLockScreenBinding
 import im.vector.app.features.pin.lockscreen.configuration.LockScreenConfiguration
 import im.vector.app.features.pin.lockscreen.configuration.LockScreenMode
 import im.vector.app.features.pin.lockscreen.views.LockScreenCodeView
-import kotlinx.coroutines.flow.distinctUntilChangedBy
-import kotlinx.coroutines.flow.filter
-import kotlinx.coroutines.flow.launchIn
-import kotlinx.coroutines.flow.onEach
 
 @AndroidEntryPoint
 class LockScreenFragment : VectorBaseFragment<FragmentLockScreenBinding>() {
@@ -59,12 +54,7 @@ class LockScreenFragment : VectorBaseFragment<FragmentLockScreenBinding>() {
             handleEvent(it)
         }
 
-        viewModel.stateFlow.distinctUntilChangedBy { it.showBiometricPromptAutomatically }
-                .filter { it.showBiometricPromptAutomatically }
-                .onEach {
-                    showBiometricPrompt()
-                }
-                .launchIn(viewLifecycleOwner.lifecycleScope)
+        viewModel.handle(LockScreenAction.OnUIReady)
     }
 
     override fun invalidate() = withState(viewModel) { state ->
@@ -119,6 +109,7 @@ class LockScreenFragment : VectorBaseFragment<FragmentLockScreenBinding>() {
             is LockScreenViewEvent.AuthFailure -> onAuthFailure(viewEvent.method)
             is LockScreenViewEvent.AuthError -> onAuthError(viewEvent.method, viewEvent.throwable)
             is LockScreenViewEvent.ShowBiometricKeyInvalidatedMessage -> lockScreenListener?.onBiometricKeyInvalidated()
+            is LockScreenViewEvent.ShowBiometricPromptAutomatically -> showBiometricPrompt()
         }
     }
 

vector/src/main/java/im/vector/app/features/pin/lockscreen/ui/LockScreenViewEvent.kt

@@ -25,4 +25,5 @@ sealed class LockScreenViewEvent : VectorViewEvents {
     data class AuthFailure(val method: AuthMethod) : LockScreenViewEvent()
     data class AuthError(val method: AuthMethod, val throwable: Throwable) : LockScreenViewEvent()
     object ShowBiometricKeyInvalidatedMessage : LockScreenViewEvent()
+    object ShowBiometricPromptAutomatically : LockScreenViewEvent()
 }

vector/src/main/java/im/vector/app/features/pin/lockscreen/ui/LockScreenViewModel.kt

@@ -20,7 +20,6 @@ import android.annotation.SuppressLint
 import android.app.KeyguardManager
 import android.os.Build
 import android.security.keystore.KeyPermanentlyInvalidatedException
-import androidx.annotation.VisibleForTesting
 import androidx.fragment.app.FragmentActivity
 import com.airbnb.mvrx.MavericksViewModelFactory
 import dagger.assisted.Assisted
@@ -37,6 +36,7 @@ import im.vector.app.features.pin.lockscreen.pincode.PinCodeHelper
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.emitAll
+import kotlinx.coroutines.flow.firstOrNull
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
@@ -77,10 +77,20 @@ class LockScreenViewModel @AssistedInject constructor(
             lockScreenKeysMigrator.migrateIfNeeded()
             // Update initial state with biometric info
             updateStateWithBiometricInfo()
+        }
+    }
 
-            val state = awaitState()
-            // If when initialized we detect a key invalidation, we should show an error message.
-            if (state.isBiometricKeyInvalidated) {
+    private fun observeStateChanges() {
+        // The first time the state allows it, show the biometric prompt
+        viewModelScope.launch {
+            if (stateFlow.firstOrNull { it.showBiometricPromptAutomatically } != null) {
+                _viewEvents.post(LockScreenViewEvent.ShowBiometricPromptAutomatically)
+            }
+        }
+
+        // The first time the state allows it, react to biometric key being invalidated
+        viewModelScope.launch {
+            if (stateFlow.firstOrNull { it.isBiometricKeyInvalidated } != null) {
                 onBiometricKeyInvalidated()
             }
         }
@@ -90,6 +100,7 @@ class LockScreenViewModel @AssistedInject constructor(
         when (action) {
             is LockScreenAction.PinCodeEntered -> onPinCodeEntered(action.value)
             is LockScreenAction.ShowBiometricPrompt -> showBiometricPrompt(action.callingActivity)
+            is LockScreenAction.OnUIReady -> observeStateChanges()
         }
     }