Use a shared text entry field for TOTP entry.

app/src/main/java/org/thoughtcrime/securesms/components/settings/app/account/authenticator/TotpCodeEntryViewModel.kt

@@ -5,11 +5,14 @@
 
 package org.thoughtcrime.securesms.components.settings.app.account.authenticator
 
+import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.update
 import org.signal.appsettings.totpcodeentry.TotpCodeEntryAction
@@ -18,6 +21,7 @@ import org.signal.appsettings.totpcodeentry.TotpCodeEntryState
 import org.signal.appsettings.totpcodeentry.TotpCodeEntryState.Error
 import org.signal.core.ui.compose.EventDrivenViewModel
 import org.signal.core.util.logging.Log
+import org.signal.uicomponents.codeentryfield.CodeEntryFieldPresenter
 
 /**
  * Drives the screen that collects a code from the user's authenticator app, which is how the service learns the user
@@ -37,16 +41,28 @@ class TotpCodeEntryViewModel(
   val state: StateFlow<TotpCodeEntryState> = _state.asStateFlow()
   val actions: Flow<TotpCodeEntryAction> = _actions.receiveAsFlow()
 
+  private val codeEntryPresenter = CodeEntryFieldPresenter(viewModelScope)
+
+  init {
+    codeEntryPresenter
+      .state
+      .onEach { onEvent(TotpCodeEntryEvent.CodeEntryStateChanged(it)) }
+      .launchIn(viewModelScope)
+  }
+
   override suspend fun processEvent(event: TotpCodeEntryEvent) {
     when (event) {
       TotpCodeEntryEvent.NavigateBackClicked -> {
         _actions.send(TotpCodeEntryAction.NavigateBack)
       }
-      is TotpCodeEntryEvent.CodeChanged -> {
-        val digits = event.code.filter { it.isDigit() }.take(TotpCodeEntryState.CODE_LENGTH)
-        _state.update { it.copy(code = digits, error = Error.None) }
+      is TotpCodeEntryEvent.CodeEntryEvent -> {
+        _state.update { it.copy(error = Error.None) }
+        codeEntryPresenter.onEvent(event.event)
       }
-      TotpCodeEntryEvent.DoneClicked -> {
+      is TotpCodeEntryEvent.CodeEntryStateChanged -> {
+        _state.update { it.copy(codeEntry = event.codeEntryState) }
+      }
+      TotpCodeEntryEvent.NextClicked -> {
         if (!_state.value.canSubmit) {
           return
         }

app/src/test/java/org/thoughtcrime/securesms/components/settings/app/account/authenticator/TotpCodeEntryViewModelTest.kt

@@ -28,6 +28,7 @@ import org.junit.Test
 import org.signal.appsettings.totpcodeentry.TotpCodeEntryAction
 import org.signal.appsettings.totpcodeentry.TotpCodeEntryEvent
 import org.signal.appsettings.totpcodeentry.TotpCodeEntryState.Error
+import org.signal.uicomponents.codeentryfield.CodeEntryFieldEvents
 import org.thoughtcrime.securesms.testing.CoroutineDispatcherRule
 
 @OptIn(ExperimentalCoroutinesApi::class)
@@ -57,25 +58,16 @@ class TotpCodeEntryViewModelTest {
     Dispatchers.resetMain()
   }
 
-  @Test
-  fun `non-digits are dropped and the code is capped at six digits`() = runTest(testDispatcher) {
-    val viewModel = createViewModel()
-
-    viewModel.onEvent(TotpCodeEntryEvent.CodeChanged("12a34 5678"))
-
-    assertThat(viewModel.state.value.code).isEqualTo(FULL_CODE)
-  }
-
   @Test
   fun `a partial code can't be submitted`() = runTest(testDispatcher) {
     val viewModel = createViewModel()
     val actions = collectActions(viewModel.actions)
 
-    viewModel.onEvent(TotpCodeEntryEvent.CodeChanged("123"))
+    enterCode(viewModel, "123")
 
     assertThat(viewModel.state.value.canSubmit).isFalse()
 
-    viewModel.onEvent(TotpCodeEntryEvent.DoneClicked)
+    viewModel.onEvent(TotpCodeEntryEvent.NextClicked)
 
     assertThat(actions).isEmpty()
   }
@@ -124,7 +116,7 @@ class TotpCodeEntryViewModelTest {
     val viewModel = createViewModel()
     submit(viewModel)
 
-    viewModel.onEvent(TotpCodeEntryEvent.CodeChanged("1"))
+    enterCode(viewModel, "1")
 
     assertThat(viewModel.state.value.error).isEqualTo(Error.None)
   }
@@ -140,8 +132,14 @@ class TotpCodeEntryViewModelTest {
   }
 
   private fun submit(viewModel: TotpCodeEntryViewModel) {
-    viewModel.onEvent(TotpCodeEntryEvent.CodeChanged(FULL_CODE))
-    viewModel.onEvent(TotpCodeEntryEvent.DoneClicked)
+    enterCode(viewModel, FULL_CODE)
+    viewModel.onEvent(TotpCodeEntryEvent.NextClicked)
+  }
+
+  private fun enterCode(viewModel: TotpCodeEntryViewModel, code: String) {
+    code.forEachIndexed { index, digit ->
+      viewModel.onEvent(TotpCodeEntryEvent.CodeEntryEvent(CodeEntryFieldEvents.DigitChanged(index, digit.toString())))
+    }
   }
 
   private fun createViewModel() = TotpCodeEntryViewModel(repository = repository)