Migrate Preferences to new architecture

libraries/architecture/build.gradle.kts

@@ -1,3 +1,5 @@
+// TODO: Remove once https://youtrack.jetbrains.com/issue/KTIJ-19369 is fixed
+@Suppress("DSL_SCOPE_VIOLATION")
 plugins {
     id("io.element.android-compose-library")
     alias(libs.plugins.molecule)

libraries/architecture/src/main/java/io/element/android/x/architecture/Async.kt

@@ -5,8 +5,17 @@ import androidx.compose.runtime.MutableState
 sealed interface Async<out T> {
     object Uninitialized : Async<Nothing>
     data class Loading<out T>(val prevState: T? = null) : Async<T>
-    data class Failure<out T>(val error: Throwable) : Async<T>
+    data class Failure<out T>(val error: Throwable, val prevState: T? = null) : Async<T>
     data class Success<out T>(val state: T) : Async<T>
+
+    fun dataOrNull(): T? {
+        return when (this) {
+            is Failure -> prevState
+            is Loading -> prevState
+            is Success -> state
+            Uninitialized -> null
+        }
+    }
 }
 
 suspend fun <T> (suspend () -> T).execute(state: MutableState<Async<T>>) {

libraries/architecture/src/main/java/io/element/android/x/architecture/PresenterConnector.kt

@@ -6,24 +6,21 @@ import app.cash.molecule.AndroidUiDispatcher
 import app.cash.molecule.RecompositionClock
 import app.cash.molecule.launchMolecule
 import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.asSharedFlow
 
 inline fun <reified State, reified Event> LifecycleOwner.presenterConnector(presenter: Presenter<State, Event>): LifecyclePresenterConnector<State, Event> =
     LifecyclePresenterConnector(lifecycleOwner = this, presenter = presenter)
 
-
 class LifecyclePresenterConnector<State, Event>(lifecycleOwner: LifecycleOwner, presenter: Presenter<State, Event>) {
 
     private val moleculeScope = CoroutineScope(lifecycleOwner.lifecycleScope.coroutineContext + AndroidUiDispatcher.Main)
-    private val mutableEventFlow: MutableSharedFlow<Event> = MutableSharedFlow(extraBufferCapacity = 64)
+    private val eventFlow = SharedFlowHolder<Event>()
 
     val stateFlow: StateFlow<State> = moleculeScope.launchMolecule(RecompositionClock.Immediate) {
-        presenter.present(events = mutableEventFlow)
+        presenter.present(events = eventFlow.asSharedFlow())
     }
 
     fun emitEvent(event: Event) {
-        mutableEventFlow.tryEmit(event)
+        eventFlow.emit(event)
     }
 }

libraries/architecture/src/main/java/io/element/android/x/architecture/SharedFlowHolder.kt

@@ -0,0 +1,12 @@
+package io.element.android.x.architecture
+
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.asSharedFlow
+
+class SharedFlowHolder<Data>(capacity: Int = 64) {
+    private val mutableFlow: MutableSharedFlow<Data> = MutableSharedFlow(extraBufferCapacity = capacity)
+
+    fun asSharedFlow() = mutableFlow.asSharedFlow()
+
+    fun emit(data: Data) = mutableFlow.tryEmit(data)
+}

libraries/designsystem/src/main/java/io/element/android/x/designsystem/components/preferences/PreferenceScreen.kt

@@ -45,7 +45,7 @@ import androidx.compose.ui.unit.sp
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
-fun PreferenceScreen(
+fun PreferenceView(
     title: String,
     modifier: Modifier = Modifier,
     onBackPressed: () -> Unit = {},
@@ -113,7 +113,7 @@ fun PreferenceTopAppBar(
 @Composable
 @Preview(showBackground = false)
 fun PreferenceScreenPreview() {
-    PreferenceScreen(
+    PreferenceView(
         title = "Preference screen"
     ) {
         PreferenceCategoryPreview()