store MultiStackNavigationExecutor in ViewModel, add SavedStateSuppor…

…t for non-Android platforms (#22)

* init simple sample

* baseName = "SolivagantSimpleSampleAppShared"

* simplify gradle

* simplify gradle

* rememberSaveable

* rememberSaveable

* rememberSaveable

* rememberSaveable

* rememberSaveable

* create MultiStackNavigationExecutor in ViewModel

* create MultiStackNavigationExecutor in ViewModel

* create MultiStackNavigationExecutor in ViewModel

* create MultiStackNavigationExecutor in ViewModel

* create MultiStackNavigationExecutor in ViewModel

* create MultiStackNavigationExecutor in ViewModel

* done ios sample

navigation/api/jvm/navigation.api

@@ -2,6 +2,18 @@ public final class com/hoc081098/solivagant/navigation/NavHostKt {
 	public static final fun NavHost (Lcom/hoc081098/solivagant/navigation/NavRoot;Lkotlinx/collections/immutable/ImmutableSet;Landroidx/compose/ui/Modifier;Lcom/hoc081098/solivagant/navigation/NavEventNavigator;Lkotlin/jvm/functions/Function1;Landroidx/compose/runtime/Composer;II)V
 }
 
+public final class com/hoc081098/solivagant/navigation/SavedStateSupport : androidx/compose/runtime/saveable/SaveableStateRegistry, com/hoc081098/kmp/viewmodel/SavedStateHandleFactory, com/hoc081098/kmp/viewmodel/ViewModelStoreOwner {
+	public static final field $stable I
+	public fun <init> ()V
+	public fun canBeSaved (Ljava/lang/Object;)Z
+	public final fun clear ()V
+	public fun consumeRestored (Ljava/lang/String;)Ljava/lang/Object;
+	public fun create ()Lcom/hoc081098/kmp/viewmodel/SavedStateHandle;
+	public fun getViewModelStore ()Lcom/hoc081098/kmp/viewmodel/ViewModelStore;
+	public fun performSave ()Ljava/util/Map;
+	public fun registerProvider (Ljava/lang/String;Lkotlin/jvm/functions/Function0;)Landroidx/compose/runtime/saveable/SaveableStateRegistry$Entry;
+}
+
 public final class com/hoc081098/solivagant/navigation/internal/RememberPlatformLifecycleOwner_jvmKt {
 	public static final fun LifecycleControllerEffect (Lcom/hoc081098/solivagant/lifecycle/LifecycleRegistry;Landroidx/compose/ui/window/WindowState;Landroidx/compose/runtime/Composer;I)V
 }

navigation/src/androidMain/kotlin/com/hoc081098/solivagant/navigation/internal/savedStateHandleAndroidSupport.android.kt

@@ -5,7 +5,7 @@ import android.os.Bundle
 import android.os.Parcelable
 import androidx.lifecycle.SavedStateHandle
 
-internal actual fun SavedStateHandle.setSavedStateProvider(
+internal actual fun SavedStateHandle.setSavedStateProviderWithMap(
   key: String,
   savedStateFactory: () -> Map<String, Any?>,
 ) = setSavedStateProvider(key) {

navigation/src/commonMain/kotlin/com/hoc081098/solivagant/navigation/internal/MultiStackNavigationExecutor.kt

@@ -38,10 +38,6 @@ internal class MultiStackNavigationExecutor(
     get() = stack.canNavigateBack
 
   init {
-    viewModel
-      .globalSavedStateHandle
-      .setSavedStateProvider(SAVED_STATE_STACK, stack::saveState)
-
     _lifecycleOwner
       .flatMapLatest { it?.lifecycle?.eventFlow ?: emptyFlow() }
       .onEach(stack::handleLifecycleEvent)
@@ -117,10 +113,7 @@ internal class MultiStackNavigationExecutor(
     _lifecycleOwner.value = lifecycleOwner
   }
 
-  internal companion object {
-    const val SAVED_STATE_STACK = "com.hoc081098.solivagant.navigation.stack"
-  }
-
+  //region RememberObserver
   override fun onAbandoned() {
     _lifecycleOwner.value = null
     scope.cancel()
@@ -132,4 +125,5 @@ internal class MultiStackNavigationExecutor(
   }
 
   override fun onRemembered() = Unit
+  //endregion
 }

navigation/src/commonMain/kotlin/com/hoc081098/solivagant/navigation/internal/MultiStackNavigationExecutorBuilder.kt

@@ -23,41 +23,16 @@ internal fun rememberNavigationExecutor(
     },
   ),
 ): MultiStackNavigationExecutor {
-  val lifecycleOwner = LocalLifecycleOwner.current
-
+  // setInputStartRoot must be called before getMultiStackNavigationExecutor
   viewModel.setInputStartRoot(startRoot)
 
+  val lifecycleOwner = LocalLifecycleOwner.current
   val executor = remember(viewModel) {
-    val contentDestinations = destinations.filterIsInstance<ContentDestination<*>>()
-
-    val navState = viewModel.getSavedStackState()
-    val hostLifecycleState = lifecycleOwner.lifecycle.currentState
-
-    val stack = if (navState == null) {
-      MultiStack.createWith(
-        root = viewModel.savedNavRoot!!,
-        destinations = contentDestinations,
-        hostLifecycleState = hostLifecycleState,
-        onStackEntryRemoved = viewModel::removeEntry,
-      )
-    } else {
-      MultiStack.fromState(
-        root = viewModel.savedNavRoot!!,
-        bundle = navState,
-        destinations = contentDestinations,
-        hostLifecycleState = hostLifecycleState,
-        onStackEntryRemoved = viewModel::removeEntry,
-      )
-    }
-
-    @Suppress("ViewModelForwarding")
-    MultiStackNavigationExecutor(
-      stack = stack,
-      viewModel = viewModel,
-      onRootChanged = viewModel::setStartRoot,
+    viewModel.createMultiStackNavigationExecutor(
+      contentDestinations = destinations.filterIsInstance<ContentDestination<*>>(),
+      hostLifecycleState = lifecycleOwner.lifecycle.currentState,
     )
   }
-
   executor.setLifecycleOwner(lifecycleOwner)
 
   return executor

navigation/src/commonMain/kotlin/com/hoc081098/solivagant/navigation/internal/StoreViewModel.kt

@@ -3,10 +3,11 @@ package com.hoc081098.solivagant.navigation.internal
 import com.hoc081098.kmp.viewmodel.SavedStateHandle
 import com.hoc081098.kmp.viewmodel.SavedStateHandleFactory
 import com.hoc081098.kmp.viewmodel.ViewModel
+import com.hoc081098.solivagant.lifecycle.Lifecycle
 import com.hoc081098.solivagant.navigation.BaseRoute
+import com.hoc081098.solivagant.navigation.ContentDestination
 import com.hoc081098.solivagant.navigation.EXTRA_ROUTE
 import com.hoc081098.solivagant.navigation.NavRoot
-import com.hoc081098.solivagant.navigation.internal.MultiStackNavigationExecutor.Companion.SAVED_STATE_STACK
 
 internal class StoreViewModel(
   internal val globalSavedStateHandle: SavedStateHandle,
@@ -15,7 +16,14 @@ internal class StoreViewModel(
   private val savedStateHandles = mutableMapOf<StackEntry.Id, SavedStateHandle>()
   private val savedStateHandleFactories = mutableMapOf<StackEntry.Id, SavedStateHandleFactory>()
 
-  internal val savedNavRoot: NavRoot? get() = globalSavedStateHandle[SAVED_START_ROOT_KEY]
+  private var stack: MultiStack? = null
+  private var executor: MultiStackNavigationExecutor? = null
+
+  init {
+    globalSavedStateHandle.setSavedStateProviderWithMap(SAVED_STATE_STACK) {
+      checkNotNull(stack) { "Stack is null. This should never happen" }.saveState()
+    }
+  }
 
   internal fun provideStore(id: StackEntry.Id): NavigationExecutor.Store {
     return stores.getOrPut(id) { NavigationExecutorStore() }
@@ -34,7 +42,7 @@ internal class StoreViewModel(
     }
   }
 
-  internal fun removeEntry(id: StackEntry.Id) {
+  private fun removeEntry(id: StackEntry.Id) {
     val store = stores.remove(id)
     store?.close()
 
@@ -82,14 +90,49 @@ internal class StoreViewModel(
     }
   }
 
-  internal fun setStartRoot(root: NavRoot) {
+  private fun setStartRoot(root: NavRoot) {
     globalSavedStateHandle[SAVED_START_ROOT_KEY] = root
   }
 
-  internal fun getSavedStackState(): Map<String, Any?>? =
-    globalSavedStateHandle.getAsMap(SAVED_STATE_STACK)
+  fun createMultiStackNavigationExecutor(
+    contentDestinations: List<ContentDestination<*>>,
+    hostLifecycleState: Lifecycle.State,
+  ): MultiStackNavigationExecutor =
+    executor
+      ?: MultiStackNavigationExecutor(
+        stack = createMultiStackIfNeeded(contentDestinations, hostLifecycleState),
+        viewModel = this,
+        onRootChanged = ::setStartRoot,
+      ).also { this.executor = it }
+
+  private fun createMultiStackIfNeeded(
+    contentDestinations: List<ContentDestination<*>>,
+    hostLifecycleState: Lifecycle.State,
+  ): MultiStack {
+    this.stack?.let { return it }
+
+    val navState = globalSavedStateHandle.getAsMap(SAVED_STATE_STACK)
+    val savedNavRoot: NavRoot? = globalSavedStateHandle[SAVED_START_ROOT_KEY]
+    return if (navState == null) {
+      MultiStack.createWith(
+        root = savedNavRoot!!,
+        destinations = contentDestinations,
+        hostLifecycleState = hostLifecycleState,
+        onStackEntryRemoved = ::removeEntry,
+      )
+    } else {
+      MultiStack.fromState(
+        root = savedNavRoot!!,
+        bundle = navState,
+        destinations = contentDestinations,
+        hostLifecycleState = hostLifecycleState,
+        onStackEntryRemoved = ::removeEntry,
+      )
+    }.also { this.stack = it }
+  }
 
   private companion object {
+    private const val SAVED_STATE_STACK = "com.hoc081098.solivagant.navigation.stack"
     private const val SAVED_START_ROOT_KEY = "com.hoc081098.solivagant.navigation.store.start_root"
     private const val SAVED_INPUT_START_ROOT_KEY = "com.hoc081098.solivagant.navigation.store.input_start_root"
   }

navigation/src/commonMain/kotlin/com/hoc081098/solivagant/navigation/internal/savedStateHandleAndroidSupport.kt

@@ -2,7 +2,7 @@ package com.hoc081098.solivagant.navigation.internal
 
 import com.hoc081098.kmp.viewmodel.SavedStateHandle
 
-internal expect fun SavedStateHandle.setSavedStateProvider(
+internal expect fun SavedStateHandle.setSavedStateProviderWithMap(
   key: String,
   savedStateFactory: () -> Map<String, Any?>,
 )

navigation/src/iosAndTvOs/kotlin/com/hoc081098/solivagant/navigation/AppLifecycleOwner.kt

@@ -0,0 +1,7 @@
+package com.hoc081098.solivagant.navigation
+
+import com.hoc081098.solivagant.lifecycle.LifecycleOwner
+import com.hoc081098.solivagant.navigation.internal.AppLifecycleOwnerImpl
+
+@Suppress("FunctionName") // Factory function
+public fun AppLifecycleOwner(): LifecycleOwner = AppLifecycleOwnerImpl()

navigation/src/iosAndTvOs/kotlin/com/hoc081098/solivagant/navigation/internal/rememberPlatformLifecycleOwner.iosAndTvOs.kt

@@ -18,7 +18,7 @@ import platform.UIKit.UIApplicationWillResignActiveNotification
 import platform.UIKit.UIApplicationWillTerminateNotification
 import platform.darwin.NSObjectProtocol
 
-private class AppLifecycleOwnerImpl : LifecycleOwner {
+internal class AppLifecycleOwnerImpl : LifecycleOwner {
   private val lifecycleRegistry = LifecycleRegistry()
   override val lifecycle: Lifecycle get() = lifecycleRegistry
 
@@ -221,9 +221,6 @@ private fun moveToDestroyed(lifecycleRegistry: LifecycleRegistry) {
   }
 }
 
-@Suppress("FunctionName") // Factory function
-public fun AppLifecycleOwner(): LifecycleOwner = AppLifecycleOwnerImpl()
-
 @Composable
 internal actual fun rememberPlatformLifecycleOwner(): LifecycleOwner {
   return remember { AppLifecycleOwnerImpl() }

navigation/src/nonAndroidMain/kotlin/com/hoc081098/solivagant/navigation/SavedStateSupport.kt

@@ -0,0 +1,63 @@
+package com.hoc081098.solivagant.navigation
+
+import androidx.compose.runtime.saveable.SaveableStateRegistry
+import com.hoc081098.kmp.viewmodel.MainThread
+import com.hoc081098.kmp.viewmodel.SavedStateHandle
+import com.hoc081098.kmp.viewmodel.SavedStateHandleFactory
+import com.hoc081098.kmp.viewmodel.ViewModelStore
+import com.hoc081098.kmp.viewmodel.ViewModelStoreOwner
+import kotlin.LazyThreadSafetyMode.NONE
+
+@MainThread
+public class SavedStateSupport :
+  SavedStateHandleFactory,
+  SaveableStateRegistry,
+  ViewModelStoreOwner {
+  private var registry: SaveableStateRegistry? = SaveableStateRegistry(
+    restoredValues = emptyMap(),
+    canBeSaved = { true },
+  )
+
+  private val savedStateHandle by lazy(NONE) { SavedStateHandle() }
+  private val viewModelStoreLazy = lazy(NONE) { ViewModelStore() }
+  override val viewModelStore: ViewModelStore by viewModelStoreLazy
+
+  public fun clear() {
+    if (registry == null) {
+      // Already cleared
+      return
+    }
+
+    registry = null
+    if (viewModelStoreLazy.isInitialized()) {
+      viewModelStore.clear()
+    }
+  }
+
+  override fun create(): SavedStateHandle = savedStateHandle
+
+  override fun canBeSaved(value: Any): Boolean = registry?.canBeSaved(value) == true
+
+  override fun consumeRestored(key: String): Any? = registry?.consumeRestored(key)
+
+  override fun performSave(): Map<String, List<Any?>> = registry
+    ?.performSave()
+    ?.also {
+      registry = SaveableStateRegistry(
+        restoredValues = it,
+        canBeSaved = { true },
+      )
+    }
+    .orEmpty()
+
+  override fun registerProvider(key: String, valueProvider: () -> Any?): SaveableStateRegistry.Entry =
+    registry
+      ?.registerProvider(key, valueProvider)
+      ?: NoOpSaveableStateRegistryEntry
+}
+
+private val NoOpSaveableStateRegistryEntry = object : SaveableStateRegistry.Entry {
+  override fun unregister() {
+    // No-op
+  }
+}

navigation/src/nonAndroidMain/kotlin/com/hoc081098/solivagant/navigation/internal/savedStateHandleAndroidSupport.nonAndroid.kt

@@ -2,7 +2,7 @@ package com.hoc081098.solivagant.navigation.internal
 
 import com.hoc081098.kmp.viewmodel.SavedStateHandle
 
-internal actual fun SavedStateHandle.setSavedStateProvider(
+internal actual fun SavedStateHandle.setSavedStateProviderWithMap(
   key: String,
   savedStateFactory: () -> Map<String, Any?>,
 ) {

obsolete/navigation-core/build.gradle.kts

@@ -170,4 +170,3 @@ android {
     targetCompatibility = JavaVersion.toVersion(libs.versions.java.target.get())
   }
 }
-

samples/sample/app/build.gradle.kts

@@ -44,4 +44,5 @@ android {
 dependencies {
   implementation(project(":samples:sample:shared"))
   implementation(libs.androidx.activity.compose)
+  implementation(libs.koin.android)
 }

samples/sample/desktop/src/commonMain/kotlin/com/hoc081098/solivagant/sample/main.kt

@@ -2,13 +2,19 @@ package com.hoc081098.solivagant.sample
 
 import androidx.compose.desktop.ui.tooling.preview.Preview
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.LocalSaveableStateRegistry
 import androidx.compose.ui.window.Window
 import androidx.compose.ui.window.application
 import androidx.compose.ui.window.rememberWindowState
+import com.hoc081098.kmp.viewmodel.compose.LocalSavedStateHandleFactory
+import com.hoc081098.kmp.viewmodel.compose.LocalViewModelStoreOwner
 import com.hoc081098.solivagant.lifecycle.LifecycleOwnerProvider
 import com.hoc081098.solivagant.lifecycle.LifecycleRegistry
 import com.hoc081098.solivagant.lifecycle.rememberLifecycleOwner
+import com.hoc081098.solivagant.navigation.SavedStateSupport
 import com.hoc081098.solivagant.navigation.internal.LifecycleControllerEffect
 import com.hoc081098.solivagant.sample.common.OnLifecycleEventWithBuilder
 import io.github.aakira.napier.Napier
@@ -19,14 +25,19 @@ fun main() {
 
   application {
     val windowState = rememberWindowState()
+
     val lifecycleRegistry = remember { LifecycleRegistry() }
     val lifecycleOwner = rememberLifecycleOwner(lifecycleRegistry)
-
     LifecycleControllerEffect(
       lifecycleRegistry = lifecycleRegistry,
       windowState = windowState,
     )
 
+    val savedStateSupport = remember { SavedStateSupport() }
+    DisposableEffect(Unit) {
+      onDispose(savedStateSupport::clear)
+    }
+
     Window(
       onCloseRequest = ::exitApplication,
       title = "Solivagant sample",
@@ -37,7 +48,20 @@ fun main() {
           onEach { Napier.d(message = "Lifecycle event: $it", tag = "[main]") }
         }
 
-        SolivagantSampleApp()
+        CompositionLocalProvider(
+          LocalViewModelStoreOwner provides savedStateSupport,
+          LocalSaveableStateRegistry provides savedStateSupport,
+          LocalSavedStateHandleFactory provides savedStateSupport,
+        ) {
+          SolivagantSampleApp()
+
+          // Must be at the last,
+          // because onDispose is called in reverse order, so we want to save state first,
+          // before [SaveableStateRegistry.Entry]s are unregistered.
+          DisposableEffect(Unit) {
+            onDispose(savedStateSupport::performSave)
+          }
+        }
       }
     }
   }