Nav: First iteration integrating Appyx

libraries/core/build.gradle.kts

@@ -10,4 +10,5 @@ dependencies {
     api(libs.mavericks.compose)
     api(libs.dagger)
     api(libs.androidx.fragment)
+    api(libs.appyx.core)
 }

libraries/core/src/main/java/io/element/android/x/core/di/Bindings.kt

@@ -3,6 +3,7 @@ package io.element.android.x.core.di
 import android.content.Context
 import android.content.ContextWrapper
 import androidx.fragment.app.Fragment
+import com.bumble.appyx.core.node.Node
 
 /**
  * Use this to get the Dagger "Bindings" for your module. Bindings are used if you need to directly interact with a dagger component such as:
@@ -20,6 +21,7 @@ import androidx.fragment.app.Fragment
  * 2) Contribute your interface to the correct component via `@ContributesTo(AppScope::class)`.
  * 3) Call bindings<YourModuleBindings>().inject(this).
  */
+
 inline fun <reified T : Any> Context.bindings() = bindings(T::class.java)
 
 /**
@@ -27,6 +29,8 @@ inline fun <reified T : Any> Context.bindings() = bindings(T::class.java)
  */
 inline fun <reified T : Any> Fragment.bindings() = bindings(T::class.java)
 
+inline fun <reified T : Any> Node.bindings() = bindings(T::class.java)
+
 /** Use no-arg extension function instead: [Context.bindings] */
 fun <T : Any> Context.bindings(klass: Class<T>): T {
     // search dagger components in the context hierarchy
@@ -50,4 +54,16 @@ fun <T : Any> Fragment.bindings(klass: Class<T>): T {
         .filterIsInstance(klass)
         .firstOrNull()
         ?: requireActivity().bindings(klass)
-}
+}
+
+/** Use no-arg extension function instead: [Node.bindings] */
+fun <T : Any> Node.bindings(klass: Class<T>): T {
+    // search dagger components in node hierarchy
+    return generateSequence(this, Node::parent)
+        .filterIsInstance<DaggerComponentOwner>()
+        .map { it.daggerComponent }
+        .flatMap { if (it is Collection<*>) it else listOf(it) }
+        .filterIsInstance(klass)
+        .firstOrNull()
+        ?: error("Unable to find bindings for ${klass.name}")
+}

libraries/core/src/main/java/io/element/android/x/core/di/ViewModelSupport.kt

@@ -0,0 +1,121 @@
+package io.element.android.x.core.di
+
+import android.os.Bundle
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.lifecycle.DEFAULT_ARGS_KEY
+import androidx.lifecycle.DefaultLifecycleObserver
+import androidx.lifecycle.HasDefaultViewModelProviderFactory
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.SAVED_STATE_REGISTRY_OWNER_KEY
+import androidx.lifecycle.SavedStateViewModelFactory
+import androidx.lifecycle.VIEW_MODEL_STORE_OWNER_KEY
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.ViewModelStore
+import androidx.lifecycle.ViewModelStoreOwner
+import androidx.lifecycle.enableSavedStateHandles
+import androidx.lifecycle.viewmodel.CreationExtras
+import androidx.lifecycle.viewmodel.MutableCreationExtras
+import androidx.savedstate.SavedStateRegistry
+import androidx.savedstate.SavedStateRegistryController
+import androidx.savedstate.SavedStateRegistryOwner
+import com.bumble.appyx.core.modality.BuildContext
+import com.bumble.appyx.core.node.Node
+import com.bumble.appyx.core.plugin.Plugin
+
+fun viewModelSupportNode(buildContext: BuildContext, plugins: List<Plugin> = emptyList(), composable: @Composable (Modifier) -> Unit): Node =
+    ViewModelSupportNode(buildContext, plugins, composable)
+
+class ViewModelSupportNode(
+    buildContext: BuildContext,
+    plugins: List<Plugin> = emptyList(),
+    private val composable: @Composable (Modifier) -> Unit,
+) : Node(
+    buildContext, plugins = plugins
+), ViewModelStoreOwner, SavedStateRegistryOwner {
+
+    private val viewModelSupport = ViewModelSupport(
+        lifecycle,
+        buildContext.savedStateMap?.get("SAVED_STATE_REGISTRY") as Bundle?,
+    )
+
+    override fun getViewModelStore(): ViewModelStore {
+        return viewModelSupport.viewModelStore
+    }
+
+    override val savedStateRegistry: SavedStateRegistry
+        get() = viewModelSupport.savedStateRegistry
+
+    @Composable
+    override fun View(modifier: Modifier) {
+        composable(modifier)
+    }
+}
+
+private class ViewModelSupport(
+    private val lifecycle: Lifecycle,
+    private val initialSavedState: Bundle?,
+    val defaultArgs: Bundle? = null,
+) : ViewModelStoreOwner, HasDefaultViewModelProviderFactory, SavedStateRegistryOwner {
+
+    private val viewModelStore = ViewModelStore()
+    private val savedStateRegistryController: SavedStateRegistryController =
+        SavedStateRegistryController.create(this)
+
+    //Don't replace the initial saved state until we have at least started
+    private var canSaveState: Boolean = false
+
+    init {
+        savedStateRegistryController.performAttach()
+
+        // We copy the bundle because the `savedStateRegistryController` will modify it.
+        // We don't want to modify `initialSavedState` since we may need to return that as our
+        // state in `saveState`.
+        savedStateRegistryController.performRestore(initialSavedState?.let { Bundle(it) })
+        enableSavedStateHandles()
+
+        lifecycle.addObserver(object : DefaultLifecycleObserver {
+            override fun onStart(owner: LifecycleOwner) {
+                canSaveState = true
+            }
+
+            override fun onDestroy(owner: LifecycleOwner) {
+                viewModelStore.clear()
+            }
+        })
+    }
+
+    override fun getViewModelStore(): ViewModelStore {
+        return viewModelStore
+    }
+
+    override fun getDefaultViewModelProviderFactory(): ViewModelProvider.Factory {
+        return SavedStateViewModelFactory(null, this, defaultArgs)
+    }
+
+    override fun getDefaultViewModelCreationExtras(): CreationExtras {
+        val extras = MutableCreationExtras()
+        extras[SAVED_STATE_REGISTRY_OWNER_KEY] = this
+        extras[VIEW_MODEL_STORE_OWNER_KEY] = this
+        defaultArgs?.let { args ->
+            extras[DEFAULT_ARGS_KEY] = args
+        }
+        return extras
+    }
+
+    override val savedStateRegistry: SavedStateRegistry
+        get() = savedStateRegistryController.savedStateRegistry
+
+    override fun getLifecycle(): Lifecycle {
+        return lifecycle
+    }
+
+    fun saveState(): Bundle? {
+        return if (canSaveState) {
+            Bundle().also(savedStateRegistryController::performSave)
+        } else {
+            initialSavedState
+        }
+    }
+}