AppyxComponent state not restored after configuration changes

CHANGELOG.md

@@ -12,6 +12,7 @@
 - [#670](https://github.com/bumble-tech/appyx/pull/670) - Fixes ios lifecycle
 - [#673](https://github.com/bumble-tech/appyx/pull/673) – Fix canHandeBackPress typo
 - [#671](https://github.com/bumble-tech/appyx/issue/671) – Fix ui state saving issue
+- [#694](https://github.com/bumble-tech/appyx/pull/694) – Fix appyxComponent state saving issue
 
 ### Enhancement
 

appyx-navigation/android/src/androidTest/kotlin/com/bumble/appyx/helpers/DummyComponent.kt

@@ -0,0 +1,50 @@
+package com.bumble.appyx.helpers
+
+import androidx.compose.animation.core.AnimationSpec
+import androidx.compose.animation.core.spring
+import com.bumble.appyx.helpers.DummyComponentModel.State
+import com.bumble.appyx.interactions.gesture.GestureFactory
+import com.bumble.appyx.interactions.gesture.GestureSettleConfig
+import com.bumble.appyx.interactions.model.BaseAppyxComponent
+import com.bumble.appyx.interactions.model.backpresshandlerstrategies.BackPressHandlerStrategy
+import com.bumble.appyx.interactions.model.backpresshandlerstrategies.DontHandleBackPress
+import com.bumble.appyx.interactions.state.MutableSavedStateMap
+import com.bumble.appyx.interactions.ui.Visualisation
+import com.bumble.appyx.interactions.ui.context.TransitionBounds
+import com.bumble.appyx.interactions.ui.context.UiContext
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+
+class DummyComponent<NavTarget : Any>(
+    scope: CoroutineScope = CoroutineScope(SupervisorJob() + Dispatchers.Main),
+    val model: DummyComponentModel<NavTarget>,
+    visualisation: (UiContext) -> Visualisation<NavTarget, State<NavTarget>>,
+    animationSpec: AnimationSpec<Float> = spring(),
+    gestureFactory: (TransitionBounds) -> GestureFactory<NavTarget, State<NavTarget>> = {
+        GestureFactory.Noop()
+    },
+    gestureSettleConfig: GestureSettleConfig = GestureSettleConfig(),
+    backPressStrategy: BackPressHandlerStrategy<NavTarget, State<NavTarget>> = DontHandleBackPress(),
+    disableAnimations: Boolean = false,
+) : BaseAppyxComponent<NavTarget, State<NavTarget>>(
+    scope = scope,
+    model = model,
+    visualisation = visualisation,
+    gestureFactory = gestureFactory,
+    gestureSettleConfig = gestureSettleConfig,
+    backPressStrategy = backPressStrategy,
+    defaultAnimationSpec = animationSpec,
+    disableAnimations = disableAnimations
+) {
+    var saveInstanceStateInvoked: Int = 0
+
+    fun resetSaveInstanceState() {
+        saveInstanceStateInvoked = 0
+    }
+
+    override fun saveInstanceState(state: MutableSavedStateMap) {
+        super.saveInstanceState(state)
+        saveInstanceStateInvoked += 1
+    }
+}

appyx-navigation/android/src/androidTest/kotlin/com/bumble/appyx/helpers/DummyComponentModel.kt

@@ -0,0 +1,32 @@
+package com.bumble.appyx.helpers
+
+import com.bumble.appyx.helpers.DummyComponentModel.State
+import com.bumble.appyx.interactions.model.Element
+import com.bumble.appyx.interactions.model.asElement
+import com.bumble.appyx.interactions.model.transition.BaseTransitionModel
+import com.bumble.appyx.utils.multiplatform.Parcelable
+import com.bumble.appyx.utils.multiplatform.Parcelize
+import com.bumble.appyx.utils.multiplatform.SavedStateMap
+
+class DummyComponentModel<NavTarget : Any>(
+    initialTarget: NavTarget,
+    savedStateMap: SavedStateMap?,
+) : BaseTransitionModel<NavTarget, State<NavTarget>>(
+    savedStateMap = savedStateMap,
+) {
+    @Parcelize
+    data class State<NavTarget>(
+        val target: Element<NavTarget>
+    ) : Parcelable
+
+    override val initialState: State<NavTarget> = State(initialTarget.asElement())
+
+    override fun State<NavTarget>.availableElements(): Set<Element<NavTarget>> = setOf(target)
+
+    override fun State<NavTarget>.removeDestroyedElement(element: Element<NavTarget>): State<NavTarget> =
+        this
+
+    override fun State<NavTarget>.removeDestroyedElements(): State<NavTarget> = this
+
+    override fun State<NavTarget>.destroyedElements(): Set<Element<NavTarget>> = emptySet()
+}

appyx-navigation/android/src/androidTest/kotlin/com/bumble/appyx/helpers/DummyVisualisation.kt

@@ -0,0 +1,32 @@
+package com.bumble.appyx.helpers
+
+import androidx.compose.animation.core.SpringSpec
+import com.bumble.appyx.helpers.DummyComponentModel.State
+import com.bumble.appyx.interactions.ui.DefaultAnimationSpec
+import com.bumble.appyx.interactions.ui.context.UiContext
+import com.bumble.appyx.interactions.ui.state.MatchedTargetUiState
+import com.bumble.appyx.transitionmodel.BaseVisualisation
+
+class DummyVisualisation<NavTarget : Any>(
+    uiContext: UiContext,
+    defaultAnimationSpec: SpringSpec<Float> = DefaultAnimationSpec
+) : BaseVisualisation<NavTarget, State<NavTarget>, TargetUiState, MutableUiState>(
+    uiContext = uiContext,
+    defaultAnimationSpec = defaultAnimationSpec,
+) {
+    override fun State<NavTarget>.toUiTargets(): List<MatchedTargetUiState<NavTarget, TargetUiState>> =
+        listOf(
+            MatchedTargetUiState(
+                element = target,
+                targetUiState = TargetUiState(0)
+            )
+        )
+
+    override fun mutableUiStateFor(
+        uiContext: UiContext,
+        targetUiState: TargetUiState
+    ): MutableUiState =
+        targetUiState.toMutableUiState(uiContext)
+
+
+}

appyx-navigation/android/src/androidTest/kotlin/com/bumble/appyx/helpers/RootNode.kt

@@ -0,0 +1,33 @@
+package com.bumble.appyx.helpers
+
+import androidx.compose.material.Text
+import com.bumble.appyx.helpers.RootNode.NavTarget
+import com.bumble.appyx.navigation.modality.NodeContext
+import com.bumble.appyx.navigation.node.Node
+import com.bumble.appyx.navigation.node.node
+
+class RootNode(
+    nodeContext: NodeContext,
+    appyxComponent: DummyComponent<NavTarget> = DummyComponent(
+        model = DummyComponentModel(
+            initialTarget = NavTarget.Child1,
+            savedStateMap = nodeContext.savedStateMap
+        ),
+        visualisation = { DummyVisualisation(it) }
+    )
+) : Node<NavTarget>(
+    nodeContext = nodeContext,
+    appyxComponent = appyxComponent,
+) {
+    sealed interface NavTarget {
+        data object Child1 : NavTarget
+        data object Child2 : NavTarget
+    }
+
+    override fun buildChildNode(navTarget: NavTarget, nodeContext: NodeContext): Node<*> =
+        when (navTarget) {
+            is NavTarget.Child1 -> node(nodeContext) { Text("Child 1") }
+            is NavTarget.Child2 -> node(nodeContext) { Text("Child 2") }
+        }
+
+}

appyx-navigation/android/src/androidTest/kotlin/com/bumble/appyx/helpers/TargetUiState.kt

@@ -0,0 +1,41 @@
+package com.bumble.appyx.helpers
+
+import androidx.compose.animation.core.SpringSpec
+import androidx.compose.ui.Modifier
+import com.bumble.appyx.interactions.ui.context.UiContext
+import com.bumble.appyx.interactions.ui.state.BaseMutableUiState
+import kotlinx.coroutines.CoroutineScope
+
+class TargetUiState(
+    val id: Int,
+)
+
+class MutableUiState(
+    uiContext: UiContext,
+    val id: Int,
+) : BaseMutableUiState<TargetUiState>(
+    uiContext, emptyList()
+) {
+    override val combinedMotionPropertyModifier: Modifier = Modifier
+
+    override suspend fun snapTo(target: TargetUiState) = Unit
+
+    override fun lerpTo(
+        scope: CoroutineScope,
+        start: TargetUiState,
+        end: TargetUiState,
+        fraction: Float
+    ) = Unit
+
+    override suspend fun animateTo(
+        scope: CoroutineScope,
+        target: TargetUiState,
+        springSpec: SpringSpec<Float>
+    ) = Unit
+}
+
+fun TargetUiState.toMutableUiState(uiContext: UiContext): MutableUiState =
+    MutableUiState(
+        uiContext = uiContext,
+        id = id,
+    )

appyx-navigation/android/src/androidTest/kotlin/com/bumble/appyx/navigation/node/NodeTest.kt

@@ -0,0 +1,50 @@
+package com.bumble.appyx.navigation.node
+
+import com.bumble.appyx.helpers.DummyComponent
+import com.bumble.appyx.helpers.DummyComponentModel
+import com.bumble.appyx.helpers.DummyVisualisation
+import com.bumble.appyx.helpers.RootNode
+import com.bumble.appyx.navigation.AppyxTestScenario
+import com.bumble.appyx.navigation.modality.NodeContext
+import org.junit.Assert.assertNotEquals
+import org.junit.Rule
+import org.junit.Test
+
+class NodeTest {
+    private var appyxComponent: DummyComponent<RootNode.NavTarget>? = null
+
+    private val nodeFactory: (nodeContext: NodeContext) -> Node<*> = { nodeContext ->
+        appyxComponent = DummyComponent(
+            model = DummyComponentModel(
+                initialTarget = RootNode.NavTarget.Child1,
+                savedStateMap = nodeContext.savedStateMap
+            ),
+            visualisation = { DummyVisualisation(it) }
+        )
+        RootNode(nodeContext = nodeContext, appyxComponent = appyxComponent!!)
+    }
+
+    @get:Rule
+    val rule = AppyxTestScenario { nodeContext ->
+        nodeFactory(nodeContext)
+    }
+
+    @Test
+    fun WHEN_node_is_create_THEN_plugins_are_setup_as_expected() {
+        rule.start()
+        assertNotEquals("Node should have some predefined plugins", 0, rule.node.plugins.size)
+    }
+
+    @Test
+    fun WHEN_node_is_create_THEN_appyx_component_state_is_saved_during_recreation() {
+        rule.start()
+        appyxComponent!!.resetSaveInstanceState()
+        rule.activityScenario.recreate()
+        assertNotEquals(
+            "AppyxComponent state should be saved",
+            0,
+            appyxComponent!!.saveInstanceStateInvoked
+        )
+    }
+
+}

appyx-navigation/common/src/commonMain/kotlin/com/bumble/appyx/navigation/node/Node.kt

@@ -91,7 +91,7 @@ abstract class Node<NavTarget : Any>(
     val id: String
         get() = nodeContext.identifier
 
-    val plugins: List<Plugin> = plugins + listOfNotNull(this as? Plugin)
+    val plugins: List<Plugin> = plugins + appyxComponent + childAware + listOfNotNull(this as? Plugin)
 
     val ancestryInfo: AncestryInfo =
         nodeContext.ancestryInfo