[#310] Ensure NavTarget and State are parcelable

libraries/core/src/main/kotlin/com/bumble/appyx/core/children/ChildEntry.kt

@@ -1,11 +1,12 @@
 package com.bumble.appyx.core.children
 
+import android.os.Parcelable
 import com.bumble.appyx.core.navigation.NavKey
 import com.bumble.appyx.core.node.Node
 import com.bumble.appyx.core.state.SavedStateMap
 
 // custom equals/hashCode for MutableStateFlow and equality checks
-sealed class ChildEntry<T> {
+sealed class ChildEntry<T : Parcelable> {
     abstract val key: NavKey<T>
 
     override fun equals(other: Any?): Boolean =
@@ -18,12 +19,12 @@ sealed class ChildEntry<T> {
         "$key@${javaClass.simpleName}"
 
     /** All public APIs should return this type of child which is ready to work with. */
-    class Initialized<T>(
+    class Initialized<T : Parcelable>(
         override val key: NavKey<T>,
         val node: Node,
     ) : ChildEntry<T>()
 
-    class Suspended<T>(
+    class Suspended<T : Parcelable>(
         override val key: NavKey<T>,
         val savedState: SavedStateMap?,
     ) : ChildEntry<T>()

libraries/core/src/main/kotlin/com/bumble/appyx/core/children/ChildEntryExt.kt

@@ -1,8 +1,9 @@
 package com.bumble.appyx.core.children
 
+import android.os.Parcelable
 import com.bumble.appyx.core.node.Node
 
-val <T> ChildEntry<T>.nodeOrNull: Node?
+val <T : Parcelable> ChildEntry<T>.nodeOrNull: Node?
     get() =
         when (this) {
             is ChildEntry.Initialized -> node

libraries/core/src/main/kotlin/com/bumble/appyx/core/children/ChildNodeCreationManager.kt

@@ -1,5 +1,6 @@
 package com.bumble.appyx.core.children
 
+import android.os.Parcelable
 import androidx.lifecycle.coroutineScope
 import com.bumble.appyx.core.modality.AncestryInfo
 import com.bumble.appyx.core.modality.BuildContext
@@ -21,7 +22,7 @@ import kotlinx.coroutines.launch
  *
  * Lifecycle of these nodes is managed in [com.bumble.appyx.core.lifecycle.ChildNodeLifecycleManager].
  */
-internal class ChildNodeCreationManager<NavTarget : Any>(
+internal class ChildNodeCreationManager<NavTarget : Parcelable>(
     private var savedStateMap: SavedStateMap?,
     private val customisations: NodeCustomisationDirectory,
     private val keepMode: ChildEntry.KeepMode,

libraries/core/src/main/kotlin/com/bumble/appyx/core/composable/Child.kt

@@ -1,5 +1,6 @@
 package com.bumble.appyx.core.composable
 
+import android.os.Parcelable
 import androidx.compose.animation.core.Transition
 import androidx.compose.foundation.layout.Box
 import androidx.compose.runtime.Composable
@@ -32,7 +33,7 @@ import com.bumble.appyx.core.navigation.transition.TransitionParams
 import kotlinx.coroutines.flow.map
 
 @Composable
-fun <NavTarget : Any, State> ParentNode<NavTarget>.Child(
+fun <NavTarget : Parcelable, State : Parcelable> ParentNode<NavTarget>.Child(
     navElement: NavElement<NavTarget, out State>,
     saveableStateHolder: SaveableStateHolder,
     transitionParams: TransitionParams,
@@ -87,7 +88,7 @@ private class ChildRendererImpl(
 }
 
 @Composable
-fun <NavTarget : Any, State> ParentNode<NavTarget>.Child(
+fun <NavTarget : Parcelable, State : Parcelable> ParentNode<NavTarget>.Child(
     navElement: NavElement<NavTarget, out State>,
     modifier: Modifier = Modifier,
     transitionHandler: TransitionHandler<NavTarget, State> = JumpToEndTransitionHandler(),
@@ -125,7 +126,7 @@ fun <NavTarget : Any, State> ParentNode<NavTarget>.Child(
     }
 }
 
-private fun <NavTarget : Any, State> NavElement<NavTarget, State>.createDescriptor(
+private fun <NavTarget : Parcelable, State : Parcelable> NavElement<NavTarget, State>.createDescriptor(
     transitionParams: TransitionParams
 ) =
     TransitionDescriptor(
@@ -137,15 +138,15 @@ private fun <NavTarget : Any, State> NavElement<NavTarget, State>.createDescript
     )
 
 @Composable
-fun <R, S> NavModel<R, S>?.childrenAsState(): State<NavElements<R, out S>> =
+fun <R : Parcelable, S : Parcelable> NavModel<R, S>?.childrenAsState(): State<NavElements<R, out S>> =
     if (this != null) {
         elements.collectAsState()
     } else {
         remember { mutableStateOf(emptyList()) }
     }
 
 @Composable
-fun <R, S> NavModel<R, S>?.visibleChildrenAsState(): State<NavElements<R, out S>> =
+fun <R : Parcelable, S : Parcelable> NavModel<R, S>?.visibleChildrenAsState(): State<NavElements<R, out S>> =
     if (this != null) {
         val visibleElementsFlow = remember { screenState.map { it.onScreen } }
         visibleElementsFlow.collectAsState(emptyList())

libraries/core/src/main/kotlin/com/bumble/appyx/core/composable/Children.kt

@@ -1,5 +1,6 @@
 package com.bumble.appyx.core.composable
 
+import android.os.Parcelable
 import androidx.compose.foundation.layout.Box
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
@@ -26,7 +27,7 @@ import kotlinx.coroutines.flow.map
 import kotlin.reflect.KClass
 
 @Composable
-inline fun <reified NavTarget : Any, State> ParentNode<NavTarget>.Children(
+inline fun <reified NavTarget : Parcelable, State : Parcelable> ParentNode<NavTarget>.Children(
     navModel: NavModel<NavTarget, State>,
     modifier: Modifier = Modifier,
     transitionHandler: TransitionHandler<NavTarget, State> = JumpToEndTransitionHandler(),
@@ -63,7 +64,7 @@ inline fun <reified NavTarget : Any, State> ParentNode<NavTarget>.Children(
     }
 }
 
-class ChildrenTransitionScope<T : Any, S>(
+class ChildrenTransitionScope<T : Parcelable, S : Parcelable>(
     private val transitionHandler: TransitionHandler<T, S>,
     private val transitionParams: TransitionParams,
     private val navModel: NavModel<T, S>

libraries/core/src/main/kotlin/com/bumble/appyx/core/lifecycle/ChildNodeLifecycleManager.kt

@@ -1,5 +1,6 @@
 package com.bumble.appyx.core.lifecycle
 
+import android.os.Parcelable
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleRegistry
 import com.bumble.appyx.core.children.ChildEntry
@@ -23,7 +24,7 @@ import kotlinx.coroutines.launch
  * Hosts [LifecycleRegistry] to manage the current node lifecycle
  * and updates lifecycle of children nodes when updated.
  */
-internal class ChildNodeLifecycleManager<NavTarget>(
+internal class ChildNodeLifecycleManager<NavTarget : Parcelable>(
     private val navModel: NavModel<NavTarget, *>,
     private val children: StateFlow<ChildEntryMap<NavTarget>>,
     private val coroutineScope: CoroutineScope,
@@ -86,7 +87,7 @@ internal class ChildNodeLifecycleManager<NavTarget>(
         }
     }
 
-    private fun <NavTarget> Flow<NavModelAdapter.ScreenState<NavTarget, *>>.keys() =
+    private fun <NavTarget : Parcelable> Flow<NavModelAdapter.ScreenState<NavTarget, *>>.keys() =
         this
             .map { screenState ->
                 ScreenState(
@@ -100,7 +101,7 @@ internal class ChildNodeLifecycleManager<NavTarget>(
         nodeOrNull?.updateLifecycleState(state)
     }
 
-    private data class ScreenState<NavTarget>(
+    private data class ScreenState<NavTarget : Parcelable>(
         val onScreen: List<NavKey<NavTarget>> = emptyList(),
         val offScreen: List<NavKey<NavTarget>> = emptyList(),
     )

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/BaseNavModel.kt

@@ -1,5 +1,6 @@
 package com.bumble.appyx.core.navigation
 
+import android.os.Parcelable
 import androidx.activity.OnBackPressedCallback
 import com.bumble.appyx.core.mapState
 import com.bumble.appyx.core.navigation.backpresshandlerstrategies.BackPressHandlerStrategy
@@ -28,7 +29,7 @@ import kotlin.coroutines.EmptyCoroutineContext
  *
  * If more granular configuration is required, you should inherit NavModel interface instead.
  */
-abstract class BaseNavModel<NavTarget, State>(
+abstract class BaseNavModel<NavTarget : Parcelable, State : Parcelable>(
     private val backPressHandler: BackPressHandlerStrategy<NavTarget, State> = DontHandleBackPress(),
     private val operationStrategy: OperationStrategy<NavTarget, State> = ExecuteImmediately(),
     private val screenResolver: OnScreenStateResolver<State>,

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/EmptyNavModel.kt

@@ -1,17 +1,18 @@
 package com.bumble.appyx.core.navigation
 
+import android.os.Parcelable
 import com.bumble.appyx.core.navigation.onscreen.OnScreenStateResolver
 
 /**
  * An implementation of a NavModel that won't add any children.
  * This is potentially useful if your ParentNode only uses
  * [com.bumble.appyx.core.navigation.model.permanent.PermanentNavModel]
  */
-class EmptyNavModel<NavTarget, State> : BaseNavModel<NavTarget, State>(
+class EmptyNavModel<NavTarget : Parcelable> : BaseNavModel<NavTarget, EmptyState>(
     savedStateMap = null,
     finalState = null,
     screenResolver = OnScreenStateResolver { true }
 ) {
-    override val initialElements: NavElements<NavTarget, State>
+    override val initialElements: NavElements<NavTarget, EmptyState>
         get() = emptyList()
 }

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/EmptyState.kt

@@ -0,0 +1,12 @@
+package com.bumble.appyx.core.navigation
+
+import android.os.Parcelable
+import kotlinx.parcelize.Parcelize
+
+@Suppress("PARCELABLE_PRIMARY_CONSTRUCTOR_IS_EMPTY")
+@Parcelize
+class EmptyState internal constructor() : Parcelable {
+    companion object {
+        val INSTANCE = EmptyState()
+    }
+}

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/NavElement.kt

@@ -7,18 +7,18 @@ import kotlinx.parcelize.RawValue
 
 @Parcelize
 @Immutable
-class NavElement<NavTarget, State> private constructor(
-    val key: @RawValue NavKey<NavTarget>,
-    val fromState: @RawValue State,
-    val targetState: @RawValue State,
-    val operation: @RawValue Operation<NavTarget, State>,
+class NavElement<NavTarget : Parcelable, State : Parcelable> private constructor(
+    val key: NavKey<NavTarget>,
+    val fromState: State,
+    val targetState: State,
+    val operation: Operation<NavTarget, State>,
     val transitionHistory: List<Pair<State, State>>
 ) : Parcelable {
     constructor(
-        key: @RawValue NavKey<NavTarget>,
-        fromState: @RawValue State,
-        targetState: @RawValue State,
-        operation: @RawValue Operation<NavTarget, State>,
+        key: NavKey<NavTarget>,
+        fromState: State,
+        targetState: State,
+        operation: Operation<NavTarget, State>,
     ) : this(
         key,
         fromState,

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/NavKey.kt

@@ -8,12 +8,12 @@ import java.util.UUID
 
 @Parcelize
 @Immutable
-class NavKey<NavTarget> private constructor(
-    val navTarget: @RawValue NavTarget,
+class NavKey<NavTarget : Parcelable> private constructor(
+    val navTarget: NavTarget,
     val id: String
 ) : Parcelable {
 
-    constructor(navTarget: @RawValue NavTarget) : this(
+    constructor(navTarget: NavTarget) : this(
         navTarget = navTarget,
         id = UUID.randomUUID().toString()
     )

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/NavModel.kt

@@ -1,13 +1,14 @@
 package com.bumble.appyx.core.navigation
 
+import android.os.Parcelable
 import androidx.compose.runtime.Stable
 import com.bumble.appyx.core.plugin.BackPressHandler
 import com.bumble.appyx.core.plugin.SavesInstanceState
 import com.bumble.appyx.core.plugin.UpNavigationHandler
 import kotlinx.coroutines.flow.StateFlow
 
 @Stable
-interface NavModel<NavTarget, State> : NavModelAdapter<NavTarget, State>,
+interface NavModel<NavTarget : Parcelable, State : Parcelable> : NavModelAdapter<NavTarget, State>,
     UpNavigationHandler,
     SavesInstanceState,
     BackPressHandler {

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/NavModelAdapter.kt

@@ -1,14 +1,15 @@
 package com.bumble.appyx.core.navigation
 
+import android.os.Parcelable
 import androidx.compose.runtime.Stable
 import kotlinx.coroutines.flow.StateFlow
 
 @Stable
-interface NavModelAdapter<NavTarget, State> {
+interface NavModelAdapter<NavTarget : Parcelable, State : Parcelable> {
 
     val screenState: StateFlow<ScreenState<NavTarget, out State>>
 
-    data class ScreenState<NavTarget, State>(
+    data class ScreenState<NavTarget : Parcelable, State : Parcelable>(
         val onScreen: NavElements<NavTarget, out State> = emptyList(),
         val offScreen: NavElements<NavTarget, out State> = emptyList(),
     )

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/Operation.kt

@@ -3,7 +3,7 @@ package com.bumble.appyx.core.navigation
 import android.os.Parcelable
 import kotlinx.parcelize.Parcelize
 
-interface Operation<NavTarget, State> :
+interface Operation<NavTarget : Parcelable, State : Parcelable> :
         (NavElements<NavTarget, State>) -> NavElements<NavTarget, State>, Parcelable {
 
     fun isApplicable(elements: NavElements<NavTarget, State>): Boolean
@@ -67,7 +67,7 @@ interface Operation<NavTarget, State> :
     }
 
     @Parcelize
-    class Noop<NavTarget, State> : Operation<NavTarget, State> {
+    class Noop<NavTarget : Parcelable, State : Parcelable> : Operation<NavTarget, State> {
 
         override fun isApplicable(elements: NavElements<NavTarget, State>) = false
 

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/backpresshandlerstrategies/BackPressHandlerStrategy.kt

@@ -1,10 +1,11 @@
 package com.bumble.appyx.core.navigation.backpresshandlerstrategies
 
+import android.os.Parcelable
 import com.bumble.appyx.core.navigation.BaseNavModel
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.StateFlow
 
-interface BackPressHandlerStrategy<NavTarget, State> {
+interface BackPressHandlerStrategy<NavTarget : Parcelable, State : Parcelable> {
 
     fun init(navModel: BaseNavModel<NavTarget, State>, scope: CoroutineScope)
 

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/backpresshandlerstrategies/BaseBackPressHandlerStrategy.kt

@@ -1,13 +1,14 @@
 package com.bumble.appyx.core.navigation.backpresshandlerstrategies
 
+import android.os.Parcelable
 import com.bumble.appyx.core.navigation.BaseNavModel
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.stateIn
 
-abstract class BaseBackPressHandlerStrategy<NavTarget, State>
+abstract class BaseBackPressHandlerStrategy<NavTarget : Parcelable, State : Parcelable>
     : BackPressHandlerStrategy<NavTarget, State> {
 
     protected lateinit var scope: CoroutineScope

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/backpresshandlerstrategies/DontHandleBackPress.kt

@@ -1,9 +1,10 @@
 package com.bumble.appyx.core.navigation.backpresshandlerstrategies
 
+import android.os.Parcelable
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flowOf
 
-class DontHandleBackPress<NavTarget, State> :
+class DontHandleBackPress<NavTarget : Parcelable, State : Parcelable> :
     BaseBackPressHandlerStrategy<NavTarget, State>() {
 
     override val canHandleBackPressFlow: Flow<Boolean> =

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/model/combined/CombinedNavModel.kt

@@ -1,5 +1,6 @@
 package com.bumble.appyx.core.navigation.model.combined
 
+import android.os.Parcelable
 import androidx.activity.OnBackPressedCallback
 import com.bumble.appyx.core.combineState
 import com.bumble.appyx.core.navigation.NavElements
@@ -14,9 +15,9 @@ import kotlinx.coroutines.cancel
 import kotlinx.coroutines.flow.StateFlow
 import kotlin.coroutines.EmptyCoroutineContext
 
-class CombinedNavModel<NavTarget>(
+class CombinedNavModel<NavTarget : Parcelable>(
     val navModels: List<NavModel<NavTarget, *>>,
-) : NavModel<NavTarget, Any?>, Destroyable {
+) : NavModel<NavTarget, Parcelable>, Destroyable {
 
     constructor(vararg navModels: NavModel<NavTarget, *>) : this(navModels.toList())
 

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/model/combined/NavModelExt.kt

@@ -1,8 +1,9 @@
 package com.bumble.appyx.core.navigation.model.combined
 
+import android.os.Parcelable
 import com.bumble.appyx.core.navigation.NavModel
 
-operator fun <NavTarget> NavModel<NavTarget, *>.plus(
+operator fun <NavTarget : Parcelable> NavModel<NavTarget, *>.plus(
     other: NavModel<NavTarget, *>,
 ): CombinedNavModel<NavTarget> {
     val currentModels = if (this is CombinedNavModel<NavTarget>) navModels else listOf(this)

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/model/permanent/PermanentElement.kt

@@ -1,5 +1,6 @@
 package com.bumble.appyx.core.navigation.model.permanent
 
+import com.bumble.appyx.core.navigation.EmptyState
 import com.bumble.appyx.core.navigation.NavElement
 
-typealias PermanentElement<T> = NavElement<T, Int>
+typealias PermanentElement<T> = NavElement<T, EmptyState>

libraries/core/src/main/kotlin/com/bumble/appyx/core/navigation/model/permanent/PermanentElements.kt

@@ -1,5 +1,6 @@
 package com.bumble.appyx.core.navigation.model.permanent
 
+import com.bumble.appyx.core.navigation.EmptyState
 import com.bumble.appyx.core.navigation.NavElements
 
-typealias PermanentElements<T> = NavElements<T, Int>
+typealias PermanentElements<T> = NavElements<T, EmptyState>