- Added shared element example without movable content

- Moved LocalMovableContentMap to Children composable and added a parameter to it.
- Added support for more movableContent API variants

libraries/core/detekt-baseline.xml

@@ -2,8 +2,8 @@
 <SmellBaseline>
   <ManuallySuppressedIssues></ManuallySuppressedIssues>
   <CurrentIssues>
+    <ID>CompositionLocalAllowlist:LocalNode.kt$LocalMovableContentMap</ID>
     <ID>CompositionLocalAllowlist:LocalNode.kt$LocalNodeTargetVisibility</ID>
-    <ID>CompositionLocalAllowlist:LocalNode.kt$LocalParentNodeMovableContent</ID>
     <ID>CompositionLocalAllowlist:LocalNode.kt$LocalSharedElementScope</ID>
   </CurrentIssues>
 </SmellBaseline>

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

@@ -28,6 +28,7 @@ import com.bumble.appyx.core.navigation.transition.TransitionBounds
 import com.bumble.appyx.core.navigation.transition.TransitionDescriptor
 import com.bumble.appyx.core.navigation.transition.TransitionHandler
 import com.bumble.appyx.core.navigation.transition.TransitionParams
+import com.bumble.appyx.core.node.LocalMovableContentMap
 import com.bumble.appyx.core.node.LocalNodeTargetVisibility
 import com.bumble.appyx.core.node.LocalSharedElementScope
 import com.bumble.appyx.core.node.ParentNode
@@ -41,6 +42,7 @@ inline fun <reified NavTarget : Any, State> ParentNode<NavTarget>.Children(
     modifier: Modifier = Modifier,
     transitionHandler: TransitionHandler<NavTarget, State> = remember { JumpToEndTransitionHandler() },
     withSharedElementTransition: Boolean = false,
+    withMovableContent: Boolean = false,
     noinline block: @Composable ChildrenTransitionScope<NavTarget, State>.() -> Unit = {
         children<NavTarget> { child ->
             child()
@@ -67,7 +69,8 @@ inline fun <reified NavTarget : Any, State> ParentNode<NavTarget>.Children(
         ) {
             CompositionLocalProvider(
                 /** LocalSharedElementScope will be consumed by children UI to apply shareElement modifier */
-                LocalSharedElementScope provides this
+                LocalSharedElementScope provides this,
+                LocalMovableContentMap provides if (withMovableContent) mutableMapOf() else null
             ) {
                 block(
                     ChildrenTransitionScope(
@@ -87,7 +90,8 @@ inline fun <reified NavTarget : Any, State> ParentNode<NavTarget>.Children(
             CompositionLocalProvider(
                 /** If sharedElement is not supported for this Node - provide null otherwise children
                  * can consume ascendant's LocalSharedElementScope */
-                LocalSharedElementScope provides null
+                LocalSharedElementScope provides null,
+                LocalMovableContentMap provides if (withMovableContent) mutableMapOf() else null
             ) {
                 block(
                     ChildrenTransitionScope(

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

@@ -2,14 +2,16 @@ package com.bumble.appyx.core.navigation.transition
 
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.movableContentOf
+import androidx.compose.runtime.movableContentWithReceiverOf
+import com.bumble.appyx.core.node.LocalMovableContentMap
 import com.bumble.appyx.core.node.LocalNodeTargetVisibility
-import com.bumble.appyx.core.node.LocalParentNodeMovableContent
 
 
 /**
  * Returns movable content for the given key. To reuse composable across Nodes movable content
- * must to be invoked only once at any time, therefore we should return null for if the Node is
- * transitioning to an invisible target and return movable content only if the targetState is visible.
+ * must to be invoked only once at any time, therefore we should return null for the case when the
+ * Node is transitioning to an invisible target and return movable content only if the targetState
+ * is visible.
  *
  * Example: ParentNode (P) has BackStack with one Active Node (A). We push Node (B) to the BackStack,
  * and we want to move content from Node (A) to Node (B). Node (A) is transitioning from Active to
@@ -23,14 +25,162 @@ import com.bumble.appyx.core.node.LocalParentNodeMovableContent
 @Composable
 fun localMovableContentWithTargetVisibility(
     key: Any,
-    defaultValue: @Composable () -> Unit
+    content: @Composable () -> Unit
 ): (@Composable () -> Unit)? {
     if (!LocalNodeTargetVisibility.current) return null
-    val movableContentMap = LocalParentNodeMovableContent.current
+    val movableContentMap = retrieveMovableContentMap()
     return movableContentMap.getOrPut(key) {
         movableContentOf {
-            defaultValue()
+            content()
         }
+    } as? @Composable () -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+@Composable
+fun <P> localMovableContentWithTargetVisibility(
+    key: Any,
+    content: @Composable (P) -> Unit
+): (@Composable (P) -> Unit)? {
+    if (!LocalNodeTargetVisibility.current) return null
+    val movableContentMap = retrieveMovableContentMap()
+    return movableContentMap.getOrPut(key) {
+        movableContentOf<P> {
+            content(it)
+        }
+    } as? @Composable (P) -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+
+@Composable
+fun <P1, P2> localMovableContentWithTargetVisibility(
+    key: Any,
+    content: @Composable (P1, P2) -> Unit
+): (@Composable (P1, P2) -> Unit)? {
+    if (!LocalNodeTargetVisibility.current) return null
+    val movableContentMap = retrieveMovableContentMap()
+    return movableContentMap.getOrPut(key) {
+        movableContentOf<P1, P2> { p1, p2 ->
+            content(p1, p2)
+        }
+    } as? @Composable (P1, P2) -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+@Composable
+fun <P1, P2, P3> localMovableContentWithTargetVisibility(
+    key: Any,
+    content: @Composable (P1, P2, P3) -> Unit
+): (@Composable (P1, P2, P3) -> Unit)? {
+    if (!LocalNodeTargetVisibility.current) return null
+    val movableContentMap = retrieveMovableContentMap()
+    return movableContentMap.getOrPut(key) {
+        movableContentOf<P1, P2, P3> { p1, p2, p3 ->
+            content(p1, p2, p3)
+        }
+    } as? @Composable (P1, P2, P3) -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+@Composable
+fun <P1, P2, P3, P4> localMovableContentWithTargetVisibility(
+    key: Any,
+    content: @Composable (P1, P2, P3, P4) -> Unit
+): (@Composable (P1, P2, P3, P4) -> Unit)? {
+    if (!LocalNodeTargetVisibility.current) return null
+    val movableContentMap = retrieveMovableContentMap()
+    return movableContentMap.getOrPut(key) {
+        movableContentOf<P1, P2, P3, P4> { p1, p2, p3, p4 ->
+            content(p1, p2, p3, p4)
+        }
+    } as? @Composable (P1, P2, P3, P4) -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+@Composable
+fun <R> localMovableContentWithReceiverAndTargetVisibility(
+    key: Any,
+    content: @Composable R.() -> Unit
+): (@Composable R.() -> Unit)? {
+    if (!LocalNodeTargetVisibility.current) return null
+    val movableContentMap = retrieveMovableContentMap()
+    return movableContentMap.getOrPut(key) {
+        movableContentWithReceiverOf<R> {
+            this.content()
+        }
+    } as? @Composable R.() -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+@Composable
+fun <R, P> localMovableContentWithReceiverAndTargetVisibility(
+    key: Any,
+    content: @Composable R.(P) -> Unit
+): (@Composable R.(P) -> Unit)? {
+    if (!LocalNodeTargetVisibility.current) return null
+    val movableContentMap = retrieveMovableContentMap()
+    return movableContentMap.getOrPut(key) {
+        movableContentWithReceiverOf<R, P> { p ->
+            this.content(p)
+        }
+    } as? @Composable R.(P) -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+@Composable
+fun <R, P1, P2> localMovableContentWithReceiverAndTargetVisibility(
+    key: Any,
+    content: @Composable R.(P1, P2) -> Unit
+): (@Composable R.(P1, P2) -> Unit)? {
+    if (!LocalNodeTargetVisibility.current) return null
+    val movableContentMap = retrieveMovableContentMap()
+    return movableContentMap.getOrPut(key) {
+        movableContentWithReceiverOf<R, P1, P2> { p1, p2 ->
+            this.content(p1, p2)
+        }
+    } as? @Composable R.(P1, P2) -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+@Composable
+fun <R, P1, P2, P3> localMovableContentWithReceiverAndTargetVisibility(
+    key: Any,
+    content: @Composable R.(P1, P2, P3) -> Unit
+): (@Composable R.(P1, P2, P3) -> Unit)? {
+    if (!LocalNodeTargetVisibility.current) return null
+    val movableContentMap = retrieveMovableContentMap()
+    return movableContentMap.getOrPut(key) {
+        movableContentWithReceiverOf<R, P1, P2, P3> { p1, p2, p3 ->
+            this.content(p1, p2, p3)
+        }
+    } as? @Composable R.(P1, P2, P3) -> Unit ?: throw IllegalStateException(
+        "Movable content for key $key is not of the expected type." +
+                " The same $key has been used for different types of content."
+    )
+}
+
+@Composable
+private fun retrieveMovableContentMap(): MutableMap<Any, Any> {
+    return requireNotNull(LocalMovableContentMap.current) {
+        "LocalMovableContentMap not found in the composition hierarchy." +
+                " Please use withMovableContent = true on Children composable."
     }
 }
 

libraries/core/src/main/kotlin/com/bumble/appyx/core/node/LocalNode.kt

@@ -2,7 +2,6 @@ package com.bumble.appyx.core.node
 
 import androidx.compose.animation.ExperimentalSharedTransitionApi
 import androidx.compose.animation.SharedTransitionScope
-import androidx.compose.runtime.Composable
 import androidx.compose.runtime.compositionLocalOf
 
 val LocalNode = compositionLocalOf<Node?> { null }
@@ -18,5 +17,7 @@ val LocalSharedElementScope = compositionLocalOf<SharedTransitionScope?> { null
  */
 val LocalNodeTargetVisibility = compositionLocalOf { false }
 
-val LocalParentNodeMovableContent =
-    compositionLocalOf<MutableMap<Any, @Composable () -> Unit>> { mutableMapOf() }
+/**
+ * Represents the map from which movable content can be retrieved.
+ */
+val LocalMovableContentMap = compositionLocalOf<MutableMap<Any, Any>?> { null }

libraries/core/src/main/kotlin/com/bumble/appyx/core/node/Node.kt

@@ -123,18 +123,11 @@ open class Node @VisibleForTesting internal constructor(
             LocalNode provides this,
             LocalLifecycleOwner provides this,
         ) {
-            DerivedSetup {
-                HandleBackPress()
-                View(modifier)
-            }
+            HandleBackPress()
+            View(modifier)
         }
     }
 
-    @Composable
-    protected open fun DerivedSetup(innerContent: @Composable () -> Unit) {
-        innerContent()
-    }
-
     @Composable
     private fun HandleBackPress() {
         // can't use BackHandler Composable because plugins provide OnBackPressedCallback which is not observable

libraries/core/src/main/kotlin/com/bumble/appyx/core/node/ParentNode.kt

@@ -2,8 +2,6 @@ package com.bumble.appyx.core.node
 
 import androidx.annotation.CallSuper
 import androidx.annotation.VisibleForTesting
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.Stable
 import androidx.lifecycle.DefaultLifecycleObserver
 import androidx.lifecycle.Lifecycle
@@ -76,15 +74,6 @@ abstract class ParentNode<NavTarget : Any>(
         manageTransitions()
     }
 
-    @Composable
-    final override fun DerivedSetup(innerContent: @Composable () -> Unit) {
-        CompositionLocalProvider(
-            LocalParentNodeMovableContent provides mutableMapOf()
-        ) {
-            innerContent()
-        }
-    }
-
     fun childOrCreate(navKey: NavKey<NavTarget>): ChildEntry.Initialized<NavTarget> =
         childNodeCreationManager.childOrCreate(navKey)
 

samples/sandbox/src/main/kotlin/com/bumble/appyx/sandbox/client/container/ContainerNode.kt

@@ -39,7 +39,8 @@ import com.bumble.appyx.sandbox.client.container.ContainerNode.NavTarget.MviCore
 import com.bumble.appyx.sandbox.client.container.ContainerNode.NavTarget.MviCoreLeafExample
 import com.bumble.appyx.sandbox.client.container.ContainerNode.NavTarget.NavModelExamples
 import com.bumble.appyx.sandbox.client.container.ContainerNode.NavTarget.Picker
-import com.bumble.appyx.sandbox.client.container.ContainerNode.NavTarget.SharedElementFaderExample
+import com.bumble.appyx.sandbox.client.container.ContainerNode.NavTarget.SharedElementExample
+import com.bumble.appyx.sandbox.client.container.ContainerNode.NavTarget.SharedElementWithMovableContentExample
 import com.bumble.appyx.sandbox.client.customisations.CustomisationsNode
 import com.bumble.appyx.sandbox.client.explicitnavigation.ExplicitNavigationExampleActivity
 import com.bumble.appyx.sandbox.client.integrationpoint.IntegrationPointExampleNode
@@ -48,7 +49,7 @@ import com.bumble.appyx.sandbox.client.list.LazyListContainerNode
 import com.bumble.appyx.sandbox.client.mvicoreexample.MviCoreExampleBuilder
 import com.bumble.appyx.sandbox.client.mvicoreexample.leaf.MviCoreLeafBuilder
 import com.bumble.appyx.sandbox.client.navmodels.NavModelExamplesNode
-import com.bumble.appyx.sandbox.client.sharedelement.SharedElementWithMovableContentExampleNode
+import com.bumble.appyx.sandbox.client.sharedelement.SharedElementExampleNode
 import com.bumble.appyx.utils.customisations.NodeCustomisation
 import kotlinx.parcelize.Parcelize
 
@@ -75,7 +76,10 @@ class ContainerNode internal constructor(
         object LazyExamples : NavTarget()
 
         @Parcelize
-        object SharedElementFaderExample : NavTarget()
+        object SharedElementExample : NavTarget()
+
+        @Parcelize
+        object SharedElementWithMovableContentExample : NavTarget()
 
         @Parcelize
         object IntegrationPointExample : NavTarget()
@@ -101,12 +105,21 @@ class ContainerNode internal constructor(
         when (navTarget) {
             is Picker -> node(buildContext) { modifier -> ExamplesList(modifier) }
             is NavModelExamples -> NavModelExamplesNode(buildContext)
-            is SharedElementFaderExample -> SharedElementWithMovableContentExampleNode(buildContext)
+            is SharedElementExample -> SharedElementExampleNode(buildContext)
+            is SharedElementWithMovableContentExample -> SharedElementExampleNode(
+                buildContext,
+                hasMovableContent = true
+            )
+
             is LazyExamples -> LazyListContainerNode(buildContext)
             is IntegrationPointExample -> IntegrationPointExampleNode(buildContext)
             is BlockerExample -> BlockerExampleNode(buildContext)
             is Customisations -> CustomisationsNode(buildContext)
-            is MviCoreExample -> MviCoreExampleBuilder().build(buildContext, "MVICore initial state")
+            is MviCoreExample -> MviCoreExampleBuilder().build(
+                buildContext,
+                "MVICore initial state"
+            )
+
             is MviCoreLeafExample -> MviCoreLeafBuilder().build(
                 buildContext,
                 "MVICore leaf initial state"
@@ -143,7 +156,12 @@ class ContainerNode internal constructor(
                 label?.let {
                     Text(it, textAlign = TextAlign.Center)
                 }
-                TextButton("Shared element with movable content") { backStack.push(SharedElementFaderExample) }
+                TextButton("Shared element ") { backStack.push(SharedElementExample) }
+                TextButton("Shared element with movable content") {
+                    backStack.push(
+                        SharedElementWithMovableContentExample
+                    )
+                }
                 TextButton("NavModel Examples") { backStack.push(NavModelExamples) }
                 TextButton("Customisations Example") { backStack.push(Customisations) }
                 TextButton("Explicit navigation example") {