Fix reset root

backstack/api/android/backstack.api

@@ -1,7 +1,9 @@
 public abstract interface class com/slack/circuit/backstack/BackStack : java/lang/Iterable, kotlin/jvm/internal/markers/KMappedMarker {
 	public abstract fun containsRecord (Lcom/slack/circuit/backstack/BackStack$Record;Z)Z
+	public abstract fun getRootRecord ()Lcom/slack/circuit/backstack/BackStack$Record;
 	public abstract fun getSize ()I
 	public abstract fun getTopRecord ()Lcom/slack/circuit/backstack/BackStack$Record;
+	public abstract fun isRecordReachable (Ljava/lang/String;IZ)Z
 	public abstract fun pop (Lcom/slack/circuit/runtime/screen/PopResult;)Lcom/slack/circuit/backstack/BackStack$Record;
 	public static synthetic fun pop$default (Lcom/slack/circuit/backstack/BackStack;Lcom/slack/circuit/runtime/screen/PopResult;ILjava/lang/Object;)Lcom/slack/circuit/backstack/BackStack$Record;
 	public fun popUntil (Lkotlin/jvm/functions/Function1;)Lkotlinx/collections/immutable/ImmutableList;
@@ -50,9 +52,12 @@ public final class com/slack/circuit/backstack/SaveableBackStack : com/slack/cir
 	public fun <init> (Lcom/slack/circuit/runtime/screen/Screen;)V
 	public synthetic fun containsRecord (Lcom/slack/circuit/backstack/BackStack$Record;Z)Z
 	public fun containsRecord (Lcom/slack/circuit/backstack/SaveableBackStack$Record;Z)Z
+	public synthetic fun getRootRecord ()Lcom/slack/circuit/backstack/BackStack$Record;
+	public fun getRootRecord ()Lcom/slack/circuit/backstack/SaveableBackStack$Record;
 	public fun getSize ()I
 	public synthetic fun getTopRecord ()Lcom/slack/circuit/backstack/BackStack$Record;
 	public fun getTopRecord ()Lcom/slack/circuit/backstack/SaveableBackStack$Record;
+	public fun isRecordReachable (Ljava/lang/String;IZ)Z
 	public fun iterator ()Ljava/util/Iterator;
 	public synthetic fun pop (Lcom/slack/circuit/runtime/screen/PopResult;)Lcom/slack/circuit/backstack/BackStack$Record;
 	public fun pop (Lcom/slack/circuit/runtime/screen/PopResult;)Lcom/slack/circuit/backstack/SaveableBackStack$Record;

backstack/api/backstack.klib.api

@@ -15,12 +15,15 @@ abstract fun interface com.slack.circuit.backstack/ProvidedValues { // com.slack
 }
 
 abstract interface <#A: com.slack.circuit.backstack/BackStack.Record> com.slack.circuit.backstack/BackStack : kotlin.collections/Iterable<#A> { // com.slack.circuit.backstack/BackStack|null[0]
+    abstract val rootRecord // com.slack.circuit.backstack/BackStack.rootRecord|{}rootRecord[0]
+        abstract fun <get-rootRecord>(): #A? // com.slack.circuit.backstack/BackStack.rootRecord.<get-rootRecord>|<get-rootRecord>(){}[0]
     abstract val size // com.slack.circuit.backstack/BackStack.size|{}size[0]
         abstract fun <get-size>(): kotlin/Int // com.slack.circuit.backstack/BackStack.size.<get-size>|<get-size>(){}[0]
     abstract val topRecord // com.slack.circuit.backstack/BackStack.topRecord|{}topRecord[0]
         abstract fun <get-topRecord>(): #A? // com.slack.circuit.backstack/BackStack.topRecord.<get-topRecord>|<get-topRecord>(){}[0]
 
     abstract fun containsRecord(#A, kotlin/Boolean): kotlin/Boolean // com.slack.circuit.backstack/BackStack.containsRecord|containsRecord(1:0;kotlin.Boolean){}[0]
+    abstract fun isRecordReachable(kotlin/String, kotlin/Int, kotlin/Boolean): kotlin/Boolean // com.slack.circuit.backstack/BackStack.isRecordReachable|isRecordReachable(kotlin.String;kotlin.Int;kotlin.Boolean){}[0]
     abstract fun pop(com.slack.circuit.runtime.screen/PopResult? = ...): #A? // com.slack.circuit.backstack/BackStack.pop|pop(com.slack.circuit.runtime.screen.PopResult?){}[0]
     abstract fun push(#A, kotlin/String? = ...): kotlin/Boolean // com.slack.circuit.backstack/BackStack.push|push(1:0;kotlin.String?){}[0]
     abstract fun push(com.slack.circuit.runtime.screen/Screen, kotlin/String? = ...): kotlin/Boolean // com.slack.circuit.backstack/BackStack.push|push(com.slack.circuit.runtime.screen.Screen;kotlin.String?){}[0]
@@ -51,12 +54,15 @@ final class com.slack.circuit.backstack/SaveableBackStack : com.slack.circuit.ba
     constructor <init>(com.slack.circuit.backstack/SaveableBackStack.Record) // com.slack.circuit.backstack/SaveableBackStack.<init>|<init>(com.slack.circuit.backstack.SaveableBackStack.Record){}[0]
     constructor <init>(com.slack.circuit.runtime.screen/Screen) // com.slack.circuit.backstack/SaveableBackStack.<init>|<init>(com.slack.circuit.runtime.screen.Screen){}[0]
 
+    final val rootRecord // com.slack.circuit.backstack/SaveableBackStack.rootRecord|{}rootRecord[0]
+        final fun <get-rootRecord>(): com.slack.circuit.backstack/SaveableBackStack.Record? // com.slack.circuit.backstack/SaveableBackStack.rootRecord.<get-rootRecord>|<get-rootRecord>(){}[0]
     final val size // com.slack.circuit.backstack/SaveableBackStack.size|{}size[0]
         final fun <get-size>(): kotlin/Int // com.slack.circuit.backstack/SaveableBackStack.size.<get-size>|<get-size>(){}[0]
     final val topRecord // com.slack.circuit.backstack/SaveableBackStack.topRecord|{}topRecord[0]
         final fun <get-topRecord>(): com.slack.circuit.backstack/SaveableBackStack.Record? // com.slack.circuit.backstack/SaveableBackStack.topRecord.<get-topRecord>|<get-topRecord>(){}[0]
 
     final fun containsRecord(com.slack.circuit.backstack/SaveableBackStack.Record, kotlin/Boolean): kotlin/Boolean // com.slack.circuit.backstack/SaveableBackStack.containsRecord|containsRecord(com.slack.circuit.backstack.SaveableBackStack.Record;kotlin.Boolean){}[0]
+    final fun isRecordReachable(kotlin/String, kotlin/Int, kotlin/Boolean): kotlin/Boolean // com.slack.circuit.backstack/SaveableBackStack.isRecordReachable|isRecordReachable(kotlin.String;kotlin.Int;kotlin.Boolean){}[0]
     final fun iterator(): kotlin.collections/Iterator<com.slack.circuit.backstack/SaveableBackStack.Record> // com.slack.circuit.backstack/SaveableBackStack.iterator|iterator(){}[0]
     final fun pop(com.slack.circuit.runtime.screen/PopResult?): com.slack.circuit.backstack/SaveableBackStack.Record? // com.slack.circuit.backstack/SaveableBackStack.pop|pop(com.slack.circuit.runtime.screen.PopResult?){}[0]
     final fun push(com.slack.circuit.backstack/SaveableBackStack.Record, kotlin/String?): kotlin/Boolean // com.slack.circuit.backstack/SaveableBackStack.push|push(com.slack.circuit.backstack.SaveableBackStack.Record;kotlin.String?){}[0]

backstack/api/jvm/backstack.api

@@ -1,7 +1,9 @@
 public abstract interface class com/slack/circuit/backstack/BackStack : java/lang/Iterable, kotlin/jvm/internal/markers/KMappedMarker {
 	public abstract fun containsRecord (Lcom/slack/circuit/backstack/BackStack$Record;Z)Z
+	public abstract fun getRootRecord ()Lcom/slack/circuit/backstack/BackStack$Record;
 	public abstract fun getSize ()I
 	public abstract fun getTopRecord ()Lcom/slack/circuit/backstack/BackStack$Record;
+	public abstract fun isRecordReachable (Ljava/lang/String;IZ)Z
 	public abstract fun pop (Lcom/slack/circuit/runtime/screen/PopResult;)Lcom/slack/circuit/backstack/BackStack$Record;
 	public static synthetic fun pop$default (Lcom/slack/circuit/backstack/BackStack;Lcom/slack/circuit/runtime/screen/PopResult;ILjava/lang/Object;)Lcom/slack/circuit/backstack/BackStack$Record;
 	public fun popUntil (Lkotlin/jvm/functions/Function1;)Lkotlinx/collections/immutable/ImmutableList;
@@ -50,9 +52,12 @@ public final class com/slack/circuit/backstack/SaveableBackStack : com/slack/cir
 	public fun <init> (Lcom/slack/circuit/runtime/screen/Screen;)V
 	public synthetic fun containsRecord (Lcom/slack/circuit/backstack/BackStack$Record;Z)Z
 	public fun containsRecord (Lcom/slack/circuit/backstack/SaveableBackStack$Record;Z)Z
+	public synthetic fun getRootRecord ()Lcom/slack/circuit/backstack/BackStack$Record;
+	public fun getRootRecord ()Lcom/slack/circuit/backstack/SaveableBackStack$Record;
 	public fun getSize ()I
 	public synthetic fun getTopRecord ()Lcom/slack/circuit/backstack/BackStack$Record;
 	public fun getTopRecord ()Lcom/slack/circuit/backstack/SaveableBackStack$Record;
+	public fun isRecordReachable (Ljava/lang/String;IZ)Z
 	public fun iterator ()Ljava/util/Iterator;
 	public synthetic fun pop (Lcom/slack/circuit/runtime/screen/PopResult;)Lcom/slack/circuit/backstack/BackStack$Record;
 	public fun pop (Lcom/slack/circuit/runtime/screen/PopResult;)Lcom/slack/circuit/backstack/SaveableBackStack$Record;

backstack/src/commonMain/kotlin/com/slack/circuit/backstack/BackStack.kt

@@ -35,6 +35,9 @@ public interface BackStack<R : Record> : Iterable<R> {
   /** The top-most record in the [BackStack], or `null` if the [BackStack] is empty. */
   public val topRecord: R?
 
+  /** The bottom-most record in the [BackStack], or `null` if the [BackStack] is empty. */
+  public val rootRecord: R?
+
   /**
    * Push a new [Record] onto the back stack. The new record will become the top of the stack.
    *
@@ -103,6 +106,20 @@ public interface BackStack<R : Record> : Iterable<R> {
    */
   public fun containsRecord(record: R, includeSaved: Boolean): Boolean
 
+  /**
+   * Whether a record with the given [key] is reachable within the back stack or saved state.
+   * Reachable means that it is either currently in the visible back stack or if we popped `depth`
+   * times, it would be found.
+   *
+   * @param key The record's key to look for.
+   * @param depth How many records to consider popping from the top of the stack before considering
+   *   the key unreachable. A depth of zero means only check the current visible stack. A depth of 1
+   *   means check the current visible stack plus one record popped off the top, and so on.
+   * @param includeSaved Whether to also check if the record is contained by any saved back stack
+   *   state. See [saveState].
+   */
+  public fun isRecordReachable(key: String, depth: Int, includeSaved: Boolean): Boolean
+
   @Stable
   public interface Record {
     /**

backstack/src/commonMain/kotlin/com/slack/circuit/backstack/SaveableBackStack.kt

@@ -24,6 +24,7 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.snapshots.Snapshot
 import com.slack.circuit.runtime.screen.PopResult
 import com.slack.circuit.runtime.screen.Screen
+import kotlin.math.min
 import kotlin.uuid.ExperimentalUuidApi
 import kotlin.uuid.Uuid
 import kotlinx.coroutines.CompletableDeferred
@@ -92,6 +93,9 @@ internal constructor(
   public override val topRecord: Record?
     get() = entryList.firstOrNull()
 
+  override val rootRecord: Record?
+    get() = entryList.lastOrNull()
+
   public override fun push(screen: Screen, resultKey: String?): Boolean {
     return push(screen, emptyMap(), resultKey)
   }
@@ -154,6 +158,24 @@ internal constructor(
     return false
   }
 
+  override fun isRecordReachable(key: String, depth: Int, includeSaved: Boolean): Boolean {
+    if (depth < 0) return false
+    // Check in the current entry list
+    for (i in 0 until min(depth, entryList.size)) {
+      if (entryList[i].key == key) return true
+    }
+    // If includeSaved, check saved backstack states too
+    if (includeSaved && stateStore.isNotEmpty()) {
+      val storedValues = stateStore.values
+      for ((i, stored) in storedValues.withIndex()) {
+        if (i >= depth) break
+        // stored can mutate, so safely get the record.
+        if (stored.getOrNull(i)?.key == key) return true
+      }
+    }
+    return false
+  }
+
   public data class Record(
     override val screen: Screen,
     val args: Map<String, Any?> = emptyMap(),

circuit-foundation/api/android/circuit-foundation.api

@@ -77,12 +77,6 @@ public final class com/slack/circuit/foundation/ComposableSingletons$CircuitKt {
 	public final fun getLambda-1$circuit_foundation_release ()Lkotlin/jvm/functions/Function4;
 }
 
-public final class com/slack/circuit/foundation/ComposableSingletons$NavigableCircuitContentKt {
-	public static final field INSTANCE Lcom/slack/circuit/foundation/ComposableSingletons$NavigableCircuitContentKt;
-	public fun <init> ()V
-	public final fun getLambda-1$circuit_foundation_release ()Lkotlin/jvm/functions/Function4;
-}
-
 public final class com/slack/circuit/foundation/ContentProviderState {
 	public static final field $stable I
 	public fun <init> (Landroidx/compose/runtime/saveable/SaveableStateHolder;Lcom/slack/circuit/retained/RetainedStateHolder;Lcom/slack/circuit/backstack/BackStack;Lcom/slack/circuit/runtime/Navigator;Lcom/slack/circuit/foundation/Circuit;Lkotlin/jvm/functions/Function4;)V

circuit-foundation/api/jvm/circuit-foundation.api

@@ -77,12 +77,6 @@ public final class com/slack/circuit/foundation/ComposableSingletons$CircuitKt {
 	public final fun getLambda-1$circuit_foundation ()Lkotlin/jvm/functions/Function4;
 }
 
-public final class com/slack/circuit/foundation/ComposableSingletons$NavigableCircuitContentKt {
-	public static final field INSTANCE Lcom/slack/circuit/foundation/ComposableSingletons$NavigableCircuitContentKt;
-	public fun <init> ()V
-	public final fun getLambda-1$circuit_foundation ()Lkotlin/jvm/functions/Function4;
-}
-
 public final class com/slack/circuit/foundation/ContentProviderState {
 	public static final field $stable I
 	public fun <init> (Landroidx/compose/runtime/saveable/SaveableStateHolder;Lcom/slack/circuit/retained/RetainedStateHolder;Lcom/slack/circuit/backstack/BackStack;Lcom/slack/circuit/runtime/Navigator;Lcom/slack/circuit/foundation/Circuit;Lkotlin/jvm/functions/Function4;)V

circuit-foundation/src/androidInstrumentedTest/kotlin/com/slack/circuit/foundation/SaveableRestRootTest.kt

@@ -50,8 +50,18 @@ class SaveableRestRootTest {
       mainClock.autoAdvance = false
       navigator.resetRoot(newRoot = TestScreen.ScreenA, saveState = true, restoreState = true)
       mainClock.advanceTimeByFrame()
-      navigator.resetRoot(newRoot = TestScreen.ScreenB, saveState = true, restoreState = true)
-      mainClock.advanceTimeByFrame()
+      repeat(10) {
+        navigator.resetRoot(newRoot = TestScreen.ScreenB, saveState = true, restoreState = true)
+        mainClock.advanceTimeByFrame()
+        navigator.resetRoot(newRoot = TestScreen.ScreenA, saveState = true, restoreState = true)
+        mainClock.advanceTimeByFrame()
+        navigator.resetRoot(newRoot = TestScreen.ScreenC, saveState = true, restoreState = true)
+        mainClock.advanceTimeByFrame()
+        navigator.resetRoot(newRoot = TestScreen.ScreenA, saveState = true, restoreState = true)
+        mainClock.advanceTimeByFrame()
+        navigator.resetRoot(newRoot = TestScreen.ScreenB, saveState = true, restoreState = true)
+        mainClock.advanceTimeByFrame()
+      }
       navigator.resetRoot(newRoot = TestScreen.ScreenA, saveState = true, restoreState = true)
       mainClock.autoAdvance = true
       onNodeWithTag(TAG_LABEL).assertTextEquals(TestScreen.ScreenA.label)

circuit-foundation/src/commonMain/kotlin/com/slack/circuit/foundation/NavigableCircuitContent.kt

@@ -32,6 +32,7 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.movableContentOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.runtime.saveable.SaveableStateHolder
 import androidx.compose.runtime.saveable.rememberSaveableStateHolder
 import androidx.compose.runtime.setValue
@@ -59,7 +60,9 @@ import com.slack.circuit.runtime.Navigator
 import com.slack.circuit.runtime.screen.Screen
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.ImmutableMap
+import kotlinx.collections.immutable.persistentSetOf
 import kotlinx.collections.immutable.toImmutableList
+import kotlinx.collections.immutable.toPersistentSet
 
 @OptIn(ExperimentalCircuitApi::class)
 @Composable
@@ -142,7 +145,6 @@ public fun <R : Record> NavigableCircuitContent(
           lastUnavailableRoute = unavailableRoute
         }
     val activeContentProviders = buildCircuitContentProviders(backStack = backStack)
-
     navDecoration.DecoratedContent(activeContentProviders, backStack.size, modifier) { provider ->
       val record = provider.record
 
@@ -188,22 +190,48 @@ private fun <R : Record> buildCircuitContentProviders(
   backStack: BackStack<R>
 ): ImmutableList<RecordContentProvider<R>> {
   val previousContentProviders = remember { mutableMapOf<String, RecordContentProvider<R>>() }
+  val activeRecordKeys = remember { mutableSetOf<String>() }
+  val recordKeys by
+    remember { mutableStateOf(persistentSetOf<String>()) }
+      .apply { value = backStack.map { it.key }.toPersistentSet() }
+  val latestBackStack by rememberUpdatedState(backStack)
+  DisposableEffect(recordKeys) {
+    // Delay cleanup until the next backstack change.
+    // - Any record in composition is considered active
+    // - Any record in the backstack can be shown by a decorator
+    // - Any reachable record can be shown on a root reset
+    val contentNotInBackStack =
+      previousContentProviders.keys.filterNot {
+        it in activeRecordKeys ||
+          it in recordKeys ||
+          latestBackStack.isRecordReachable(key = it, depth = 1, includeSaved = true)
+      }
+    onDispose {
+      // Only remove the keys that are no longer in the backstack or composition.
+      contentNotInBackStack
+        .filterNot {
+          latestBackStack.isRecordReachable(key = it, depth = 1, includeSaved = true) ||
+            it in activeRecordKeys
+        }
+        .forEach { previousContentProviders.remove(it) }
+    }
+  }
   return backStack
     .map { record ->
       // Query the previous content providers map, so that we use the same
       // RecordContentProvider instances across calls.
       previousContentProviders.getOrPut(record.key) {
-        RecordContentProvider(record = record, content = createRecordContent())
+        RecordContentProvider(
+          record = record,
+          content =
+            createRecordContent(
+              onActive = { activeRecordKeys.add(record.key) },
+              onDispose = { activeRecordKeys.remove(record.key) },
+            ),
+        )
       }
     }
     .toImmutableList()
-    .also { list ->
-      // Update the previousContentProviders map so we can reference it on the next call
-      previousContentProviders.clear()
-      for (provider in list) {
-        previousContentProviders[provider.record.key] = provider
-      }
-    }
 }
 
 @Stable
@@ -238,12 +266,11 @@ public class ContentProviderState<R : Record>(
   }
 }
 
-private fun <R : Record> createRecordContent() =
+private fun <R : Record> createRecordContent(onActive: () -> Unit, onDispose: () -> Unit) =
   movableContentOf<R, ContentProviderState<R>> { record, contentProviderState ->
     with(contentProviderState) {
       val lifecycle =
         remember { MutableRecordLifecycle() }.apply { isActive = lastBackStack.topRecord == record }
-
       saveableStateHolder.SaveableStateProvider(record.registryKey) {
         // Provides a RetainedStateRegistry that is maintained independently for each record while
         // the record exists in the back stack.
@@ -269,6 +296,11 @@ private fun <R : Record> createRecordContent() =
         }
       }
     }
+    // Track if the movableContent is still active to correctly reuse it and not create a new one.
+    DisposableEffect(Unit) {
+      onActive()
+      onDispose { onDispose() }
+    }
   }
 
 /** The maximum radix available for conversion to and from strings. */

circuitx/gesture-navigation/src/commonMain/kotlin/com/slack/circuitx/gesturenavigation/TransitionUtils.kt → circuitx/gesture-navigation/src/commonMain/kotlin/com/slack/circuitx/gesturenavigation/GestureNavTransitionHolder.kt

@@ -2,19 +2,11 @@
 // SPDX-License-Identifier: Apache-2.0
 package com.slack.circuitx.gesturenavigation
 
-import androidx.compose.animation.core.Transition
 import androidx.compose.runtime.Immutable
 import com.slack.circuit.backstack.NavArgument
 import com.slack.circuit.foundation.animation.AnimatedNavState
 import com.slack.circuit.runtime.screen.Screen
 
-internal fun <T> Transition<T>.isStateBeingAnimated(equals: (T) -> Boolean): Boolean {
-  return isRunning && (equals(currentState) || equals(targetState))
-}
-
-internal val Transition<*>.isPending: Boolean
-  get() = this.currentState != this.targetState
-
 /**
  * A holder class used by the `AnimatedContent` composables. This enables us to pass through all of
  * the necessary information as an argument, which is optimal for `AnimatedContent`.

samples/star/build.gradle.kts

@@ -171,11 +171,16 @@ kotlin {
       val androidInstrumentedTest by getting {
         // Annoyingly cannot depend on commonJvmTest
         dependencies {
+          implementation(libs.androidx.activity.compose)
           implementation(libs.androidx.compose.ui.testing.junit)
           implementation(libs.androidx.compose.ui.testing.manifest)
+          implementation(libs.compose.ui.testing.junit)
+          implementation(libs.coroutines.android)
           implementation(libs.coroutines.test)
+          implementation(libs.junit)
           implementation(libs.leakcanary.android.instrumentation)
           implementation(projects.circuitTest)
+          implementation(projects.internalTestUtils)
           implementation(projects.samples.star.coilRule)
         }
       }