[WIP] Make the bottom nav sample adaptive

.gitignore

@@ -70,3 +70,7 @@ fastlane/report.xml
 # Xcode automatically generates this directory with a .xcworkspacedata file and xcuserdata
 # hence it is not needed unless you have added a package configuration file to your project
 # .swiftpm
+
+# AI Stuff
+/.claude/settings.local.json
+/CLAUDE.local.md

backstack/build.gradle.kts

@@ -61,7 +61,7 @@ kotlin {
         api(libs.compose.runtime)
         api(libs.compose.ui)
         api(libs.coroutines)
-        api(projects.circuitRuntimeScreen)
+        api(projects.circuitRuntime)
         implementation(libs.compose.runtime.saveable)
       }
     }

backstack/dependencies/androidReleaseRuntimeClasspath.txt

@@ -12,6 +12,8 @@ androidx.collection:collection
 androidx.compose.runtime:runtime-android
 androidx.compose.runtime:runtime-annotation-android
 androidx.compose.runtime:runtime-annotation
+androidx.compose.runtime:runtime-retain-android
+androidx.compose.runtime:runtime-retain
 androidx.compose.runtime:runtime-saveable-android
 androidx.compose.runtime:runtime-saveable
 androidx.compose.runtime:runtime
@@ -32,12 +34,17 @@ androidx.core:core-ktx
 androidx.core:core-viewtree
 androidx.core:core
 androidx.customview:customview-poolingcontainer
+androidx.documentfile:documentfile
+androidx.dynamicanimation:dynamicanimation
 androidx.emoji2:emoji2
 androidx.graphics:graphics-path
 androidx.interpolator:interpolator
+androidx.legacy:legacy-support-core-utils
 androidx.lifecycle:lifecycle-common-jvm
 androidx.lifecycle:lifecycle-common
+androidx.lifecycle:lifecycle-livedata-core-ktx
 androidx.lifecycle:lifecycle-livedata-core
+androidx.lifecycle:lifecycle-livedata
 androidx.lifecycle:lifecycle-process
 androidx.lifecycle:lifecycle-runtime-android
 androidx.lifecycle:lifecycle-runtime-compose-android
@@ -50,6 +57,9 @@ androidx.lifecycle:lifecycle-viewmodel-ktx
 androidx.lifecycle:lifecycle-viewmodel-savedstate-android
 androidx.lifecycle:lifecycle-viewmodel-savedstate
 androidx.lifecycle:lifecycle-viewmodel
+androidx.loader:loader
+androidx.localbroadcastmanager:localbroadcastmanager
+androidx.print:print
 androidx.profileinstaller:profileinstaller
 androidx.savedstate:savedstate-android
 androidx.savedstate:savedstate-compose-android
@@ -58,7 +68,11 @@ androidx.savedstate:savedstate-ktx
 androidx.savedstate:savedstate
 androidx.startup:startup-runtime
 androidx.tracing:tracing
+androidx.transition:transition
 androidx.versionedparcelable:versionedparcelable
+androidx.window:window-core-android
+androidx.window:window-core
+androidx.window:window
 com.google.guava:listenablefuture
 org.jetbrains.androidx.lifecycle:lifecycle-common
 org.jetbrains.androidx.lifecycle:lifecycle-runtime-compose

backstack/dependencies/jvmRuntimeClasspath.txt

@@ -6,6 +6,8 @@ androidx.collection:collection
 androidx.compose.runtime:runtime-annotation-jvm
 androidx.compose.runtime:runtime-annotation
 androidx.compose.runtime:runtime-desktop
+androidx.compose.runtime:runtime-retain-desktop
+androidx.compose.runtime:runtime-retain
 androidx.compose.runtime:runtime-saveable-desktop
 androidx.compose.runtime:runtime-saveable
 androidx.compose.runtime:runtime
@@ -19,6 +21,8 @@ androidx.lifecycle:lifecycle-viewmodel-desktop
 androidx.lifecycle:lifecycle-viewmodel-savedstate-desktop
 androidx.lifecycle:lifecycle-viewmodel-savedstate
 androidx.lifecycle:lifecycle-viewmodel
+androidx.navigationevent:navigationevent-desktop
+androidx.navigationevent:navigationevent
 androidx.savedstate:savedstate-compose-desktop
 androidx.savedstate:savedstate-compose
 androidx.savedstate:savedstate-desktop

backstack/src/commonJvmTest/kotlin/com/slack/circuit/backstack/RememberSaveableBackstackTest.kt

@@ -20,7 +20,7 @@ class RememberSaveableBackstackTest {
   fun backStackStartsWithRootScreen() = runTest {
     moleculeFlow(RecompositionMode.Immediate) {
         val backStack = rememberSaveableBackStack(TestScreen.ScreenA)
-        backStack.toList()
+        backStack.peekNavStack()
       }
       .test { assertEquals(awaitItem().first().screen, TestScreen.ScreenA) }
   }
@@ -52,8 +52,8 @@ class RememberSaveableBackstackTest {
         val secondStack = awaitItem()
 
         assertNotSame(firstStack, secondStack)
-        assertEquals(firstStack.toList().first().screen, TestScreen.ScreenA)
-        assertEquals(secondStack.toList().first().screen, TestScreen.ScreenB)
+        assertEquals(firstStack.peekNavStack().first().screen, TestScreen.ScreenA)
+        assertEquals(secondStack.peekNavStack().first().screen, TestScreen.ScreenB)
       }
   }
 
@@ -67,8 +67,8 @@ class RememberSaveableBackstackTest {
         val secondStack = awaitItem()
 
         assertNotSame(firstStack, secondStack)
-        assertEquals(firstStack.toList().first().screen, TestScreen.ScreenA)
-        assertEquals(secondStack.toList().first().screen, TestScreen.ScreenB)
+        assertEquals(firstStack.peekNavStack().first().screen, TestScreen.ScreenA)
+        assertEquals(secondStack.peekNavStack().first().screen, TestScreen.ScreenB)
       }
   }
 }

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

@@ -16,144 +16,17 @@
 package com.slack.circuit.backstack
 
 import androidx.compose.runtime.Stable
-import androidx.compose.runtime.snapshots.Snapshot
-import com.slack.circuit.backstack.BackStack.Record
-import com.slack.circuit.runtime.screen.Screen
+import com.slack.circuit.backstack.NavStack.Record
 
 /**
  * A caller-supplied stack of [Record]s for presentation with a `Navigator`. Iteration order is
  * top-first (first element is the top of the stack).
+ *
+ * BackStack extends NavStack but is intended for backward-only navigation patterns. Implementations
+ * may provide no-op implementations for forward navigation methods.
  */
 @Stable
-public interface BackStack<R : Record> : Iterable<R> {
-  /** The number of records contained in this [BackStack] that will be seen by an iterator. */
-  public val size: Int
-
-  /** 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.
-   *
-   * @param record The record to push onto the stack.
-   * @return If the [record] was successfully pushed onto the back stack
-   */
-  public fun push(record: R): Boolean
-
-  /**
-   * Push a new [Screen] onto the back stack. This will be enveloped in a [Record] and the new
-   * record will become the top of the stack.
-   *
-   * @param screen The screen to push onto the stack.
-   * @return If the [screen] was successfully pushed onto the back stack
-   */
-  public fun push(screen: Screen): Boolean
-
-  /**
-   * Attempt to pop the top item off of the back stack, returning the popped [Record] if popping was
-   * successful or `null` if no entry was popped.
-   */
-  public fun pop(): R?
-
-  /**
-   * Pop records off the top of the backstack until one is found that matches the given predicate.
-   */
-  public fun popUntil(predicate: (R) -> Boolean): List<R> {
-    return buildList {
-      while (topRecord?.let(predicate) == false) {
-        val popped = pop() ?: break
-        add(popped)
-      }
-    }
-  }
-
-  /**
-   * Saves the current back stack entry list in an internal state store. It can be later restored by
-   * the root screen to [restoreState].
-   *
-   * This call will overwrite any existing stored state with the same root screen.
-   */
-  public fun saveState()
-
-  /**
-   * Restores the saved state with the given [screen], adding it on top of the existing entry list.
-   * If you wish to replace the current entry list, you should [pop] all of the existing entries off
-   * before calling this function.
-   *
-   * @param screen The root screen which was previously saved using [saveState].
-   * @return Returns true if there was any back stack state to restore.
-   */
-  public fun restoreState(screen: Screen): Boolean
-
-  /**
-   * Peek at the [Screen] in the internal state store that have been saved using [saveState].
-   *
-   * @return The list of [Screen]s currently in the internal state store, will be empty if there is
-   *   no saved state.
-   */
-  public fun peekState(): List<Screen>
-
-  /**
-   * Removes the state associated with the given [screen] from the internal state store.
-   *
-   * @return true if the state was removed, false if no state was found for the given screen.
-   */
-  public fun removeState(screen: Screen): Boolean
-
-  /**
-   * Whether the back stack contains the given [record].
-   *
-   * @param includeSaved Whether to also check if the record is contained by any saved back stack
-   *   state. See [saveState].
-   */
-  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 {
-    /**
-     * A value that identifies this record uniquely, even if it shares the same [screen] with
-     * another record. This key may be used by [BackStackRecordLocalProvider]s to associate
-     * presentation data with a record across composition recreation.
-     *
-     * [key] MUST NOT change for the life of the record.
-     */
-    public val key: String
-
-    /** The [Screen] that should present this record. */
-    public val screen: Screen
-  }
-}
-
-/** `true` if the [BackStack] contains no records. [Iterable.firstOrNull] will return `null`. */
-public val BackStack<out Record>.isEmpty: Boolean
-  get() = size == 0
-
-/** `true` if the [BackStack] contains exactly one record. */
-public val BackStack<out Record>.isAtRoot: Boolean
-  get() = size == 1
+public interface BackStack<R : Record> : NavStack<R>, Iterable<R> {
 
-/** Clear any saved state from the [BackStack]. */
-public fun BackStack<out Record>.clearState() {
-  Snapshot.withMutableSnapshot {
-    for (screen in peekState()) {
-      removeState(screen)
-    }
-  }
+  @Stable public interface Record : NavStack.Record
 }