API overhaul because splitting the keys and the composables don't work.

buildSrc/src/main/resources/versions.properties

@@ -1,3 +1,3 @@
 # -SNAPSHOT will automatically be appended. Pass -PisRelease=true to gradlew to release (this will
 # also append the current compose version number after a +).
-releaseVersion=0.10.0
+releaseVersion=0.11.0

compose-backstack-viewer/src/main/java/com/zachklipp/compose/backstack/viewer/BackstackViewerApp.kt

@@ -41,6 +41,7 @@ import com.zachklipp.compose.backstack.BackstackTransition.Crossfade
 import com.zachklipp.compose.backstack.BackstackTransition.Slide
 import com.zachklipp.compose.backstack.defaultBackstackAnimation
 import com.zachklipp.compose.backstack.rememberTransitionController
+import com.zachklipp.compose.backstack.toBackstackModel
 import com.zachklipp.compose.backstack.xray.xrayed
 
 private val DEFAULT_BACKSTACKS = listOf(
@@ -147,7 +148,14 @@ private fun AppScreens(model: AppModel) {
 
   MaterialTheme(colors = lightColors()) {
     Backstack(
-      backstack = model.currentBackstack,
+      frames = model.currentBackstack.toBackstackModel { screen ->
+        AppScreen(
+          name = screen,
+          showBack = screen != model.bottomScreen,
+          onAdd = { model.pushScreen("$screen+") },
+          onBack = model::popScreen
+        )
+      },
       frameController = rememberTransitionController<String>(
         transition = model.selectedTransition.second,
         animationSpec = animation ?: defaultBackstackAnimation(),
@@ -165,14 +173,7 @@ private fun AppScreens(model: AppModel) {
       modifier = Modifier
         .fillMaxSize()
         .border(width = 3.dp, color = Color.Red),
-    ) { screen ->
-      AppScreen(
-        name = screen,
-        showBack = screen != model.bottomScreen,
-        onAdd = { model.pushScreen("$screen+") },
-        onBack = model::popScreen
-      )
-    }
+    )
   }
 }
 

compose-backstack-xray/src/main/java/com/zachklipp/compose/backstack/xray/XrayController.kt

@@ -12,8 +12,9 @@ import androidx.compose.ui.graphics.DefaultCameraDistance
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.unit.dp
+import com.zachklipp.compose.backstack.BackstackFrame
 import com.zachklipp.compose.backstack.FrameController
-import com.zachklipp.compose.backstack.FrameController.BackstackFrame
+import com.zachklipp.compose.backstack.FrameController.FrameAndModifier
 import com.zachklipp.compose.backstack.NoopFrameController
 import kotlin.math.sin
 
@@ -22,16 +23,16 @@ import kotlin.math.sin
  * the screens in the backstack in pseudo-3D space. The 3D stack can be navigated via touch
  * gestures.
  */
-@Composable fun <T : Any> FrameController<T>.xrayed(enabled: Boolean): FrameController<T> =
-  remember { XrayController<T>() }.also {
+@Composable fun <K : Any> FrameController<K>.xrayed(enabled: Boolean): FrameController<K> =
+  remember { XrayController<K>() }.also {
     it.enabled = enabled
     it.wrappedController = this
   }
 
-private class XrayController<T : Any> : FrameController<T> {
+private class XrayController<K : Any> : FrameController<K> {
 
   var enabled: Boolean by mutableStateOf(false)
-  var wrappedController: FrameController<T> by mutableStateOf(NoopFrameController())
+  var wrappedController: FrameController<K> by mutableStateOf(NoopFrameController())
 
   private var offsetDpX by mutableStateOf(500.dp)
   private var offsetDpY by mutableStateOf(10.dp)
@@ -41,7 +42,7 @@ private class XrayController<T : Any> : FrameController<T> {
   private var alpha by mutableStateOf(.4f)
   private var overlayAlpha by mutableStateOf(.2f)
 
-  private var activeKeys by mutableStateOf(emptyList<T>())
+  private var activeKeys by mutableStateOf(emptyList<BackstackFrame<K>>())
 
   private val controlModifier = Modifier.pointerInput(Unit) {
     detectTransformGestures { _, pan, zoom, _ ->
@@ -56,14 +57,14 @@ private class XrayController<T : Any> : FrameController<T> {
     if (!enabled) wrappedController.activeFrames else {
       activeKeys.mapIndexed { index, key ->
         val modifier = Modifier.modifierForFrame(index, activeKeys.size, 1f)
-        return@mapIndexed BackstackFrame(key, modifier)
+        return@mapIndexed FrameAndModifier(key, modifier)
       }
     }
   }
 
-  override fun updateBackstack(keys: List<T>) {
-    activeKeys = keys
-    wrappedController.updateBackstack(keys)
+  override fun updateBackstack(frames: List<BackstackFrame<K>>) {
+    activeKeys = frames
+    wrappedController.updateBackstack(frames)
   }
 
   /**

compose-backstack/api/compose-backstack.api

@@ -1,8 +1,11 @@
+public abstract interface class com/zachklipp/compose/backstack/BackstackFrame {
+	public abstract fun Content (Landroidx/compose/runtime/Composer;I)V
+	public abstract fun getKey ()Ljava/lang/Object;
+}
+
 public final class com/zachklipp/compose/backstack/BackstackKt {
-	public static final fun Backstack (Ljava/util/List;Landroidx/compose/ui/Modifier;Lcom/zachklipp/compose/backstack/BackstackTransition;Landroidx/compose/animation/core/AnimationSpec;Lkotlin/jvm/functions/Function3;Lkotlin/jvm/functions/Function0;Ljava/lang/Object;Lkotlin/jvm/functions/Function3;)V
-	public static final fun Backstack (Ljava/util/List;Landroidx/compose/ui/Modifier;Lcom/zachklipp/compose/backstack/BackstackTransition;Lkotlin/jvm/functions/Function3;Landroidx/compose/runtime/Composer;II)V
-	public static final fun Backstack (Ljava/util/List;Landroidx/compose/ui/Modifier;Lcom/zachklipp/compose/backstack/FrameController;Lkotlin/jvm/functions/Function3;Landroidx/compose/runtime/Composer;II)V
-	public static synthetic fun Backstack$default (Ljava/util/List;Landroidx/compose/ui/Modifier;Lcom/zachklipp/compose/backstack/BackstackTransition;Landroidx/compose/animation/core/AnimationSpec;Lkotlin/jvm/functions/Function3;Lkotlin/jvm/functions/Function0;Ljava/lang/Object;Lkotlin/jvm/functions/Function3;ILjava/lang/Object;)V
+	public static final fun Backstack (Ljava/util/List;Landroidx/compose/ui/Modifier;Lcom/zachklipp/compose/backstack/BackstackTransition;Landroidx/compose/runtime/Composer;II)V
+	public static final fun Backstack (Ljava/util/List;Landroidx/compose/ui/Modifier;Lcom/zachklipp/compose/backstack/FrameController;Landroidx/compose/runtime/Composer;II)V
 }
 
 public abstract interface class com/zachklipp/compose/backstack/BackstackTransition {
@@ -30,15 +33,15 @@ public abstract interface class com/zachklipp/compose/backstack/FrameController
 	public abstract fun updateBackstack (Ljava/util/List;)V
 }
 
-public final class com/zachklipp/compose/backstack/FrameController$BackstackFrame {
-	public fun <init> (Ljava/lang/Object;Landroidx/compose/ui/Modifier;)V
-	public synthetic fun <init> (Ljava/lang/Object;Landroidx/compose/ui/Modifier;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public final fun component1 ()Ljava/lang/Object;
+public final class com/zachklipp/compose/backstack/FrameController$FrameAndModifier {
+	public fun <init> (Lcom/zachklipp/compose/backstack/BackstackFrame;Landroidx/compose/ui/Modifier;)V
+	public synthetic fun <init> (Lcom/zachklipp/compose/backstack/BackstackFrame;Landroidx/compose/ui/Modifier;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun component1 ()Lcom/zachklipp/compose/backstack/BackstackFrame;
 	public final fun component2 ()Landroidx/compose/ui/Modifier;
-	public final fun copy (Ljava/lang/Object;Landroidx/compose/ui/Modifier;)Lcom/zachklipp/compose/backstack/FrameController$BackstackFrame;
-	public static synthetic fun copy$default (Lcom/zachklipp/compose/backstack/FrameController$BackstackFrame;Ljava/lang/Object;Landroidx/compose/ui/Modifier;ILjava/lang/Object;)Lcom/zachklipp/compose/backstack/FrameController$BackstackFrame;
+	public final fun copy (Lcom/zachklipp/compose/backstack/BackstackFrame;Landroidx/compose/ui/Modifier;)Lcom/zachklipp/compose/backstack/FrameController$FrameAndModifier;
+	public static synthetic fun copy$default (Lcom/zachklipp/compose/backstack/FrameController$FrameAndModifier;Lcom/zachklipp/compose/backstack/BackstackFrame;Landroidx/compose/ui/Modifier;ILjava/lang/Object;)Lcom/zachklipp/compose/backstack/FrameController$FrameAndModifier;
 	public fun equals (Ljava/lang/Object;)Z
-	public final fun getKey ()Ljava/lang/Object;
+	public final fun getFrame ()Lcom/zachklipp/compose/backstack/BackstackFrame;
 	public final fun getModifier ()Landroidx/compose/ui/Modifier;
 	public fun hashCode ()I
 	public fun toString ()Ljava/lang/String;

compose-backstack/src/androidTest/java/com/zachklipp/compose/backstack/BackstackStateTest.kt

@@ -10,11 +10,9 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.test.assertIsDisplayed
-import androidx.compose.ui.test.junit4.AndroidComposeTestRule
 import androidx.compose.ui.test.junit4.createComposeRule
 import androidx.compose.ui.test.onNodeWithText
 import androidx.compose.ui.test.performClick
-import androidx.test.ext.junit.rules.ActivityScenarioRule
 import com.google.common.truth.Truth.assertThat
 import org.junit.Rule
 import org.junit.Test
@@ -24,13 +22,15 @@ class BackstackStateTest {
   @get:Rule
   val compose = createComposeRule()
 
+  private fun List<String>.toCounters() = toBackstackModel {
+    var counter by rememberSaveable { mutableStateOf(0) }
+    BasicText("$it: $counter", Modifier.clickable { counter++ })
+  }
+
   @Test fun screen_state_is_restored_on_pop() {
     val backstack = mutableStateListOf("one")
     compose.setContent {
-      Backstack(backstack, frameController = NoopFrameController()) {
-        var counter by rememberSaveable { mutableStateOf(0) }
-        BasicText("$it: $counter", Modifier.clickable { counter++ })
-      }
+      Backstack(backstack.toCounters(), frameController = NoopFrameController())
     }
 
     // Update some state on the first screen.
@@ -55,10 +55,7 @@ class BackstackStateTest {
   @Test fun screen_state_is_discarded_after_pop() {
     val backstack = mutableStateListOf("one", "two")
     compose.setContent {
-      Backstack(backstack, frameController = NoopFrameController()) {
-        var counter by rememberSaveable { mutableStateOf(0) }
-        BasicText("$it: $counter", Modifier.clickable { counter++ })
-      }
+      Backstack(backstack.toCounters(), frameController = NoopFrameController())
     }
 
     // Update some state on the second screen.
@@ -78,10 +75,7 @@ class BackstackStateTest {
   @Test fun screen_state_is_discarded_when_removed_from_backstack_while_hidden() {
     var backstack by mutableStateOf(listOf("one"))
     compose.setContent {
-      Backstack(backstack, frameController = NoopFrameController()) {
-        var counter by rememberSaveable { mutableStateOf(0) }
-        BasicText("$it: $counter", Modifier.clickable { counter++ })
-      }
+      Backstack(backstack.toCounters(), frameController = NoopFrameController())
     }
 
     // Update some state on the first screen.
@@ -112,13 +106,16 @@ class BackstackStateTest {
     val backstack = mutableStateListOf("one")
     val transcript = mutableListOf<String>()
     compose.setContent {
-      Backstack(backstack, frameController = NoopFrameController()) {
-        BasicText(it)
-        DisposableEffect(Unit) {
-          transcript += "+$it"
-          onDispose { transcript += "-$it" }
-        }
-      }
+      Backstack(
+        backstack.toBackstackModel {
+          BasicText(it)
+          DisposableEffect(Unit) {
+            transcript += "+$it"
+            onDispose { transcript += "-$it" }
+          }
+        },
+        frameController = NoopFrameController()
+      )
     }
 
     assertThat(transcript).containsExactly("+one")
@@ -143,10 +140,13 @@ class BackstackStateTest {
 
     val backstack = mutableStateListOf(Screen("one"))
     compose.setContent {
-      Backstack(backstack, frameController = NoopFrameController()) {
-        var counter by rememberSaveable { mutableStateOf(0) }
-        BasicText("${it.name}: $counter", Modifier.clickable { counter++ })
-      }
+      Backstack(
+        backstack.toBackstackModel {
+          var counter by rememberSaveable { mutableStateOf(0) }
+          BasicText("${it.name}: $counter", Modifier.clickable { counter++ })
+        },
+        frameController = NoopFrameController()
+      )
     }
 
     // Update some state on the first screen.

compose-backstack/src/androidTest/java/com/zachklipp/compose/backstack/BackstackTransitionsTest.kt

@@ -63,10 +63,12 @@ class BackstackTransitionsTest {
     assertTransition(Crossfade, forward = false)
   }
 
+  private fun List<String>.toBackstack() = toBackstackModel { BasicText(it) }
+
   private fun assertInitialStateWithSingleScreen(transition: BackstackTransition) {
     val originalBackstack = listOf("one")
     compose.setContent {
-      Backstack(originalBackstack, transition = transition) { BasicText(it) }
+      Backstack(originalBackstack.toBackstack(), transition = transition)
     }
 
     compose.onNodeWithText("one").assertIsDisplayed()
@@ -75,7 +77,7 @@ class BackstackTransitionsTest {
   private fun assertInitialStateWithMultipleScreens(transition: BackstackTransition) {
     val originalBackstack = listOf("one", "two")
     compose.setContent {
-      Backstack(originalBackstack, transition = transition) { BasicText(it) }
+      Backstack(originalBackstack.toBackstack(), transition = transition)
     }
 
     compose.onNodeWithText("two").assertIsDisplayed()
@@ -87,15 +89,17 @@ class BackstackTransitionsTest {
     val secondBackstack = listOf("one", "two")
     var backstack by mutableStateOf(if (forward) firstBackstack else secondBackstack)
     compose.mainClock.autoAdvance = false
+
     compose.setContent {
       Backstack(
-        backstack,
+        backstack.toBackstack(),
         frameController = rememberTransitionController(
           animationSpec = animation,
           transition = transition
         )
-      ) { BasicText(it) }
+      )
     }
+
     val initialText = if (forward) "one" else "two"
     val newText = if (forward) "two" else "one"