Introduce TransitionKey (aa58dfb9) · Commits · e / os / android_frameworks_base

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/AnimateToScene.kt

+13 −5

Original line number	Diff line number	Diff line
		@@ -30,6 +30,7 @@ import kotlinx.coroutines.launch
		internal fun CoroutineScope.animateToScene(
		layoutState: BaseSceneTransitionLayoutState,
		target: SceneKey,
		transitionKey: TransitionKey?,
		): TransitionState.Transition? {
		val transitionState = layoutState.transitionState
		if (transitionState.currentScene == target) {
		@@ -45,7 +46,7 @@ internal fun CoroutineScope.animateToScene(
		}

		return when (transitionState) {
		is TransitionState.Idle -> animate(layoutState, target)
		is TransitionState.Idle -> animate(layoutState, target, transitionKey)
		is TransitionState.Transition -> {
		// A transition is currently running: first check whether `transition.toScene` or
		// `transition.fromScene` is the same as our target scene, in which case the transition
		@@ -67,7 +68,7 @@ internal fun CoroutineScope.animateToScene(
		// The transition is in progress: start the canned animation at the same
		// progress as it was in.
		// TODO(b/290184746): Also take the current velocity into account.
		animate(layoutState, target, startProgress = progress)
		animate(layoutState, target, transitionKey, startProgress = progress)
		}
		} else if (transitionState.fromScene == target) {
		// There is a transition from [target] to another scene: simply animate the same
		@@ -82,12 +83,18 @@ internal fun CoroutineScope.animateToScene(
		null
		} else {
		// TODO(b/290184746): Also take the current velocity into account.
		animate(layoutState, target, startProgress = progress, reversed = true)
		animate(
		layoutState,
		target,
		transitionKey,
		startProgress = progress,
		reversed = true,
		)
		}
		} else {
		// Generic interruption; the current transition is neither from or to [target].
		// TODO(b/290930950): Better handle interruptions here.
		animate(layoutState, target)
		animate(layoutState, target, transitionKey)
		}
		}
		}
		@@ -96,6 +103,7 @@ internal fun CoroutineScope.animateToScene(
		private fun CoroutineScope.animate(
		layoutState: BaseSceneTransitionLayoutState,
		target: SceneKey,
		transitionKey: TransitionKey?,
		startProgress: Float = 0f,
		reversed: Boolean = false,
		): TransitionState.Transition {
		@@ -127,7 +135,7 @@ private fun CoroutineScope.animate(
		// Change the current layout state to start this new transition. This will compute the
		// TransformationSpec associated to this transition, which we need to initialize the Animatable
		// that will actually animate it.
		layoutState.startTransition(transition)
		layoutState.startTransition(transition, transitionKey)

		// The transformation now contains the spec that we should use to instantiate the Animatable.
		val animationSpec = layoutState.transformationSpec.progressSpec

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/Key.kt

+11 −0

Original line number	Diff line number	Diff line
		@@ -55,6 +55,7 @@ class SceneKey(

		// Implementation of [UserActionResult].
		override val toScene: SceneKey = this
		override val transitionKey: TransitionKey? = null
		override val distance: UserActionDistance? = null

		override fun toString(): String {
		@@ -104,3 +105,13 @@ class ValueKey(debugName: String, identity: Any = Object()) : Key(debugName, ide
		return "ValueKey(debugName=$debugName)"
		}
		}

		/**
		* Key for a transition. This can be used to specify which transition spec should be used when
		* starting the transition between two scenes.
		*/
		class TransitionKey(debugName: String, identity: Any = Object()) : Key(debugName, identity) {
		override fun toString(): String {
		return "TransitionKey(debugName=$debugName)"
		}
		}

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneGestureHandler.kt

+8 −2

Original line number	Diff line number	Diff line
		@@ -54,7 +54,7 @@ internal class SceneGestureHandler(

		private fun updateTransition(newTransition: SwipeTransition, force: Boolean = false) {
		if (isDrivingTransition \|\| force) {
		layoutState.startTransition(newTransition)
		layoutState.startTransition(newTransition, newTransition.key)

		// Initialize SwipeTransition.swipeSpec. Note that this must be called right after
		// layoutState.startTransition() is called, because it computes the
		@@ -237,7 +237,11 @@ internal class SceneGestureHandler(
		}
		swipeTransition.dragOffset += acceleratedOffset

		if (isNewFromScene \|\| result.toScene != swipeTransition.toScene) {
		if (
		isNewFromScene \|\|
		result.toScene != swipeTransition.toScene \|\|
		result.transitionKey != swipeTransition.key
		) {
		updateTransition(
		SwipeTransition(fromScene, result).apply {
		this.dragOffset = swipeTransition.dragOffset
		@@ -484,6 +488,7 @@ internal class SceneGestureHandler(

		private fun SwipeTransition(fromScene: Scene, result: UserActionResult): SwipeTransition {
		return SwipeTransition(
		result.transitionKey,
		fromScene,
		layoutImpl.scene(result.toScene),
		computeAbsoluteDistance(fromScene, result),
		@@ -491,6 +496,7 @@ internal class SceneGestureHandler(
		}

		internal class SwipeTransition(
		val key: TransitionKey?,
		val _fromScene: Scene,
		val _toScene: Scene,
		/**

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitionLayout.kt

+33 −19

Original line number	Diff line number	Diff line
		@@ -388,8 +388,9 @@ interface SwipeSourceDetector {
		/**
		* The result of performing a [UserAction].
		*
		* Note: [UserActionResult] is implemented by [SceneKey], and you can also use [withDistance] to
		* easily create a [UserActionResult] with a fixed distance:
		* Note: [UserActionResult] is implemented by [SceneKey], so you can also use scene keys directly
		* when defining your [UserActionResult]s.
		*
		* ```
		* SceneTransitionLayout(...) {
		* scene(
		@@ -397,7 +398,7 @@ interface SwipeSourceDetector {
		* userActions =
		* mapOf(
		* Swipe.Right to Scene.Bar,
		* Swipe.Down to Scene.Doe withDistance 100.dp,
		* Swipe.Down to Scene.Doe,
		* )
		* )
		* ) { ... }
		@@ -408,6 +409,9 @@ interface UserActionResult {
		/** The scene we should be transitioning to during the [UserAction]. */
		val toScene: SceneKey

		/** The key of the transition that should be used. */
		val transitionKey: TransitionKey?

		/**
		* The distance the action takes to animate from 0% to 100%.
		*
		@@ -416,6 +420,32 @@ interface UserActionResult {
		val distance: UserActionDistance?
		}

		/** Create a [UserActionResult] to [toScene] with the given [distance] and [transitionKey]. */
		fun UserActionResult(
		toScene: SceneKey,
		distance: UserActionDistance? = null,
		transitionKey: TransitionKey? = null,
		): UserActionResult {
		return object : UserActionResult {
		override val toScene: SceneKey = toScene
		override val transitionKey: TransitionKey? = transitionKey
		override val distance: UserActionDistance? = distance
		}
		}

		/** Create a [UserActionResult] to [toScene] with the given fixed [distance] and [transitionKey]. */
		fun UserActionResult(
		toScene: SceneKey,
		distance: Dp,
		transitionKey: TransitionKey? = null,
		): UserActionResult {
		return UserActionResult(
		toScene = toScene,
		distance = FixedDistance(distance),
		transitionKey = transitionKey,
		)
		}

		interface UserActionDistance {
		/**
		* Return the absolute distance of the user action given the size of the scene we are
		@@ -424,22 +454,6 @@ interface UserActionDistance {
		fun Density.absoluteDistance(fromSceneSize: IntSize, orientation: Orientation): Float
		}

		/**
		* A utility function to make it possible to define user actions with a distance using the syntax
		* `Swipe.Up to Scene.foo withDistance 100.dp`
		*/
		infix fun Pair<UserAction, SceneKey>.withDistance(
		distance: Dp
		): Pair<UserAction, UserActionResult> {
		val scene = second
		val distance = FixedDistance(distance)
		return first to
		object : UserActionResult {
		override val toScene: SceneKey = scene
		override val distance: UserActionDistance = distance
		}
		}

		/** The user action has a fixed [absoluteDistance]. */
		private class FixedDistance(private val distance: Dp) : UserActionDistance {
		override fun Density.absoluteDistance(fromSceneSize: IntSize, orientation: Orientation): Float {

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitionLayoutState.kt

+18 −10

Original line number	Diff line number	Diff line
		@@ -92,6 +92,7 @@ sealed interface MutableSceneTransitionLayoutState : SceneTransitionLayoutState
		fun setTargetScene(
		targetScene: SceneKey,
		coroutineScope: CoroutineScope,
		transitionKey: TransitionKey? = null,
		): TransitionState.Transition?
		}

		@@ -213,11 +214,14 @@ internal abstract class BaseSceneTransitionLayoutState(initialScene: SceneKey) :
		}

		/** Start a new [transition], instantly interrupting any ongoing transition if there was one. */
		internal fun startTransition(transition: TransitionState.Transition) {
		internal fun startTransition(
		transition: TransitionState.Transition,
		transitionKey: TransitionKey?,
		) {
		// Compute the [TransformationSpec] when the transition starts.
		transformationSpec =
		transitions
		.transitionSpec(transition.fromScene, transition.toScene)
		.transitionSpec(transition.fromScene, transition.toScene, key = transitionKey)
		.transformationSpec()

		transitionState = transition
		@@ -265,7 +269,11 @@ internal class HoistedSceneTransitionLayoutScene(
		// Inspired by AnimateAsState.kt: let's poll the last value to avoid being one frame
		// late.
		val newKey = targetSceneChannel.tryReceive().getOrNull() ?: newKey
		animateToScene(layoutState = this@HoistedSceneTransitionLayoutScene, newKey)
		animateToScene(
		layoutState = this@HoistedSceneTransitionLayoutScene,
		target = newKey,
		transitionKey = null,
		)
		}
		}
		}
		@@ -278,15 +286,15 @@ internal class MutableSceneTransitionLayoutStateImpl(
		) : MutableSceneTransitionLayoutState, BaseSceneTransitionLayoutState(initialScene) {
		override fun setTargetScene(
		targetScene: SceneKey,
		coroutineScope: CoroutineScope
		coroutineScope: CoroutineScope,
		transitionKey: TransitionKey?,
		): TransitionState.Transition? {
		return with(this) {
		coroutineScope.animateToScene(
		return coroutineScope.animateToScene(
		layoutState = this@MutableSceneTransitionLayoutStateImpl,
		target = targetScene,
		transitionKey = transitionKey,
		)
		}
		}

		override fun CoroutineScope.onChangeScene(scene: SceneKey) {
		setTargetScene(scene, coroutineScope = this)