[kairos] introduce sync observation APIs (1cd4c618) · Commits · e / os / android_frameworks_base

packages/SystemUI/src/com/android/systemui/log/table/Diffable.kt

+3 −3

Original line number	Diff line number	Diff line
		@@ -20,7 +20,7 @@ import com.android.systemui.kairos.BuildScope
		import com.android.systemui.kairos.ExperimentalKairosApi
		import com.android.systemui.kairos.State
		import com.android.systemui.kairos.changes
		import com.android.systemui.kairos.effect
		import com.android.systemui.kairos.effectSync
		import com.android.systemui.util.kotlin.pairwiseBy
		import kotlinx.coroutines.flow.Flow

		@@ -221,13 +221,13 @@ fun <T : Diffable<T>> BuildScope.logDiffsForTable(
		columnPrefix: String = "",
		) {
		val initialValue = diffableState.sampleDeferred()
		effect {
		effectSync {
		// Fully log the initial value to the table.
		tableLogBuffer.logChange(columnPrefix, isInitial = true) { row ->
		initialValue.value.logFull(row)
		}
		}
		diffableState.changes.observe { newState ->
		diffableState.changes.observeSync { newState ->
		val prevState = diffableState.sample()
		tableLogBuffer.logDiffs(columnPrefix, prevVal = prevState, newVal = newState)
		}

packages/SystemUI/src/com/android/systemui/statusbar/pipeline/mobile/ui/binder/MobileIconBinderKairos.kt

+39 −32

Original line number	Diff line number	Diff line
		@@ -136,8 +136,9 @@ object MobileIconBinderKairos {
		val roamingSpace = view.requireViewById<Space>(R.id.mobile_roaming_space)
		val dotView = view.requireViewById<StatusBarIconView>(R.id.status_bar_dot)

		val isVisible = viewModel.isVisible.sample()
		effect {
		view.isVisible = viewModel.isVisible.sample()
		view.isVisible = isVisible
		iconView.isVisible = true
		launch {
		view.repeatWhenAttachedToWindow {
		@@ -182,6 +183,7 @@ object MobileIconBinderKairos {
		oldIcon is SignalIconModel.Cellular &&
		newIcon is SignalIconModel.Cellular ->
		oldIcon.numberOfLevels != newIcon.numberOfLevels

		else -> false
		}
		viewModel.verboseLogger?.logBinderReceivedSignalIcon(
		@@ -222,18 +224,21 @@ object MobileIconBinderKairos {
		}

		// Set the network type background
		viewModel.networkTypeBackground.observe { background ->

		viewModel.networkTypeIcon
		.mapTransactionally { it to binding.iconTint.sample() }
		.observe { (background, iconTintColors) ->
		networkTypeContainer.setBackgroundResource(background?.res ?: 0)

		// Tint will invert when this bit changes
		if (background?.res != null) {
		networkTypeContainer.backgroundTintList =
		ColorStateList.valueOf(binding.iconTint.sample().tint)
		ColorStateList.valueOf(iconTintColors.tint)
		networkTypeView.imageTintList =
		ColorStateList.valueOf(binding.iconTint.sample().contrast)
		ColorStateList.valueOf(iconTintColors.contrast)
		} else {
		networkTypeView.imageTintList =
		ColorStateList.valueOf(binding.iconTint.sample().tint)
		ColorStateList.valueOf(iconTintColors.tint)
		}
		}

		@@ -266,14 +271,16 @@ object MobileIconBinderKairos {
		}

		// Set the tint
		binding.iconTint.observe { colors ->
		binding.iconTint
		.mapTransactionally { it to viewModel.networkTypeBackground.sample() }
		.observe { (colors, networkTypeBackground) ->
		val tint = ColorStateList.valueOf(colors.tint)
		val contrast = ColorStateList.valueOf(colors.contrast)

		iconView.imageTintList = tint

		// If the bg is visible, tint it and use the contrast for the fg
		if (viewModel.networkTypeBackground.sample() != null) {
		if (networkTypeBackground != null) {
		networkTypeContainer.backgroundTintList = tint
		networkTypeView.imageTintList = contrast
		} else {

packages/SystemUI/utils/kairos/src/com/android/systemui/kairos/BuildScope.kt

+99 −22

Original line number	Diff line number	Diff line
		@@ -23,6 +23,7 @@ import kotlin.coroutines.EmptyCoroutineContext
		import kotlinx.coroutines.CompletableDeferred
		import kotlinx.coroutines.Deferred
		import kotlinx.coroutines.DisposableHandle
		import kotlinx.coroutines.ExperimentalForInheritanceCoroutinesApi
		import kotlinx.coroutines.Job
		import kotlinx.coroutines.awaitCancellation
		import kotlinx.coroutines.flow.Flow
		@@ -113,9 +114,29 @@ interface BuildScope : HasNetwork, StateScope {
		// TODO: remove disposable handle return? might add more confusion than convenience
		fun <A> Events<A>.observe(
		coroutineContext: CoroutineContext = EmptyCoroutineContext,
		block: EffectScope.(A) -> Unit = {},
		block: suspend EffectScope.(A) -> Unit,
		): DisposableHandle

		/**
		* Invokes [block] whenever this [Events] emits a value, allowing side-effects to be safely
		* performed in reaction to the emission.
		*
		* Specifically, [block] is deferred to the end of the transaction, and is only actually
		* executed if this [BuildScope] is still active by that time. It can be deactivated due to a
		* -Latest combinator, for example.
		*
		* Note that unlike with [observe], [block] will be invoked synchronously within the current
		* transaction. This means that it will run on whatever thread the current transaction is
		* running on (determined by the [dispatcher][kotlinx.coroutines.CoroutineDispatcher] used to
		* stand up the [KairosNetwork]), and will ignore whatever dispatcher is specified for this
		* [BuildScope]. This avoids the overhead associated with the dispatcher.
		*
		* Generally, you should prefer [observe] over this method.
		*
		* @see observe
		*/
		fun <A> Events<A>.observeSync(block: TransactionEffectScope.(A) -> Unit = {}): DisposableHandle

		/**
		* Returns an [Events] containing the results of applying each [BuildSpec] emitted from the
		* original [Events], and a [DeferredValue] containing the result of applying [initialSpecs]
		@@ -169,7 +190,7 @@ interface BuildScope : HasNetwork, StateScope {
		*/
		// TODO: see TODO for [events]
		fun <In, Out> coalescingEvents(
		getInitialValue: () -> Out,
		getInitialValue: KairosScope.() -> Out,
		coalesce: (old: Out, new: In) -> Out,
		builder: suspend CoalescingEventProducerScope<In>.() -> Unit,
		): Events<Out>
		@@ -214,16 +235,17 @@ interface BuildScope : HasNetwork, StateScope {
		*
		* @see observe
		*/
		fun <A> Events<A>.observeBuild(block: BuildScope.(A) -> Unit = {}): DisposableHandle =
		mapBuild(block).observe()
		fun <A> Events<A>.observeBuild(block: BuildScope.(A) -> Unit): DisposableHandle =
		mapBuild(block).observeSync()

		/**
		* Returns a [StateFlow] whose [value][StateFlow.value] tracks the current
		* [value of this State][State.sample], and will emit at the same rate as [State.changes].
		*/
		@OptIn(ExperimentalForInheritanceCoroutinesApi::class)
		fun <A> State<A>.toStateFlow(): StateFlow<A> {
		val innerStateFlow = MutableStateFlow(sampleDeferred())
		changes.observe { innerStateFlow.value = deferredOf(it) }
		changes.observeSync { innerStateFlow.value = deferredOf(it) }
		return object : StateFlow<A> {
		override val replayCache: List<A>
		get() = innerStateFlow.replayCache.map { it.value }
		@@ -245,7 +267,7 @@ interface BuildScope : HasNetwork, StateScope {
		val result = MutableSharedFlow<A>(replay, extraBufferCapacity = 1)
		deferredBuildScope {
		result.tryEmit(sample())
		changes.observe { a -> result.tryEmit(a) }
		changes.observeSync { a -> result.tryEmit(a) }
		}
		return result
		}
		@@ -256,7 +278,7 @@ interface BuildScope : HasNetwork, StateScope {
		*/
		fun <A> Events<A>.toSharedFlow(replay: Int = 0): SharedFlow<A> {
		val result = MutableSharedFlow<A>(replay, extraBufferCapacity = 1)
		observe { a -> result.tryEmit(a) }
		observeSync { a -> result.tryEmit(a) }
		return result
		}

		@@ -558,7 +580,7 @@ interface BuildScope : HasNetwork, StateScope {
		/** Returns a [Deferred] containing the next value to be emitted from this [Events]. */
		fun <R> Events<R>.nextDeferred(): Deferred<R> {
		lateinit var next: CompletableDeferred<R>
		val job = launchScope { nextOnly().observe { next.complete(it) } }
		val job = launchScope { nextOnly().observeSync { next.complete(it) } }
		next = CompletableDeferred(parent = job)
		return next
		}
		@@ -607,8 +629,8 @@ interface BuildScope : HasNetwork, StateScope {
		* registered [observers][observe] are unregistered, and any pending [side-effects][effect] are
		* cancelled).
		*/
		fun <A> Events<A>.observeLatestBuild(block: BuildScope.(A) -> Unit = {}): DisposableHandle =
		mapLatestBuild { block(it) }.observe()
		fun <A> Events<A>.observeLatestBuild(block: BuildScope.(A) -> Unit): DisposableHandle =
		mapLatestBuild { block(it) }.observeSync()

		/**
		* Invokes [block] whenever this [Events] emits a value, allowing side-effects to be safely
		@@ -616,7 +638,7 @@ interface BuildScope : HasNetwork, StateScope {
		*
		* With each invocation of [block], running effects from the previous invocation are cancelled.
		*/
		fun <A> Events<A>.observeLatest(block: EffectScope.(A) -> Unit = {}): DisposableHandle {
		fun <A> Events<A>.observeLatest(block: suspend EffectScope.(A) -> Unit): DisposableHandle {
		var innerJob: Job? = null
		return observeBuild {
		innerJob?.cancel()
		@@ -630,11 +652,11 @@ interface BuildScope : HasNetwork, StateScope {
		*
		* With each invocation of [block], running effects from the previous invocation are cancelled.
		*/
		fun <A> State<A>.observeLatest(block: EffectScope.(A) -> Unit = {}): Job = launchScope {
		var innerJob = effect { block(sample()) }
		fun <A> State<A>.observeLatest(block: TransactionEffectScope.(A) -> Unit): Job = launchScope {
		var innerJob = effectSync { block(sample()) }
		changes.observeBuild {
		innerJob.cancel()
		innerJob = effect { block(it) }
		innerJob = effectSync { block(it) }
		}
		}

		@@ -647,7 +669,7 @@ interface BuildScope : HasNetwork, StateScope {
		* each invocation of [block], changes from the previous invocation are undone (any registered
		* [observers][observe] are unregistered, and any pending [side-effects][effect] are cancelled).
		*/
		fun <A> State<A>.observeLatestBuild(block: BuildScope.(A) -> Unit = {}): Job = launchScope {
		fun <A> State<A>.observeLatestBuild(block: BuildScope.(A) -> Unit): Job = launchScope {
		var innerJob: Job = launchScope { block(sample()) }
		changes.observeBuild {
		innerJob.cancel()
		@@ -669,20 +691,20 @@ interface BuildScope : HasNetwork, StateScope {
		* [effect].
		*
		* ```
		* fun <A> State<A>.observeBuild(block: BuildScope.(A) -> Unit = {}): Job = launchScope {
		* fun <A> State<A>.observeBuild(block: BuildScope.(A) -> Unit): Job = launchScope {
		* block(sample())
		* changes.observeBuild(block)
		* }
		* ```
		*/
		fun <A> State<A>.observeBuild(block: BuildScope.(A) -> Unit = {}): Job = launchScope {
		fun <A> State<A>.observeBuild(block: BuildScope.(A) -> Unit): Job = launchScope {
		block(sample())
		changes.observeBuild(block)
		}

		/**
		* Invokes [block] with the current value of this [State], re-invoking whenever it changes,
		* allowing side-effects to be safely performed in reaction value changing.
		* allowing side-effects to be safely performed in reaction to the value changing.
		*
		* Specifically, [block] is deferred to the end of the transaction, and is only actually
		* executed if this [BuildScope] is still active by that time. It can be deactivated due to a
		@@ -694,9 +716,34 @@ interface BuildScope : HasNetwork, StateScope {
		*/
		fun <A> State<A>.observe(
		coroutineContext: CoroutineContext = EmptyCoroutineContext,
		block: EffectScope.(A) -> Unit = {},
		block: suspend EffectScope.(A) -> Unit,
		): DisposableHandle =
		now.map { sample() }.mergeWith(changes) { _, new -> new }.observe(coroutineContext, block)

		/**
		* Invokes [block] with the current value of this [State], re-invoking whenever it changes,
		* allowing side-effects to be safely performed in reaction to the value changing.
		*
		* Specifically, [block] is deferred to the end of the transaction, and is only actually
		* executed if this [BuildScope] is still active by that time. It can be deactivated due to a
		* -Latest combinator, for example.
		*
		* If the [State] is changing within the current transaction (i.e. [changes] is presently
		* emitting) then [block] will be invoked for the first time with the new value; otherwise, it
		* will be invoked with the [current][sample] value.
		*
		* Note that unlike with [observe], [block] will be invoked synchronously within the current
		* transaction. This means that it will run on whatever thread the current transaction is
		* running on (determined by the [dispatcher][kotlinx.coroutines.CoroutineDispatcher] used to
		* stand up the [KairosNetwork]), and will ignore whatever dispatcher is specified for this
		* [BuildScope]. This avoids the overhead associated with the dispatcher.
		*
		* Generally, you should prefer [observe] over this method.
		*
		* @see observe
		*/
		fun <A> State<A>.observeSync(block: TransactionEffectScope.(A) -> Unit = {}): DisposableHandle =
		now.map { sample() }.mergeWith(changes) { _, new -> new }.observeSync(block)
		}

		/**
		@@ -710,13 +757,13 @@ interface BuildScope : HasNetwork, StateScope {
		* ```
		*/
		@ExperimentalKairosApi
		fun <A> BuildScope.asyncEvent(block: suspend () -> A): Events<A> =
		fun <A> BuildScope.asyncEvent(block: suspend KairosScope.() -> A): Events<A> =
		events {
		// TODO: if block completes synchronously, it would be nice to emit within this
		// transaction
		emit(block())
		}
		.apply { observe() }
		.apply { observeSync() }

		/**
		* Performs a side-effect in a safe manner w/r/t the current Kairos transaction.
		@@ -736,9 +783,39 @@ fun <A> BuildScope.asyncEvent(block: suspend () -> A): Events<A> =
		@ExperimentalKairosApi
		fun BuildScope.effect(
		context: CoroutineContext = EmptyCoroutineContext,
		block: EffectScope.() -> Unit,
		block: suspend EffectScope.() -> Unit,
		): Job = launchScope(context) { now.observe { block() } }

		/**
		* Performs a side-effect in a safe manner w/r/t the current Kairos transaction.
		*
		* Specifically, [block] is deferred to the end of the current transaction, and is only actually
		* executed if this [BuildScope] is still active by that time. It can be deactivated due to a
		* -Latest combinator, for example.
		*
		* Note that unlike with [effect], [block] will be invoked synchronously within the current
		* transaction. This means that it will run on whatever thread the current transaction is running on
		* (determined by the [dispatcher][kotlinx.coroutines.CoroutineDispatcher] used to stand up the
		* [KairosNetwork]), and will ignore whatever dispatcher is specified for this [BuildScope]. This
		* avoids the overhead associated with the dispatcher.
		*
		* Generally, you should prefer [effect] over this method.
		*
		* ```
		* fun BuildScope.effectImmediate(
		* context: CoroutineContext = EmptyCoroutineContext,
		* block: EffectScope.() -> Unit,
		* ): Job =
		* launchScope(context) { now.observeImmediate { block() } }
		* ```
		*
		* @see effect
		*/
		@ExperimentalKairosApi
		fun BuildScope.effectSync(block: TransactionEffectScope.() -> Unit): Job = launchScope {
		now.observeSync { block() }
		}

		/**
		* Launches [block] in a new coroutine, returning a [Job] bound to the coroutine.
		*

packages/SystemUI/utils/kairos/src/com/android/systemui/kairos/EffectScope.kt

+21 −5

Original line number	Diff line number	Diff line
		@@ -26,13 +26,12 @@ import kotlinx.coroutines.Job
		/**
		* Scope for external side-effects triggered by the Kairos network.
		*
		* This still occurs within the context of a transaction, so general suspending calls are disallowed
		* to prevent blocking the transaction. You can [launch] new coroutines to perform long-running
		* asynchronous work. These coroutines are kept alive for the duration of the containing
		* [BuildScope] that this side-effect scope is running in.
		* You can [launch] new coroutines to perform long-running asynchronous work. These coroutines are
		* kept alive for the duration of the containing [BuildScope] that this side-effect scope is running
		* in.
		*/
		@ExperimentalKairosApi
		interface EffectScope : HasNetwork, TransactionScope {
		interface EffectScope : HasNetwork {
		/**
		* Creates a coroutine that is a child of this [EffectScope], and returns its future result as a
		* [Deferred].
		@@ -58,4 +57,21 @@ interface EffectScope : HasNetwork, TransactionScope {
		): Job = async(context, start, block)
		}

		/**
		* A combination of an [EffectScope] and a [TransactionScope], available within the lambda arguments
		* passed to [BuildScope] `-Sync` APIs, such as [BuildScope.observeSync].
		*
		* This scope occurs within the context of a transaction, allowing you to
		* [sample][TransactionScope.sample] states, but general suspending calls are disallowed to prevent
		* blocking the transaction. You can [launch] new coroutines to perform long-running asynchronous
		* work. These coroutines are kept alive for the duration of the containing [BuildScope] that this
		* side-effect scope is running in.
		*/
		@ExperimentalKairosApi interface TransactionEffectScope : EffectScope, TransactionScope

		/**
		* A [CoroutineScope] that also has access to a [KairosNetwork] that is bound to the former. All
		* usages of [KairosNetwork.activateSpec] with the [kairosNetwork] will be canceled when this
		* coroutine scope is canceled.
		*/
		@ExperimentalKairosApi interface KairosCoroutineScope : HasNetwork, CoroutineScope

packages/SystemUI/utils/kairos/src/com/android/systemui/kairos/Incremental.kt

+1 −1

Original line number	Diff line number	Diff line
		@@ -137,7 +137,7 @@ fun <K, V, U> Incremental<K, V>.mapValues(
		* [loopback] is unset before it is [observed][BuildScope.observe] or
		* [sampled][TransactionScope.sample]. Note that it is safe to invoke
		* [TransactionScope.sampleDeferred] before [loopback] is set, provided the [DeferredValue] is not
		* [queried][KairosScope.get].
		* [queried][DeferredValue.value].
		*/
		@ExperimentalKairosApi
		class IncrementalLoop<K, V>(private val name: String? = null) : Incremental<K, V>() {