repeatWhenAttached (c738a8cc) · Commits · e / os / android_frameworks_base

packages/SystemUI/Android.bp

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		@@ -225,6 +225,7 @@ android_library {
		"androidx.exifinterface_exifinterface",
		"kotlinx-coroutines-android",
		"kotlinx-coroutines-core",
		"kotlinx_coroutines_test",
		"iconloader_base",
		"SystemUI-tags",
		"SystemUI-proto",

packages/SystemUI/src/com/android/systemui/lifecycle/RepeatWhenAttached.kt

0 → 100644

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		/*
		* Copyright (C) 2022 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*
		*/

		package com.android.systemui.lifecycle

		import android.view.View
		import android.view.ViewTreeObserver
		import androidx.annotation.MainThread
		import androidx.lifecycle.Lifecycle
		import androidx.lifecycle.LifecycleOwner
		import androidx.lifecycle.LifecycleRegistry
		import androidx.lifecycle.lifecycleScope
		import com.android.systemui.util.Assert
		import kotlin.coroutines.CoroutineContext
		import kotlin.coroutines.EmptyCoroutineContext
		import kotlinx.coroutines.Dispatchers
		import kotlinx.coroutines.DisposableHandle
		import kotlinx.coroutines.launch

		/**
		* Runs the given [block] every time the [View] becomes attached (or immediately after calling this
		* function, if the view was already attached), automatically canceling the work when the `View`
		* becomes detached.
		*
		* Only use from the main thread.
		*
		* When [block] is run, it is run in the context of a [ViewLifecycleOwner] which the caller can use
		* to launch jobs, with confidence that the jobs will be properly canceled when the view is
		* detached.
		*
		* The [block] may be run multiple times, running once per every time the view is attached. Each
		* time the block is run for a new attachment event, the [ViewLifecycleOwner] provided will be a
		* fresh one.
		*
		* @param coroutineContext An optional [CoroutineContext] to replace the dispatcher [block] is
		* invoked on.
		* @param block The block of code that should be run when the view becomes attached. It can end up
		* being invoked multiple times if the view is reattached after being detached.
		* @return A [DisposableHandle] to invoke when the caller of the function destroys its [View] and is
		* no longer interested in the [block] being run the next time its attached. Calling this is an
		* optional optimization as the logic will be properly cleaned up and destroyed each time the view
		* is detached. Using this is not thread-safe and should only be used on the main thread.
		*/
		@MainThread
		fun View.repeatWhenAttached(
		coroutineContext: CoroutineContext = EmptyCoroutineContext,
		block: suspend LifecycleOwner.(View) -> Unit,
		): DisposableHandle {
		Assert.isMainThread()
		val view = this
		// The suspend block will run on the app's main thread unless the caller supplies a different
		// dispatcher to use. We don't want it to run on the Dispatchers.Default thread pool as
		// default behavior. Instead, we want it to run on the view's UI thread since the user will
		// presumably want to call view methods that require being called from said UI thread.
		val lifecycleCoroutineContext = Dispatchers.Main + coroutineContext
		var lifecycleOwner: ViewLifecycleOwner? = null
		val onAttachListener =
		object : View.OnAttachStateChangeListener {
		override fun onViewAttachedToWindow(v: View?) {
		Assert.isMainThread()
		lifecycleOwner?.onDestroy()
		lifecycleOwner =
		createLifecycleOwnerAndRun(
		view,
		lifecycleCoroutineContext,
		block,
		)
		}

		override fun onViewDetachedFromWindow(v: View?) {
		lifecycleOwner?.onDestroy()
		lifecycleOwner = null
		}
		}

		addOnAttachStateChangeListener(onAttachListener)
		if (view.isAttachedToWindow) {
		lifecycleOwner =
		createLifecycleOwnerAndRun(
		view,
		lifecycleCoroutineContext,
		block,
		)
		}

		return object : DisposableHandle {
		override fun dispose() {
		Assert.isMainThread()

		lifecycleOwner?.onDestroy()
		lifecycleOwner = null
		view.removeOnAttachStateChangeListener(onAttachListener)
		}
		}
		}

		private fun createLifecycleOwnerAndRun(
		view: View,
		coroutineContext: CoroutineContext,
		block: suspend LifecycleOwner.(View) -> Unit,
		): ViewLifecycleOwner {
		return ViewLifecycleOwner(view).apply {
		onCreate()
		lifecycleScope.launch(coroutineContext) { block(view) }
		}
		}

		/**
		* A [LifecycleOwner] for a [View] for exclusive use by the [repeatWhenAttached] extension function.
		*
		* The implementation requires the caller to call [onCreate] and [onDestroy] when the view is
		* attached to or detached from a view hierarchy. After [onCreate] and before [onDestroy] is called,
		* the implementation monitors window state in the following way
		*
		* * If the window is not visible, we are in the [Lifecycle.State.CREATED] state
		* * If the window is visible but not focused, we are in the [Lifecycle.State.STARTED] state
		* * If the window is visible and focused, we are in the [Lifecycle.State.RESUMED] state
		*
		* Or in table format:
		* ```
		* ┌───────────────┬───────────────────┬──────────────┬─────────────────┐
		* │ View attached │ Window Visibility │ Window Focus │ Lifecycle State │
		* ├───────────────┼───────────────────┴──────────────┼─────────────────┤
		* │ Not attached │ Any │ N/A │
		* ├───────────────┼───────────────────┬──────────────┼─────────────────┤
		* │ │ Not visible │ Any │ CREATED │
		* │ ├───────────────────┼──────────────┼─────────────────┤
		* │ Attached │ │ No focus │ STARTED │
		* │ │ Visible ├──────────────┼─────────────────┤
		* │ │ │ Has focus │ RESUMED │
		* └───────────────┴───────────────────┴──────────────┴─────────────────┘
		* ```
		*/
		private class ViewLifecycleOwner(
		private val view: View,
		) : LifecycleOwner {

		private val windowVisibleListener =
		ViewTreeObserver.OnWindowVisibilityChangeListener { updateState() }
		private val windowFocusListener = ViewTreeObserver.OnWindowFocusChangeListener { updateState() }

		private val registry = LifecycleRegistry(this)

		fun onCreate() {
		registry.currentState = Lifecycle.State.CREATED
		view.viewTreeObserver.addOnWindowVisibilityChangeListener(windowVisibleListener)
		view.viewTreeObserver.addOnWindowFocusChangeListener(windowFocusListener)
		updateState()
		}

		fun onDestroy() {
		view.viewTreeObserver.removeOnWindowVisibilityChangeListener(windowVisibleListener)
		view.viewTreeObserver.removeOnWindowFocusChangeListener(windowFocusListener)
		registry.currentState = Lifecycle.State.DESTROYED
		}

		override fun getLifecycle(): Lifecycle {
		return registry
		}

		private fun updateState() {
		registry.currentState =
		when {
		view.windowVisibility != View.VISIBLE -> Lifecycle.State.CREATED
		!view.hasWindowFocus() -> Lifecycle.State.STARTED
		else -> Lifecycle.State.RESUMED
		}
		}
		}

packages/SystemUI/src/com/android/systemui/lifecycle/WindowAddedViewLifecycleOwner.kt

deleted100644 → 0

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		package com.android.systemui.lifecycle

		import android.view.View
		import android.view.ViewTreeObserver
		import androidx.lifecycle.Lifecycle
		import androidx.lifecycle.LifecycleOwner
		import androidx.lifecycle.LifecycleRegistry

		/**
		* [LifecycleOwner] for Window-added Views.
		*
		* These are [View] instances that are added to a `Window` using the `WindowManager` API.
		*
		* This implementation goes to:
		* * The <b>CREATED</b> `Lifecycle.State` when the view gets attached to the window but the window
		* is not yet visible
		* * The <b>STARTED</b> `Lifecycle.State` when the view is attached to the window and the window is
		* visible
		* * The <b>RESUMED</b> `Lifecycle.State` when the view is attached to the window and the window is
		* visible and the window receives focus
		*
		* In table format:
		* ```
		* \| ----------------------------------------------------------------------------- \|
		* \| View attached to window \| Window visible \| Window has focus \| Lifecycle state \|
		* \| ----------------------------------------------------------------------------- \|
		* \| not attached \| Any \| INITIALIZED \|
		* \| ----------------------------------------------------------------------------- \|
		* \| \| not visible \| Any \| CREATED \|
		* \| ----------------------------------------------------- \|
		* \| attached \| \| not focused \| STARTED \|
		* \| \| is visible \|----------------------------------- \|
		* \| \| \| has focus \| RESUMED \|
		* \| ----------------------------------------------------------------------------- \|
		* ```
		* ### Notes
		* * [dispose] must be invoked when the [LifecycleOwner] is done and won't be reused
		* * It is always better for [LifecycleOwner] implementations to be more explicit than just
		* listening to the state of the `Window`. E.g. if the code that added the `View` to the `Window`
		* already has access to the correct state to know when that `View` should become visible and when
		* it is ready to receive interaction from the user then it already knows when to move to `STARTED`
		* and `RESUMED`, respectively. In that case, it's better to implement your own `LifecycleOwner`
		* instead of relying on the `Window` callbacks.
		*/
		class WindowAddedViewLifecycleOwner
		@JvmOverloads
		constructor(
		private val view: View,
		registryFactory: (LifecycleOwner) -> LifecycleRegistry = { LifecycleRegistry(it) },
		) : LifecycleOwner {

		private val windowAttachListener =
		object : ViewTreeObserver.OnWindowAttachListener {
		override fun onWindowAttached() {
		updateCurrentState()
		}

		override fun onWindowDetached() {
		updateCurrentState()
		}
		}
		private val windowFocusListener =
		ViewTreeObserver.OnWindowFocusChangeListener { updateCurrentState() }
		private val windowVisibilityListener =
		ViewTreeObserver.OnWindowVisibilityChangeListener { updateCurrentState() }

		private val registry = registryFactory(this)

		init {
		setCurrentState(Lifecycle.State.INITIALIZED)

		with(view.viewTreeObserver) {
		addOnWindowAttachListener(windowAttachListener)
		addOnWindowVisibilityChangeListener(windowVisibilityListener)
		addOnWindowFocusChangeListener(windowFocusListener)
		}

		updateCurrentState()
		}

		override fun getLifecycle(): Lifecycle {
		return registry
		}

		/**
		* Disposes of this [LifecycleOwner], performing proper clean-up.
		*
		* <p>Invoke this when the instance is finished and won't be reused.
		*/
		fun dispose() {
		with(view.viewTreeObserver) {
		removeOnWindowAttachListener(windowAttachListener)
		removeOnWindowVisibilityChangeListener(windowVisibilityListener)
		removeOnWindowFocusChangeListener(windowFocusListener)
		}
		}

		private fun updateCurrentState() {
		val state =
		when {
		!view.isAttachedToWindow -> Lifecycle.State.INITIALIZED
		view.windowVisibility != View.VISIBLE -> Lifecycle.State.CREATED
		!view.hasWindowFocus() -> Lifecycle.State.STARTED
		else -> Lifecycle.State.RESUMED
		}
		setCurrentState(state)
		}

		private fun setCurrentState(state: Lifecycle.State) {
		if (registry.currentState != state) {
		registry.currentState = state
		}
		}
		}

packages/SystemUI/src/com/android/systemui/shade/NotificationShadeWindowControllerImpl.java

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		@@ -44,8 +44,6 @@ import android.view.WindowManager;
		import android.view.WindowManager.LayoutParams;
		import android.view.WindowManagerGlobal;

		import androidx.lifecycle.ViewTreeLifecycleOwner;

		import com.android.keyguard.KeyguardUpdateMonitor;
		import com.android.systemui.Dumpable;
		import com.android.systemui.R;
		@@ -54,7 +52,6 @@ import com.android.systemui.colorextraction.SysuiColorExtractor;
		import com.android.systemui.dagger.SysUISingleton;
		import com.android.systemui.dump.DumpManager;
		import com.android.systemui.keyguard.KeyguardViewMediator;
		import com.android.systemui.lifecycle.WindowAddedViewLifecycleOwner;
		import com.android.systemui.plugins.statusbar.StatusBarStateController;
		import com.android.systemui.plugins.statusbar.StatusBarStateController.StateListener;
		import com.android.systemui.statusbar.NotificationShadeWindowController;
		@@ -251,15 +248,6 @@ public class NotificationShadeWindowControllerImpl implements NotificationShadeW

		mWindowManager.addView(mNotificationShadeView, mLp);

		// Set up and "inject" a LifecycleOwner bound to the Window-View relationship such that all
		// views in the sub-tree rooted under this view can access the LifecycleOwner using
		// ViewTreeLifecycleOwner.get(...).
		if (ViewTreeLifecycleOwner.get(mNotificationShadeView) == null) {
		ViewTreeLifecycleOwner.set(
		mNotificationShadeView,
		new WindowAddedViewLifecycleOwner(mNotificationShadeView));
		}

		mLpChanged.copyFrom(mLp);
		onThemeChanged();

packages/SystemUI/tests/src/com/android/systemui/lifecycle/RepeatWhenAttachedTest.kt

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