| /* |
| * Copyright 2020 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 androidx.compose.animation |
| |
| import androidx.compose.animation.core.AnimationClockObservable |
| import androidx.compose.animation.core.AnimationClockObserver |
| import androidx.compose.Composable |
| import androidx.compose.onCommit |
| import androidx.compose.remember |
| |
| /** |
| * Return a new [AnimationClockObservable] wrapping this one that will auto-unsubscribe all |
| * [AnimationClockObserver]s when this call leaves the composition, preventing clock |
| * subscriptions from persisting beyond the composition lifecycle. |
| * |
| * If you are creating an animation object during composition that will subscribe to an |
| * [AnimationClockObservable] or otherwise hold a long-lived reference to one to subscribe to later, |
| * create that object with a clock returned by this method. |
| */ |
| @Composable |
| fun AnimationClockObservable.asDisposableClock(): DisposableAnimationClock { |
| val disposable = remember(this) { DisposableAnimationClock(this) } |
| onCommit(disposable) { |
| onDispose { |
| disposable.dispose() |
| } |
| } |
| return disposable |
| } |
| |
| /** |
| * Clock that remembers all of its active subscriptions so that it can dispose of upstream |
| * subscriptions. Create auto-disposing clocks in composition using [asDisposableClock]. |
| */ |
| class DisposableAnimationClock( |
| private val clock: AnimationClockObservable |
| ) : AnimationClockObservable { |
| |
| // TODO switch to atomicfu if this class survives a move to suspending animation API |
| private val allSubscriptions = mutableSetOf<AnimationClockObserver>() |
| private var disposed = false |
| |
| override fun subscribe(observer: AnimationClockObserver) { |
| @Suppress("DEPRECATION_ERROR") |
| synchronized(allSubscriptions) { |
| if (!disposed) { |
| allSubscriptions += observer |
| clock.subscribe(observer) |
| } |
| } |
| } |
| |
| override fun unsubscribe(observer: AnimationClockObserver) { |
| @Suppress("DEPRECATION_ERROR") |
| synchronized(allSubscriptions) { |
| if (allSubscriptions.remove(observer)) { |
| clock.unsubscribe(observer) |
| } |
| } |
| } |
| |
| /** |
| * Unsubscribe all current subscriptions to the clock. No new subscriptions are permitted; |
| * further calls to [subscribe] will be ignored. |
| * After a call to [dispose], [isDisposed] will return `true`. |
| */ |
| fun dispose() { |
| @Suppress("DEPRECATION_ERROR") |
| synchronized(allSubscriptions) { |
| allSubscriptions.forEach { clock.unsubscribe(it) } |
| allSubscriptions.clear() |
| disposed = true |
| } |
| } |
| |
| /** |
| * `true` if [dispose] has been called and no new subscriptions are permitted. |
| */ |
| @Suppress("DEPRECATION_ERROR") |
| val isDisposed: Boolean get() = synchronized(allSubscriptions) { disposed == true } |
| } |