ListenableWatchFaceService.kt
/*
* Copyright 2021 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.wear.watchface
import android.view.SurfaceHolder
import androidx.wear.watchface.WatchFaceService.Companion.MAX_CREATE_WATCHFACE_TIME_MILLIS
import androidx.wear.watchface.style.CurrentUserStyleRepository
import androidx.wear.watchface.style.UserStyleSchema
import com.google.common.util.concurrent.ListenableFuture
import kotlinx.coroutines.suspendCancellableCoroutine
import kotlin.coroutines.resume
/**
* [ListenableFuture]-based compatibility wrapper around [WatchFaceService]'s suspending
* [WatchFaceService.createWatchFace].
*/
public abstract class ListenableWatchFaceService : WatchFaceService() {
/**
* Override this factory method to create your WatchFaceImpl. This method will be called by the
* library on a background thread, if possible any expensive initialization should be done
* asynchronously. The [WatchFace] and its [Renderer] should be accessed exclusively from the
* UiThread afterwards. There is a memory barrier between construction and rendering so no
* special threading primitives are required.
*
* Warning the system will likely time out waiting for watch face initialization if it takes
* longer than [MAX_CREATE_WATCHFACE_TIME_MILLIS] milliseconds.
*
* Note cancellation of the returned future is not supported.
*
* @param surfaceHolder The [SurfaceHolder] to pass to the [Renderer]'s constructor.
* @param watchState The [WatchState] for the watch face.
* @param complicationSlotsManager The [ComplicationSlotsManager] returned by
* [createComplicationSlotsManager].
* @param currentUserStyleRepository The [CurrentUserStyleRepository] constructed using the
* [UserStyleSchema] returned by [createUserStyleSchema].
* @return A [ListenableFuture] for a [WatchFace] whose [Renderer] uses the provided
* [surfaceHolder].
*/
protected abstract fun createWatchFaceFuture(
surfaceHolder: SurfaceHolder,
watchState: WatchState,
complicationSlotsManager: ComplicationSlotsManager,
currentUserStyleRepository: CurrentUserStyleRepository
): ListenableFuture<WatchFace>
override suspend fun createWatchFace(
surfaceHolder: SurfaceHolder,
watchState: WatchState,
complicationSlotsManager: ComplicationSlotsManager,
currentUserStyleRepository: CurrentUserStyleRepository
): WatchFace = suspendCancellableCoroutine {
val future = createWatchFaceFuture(
surfaceHolder,
watchState,
complicationSlotsManager,
currentUserStyleRepository
)
future.addListener(
{ it.resume(future.get()) },
{ runnable -> runnable.run() }
)
}
}