LifecycleCameraProvider.java

/*
 * Copyright 2019 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.camera.lifecycle;

import androidx.annotation.NonNull;
import androidx.camera.core.CameraProvider;
import androidx.camera.core.UseCase;
import androidx.lifecycle.Lifecycle;
import androidx.lifecycle.LifecycleOwner;

/**
 * Provides access to a camera which has has its opening and closing controlled by a
 * {@link LifecycleOwner}.
 */
interface LifecycleCameraProvider extends CameraProvider {

    /**
     * Returns true if the {@link UseCase} is bound to a lifecycle. Otherwise returns false.
     *
     * <p>After binding a use case, use cases remain bound until the lifecycle reaches a
     * {@link Lifecycle.State#DESTROYED} state or if is unbound by calls to
     * {@link #unbind(UseCase...)} or {@link #unbindAll()}.
     */
    boolean isBound(@NonNull UseCase useCase);

    /**
     * Unbinds all specified use cases from the lifecycle provider.
     *
     * <p>This will initiate a close of every open camera which has zero {@link UseCase}
     * associated with it at the end of this call.
     *
     * <p>If a use case in the argument list is not bound, then it is simply ignored.
     *
     * <p>After unbinding a UseCase, the UseCase can be bound to another {@link Lifecycle}
     * however listeners and settings should be reset by the application.
     *
     * @param useCases The collection of use cases to remove.
     * @throws IllegalStateException If not called on main thread.
     */
    void unbind(@NonNull UseCase... useCases);

    /**
     * Unbinds all use cases from the lifecycle provider and removes them from CameraX.
     *
     * <p>This will initiate a close of every currently open camera.
     *
     * @throws IllegalStateException If not called on main thread.
     */
    void unbindAll();
}