ExperimentalAvailableCamerasLimiter.java
/*
* 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.camera.core;
import static java.lang.annotation.RetentionPolicy.CLASS;
import androidx.annotation.experimental.Experimental;
import java.lang.annotation.Retention;
/**
* Denotes that the annotated method uses an experimental API that configures CameraX to
* limit the available cameras applications can use in order to optimize the initialization
* latency.
*
* <p>Once the configuration is enabled, only cameras selected by this CameraSelector can be used
* in the applications. If the application binds the use cases with a CameraSelector that selects
* a unavailable camera, a {@link IllegalArgumentException} will be thrown.
*
* <p>CameraX initialization performs tasks including enumerating cameras, querying
* CameraCharacteristics and retrieving properties preparing for resolution determination. On
* some low end devices, these could take significant amount of time. Using the API can avoid the
* initialization of unnecessary cameras and speed up the time for camera start-up. For example,
* if the application uses only back cameras, it can set this configuration by
* CameraSelector.DEFAULT_BACK_CAMERA and then CameraX will avoid initializing front cameras to
* reduce the latency.
*/
@Retention(CLASS)
@Experimental
public @interface ExperimentalAvailableCamerasLimiter {
}