CameraFilter.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 androidx.annotation.NonNull;
import java.util.LinkedHashSet;
/**
* An interface for filtering cameras.
*/
@ExperimentalCameraFilter
public interface CameraFilter {
/**
* Filters a set of {@link Camera}s and returns those matching the requirements.
*
* <p>If the output set contains cameras not in the input set, when used by a
* {@link androidx.camera.core.CameraSelector} then it will result in an
* IllegalArgumentException thrown when calling bindToLifecycle.
*
* <p>The camera that has lower index in the set has higher priority. When used by
* {@link androidx.camera.core.CameraSelector.Builder#addCameraFilter(CameraFilter)}, the
* available cameras will be filtered by all {@link CameraFilter}s by the order they were
* added. The first camera in the result will be selected if there are multiple cameras left.
*
* @param cameras The input set of {@link Camera}s being filtered. It's not expected to be
* modified.
* @return The output set of {@link Camera}s that match the requirements. Users are expected
* to create a new set to return with.
*/
@NonNull
LinkedHashSet<Camera> filter(@NonNull LinkedHashSet<Camera> cameras);
}