CameraRepository.java
/*
* Copyright (C) 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.core;
import android.content.Context;
import android.util.Log;
import androidx.annotation.GuardedBy;
import androidx.annotation.RestrictTo;
import androidx.annotation.RestrictTo.Scope;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* A collection of {@link BaseCamera} instances.
*
* @hide
*/
@RestrictTo(Scope.LIBRARY_GROUP)
public final class CameraRepository implements UseCaseGroup.StateChangeListener {
private static final String TAG = "CameraRepository";
private final Object mCamerasLock = new Object();
@GuardedBy("mCamerasLock")
private final Map<String, BaseCamera> mCameras = new HashMap<>();
/**
* Initializes the repository from a {@link Context}.
*
* <p>All cameras queried from the {@link CameraFactory} will be added to the repository.
*
* @hide
*/
@RestrictTo(Scope.LIBRARY_GROUP)
public void init(CameraFactory cameraFactory) {
synchronized (mCamerasLock) {
try {
Set<String> camerasList = cameraFactory.getAvailableCameraIds();
for (String id : camerasList) {
Log.d(TAG, "Added camera: " + id);
mCameras.put(id, cameraFactory.getCamera(id));
}
} catch (Exception e) {
throw new IllegalStateException("Unable to enumerate cameras", e);
}
}
}
/**
* Gets a {@link BaseCamera} for the given id.
*
* @param cameraId id for the camera
* @return a {@link BaseCamera} paired to this id
* @throws IllegalArgumentException if there is no camera paired with the id
*
* @hide
*/
@RestrictTo(Scope.LIBRARY_GROUP)
public BaseCamera getCamera(String cameraId) {
synchronized (mCamerasLock) {
BaseCamera camera = mCameras.get(cameraId);
if (camera == null) {
throw new IllegalArgumentException("Invalid camera: " + cameraId);
}
return camera;
}
}
/**
* Gets the set of all camera ids.
*
* @return set of all camera ids
*/
Set<String> getCameraIds() {
synchronized (mCamerasLock) {
return Collections.unmodifiableSet(mCameras.keySet());
}
}
/**
* Attaches all the use cases in the {@link UseCaseGroup} and opens all the associated cameras.
*
* <p>This will start streaming data to the uses cases which are also online.
*/
@Override
public void onGroupActive(UseCaseGroup useCaseGroup) {
synchronized (mCamerasLock) {
Map<String, Set<UseCase>> cameraIdToUseCaseMap = useCaseGroup.getCameraIdToUseCaseMap();
for (Map.Entry<String, Set<UseCase>> cameraUseCaseEntry :
cameraIdToUseCaseMap.entrySet()) {
BaseCamera camera = getCamera(cameraUseCaseEntry.getKey());
attachUseCasesToCamera(camera, cameraUseCaseEntry.getValue());
}
}
}
/** Attaches a set of use cases to a camera. */
@GuardedBy("mCamerasLock")
private void attachUseCasesToCamera(BaseCamera camera, Set<UseCase> useCases) {
camera.addOnlineUseCase(useCases);
}
/**
* Detaches all the use cases in the {@link UseCaseGroup} and closes the camera with no attached
* use cases.
*/
@Override
public void onGroupInactive(UseCaseGroup useCaseGroup) {
synchronized (mCamerasLock) {
Map<String, Set<UseCase>> cameraIdToUseCaseMap = useCaseGroup.getCameraIdToUseCaseMap();
for (Map.Entry<String, Set<UseCase>> cameraUseCaseEntry :
cameraIdToUseCaseMap.entrySet()) {
BaseCamera camera = getCamera(cameraUseCaseEntry.getKey());
detachUseCasesFromCamera(camera, cameraUseCaseEntry.getValue());
}
}
}
/** Detaches a set of use cases from a camera. */
@GuardedBy("mCamerasLock")
private void detachUseCasesFromCamera(BaseCamera camera, Set<UseCase> useCases) {
camera.removeOnlineUseCase(useCases);
}
}