Camera2CameraFactory.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.camera2.impl;
import android.content.Context;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCharacteristics;
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CameraMetadata;
import android.os.Handler;
import android.os.HandlerThread;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
import androidx.annotation.RestrictTo.Scope;
import androidx.camera.core.BaseCamera;
import androidx.camera.core.CameraFactory;
import androidx.camera.core.CameraInfoUnavailableException;
import androidx.camera.core.CameraX.LensFacing;
import androidx.camera.core.CameraXThreads;
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
/**
* The factory class that creates {@link Camera} instances.
* @hide
*/
@RestrictTo(Scope.LIBRARY)
public final class Camera2CameraFactory implements CameraFactory {
private static final String TAG = "Camera2CameraFactory";
private static final HandlerThread sHandlerThread = new HandlerThread(CameraXThreads.TAG);
private static final Handler sHandler;
static {
sHandlerThread.start();
sHandler = new Handler(sHandlerThread.getLooper());
}
private final CameraManager mCameraManager;
public Camera2CameraFactory(Context context) {
mCameraManager = (CameraManager) context.getSystemService(Context.CAMERA_SERVICE);
}
@Override
public BaseCamera getCamera(String cameraId) {
return new Camera(mCameraManager, cameraId, sHandler);
}
@Override
public Set<String> getAvailableCameraIds() throws CameraInfoUnavailableException {
List<String> camerasList = null;
try {
camerasList = Arrays.asList(mCameraManager.getCameraIdList());
} catch (CameraAccessException e) {
throw new CameraInfoUnavailableException(
"Unable to retrieve list of cameras on device.", e);
}
// Use a LinkedHashSet to preserve order
return new LinkedHashSet<>(camerasList);
}
@Nullable
@Override
public String cameraIdForLensFacing(LensFacing lensFacing)
throws CameraInfoUnavailableException {
Set<String> cameraIds = getAvailableCameraIds();
// Convert to from CameraX enum to Camera2 CameraMetadata
Integer lensFacingInteger = -1;
switch (lensFacing) {
case BACK:
lensFacingInteger = CameraMetadata.LENS_FACING_BACK;
break;
case FRONT:
lensFacingInteger = CameraMetadata.LENS_FACING_FRONT;
break;
}
for (String cameraId : cameraIds) {
CameraCharacteristics characteristics = null;
try {
characteristics = mCameraManager.getCameraCharacteristics(cameraId);
} catch (CameraAccessException e) {
throw new CameraInfoUnavailableException(
"Unable to retrieve info for camera with id " + cameraId + ".", e);
}
Integer cameraLensFacing = characteristics.get(CameraCharacteristics.LENS_FACING);
if (cameraLensFacing == null) {
continue;
}
if (cameraLensFacing.equals(lensFacingInteger)) {
return cameraId;
}
}
return null;
}
}