ExposureStateImpl.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.camera2.internal;
import android.hardware.camera2.CameraCharacteristics;
import android.util.Range;
import android.util.Rational;
import androidx.annotation.GuardedBy;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.camera.camera2.internal.compat.CameraCharacteristicsCompat;
import androidx.camera.core.ExposureState;
/**
* An implementation of {@link ExposureState} where the values can be set.
*/
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
class ExposureStateImpl implements ExposureState {
private final Object mLock = new Object();
private final CameraCharacteristicsCompat mCameraCharacteristics;
@GuardedBy("mLock")
private int mExposureCompensation;
ExposureStateImpl(CameraCharacteristicsCompat characteristics, int exposureCompensation) {
mCameraCharacteristics = characteristics;
mExposureCompensation = exposureCompensation;
}
@Override
public int getExposureCompensationIndex() {
synchronized (mLock) {
return mExposureCompensation;
}
}
void setExposureCompensationIndex(int value) {
synchronized (mLock) {
mExposureCompensation = value;
}
}
@NonNull
@Override
public Range<Integer> getExposureCompensationRange() {
return mCameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_COMPENSATION_RANGE);
}
@NonNull
@Override
public Rational getExposureCompensationStep() {
if (!isExposureCompensationSupported()) {
return Rational.ZERO;
}
return mCameraCharacteristics.get(
CameraCharacteristics.CONTROL_AE_COMPENSATION_STEP);
}
@Override
public boolean isExposureCompensationSupported() {
Range<Integer> compensationRange =
mCameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_COMPENSATION_RANGE);
return compensationRange != null
&& compensationRange.getLower() != 0
&& compensationRange.getUpper() != 0;
}
}