PreviewViewMeteringPointFactory.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.view;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.Size;
import androidx.annotation.AnyThread;
import androidx.annotation.GuardedBy;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.annotation.RestrictTo;
import androidx.annotation.UiThread;
import androidx.camera.core.MeteringPointFactory;
import androidx.camera.core.impl.utils.Threads;
/**
* {@link MeteringPointFactory} for {@link PreviewView}.
*
* @hide
*/
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
class PreviewViewMeteringPointFactory extends MeteringPointFactory {
static final PointF INVALID_POINT = new PointF(2F, 2F);
@NonNull
private final PreviewTransformation mPreviewTransformation;
@GuardedBy("this")
@Nullable
private Matrix mMatrix;
PreviewViewMeteringPointFactory(@NonNull PreviewTransformation previewTransformation) {
mPreviewTransformation = previewTransformation;
}
@AnyThread
@NonNull
@Override
protected PointF convertPoint(float x, float y) {
float[] point = new float[]{x, y};
synchronized (this) {
if (mMatrix == null) {
return INVALID_POINT;
}
mMatrix.mapPoints(point);
}
return new PointF(point[0], point[1]);
}
@UiThread
void recalculate(@NonNull Size previewViewSize, int layoutDirection) {
Threads.checkMainThread();
synchronized (this) {
if (previewViewSize.getWidth() == 0 || previewViewSize.getHeight() == 0) {
mMatrix = null;
return;
}
mMatrix = mPreviewTransformation.getPreviewViewToNormalizedSurfaceMatrix(
previewViewSize,
layoutDirection);
}
}
}