CameraCaptureSessionStateCallbacks.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.internal;
import android.hardware.camera2.CameraCaptureSession;
import android.os.Build;
import android.view.Surface;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.camera.camera2.internal.compat.ApiCompat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* Different implementations of {@link CameraCaptureSession.StateCallback}.
*/
public final class CameraCaptureSessionStateCallbacks {
private CameraCaptureSessionStateCallbacks() {
}
/**
* Returns a session state callback which does nothing.
**/
@NonNull
public static CameraCaptureSession.StateCallback createNoOpCallback() {
return new NoOpSessionStateCallback();
}
/**
* Returns a session state callback which calls a list of other callbacks.
*/
@NonNull
public static CameraCaptureSession.StateCallback createComboCallback(
@NonNull List<CameraCaptureSession.StateCallback> callbacks) {
if (callbacks.isEmpty()) {
return createNoOpCallback();
} else if (callbacks.size() == 1) {
return callbacks.get(0);
}
return new ComboSessionStateCallback(callbacks);
}
/**
* Returns a session state callback which calls a list of other callbacks.
*/
@NonNull
public static CameraCaptureSession.StateCallback createComboCallback(
@NonNull CameraCaptureSession.StateCallback... callbacks) {
return createComboCallback(Arrays.asList(callbacks));
}
static final class NoOpSessionStateCallback extends CameraCaptureSession.StateCallback {
@Override
public void onConfigured(@NonNull CameraCaptureSession session) {
}
@Override
public void onActive(@NonNull CameraCaptureSession session) {
}
@Override
public void onClosed(@NonNull CameraCaptureSession session) {
}
@Override
public void onReady(@NonNull CameraCaptureSession session) {
}
@Override
public void onCaptureQueueEmpty(@NonNull CameraCaptureSession session) {
}
@Override
public void onSurfacePrepared(@NonNull CameraCaptureSession session,
@NonNull Surface surface) {
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession session) {
}
}
static final class ComboSessionStateCallback
extends CameraCaptureSession.StateCallback {
private final List<CameraCaptureSession.StateCallback> mCallbacks = new ArrayList<>();
ComboSessionStateCallback(@NonNull List<CameraCaptureSession.StateCallback> callbacks) {
for (CameraCaptureSession.StateCallback callback : callbacks) {
// A no-op callback doesn't do anything, so avoid adding it to the final list.
if (!(callback instanceof NoOpSessionStateCallback)) {
mCallbacks.add(callback);
}
}
}
@Override
public void onConfigured(@NonNull CameraCaptureSession session) {
for (CameraCaptureSession.StateCallback callback : mCallbacks) {
callback.onConfigured(session);
}
}
@Override
public void onActive(@NonNull CameraCaptureSession session) {
for (CameraCaptureSession.StateCallback callback : mCallbacks) {
callback.onActive(session);
}
}
@Override
public void onClosed(@NonNull CameraCaptureSession session) {
for (CameraCaptureSession.StateCallback callback : mCallbacks) {
callback.onClosed(session);
}
}
@Override
public void onReady(@NonNull CameraCaptureSession session) {
for (CameraCaptureSession.StateCallback callback : mCallbacks) {
callback.onReady(session);
}
}
@RequiresApi(api = Build.VERSION_CODES.O)
@Override
public void onCaptureQueueEmpty(@NonNull CameraCaptureSession session) {
for (CameraCaptureSession.StateCallback callback : mCallbacks) {
ApiCompat.Api26Impl.onCaptureQueueEmpty(callback, session);
}
}
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void onSurfacePrepared(@NonNull CameraCaptureSession session,
@NonNull Surface surface) {
for (CameraCaptureSession.StateCallback callback : mCallbacks) {
ApiCompat.Api23Impl.onSurfacePrepared(callback, session, surface);
}
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession session) {
for (CameraCaptureSession.StateCallback callback : mCallbacks) {
callback.onConfigureFailed(session);
}
}
}
}