OpenMicrophoneResponse.java
/*
* Copyright 2022 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.car.app.media;
import static java.util.Objects.requireNonNull;
import android.annotation.SuppressLint;
import android.os.ParcelFileDescriptor;
import androidx.annotation.Keep;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.car.app.annotations.CarProtocol;
import androidx.car.app.annotations.RequiresCarApi;
import java.io.IOException;
import java.io.InputStream;
/**
* The response for a call to open microphone.
*
* <p>This is a host-side interface for handling audio callbacks. To record the microphone, use
* {@link CarAudioRecord}.
*/
@CarProtocol
@RequiresCarApi(5)
public final class OpenMicrophoneResponse {
@Keep
@Nullable
private final CarAudioCallbackDelegate mCarAudioCallbackDelegate;
@Keep
@Nullable
private final ParcelFileDescriptor mCarMicrophoneDescriptor;
OpenMicrophoneResponse(@NonNull Builder builder) {
mCarAudioCallbackDelegate = builder.mCarAudioCallbackDelegate;
mCarMicrophoneDescriptor = builder.mCarMicrophoneDescriptor;
}
/** Constructs an empty instance, used by serialization code. */
private OpenMicrophoneResponse() {
mCarMicrophoneDescriptor = null;
mCarAudioCallbackDelegate = null;
}
/**
* Returns the callback to use to communicate recording state.
*/
@NonNull
public CarAudioCallbackDelegate getCarAudioCallback() {
return requireNonNull(mCarAudioCallbackDelegate);
}
/**
* Returns an {@link InputStream} to read the microphone bytes from.
*/
@NonNull
public InputStream getCarMicrophoneInputStream() {
ParcelFileDescriptor pfd = mCarMicrophoneDescriptor;
if (pfd == null) {
try {
// For no pfd return a closed pfd.
ParcelFileDescriptor[] pfds = ParcelFileDescriptor.createReliablePipe();
pfds[1].close();
pfd = pfds[0];
} catch (IOException e) {
throw new IllegalStateException(e);
}
}
return new ParcelFileDescriptor.AutoCloseInputStream(pfd);
}
/**
* A builder for {@link OpenMicrophoneResponse}s.
*/
public static final class Builder {
@NonNull
final CarAudioCallbackDelegate mCarAudioCallbackDelegate;
@Nullable
ParcelFileDescriptor mCarMicrophoneDescriptor;
@SuppressLint("ExecutorRegistration")
public Builder(@NonNull CarAudioCallback callback) {
mCarAudioCallbackDelegate = CarAudioCallbackDelegate.create(requireNonNull(callback));
}
/**
* Sets the {@link ParcelFileDescriptor} that is to be used to read microphone bytes from
* the car.
*
* <p>This is only needed in projected case, where the car microphone comes from the host.
*/
@NonNull
@SuppressLint("MissingGetterMatchingBuilder")
public Builder setCarMicrophoneDescriptor(
@NonNull ParcelFileDescriptor carMicrophoneDescriptor) {
mCarMicrophoneDescriptor = requireNonNull(carMicrophoneDescriptor);
return this;
}
/**
* Builds the {@link OpenMicrophoneResponse} for this builder.
*/
@NonNull
public OpenMicrophoneResponse build() {
return new OpenMicrophoneResponse(this);
}
}
}