xref: /packages/services/Car/car-support-lib/src/android/support/car/media/CarAudioManager.java

/*
 * Copyright (C) 2015 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 android.support.car.media;

import android.Manifest;
import android.media.AudioAttributes;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioManager.OnAudioFocusChangeListener;
import android.support.annotation.IntDef;
import android.support.annotation.RequiresPermission;
import android.support.car.CarManagerBase;
import android.support.car.CarNotConnectedException;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/**
 * APIs for handling car-specific audio use cases. Provides a set of CAR_AUDIO_USAGE_* constants
 * that can be used to route audio by use case to the car. Important beyond the normal
 * {@link AudioManager} class methods because it handles multi channel audio. Includes use cases
 * such as routing call audio only to the driver and not through all speakers.
 */
public abstract class CarAudioManager implements CarManagerBase {

    /**
     * Audio usage for unspecified type.
     */
    public static final int CAR_AUDIO_USAGE_DEFAULT = 0;
    /**
     * Audio usage for playing music.
     */
    public static final int CAR_AUDIO_USAGE_MUSIC = 1;
    /**
     * Audio usage for hardware radio.
     * @hide
     */
    public static final int CAR_AUDIO_USAGE_RADIO = 2;
    /**
     * Audio usage for playing navigation guidance.
     */
    public static final int CAR_AUDIO_USAGE_NAVIGATION_GUIDANCE = 3;
    /**
     * Audio usage for voice call.
     */
    public static final int CAR_AUDIO_USAGE_VOICE_CALL = 4;
    /**
     * Audio usage for voice search or voice command.
     */
    public static final int CAR_AUDIO_USAGE_VOICE_COMMAND = 5;
    /**
     * Audio usage for playing alarm.
     */
    public static final int CAR_AUDIO_USAGE_ALARM = 6;
    /**
     * Audio usage for notification sound.
     */
    public static final int CAR_AUDIO_USAGE_NOTIFICATION = 7;
    /**
     * Audio usage for system sound (such as UI feedback).
     */
    public static final int CAR_AUDIO_USAGE_SYSTEM_SOUND = 8;
    /**
     * Audio usage for playing safety alerts.
     */
    public static final int CAR_AUDIO_USAGE_SYSTEM_SAFETY_ALERT = 9;

    /** @hide */
    public static final int CAR_AUDIO_USAGE_MAX = CAR_AUDIO_USAGE_SYSTEM_SAFETY_ALERT;

    /** @hide */
    @IntDef({CAR_AUDIO_USAGE_DEFAULT, CAR_AUDIO_USAGE_MUSIC, CAR_AUDIO_USAGE_RADIO,
        CAR_AUDIO_USAGE_NAVIGATION_GUIDANCE, CAR_AUDIO_USAGE_VOICE_CALL,
        CAR_AUDIO_USAGE_VOICE_COMMAND, CAR_AUDIO_USAGE_ALARM, CAR_AUDIO_USAGE_NOTIFICATION,
        CAR_AUDIO_USAGE_SYSTEM_SOUND, CAR_AUDIO_USAGE_SYSTEM_SAFETY_ALERT})
    @Retention(RetentionPolicy.SOURCE)
    public @interface CarAudioUsage {}

    /**
     * Return {@link AudioAttributes} relevant for the given usage in car.
     */
    public abstract AudioAttributes getAudioAttributesForCarUsage(@CarAudioUsage int carUsage)
            throws CarNotConnectedException;

    /**
     * Request audio focus. Send a request to obtain audio focus.
     *
     * @param listener The listener to be notified of audio focus changes.
     * @param requestAttributes Obtained from {@link #getAudioAttributesForCarUsage(int)}.
     * @param durationHint Use {@link AudioManager#AUDIOFOCUS_GAIN_TRANSIENT} to indicate this
     * focus request is temporary and focus will be abandoned shortly. Examples of transient
     * requests include playback of driving directions and notification sounds.
     * </p>
     * Use {@link AudioManager#AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK} to indicate it's OK for the
     * previous focus owner to keep playing if it ducks its audio output.
     * </p>
     * Use {@link AudioManager#AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE} for a temporary request that
     * benefits from the system not playing disruptive sounds such as notifications, for use cases
     * such as voice memo recording, or speech recognition.
     * </p>
     * Use {@link AudioManager#AUDIOFOCUS_GAIN} for a focus request of unknown duration, such as
     * the playback of a song or a video.
     * @return {@link AudioManager#AUDIOFOCUS_REQUEST_FAILED}, or
     * {@link AudioManager#AUDIOFOCUS_REQUEST_GRANTED}.
     * @throws IllegalArgumentException
     */
    public abstract int requestAudioFocus(OnAudioFocusChangeListener listener,
            AudioAttributes requestAttributes,
            int durationHint) throws CarNotConnectedException, IllegalArgumentException;

    /**
     * @hide
     */
    public abstract int requestAudioFocus(OnAudioFocusChangeListener listener,
            AudioAttributes requestAttributes,
            int durationHint,
            int flags) throws CarNotConnectedException, IllegalArgumentException;
    /**
     * Abandon audio focus. Causes the previous focus owner (if any) to receive focus.
     * @param listener The listener with which focus was requested.
     * @param aa
     */
    public abstract void abandonAudioFocus(OnAudioFocusChangeListener listener, AudioAttributes aa);

    /**
     * Get {@link AudioFormat} for audio record.
     * @return {@link AudioFormat} for audio record.
     */
    public abstract AudioFormat getAudioRecordAudioFormat() throws CarNotConnectedException;

    public abstract boolean isAudioRecordSupported() throws CarNotConnectedException;

    /**
     * Get minimum buffer size for {@link CarAudioRecord}.
     *
     * @return Buffer size in bytes.
     */
    public abstract int getAudioRecordMinBufferSize()
            throws CarNotConnectedException;

    /**
     * Get maximum buffer size for {@link CarAudioRecord}.
     *
     * @return Buffer size in bytes.
     */
    public abstract int getAudioRecordMaxBufferSize()
            throws CarNotConnectedException;

    /**
     * Create a {@link CarAudioRecord} for the current {@link CarAudioManager}. There can be
     * multiple instances of {@link CarAudioRecord}. Requires {@link
     * android.Manifest.permission#RECORD_AUDIO} permission.
     *
     * @param bufferSize Should be a multiple of minimum buffer size acquired from {@link
     * #getAudioRecordMinBufferSize()}. Cannot exceed {@link #getAudioRecordMaxBufferSize()}.
     *
     * @return {@link CarAudioRecord} instance for the given stream.
     * @throws IllegalArgumentException if passed parameter (such as bufferSize) is wrong.
     * @throws SecurityException if client does not have
     * {@link android.Manifest.permission#RECORD_AUDIO} permission.
     */
    @RequiresPermission(Manifest.permission.RECORD_AUDIO)
    public abstract CarAudioRecord createCarAudioRecord(int bufferSize)
            throws SecurityException, CarNotConnectedException;

    /**
     * Check if media audio is muted or not (includes music and radio). Any application
     * taking audio focus for media stream will move it out of a mute state.
     *
     * @return Returns {@code true} if media is muted.
     */
    public abstract boolean isMediaMuted() throws CarNotConnectedException;

    /**
     * Mute or unmute media stream including radio. Can involve audio focus change to stop
     * the the app currently holding audio focus. If requester is currently holding audio focus,
     * it gets LOSS_TRANSIENT focus loss. Requires
     * {@link android.support.car.Car#PERMISSION_CAR_CONTROL_AUDIO_VOLUME}
     * permission.
     *
     * @param mute Returns {@code true} if media stream should be muted.
     * @return Mute state of system after the request. A mute request can fail if a higher priority
     * audio stream (such as a voice call) is already being played.
     * @hide
     */
    public abstract boolean setMediaMute(boolean mute) throws CarNotConnectedException;
}