src/com/android/telecomm/CallAudioManager.java

/*
 * Copyright (C) 2014 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 com.android.telecomm;

import android.content.Context;
import android.media.AudioManager;
import android.telecomm.CallAudioState;
import android.telecomm.CallState;

import com.google.common.base.Preconditions;

/**
 * This class manages audio modes, streams and other properties.
 */
final class CallAudioManager extends CallsManagerListenerBase {
    private static final int STREAM_NONE = -1;

    private final AudioManager mAudioManager;
    private final WiredHeadsetManager mWiredHeadsetManager;
    private CallAudioState mAudioState;
    private int mAudioFocusStreamType;
    private boolean mIsRinging;
    private boolean mWasSpeakerOn;

    CallAudioManager() {
        Context context = TelecommApp.getInstance();
        mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
        mWiredHeadsetManager = new WiredHeadsetManager(this);
        mAudioState = getInitialAudioState();
        mAudioFocusStreamType = STREAM_NONE;
    }

    CallAudioState getAudioState() {
        return mAudioState;
    }

    @Override
    public void onCallAdded(Call call) {
        updateAudioStreamAndMode();
        if (CallsManager.getInstance().getCalls().size() == 1) {
            Log.v(this, "first call added, reseting system audio to default state");
            setInitialAudioState();
        } else if (!call.isIncoming()) {
            // Unmute new outgoing call.
            setSystemAudioState(false, mAudioState.route, mAudioState.supportedRouteMask);
        }
    }

    @Override
    public void onCallRemoved(Call call) {
        if (CallsManager.getInstance().getCalls().isEmpty()) {
            Log.v(this, "all calls removed, reseting system audio to default state");
            setInitialAudioState();
        }
        updateAudioStreamAndMode();
    }

    @Override
    public void onCallStateChanged(Call call, CallState oldState, CallState newState) {
        updateAudioStreamAndMode();
    }

    @Override
    public void onIncomingCallAnswered(Call call) {
        // Unmute new incoming call.
        setSystemAudioState(false, mAudioState.route, mAudioState.supportedRouteMask);
    }

    @Override
    public void onForegroundCallChanged(Call oldForegroundCall, Call newForegroundCall) {
        updateAudioStreamAndMode();
        // Ensure that the foreground call knows about the latest audio state.
        updateAudioForForegroundCall();
    }

    void mute(boolean shouldMute) {
        Log.v(this, "mute, shouldMute: %b", shouldMute);

        // Don't mute if there are any emergency calls.
        if (CallsManager.getInstance().hasEmergencyCall()) {
            shouldMute = false;
            Log.v(this, "ignoring mute for emergency call");
        }

        if (mAudioState.isMuted != shouldMute) {
            setSystemAudioState(shouldMute, mAudioState.route, mAudioState.supportedRouteMask);
        }
    }

    /**
     * Changed the audio route, for example from earpiece to speaker phone.
     *
     * @param route The new audio route to use. See {@link CallAudioState}.
     */
    void setAudioRoute(int route) {
        Log.v(this, "setAudioRoute, route: %s", CallAudioState.audioRouteToString(route));

        // Change ROUTE_WIRED_OR_EARPIECE to a single entry.
        int newRoute = selectWiredOrEarpiece(route, mAudioState.supportedRouteMask);

        // If route is unsupported, do nothing.
        if ((mAudioState.supportedRouteMask | newRoute) == 0) {
            Log.wtf(this, "Asking to set to a route that is unsupported: %d", newRoute);
            return;
        }

        if (mAudioState.route != newRoute) {
            // Remember the new speaker state so it can be restored when the user plugs and unplugs
            // a headset.
            mWasSpeakerOn = newRoute == CallAudioState.ROUTE_SPEAKER;
            setSystemAudioState(mAudioState.isMuted, newRoute, mAudioState.supportedRouteMask);
        }
    }

    void setIsRinging(boolean isRinging) {
        if (mIsRinging != isRinging) {
            Log.v(this, "setIsRinging %b -> %b", mIsRinging, isRinging);
            mIsRinging = isRinging;
            updateAudioStreamAndMode();
        }
    }

    /**
      * Updates the audio route when the headset plugged in state changes. For example, if audio is
      * being routed over speakerphone and a headset is plugged in then switch to wired headset.
      */
    void onHeadsetPluggedInChanged(boolean oldIsPluggedIn, boolean newIsPluggedIn) {
        int newRoute = CallAudioState.ROUTE_EARPIECE;
        if (newIsPluggedIn) {
            newRoute = CallAudioState.ROUTE_WIRED_HEADSET;
        } else if (mWasSpeakerOn) {
            Call call = CallsManager.getInstance().getForegroundCall();
            if (call != null && call.isAlive()) {
                // Restore the speaker state.
                newRoute = CallAudioState.ROUTE_SPEAKER;
            }
        }
        setSystemAudioState(mAudioState.isMuted, newRoute, calculateSupportedRoutes());
    }

    private void setSystemAudioState(boolean isMuted, int route, int supportedRouteMask) {
        CallAudioState oldAudioState = mAudioState;
        mAudioState = new CallAudioState(isMuted, route, supportedRouteMask);
        Log.i(this, "changing audio state from %s to %s", oldAudioState, mAudioState);

        // Mute.
        if (mAudioState.isMuted != mAudioManager.isMicrophoneMute()) {
            Log.i(this, "changing microphone mute state to: %b", mAudioState.isMuted);
            mAudioManager.setMicrophoneMute(mAudioState.isMuted);
        }

        // Audio route.
        if (mAudioState.route == CallAudioState.ROUTE_SPEAKER) {
            if (!mAudioManager.isSpeakerphoneOn()) {
                Log.i(this, "turning speaker phone on");
                mAudioManager.setSpeakerphoneOn(true);
            }
        } else if (mAudioState.route == CallAudioState.ROUTE_EARPIECE ||
                mAudioState.route == CallAudioState.ROUTE_WIRED_HEADSET) {
            // Wired headset and earpiece work the same way
            if (mAudioManager.isSpeakerphoneOn()) {
                Log.i(this, "turning speaker phone off");
                mAudioManager.setSpeakerphoneOn(false);
            }
        }

        if (!oldAudioState.equals(mAudioState)) {
            CallsManager.getInstance().onAudioStateChanged(oldAudioState, mAudioState);
            updateAudioForForegroundCall();
        }
    }

    private void updateAudioStreamAndMode() {
        Log.v(this, "updateAudioStreamAndMode, mIsRinging: %b", mIsRinging);
        if (mIsRinging) {
            requestAudioFocusAndSetMode(AudioManager.STREAM_RING, AudioManager.MODE_RINGTONE);
        } else {
            Call call = CallsManager.getInstance().getForegroundCall();
            if (call != null) {
                int mode = TelephonyUtil.isCurrentlyPSTNCall(call) ?
                        AudioManager.MODE_IN_CALL : AudioManager.MODE_IN_COMMUNICATION;
                requestAudioFocusAndSetMode(AudioManager.STREAM_VOICE_CALL, mode);
            } else {
                abandonAudioFocus();
            }
        }
    }

    private void requestAudioFocusAndSetMode(int stream, int mode) {
        Log.v(this, "setSystemAudioStreamAndMode, stream: %d -> %d", mAudioFocusStreamType, stream);
        Preconditions.checkState(stream != STREAM_NONE);

        // Only request audio focus once. If the stream type changes there's no need to abandon
        // and re-request audio focus.  The system doesn't really care about the stream we requested
        // focus for so just silently switch.
        if (mAudioFocusStreamType == STREAM_NONE) {
            Log.v(this, "requesting audio focus for stream: %d", stream);
            mAudioManager.requestAudioFocusForCall(stream,
                    AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);
        }
        mAudioFocusStreamType = stream;
        setMode(mode);
    }

    private void abandonAudioFocus() {
        if (mAudioFocusStreamType != STREAM_NONE) {
            setMode(AudioManager.MODE_NORMAL);
            Log.v(this, "abandoning audio focus");
            mAudioManager.abandonAudioFocusForCall();
            mAudioFocusStreamType = STREAM_NONE;
        }
    }

    /**
     * Sets the audio mode.
     *
     * @param newMode Mode constant from AudioManager.MODE_*.
     */
    private void setMode(int newMode) {
        Preconditions.checkState(mAudioFocusStreamType != STREAM_NONE);
        int oldMode = mAudioManager.getMode();
        Log.v(this, "Request to change audio mode from %d to %d", oldMode, newMode);
        if (oldMode != newMode) {
            mAudioManager.setMode(newMode);
        }
    }

    private int selectWiredOrEarpiece(int route, int supportedRouteMask) {
        // Since they are mutually exclusive and one is ALWAYS valid, we allow a special input of
        // ROUTE_WIRED_OR_EARPIECE so that callers dont have to make a call to check which is
        // supported before calling setAudioRoute.
        if (route == CallAudioState.ROUTE_WIRED_OR_EARPIECE) {
            route = CallAudioState.ROUTE_WIRED_OR_EARPIECE & supportedRouteMask;
            if (route == 0) {
                Log.wtf(this, "One of wired headset or earpiece should always be valid.");
                // assume earpiece in this case.
                route = CallAudioState.ROUTE_EARPIECE;
            }
        }
        return route;
    }

    private int calculateSupportedRoutes() {
        int routeMask = CallAudioState.ROUTE_SPEAKER;

        if (mWiredHeadsetManager.isPluggedIn()) {
            routeMask |= CallAudioState.ROUTE_WIRED_HEADSET;
        } else {
            routeMask |= CallAudioState.ROUTE_EARPIECE;
        }

        return routeMask;
    }

    private CallAudioState getInitialAudioState() {
        int supportedRouteMask = calculateSupportedRoutes();
        return new CallAudioState(false,
                selectWiredOrEarpiece(CallAudioState.ROUTE_WIRED_OR_EARPIECE, supportedRouteMask),
                supportedRouteMask);
    }

    private void setInitialAudioState() {
        CallAudioState audioState = getInitialAudioState();
        setSystemAudioState(audioState.isMuted, audioState.route, audioState.supportedRouteMask);
    }

    private void updateAudioForForegroundCall() {
        Call call = CallsManager.getInstance().getForegroundCall();
        if (call != null && call.getCallService() != null) {
            call.getCallService().onAudioStateChanged(call.getId(), mAudioState);
        }
    }
}