Home | History | Annotate | Download | only in telecom 
      1 /*
      2  * Copyright 2014, The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.server.telecom;
     18 
     19 import android.content.Context;
     20 import android.media.AudioManager;
     21 import android.media.ToneGenerator;
     22 import android.provider.Settings;
     23 
     24 // TODO: Needed for move to system service: import com.android.internal.R;
     25 
     26 /**
     27  * Plays DTMF tones locally for the caller to hear. In order to reduce (1) the amount of times we
     28  * check the "play local tones" setting and (2) the length of time we keep the tone generator, this
     29  * class employs a concept of a call "session" that starts and stops when the foreground call
     30  * changes.
     31  */
     32 class DtmfLocalTonePlayer extends CallsManagerListenerBase {
     33     /** Generator used to actually play the tone. */
     34     private ToneGenerator mToneGenerator;
     35 
     36     /** The current call associated with an existing dtmf session. */
     37     private Call mCall;
     38 
     39     /** The context. */
     40     private final Context mContext;
     41 
     42     public DtmfLocalTonePlayer(Context context) {
     43         mContext = context;
     44     }
     45 
     46     /** {@inheritDoc} */
     47     @Override
     48     public void onForegroundCallChanged(Call oldForegroundCall, Call newForegroundCall) {
     49         endDtmfSession(oldForegroundCall);
     50         startDtmfSession(newForegroundCall);
     51     }
     52 
     53     /**
     54      * Starts playing the dtmf tone specified by c.
     55      *
     56      * @param call The associated call.
     57      * @param c The digit to play.
     58      */
     59     void playTone(Call call, char c) {
     60         // Do nothing if it is not the right call.
     61         if (mCall != call) {
     62             return;
     63         }
     64 
     65         if (mToneGenerator == null) {
     66             Log.d(this, "playTone: mToneGenerator == null, %c.", c);
     67         } else {
     68             Log.d(this, "starting local tone: %c.", c);
     69             int tone = getMappedTone(c);
     70             if (tone != ToneGenerator.TONE_UNKNOWN) {
     71                 mToneGenerator.startTone(tone, -1 /* toneDuration */);
     72             }
     73         }
     74     }
     75 
     76     /**
     77      * Stops any currently playing dtmf tone.
     78      *
     79      * @param call The associated call.
     80      */
     81     void stopTone(Call call) {
     82         // Do nothing if it's not the right call.
     83         if (mCall != call) {
     84             return;
     85         }
     86 
     87         if (mToneGenerator == null) {
     88             Log.d(this, "stopTone: mToneGenerator == null.");
     89         } else {
     90             Log.d(this, "stopping local tone.");
     91             mToneGenerator.stopTone();
     92         }
     93     }
     94 
     95     /**
     96      * Runs initialization requires to play local tones during a call.
     97      *
     98      * @param call The call associated with this dtmf session.
     99      */
    100     private void startDtmfSession(Call call) {
    101         if (call == null) {
    102             return;
    103         }
    104         final Context context = call.getContext();
    105         final boolean areLocalTonesEnabled;
    106         if (context.getResources().getBoolean(R.bool.allow_local_dtmf_tones)) {
    107             areLocalTonesEnabled = Settings.System.getInt(
    108                     context.getContentResolver(), Settings.System.DTMF_TONE_WHEN_DIALING, 1) == 1;
    109         } else {
    110             areLocalTonesEnabled = false;
    111         }
    112 
    113         mCall = call;
    114 
    115         if (areLocalTonesEnabled) {
    116             if (mToneGenerator == null) {
    117                 try {
    118                     mToneGenerator = new ToneGenerator(AudioManager.STREAM_DTMF, 80);
    119                 } catch (RuntimeException e) {
    120                     Log.e(this, e, "Error creating local tone generator.");
    121                     mToneGenerator = null;
    122                 }
    123             }
    124         }
    125     }
    126 
    127     /**
    128      * Releases resources needed for playing local dtmf tones.
    129      *
    130      * @param call The call associated with the session to end.
    131      */
    132     private void endDtmfSession(Call call) {
    133         if (call != null && mCall == call) {
    134             // Do a stopTone() in case the sessions ends before we are told to stop the tone.
    135             stopTone(call);
    136 
    137             mCall = null;
    138 
    139             if (mToneGenerator != null) {
    140                 mToneGenerator.release();
    141                 mToneGenerator = null;
    142             }
    143         }
    144     }
    145 
    146     private static final int getMappedTone(char digit) {
    147         if (digit >= '0' && digit <= '9') {
    148             return ToneGenerator.TONE_DTMF_0 + digit - '0';
    149         } else if (digit == '#') {
    150             return ToneGenerator.TONE_DTMF_P;
    151         } else if (digit == '*') {
    152             return ToneGenerator.TONE_DTMF_S;
    153         }
    154         return ToneGenerator.TONE_UNKNOWN;
    155     }
    156 }
    157