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      1 /*
      2  * Copyright (C) 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 android.alsa;
     18 
     19 import android.util.Slog;
     20 import java.io.BufferedReader;
     21 import java.io.File;
     22 import java.io.FileNotFoundException;
     23 import java.io.FileReader;
     24 import java.io.IOException;
     25 import java.util.Vector;
     26 
     27 /**
     28  * @hide Retrieves information from an ALSA "cards" file.
     29  */
     30 public class AlsaCardsParser {
     31     private static final String TAG = "AlsaCardsParser";
     32 
     33     private static LineTokenizer tokenizer_ = new LineTokenizer(" :[]");
     34 
     35     public class AlsaCardRecord {
     36         public int mCardNum = -1;
     37         public String mField1 = "";
     38         public String mCardName = "";
     39         public String mCardDescription = "";
     40 
     41         public AlsaCardRecord() {}
     42 
     43         public boolean parse(String line, int lineIndex) {
     44             int tokenIndex = 0;
     45             int delimIndex = 0;
     46             if (lineIndex == 0) {
     47                 // line # (skip)
     48                 tokenIndex = tokenizer_.nextToken(line, tokenIndex);
     49                 delimIndex = tokenizer_.nextDelimiter(line, tokenIndex);
     50 
     51                 // mField1
     52                 tokenIndex = tokenizer_.nextToken(line, delimIndex);
     53                 delimIndex = tokenizer_.nextDelimiter(line, tokenIndex);
     54                 mField1 = line.substring(tokenIndex, delimIndex);
     55 
     56                 // mCardName
     57                 tokenIndex = tokenizer_.nextToken(line, delimIndex);
     58                 // delimIndex = tokenizer_.nextDelimiter(line, tokenIndex);
     59                 mCardName = line.substring(tokenIndex);
     60                 // done
     61               } else if (lineIndex == 1) {
     62                   tokenIndex = tokenizer_.nextToken(line, 0);
     63                   if (tokenIndex != -1) {
     64                       mCardDescription = line.substring(tokenIndex);
     65                   }
     66             }
     67 
     68             return true;
     69         }
     70 
     71         public String textFormat() {
     72           return mCardName + " : " + mCardDescription;
     73         }
     74     }
     75 
     76     private Vector<AlsaCardRecord> cardRecords_ = new Vector<AlsaCardRecord>();
     77 
     78     public void scan() {
     79           cardRecords_.clear();
     80           final String cardsFilePath = "/proc/asound/cards";
     81           File cardsFile = new File(cardsFilePath);
     82           try {
     83               FileReader reader = new FileReader(cardsFile);
     84               BufferedReader bufferedReader = new BufferedReader(reader);
     85               String line = "";
     86               while ((line = bufferedReader.readLine()) != null) {
     87                   AlsaCardRecord cardRecord = new AlsaCardRecord();
     88                   cardRecord.parse(line, 0);
     89                   cardRecord.parse(line = bufferedReader.readLine(), 1);
     90                   cardRecords_.add(cardRecord);
     91               }
     92               reader.close();
     93           } catch (FileNotFoundException e) {
     94               e.printStackTrace();
     95           } catch (IOException e) {
     96               e.printStackTrace();
     97           }
     98       }
     99 
    100       public AlsaCardRecord getCardRecordAt(int index) {
    101           return cardRecords_.get(index);
    102       }
    103 
    104       public int getNumCardRecords() {
    105           return cardRecords_.size();
    106       }
    107 
    108     public void Log() {
    109       int numCardRecs = getNumCardRecords();
    110       for (int index = 0; index < numCardRecs; ++index) {
    111           Slog.w(TAG, "usb:" + getCardRecordAt(index).textFormat());
    112       }
    113     }
    114 
    115     public AlsaCardsParser() {}
    116 }
    117