/* * 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.internal.alsa; import android.util.Slog; import java.io.BufferedReader; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList; /** * @hide Retrieves information from an ALSA "cards" file. */ public class AlsaCardsParser { private static final String TAG = "AlsaCardsParser"; protected static final boolean DEBUG = false; private static final String kCardsFilePath = "/proc/asound/cards"; private static LineTokenizer mTokenizer = new LineTokenizer(" :[]"); private ArrayList mCardRecords = new ArrayList(); public class AlsaCardRecord { private static final String TAG = "AlsaCardRecord"; private static final String kUsbCardKeyStr = "at usb-"; public int mCardNum = -1; public String mField1 = ""; public String mCardName = ""; public String mCardDescription = ""; public boolean mIsUsb = false; public AlsaCardRecord() {} public boolean parse(String line, int lineIndex) { int tokenIndex = 0; int delimIndex = 0; if (lineIndex == 0) { // line # (skip) tokenIndex = mTokenizer.nextToken(line, tokenIndex); delimIndex = mTokenizer.nextDelimiter(line, tokenIndex); try { // mCardNum mCardNum = Integer.parseInt(line.substring(tokenIndex, delimIndex)); } catch (NumberFormatException e) { Slog.e(TAG, "Failed to parse line " + lineIndex + " of " + kCardsFilePath + ": " + line.substring(tokenIndex, delimIndex)); return false; } // mField1 tokenIndex = mTokenizer.nextToken(line, delimIndex); delimIndex = mTokenizer.nextDelimiter(line, tokenIndex); mField1 = line.substring(tokenIndex, delimIndex); // mCardName tokenIndex = mTokenizer.nextToken(line, delimIndex); mCardName = line.substring(tokenIndex); // done } else if (lineIndex == 1) { tokenIndex = mTokenizer.nextToken(line, 0); if (tokenIndex != -1) { int keyIndex = line.indexOf(kUsbCardKeyStr); mIsUsb = keyIndex != -1; if (mIsUsb) { mCardDescription = line.substring(tokenIndex, keyIndex - 1); } } } return true; } public String textFormat() { return mCardName + " : " + mCardDescription; } public void log(int listIndex) { Slog.d(TAG, "" + listIndex + " [" + mCardNum + " " + mCardName + " : " + mCardDescription + " usb:" + mIsUsb); } } public AlsaCardsParser() {} public void scan() { if (DEBUG) { Slog.i(TAG, "AlsaCardsParser.scan()"); } mCardRecords = new ArrayList(); File cardsFile = new File(kCardsFilePath); try { FileReader reader = new FileReader(cardsFile); BufferedReader bufferedReader = new BufferedReader(reader); String line = ""; while ((line = bufferedReader.readLine()) != null) { AlsaCardRecord cardRecord = new AlsaCardRecord(); if (DEBUG) { Slog.i(TAG, " " + line); } cardRecord.parse(line, 0); line = bufferedReader.readLine(); if (line == null) { break; } if (DEBUG) { Slog.i(TAG, " " + line); } cardRecord.parse(line, 1); mCardRecords.add(cardRecord); } reader.close(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } public ArrayList getScanRecords() { return mCardRecords; } public AlsaCardRecord getCardRecordAt(int index) { return mCardRecords.get(index); } public AlsaCardRecord getCardRecordFor(int cardNum) { for (AlsaCardRecord rec : mCardRecords) { if (rec.mCardNum == cardNum) { return rec; } } return null; } public int getNumCardRecords() { return mCardRecords.size(); } public boolean isCardUsb(int cardNum) { for (AlsaCardRecord rec : mCardRecords) { if (rec.mCardNum == cardNum) { return rec.mIsUsb; } } return false; } // return -1 if none found public int getDefaultUsbCard() { // save the current list of devices ArrayList prevRecs = mCardRecords; if (DEBUG) { LogDevices("Previous Devices:", prevRecs); } // get the new list of devices scan(); if (DEBUG) { LogDevices("Current Devices:", mCardRecords); } // Calculate the difference between the old and new device list ArrayList newRecs = getNewCardRecords(prevRecs); if (DEBUG) { LogDevices("New Devices:", newRecs); } // Choose the most-recently added EXTERNAL card // Check recently added devices for (AlsaCardRecord rec : newRecs) { if (DEBUG) { Slog.d(TAG, rec.mCardName + " card:" + rec.mCardNum + " usb:" + rec.mIsUsb); } if (rec.mIsUsb) { // Found it return rec.mCardNum; } } // or return the first added EXTERNAL card? for (AlsaCardRecord rec : prevRecs) { if (DEBUG) { Slog.d(TAG, rec.mCardName + " card:" + rec.mCardNum + " usb:" + rec.mIsUsb); } if (rec.mIsUsb) { return rec.mCardNum; } } return -1; } public int getDefaultCard() { // return an external card if possible int card = getDefaultUsbCard(); if (DEBUG) { Slog.d(TAG, "getDefaultCard() default usb card:" + card); } if (card < 0 && getNumCardRecords() > 0) { // otherwise return the (internal) card with the highest number card = getCardRecordAt(getNumCardRecords() - 1).mCardNum; } if (DEBUG) { Slog.d(TAG, " returns card:" + card); } return card; } static public boolean hasCardNumber(ArrayList recs, int cardNum) { for (AlsaCardRecord cardRec : recs) { if (cardRec.mCardNum == cardNum) { return true; } } return false; } public ArrayList getNewCardRecords(ArrayList prevScanRecs) { ArrayList newRecs = new ArrayList(); for (AlsaCardRecord rec : mCardRecords) { // now scan to see if this card number is in the previous scan list if (!hasCardNumber(prevScanRecs, rec.mCardNum)) { newRecs.add(rec); } } return newRecs; } // // Logging // public void Log(String heading) { if (DEBUG) { Slog.i(TAG, heading); for (AlsaCardRecord cardRec : mCardRecords) { Slog.i(TAG, cardRec.textFormat()); } } } static public void LogDevices(String caption, ArrayList deviceList) { Slog.d(TAG, caption + " ----------------"); int listIndex = 0; for (AlsaCardRecord device : deviceList) { device.log(listIndex++); } Slog.d(TAG, "----------------"); } }