tuner/src/com/android/tv/tuner/setup/ChannelScanFileParser.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 com.android.tv.tuner.setup;

import android.util.Log;
import com.android.tv.tuner.api.ScanChannel;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

/** Parses plain text formatted scan files, which contain the list of channels. */
public final class ChannelScanFileParser {
    private static final String TAG = "ChannelScanFileParser";

    /**
     * Parses a given scan file and returns the list of {@link ScanChannel} objects.
     *
     * @param is {@link InputStream} of a scan file. Each line matches one channel. The line format
     *     of the scan file is as follows:<br>
     *     "A &lt;frequency&gt; &lt;modulation&gt;".
     * @return a list of {@link ScanChannel} objects parsed
     */
    public static List<ScanChannel> parseScanFile(InputStream is) {
        BufferedReader in = new BufferedReader(new InputStreamReader(is));
        String line;
        List<ScanChannel> scanChannelList = new ArrayList<>();
        try {
            while ((line = in.readLine()) != null) {
                if (line.isEmpty()) {
                    continue;
                }
                if (line.charAt(0) == '#') {
                    // Skip comment line
                    continue;
                }
                String[] tokens = line.split("\\s+");
                if (tokens.length != 3 && tokens.length != 4) {
                    continue;
                }
                scanChannelList.add(
                        ScanChannel.forTuner(
                                Integer.parseInt(tokens[1]),
                                tokens[2],
                                tokens.length == 4 ? Integer.parseInt(tokens[3]) : null));
            }
        } catch (IOException e) {
            Log.e(TAG, "error on parseScanFile()", e);
        }
        return scanChannelList;
    }

   private ChannelScanFileParser(){}
}