my.extensions.app.AudioFileLister.java Source code

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Here is the source code for my.extensions.app.AudioFileLister.java

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/* Copyright (c) 2014 Intel Corporation. All rights reserved.
 * Use of this source code is governed by an Apache v2 license that can be
 * found in the LICENSE-APACHE-V2 file. */
package my.extensions.app;

import java.io.File;
import java.util.Iterator;
import java.util.List;
import java.util.ArrayList;
import org.xwalk.app.runtime.extension.XWalkExtensionClient;
import org.xwalk.app.runtime.extension.XWalkExtensionContextClient;
import org.apache.commons.io.FileUtils;
import com.google.gson.Gson;
import android.os.Environment;
import android.content.Context;

public class AudioFileLister extends XWalkExtensionClient {
    public AudioFileLister(String name, String jsApiContent, XWalkExtensionContextClient context) {
        super(name, jsApiContent, context);
    }

    private static String[] FILE_EXTS = { "mp3" };
    private Gson gson = new Gson();

    private boolean musicDirectoryReadable() {
        String state = Environment.getExternalStorageState();
        return Environment.MEDIA_MOUNTED_READ_ONLY.equals(state) || Environment.MEDIA_MOUNTED.equals(state);
    }

    // returns JSON stringified version of:
    // {success: false, error: <error message>} on error
    // {success: true, files: [<file URI>, ...]} on success
    private String listFiles() {
        if (musicDirectoryReadable()) {
            File audioDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC);

            Iterator<File> fileIterator = FileUtils.iterateFiles(audioDir, FILE_EXTS, true);

            List<FileInfo> files = new ArrayList<FileInfo>();

            File f;
            while (fileIterator.hasNext()) {
                f = fileIterator.next();
                files.add(new FileInfo(f));
            }

            String filesJson = gson.toJson(files);

            return "{\"success\": true, \"files\": " + filesJson + "}";
        } else {
            return "{\"success\": false, \"error\":\"audio directory not readable\"}";
        }
    }

    // message is "list-files"
    private String runCmd(String message) {
        if (message.equals("list-files")) {
            return listFiles();
        } else {
            return "{\"success\": false, \"error\":\"invalid command specified\"}";
        }
    }

    @Override
    public void onMessage(int instanceId, String message) {
        postMessage(instanceId, runCmd(message));
    }

    @Override
    public String onSyncMessage(int instanceId, String message) {
        return runCmd(message);
    }
}