Core Apps » Bazaar

package org.fdroid.fdroid.net;

import android.annotation.TargetApi;

import android.app.DownloadManager;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.database.Cursor;

import android.net.Uri;

import android.os.Build;

import android.os.ParcelFileDescriptor;

import java.io.File;

import java.io.FileDescriptor;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

/**

 * A downloader that uses Android's DownloadManager to perform a download.

 */

@TargetApi(Build.VERSION_CODES.GINGERBREAD)

public class AsyncDownloaderFromAndroid implements AsyncDownloader {

    private final Context context;

    private final DownloadManager dm;

    private File localFile;

    private String remoteAddress;

    private String downloadTitle;

    private String uniqueDownloadId;

    private Listener listener;

    private long downloadManagerId = -1;

    /**

     * Normally the listener would be provided using a setListener method.

     * However for the purposes of this async downloader, it doesn't make

     * sense to have an async task without any way to notify the outside

     * world about completion. Therefore, we require the listener as a

     * parameter to the constructor.

     */

    public AsyncDownloaderFromAndroid(Context context, Listener listener, String downloadTitle, String downloadId, String remoteAddress, File localFile) {

        this.context = context;

        this.downloadTitle = downloadTitle;

        this.uniqueDownloadId = downloadId;

        this.remoteAddress = remoteAddress;

        this.listener = listener;

        this.localFile = localFile;

        if (downloadTitle == null || downloadTitle.trim().length() == 0) {

            this.downloadTitle = remoteAddress;

        }

        dm = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);

    }

    @Override

    public void download() {

        // Check if the download is complete

        if ((downloadManagerId = isDownloadComplete(context, uniqueDownloadId)) > 0) {

            // clear the notification

            dm.remove(downloadManagerId);

            try {

                // write the downloaded file to the expected location

                ParcelFileDescriptor fd = dm.openDownloadedFile(downloadManagerId);

                copyFile(fd.getFileDescriptor(), localFile);

                listener.onDownloadComplete();

            } catch (IOException e) {

                listener.onErrorDownloading(e.getLocalizedMessage());

            }

            return;

        }

        // Check if the download is still in progress

        if (downloadManagerId < 0) {

            downloadManagerId = isDownloading(context, uniqueDownloadId);

        }

        // Start a new download

        if (downloadManagerId < 0) {

            // set up download request

            DownloadManager.Request request = new DownloadManager.Request(Uri.parse(remoteAddress));

            request.setTitle(downloadTitle);

            request.setDescription(uniqueDownloadId); // we will retrieve this later from the description field

            this.downloadManagerId = dm.enqueue(request);

        }

        context.registerReceiver(receiver,

                new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));

    }

    /**

     * Copy input file to output file

     * @throws IOException

     */

    private void copyFile(FileDescriptor inputFile, File outputFile) throws IOException {

        InputStream is = new FileInputStream(inputFile);

        OutputStream os = new FileOutputStream(outputFile);

        byte[] buffer = new byte[1024];

        int count = 0;

        try {

            while ((count = is.read(buffer, 0, buffer.length)) > 0) {

                os.write(buffer, 0, count);

            }

        } finally {

            os.close();

            is.close();

        }

    }

    @Override

    public int getBytesRead() {

        if (downloadManagerId < 0) return 0;

        DownloadManager.Query query = new DownloadManager.Query();

        query.setFilterById(downloadManagerId);

        Cursor c = dm.query(query);

        try {

            if (c.moveToFirst()) {

                // we use the description column to store the unique id of this download

                int columnIndex = c.getColumnIndex(DownloadManager.COLUMN_BYTES_DOWNLOADED_SO_FAR);

                return c.getInt(columnIndex);

            }

        } finally {

            c.close();

        }

        return 0;

    }

    @Override

    public int getTotalBytes() {

        if (downloadManagerId < 0) return 0;

        DownloadManager.Query query = new DownloadManager.Query();

        query.setFilterById(downloadManagerId);

        Cursor c = dm.query(query);

        try {

            if (c.moveToFirst()) {

                // we use the description column to store the unique id for this download

                int columnIndex = c.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES);

                return c.getInt(columnIndex);

            }

        } finally {

            c.close();

        }

        return 0;

    }

    @Override

    public void attemptCancel(boolean userRequested) {

        try {

            context.unregisterReceiver(receiver);

        } catch (Exception e) {

            // ignore if receiver already unregistered

        }

        if (userRequested && downloadManagerId >= 0) {

            dm.remove(downloadManagerId);

        }

    }

    /**

     * Extract the uniqueDownloadId from a given download id.

     * @return - uniqueDownloadId or null if not found

     */

    public static String getDownloadId(Context context, long downloadId) {

        DownloadManager dm = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);

        DownloadManager.Query query = new DownloadManager.Query();

        query.setFilterById(downloadId);

        Cursor c = dm.query(query);

        try {

            if (c.moveToFirst()) {

                // we use the description column to store the unique id for this download

                int columnIndex = c.getColumnIndex(DownloadManager.COLUMN_DESCRIPTION);

                return c.getString(columnIndex);

            }

        } finally {

            c.close();

        }

        return null;

    }

    /**

     * Extract the download title from a given download id.

     * @return - title or null if not found

     */

    public static String getDownloadTitle(Context context, long downloadId) {

        DownloadManager dm = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);

        DownloadManager.Query query = new DownloadManager.Query();

        query.setFilterById(downloadId);

        Cursor c = dm.query(query);

        try {

            if (c.moveToFirst()) {

                int columnIndex = c.getColumnIndex(DownloadManager.COLUMN_TITLE);

                return c.getString(columnIndex);

            }

        } finally {

            c.close();

        }

        return null;

    }

    /**

     * Get the downloadManagerId from an Intent sent by the DownloadManagerReceiver

     */

    public static long getDownloadId(Intent intent) {

        if (intent != null) {

            if (intent.hasExtra(DownloadManager.EXTRA_DOWNLOAD_ID)) {

                // we have been passed a DownloadManager download id, so get the unique id for that download

                return intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);

            }

            if (intent.hasExtra(DownloadManager.EXTRA_NOTIFICATION_CLICK_DOWNLOAD_IDS)) {

                // we have been passed multiple download id's - just return the first one

                long[] downloadIds = intent.getLongArrayExtra(DownloadManager.EXTRA_NOTIFICATION_CLICK_DOWNLOAD_IDS);

                if (downloadIds != null && downloadIds.length > 0) {

                    return downloadIds[0];

                }

            }

        }

        return -1;

    }

    /**

     * Check if a download is running for the specified id

     * @return -1 if not downloading, else the id from the Android download manager

     */

    public static long isDownloading(Context context, String uniqueDownloadId) {

        DownloadManager dm = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);

        DownloadManager.Query query = new DownloadManager.Query();

        Cursor c = dm.query(query);

        int columnUniqueDownloadId = c.getColumnIndex(DownloadManager.COLUMN_DESCRIPTION);

        int columnId = c.getColumnIndex(DownloadManager.COLUMN_ID);

        try {

            while (c.moveToNext()) {

                if (uniqueDownloadId.equals(c.getString(columnUniqueDownloadId))) {

                    return c.getLong(columnId);

                }

            }

        } finally {

            c.close();

        }

        return -1;

    }

    /**

     * Check if a specific download is complete.

     * @return -1 if download is not complete, otherwise the download id

     */

    public static long isDownloadComplete(Context context, String uniqueDownloadId) {

        DownloadManager dm = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);

        DownloadManager.Query query = new DownloadManager.Query();

        query.setFilterByStatus(DownloadManager.STATUS_SUCCESSFUL);

        Cursor c = dm.query(query);

        int columnUniqueDownloadId = c.getColumnIndex(DownloadManager.COLUMN_DESCRIPTION);

        int columnId = c.getColumnIndex(DownloadManager.COLUMN_ID);

        try {

            while (c.moveToNext()) {

                if (uniqueDownloadId.equals(c.getString(columnUniqueDownloadId))) {

                    return c.getLong(columnId);

                }

            }

        } finally {

            c.close();

        }

        return -1;

    }

    /**

     * Broadcast receiver to listen for ACTION_DOWNLOAD_COMPLETE broadcasts

     */

    BroadcastReceiver receiver = new BroadcastReceiver() {

        @Override

        public void onReceive(Context context, Intent intent) {

            if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(intent.getAction())) {

                long dId = getDownloadId(intent);

                String downloadId = getDownloadId(context, dId);

                if (listener != null && dId == AsyncDownloaderFromAndroid.this.downloadManagerId && downloadId != null) {

                    // our current download has just completed, so let's throw up install dialog

                    // immediately

                    try {

                        context.unregisterReceiver(receiver);

                    } catch (Exception e) {

                        // ignore if receiver already unregistered

                    }

                    // call download() to copy the file and start the installer

                    download();

                }

            }

        }

    };

}