DownloadManager.java

package net.impjq.download;

import net.impjq.providers.downloads.Downloads;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Context;
import android.database.ContentObserver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Handler;

public class DownloadManager {
	private static final String TAG = DownloadManager.class.getSimpleName();
	private Context mContext;
	private Uri mUri;

	/**
	 * The {@link DownloadProgressListener mDownloadProgressListener}
	 */
	private DownloadProgressListener mDownloadProgressListener;

	/**
	 * Choose Which columns should query about the downloaded Media Ojbect.
	 */
	private static final String[] sProjection = new String[] { "_id",
			Downloads.COLUMN_TITLE, Downloads.COLUMN_STATUS,
			Downloads.COLUMN_TOTAL_BYTES, Downloads.COLUMN_CURRENT_BYTES,
			Downloads._DATA, Downloads.COLUMN_DESCRIPTION,
			Downloads.COLUMN_MIME_TYPE, Downloads.COLUMN_LAST_MODIFICATION,
			Downloads.COLUMN_VISIBILITY };

	public DownloadManager(Context context) {
		// TODO Auto-generated constructor stub
		mContext = context;
	}

	public void setDownloadProgressListener(DownloadProgressListener listener) {
		mDownloadProgressListener = listener;
	}

	/**
	 * Use the Android Defaul Download Provider to download the MediaObject.
	 * 
	 * @param url
	 */
	public void insertDownload(String url, String hintName) {
		Utils.log(TAG, "Start download,url=" + url);

		ContentValues values = new ContentValues();
		values.put(Downloads.COLUMN_URI, url);
		values.put(Downloads.COLUMN_NOTIFICATION_PACKAGE, mContext
				.getPackageName());
		values.put(Downloads.COLUMN_NOTIFICATION_PACKAGE, "com.bookfm");
		values.put(Downloads.COLUMN_NOTIFICATION_CLASS,
				"com.bookfm.download.DownloadActivity");
		values.put(Downloads.COLUMN_VISIBILITY,
				Downloads.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
		values.put(Downloads.COLUMN_FILE_NAME_HINT, hintName);

		Uri uri = mContext.getContentResolver().insert(Downloads.CONTENT_URI,
				values);

		mUri = uri;
		Utils.log(TAG, "Insert to Download Provider,uri=" + uri);

		setDownloadsChangeObserver(uri);
	}

	public void cancelDownload() {
		Utils.log(TAG, "Cancel download,mUri=" + mUri);

		cancelDownload(mUri);
	}

	public void cancelDownload(Uri uri) {
		Utils.log(TAG, "Cancel download,uri=" + uri);

		ContentValues values = new ContentValues();
		values.put(Downloads.Impl.COLUMN_CONTROL,
				Downloads.Impl.STATUS_CANCELED);
		// mContext.getContentResolver().update(uri, values, null, null);
		mContext.getContentResolver().delete(uri, null, null);
	}
	

	// /**
	// * Remove the file from the list of downloads.
	// * @param id Unique ID of the download to remove.
	// */
	// private void clearFromDownloads(long id) {
	// getContentResolver().delete(ContentUris.withAppendedId(
	// Downloads.Impl.CONTENT_URI, id), null, null);
	// }


	public void pauseDownload() {
		Utils.log(TAG, "Pause download,mUri=" + mUri);

		pauseDownload(mUri);
	}
	

	public void pauseDownload(Uri uri) {
		Utils.log(TAG, "Pause download,uri=" + uri);

		ContentValues values = new ContentValues();
		values
				.put(Downloads.Impl.COLUMN_CONTROL,
						Downloads.Impl.CONTROL_PAUSED);
		mContext.getContentResolver().update(uri, values, null, null);
	}

	public void resumeDownload() {
		Utils.log(TAG, "Resume download,mUri=" + mUri);

		resumeDownload(mUri);
	}

	public void resumeDownload(Uri uri) {
		Utils.log(TAG, "Resume download,uri=" + uri);

		ContentValues values = new ContentValues();
		values.put(Downloads.Impl.COLUMN_CONTROL, Downloads.Impl.CONTROL_RUN);
		mContext.getContentResolver().update(uri, values, null, null);
	}

	/**
	 * Set the DownloadsChangeObserver
	 * 
	 * @param uri
	 *            The inserted uri to watch.
	 */
	public void setDownloadsChangeObserver(Uri uri) {
		Utils.log(TAG, "setContentObserver");
		mDownloadsObserver = new DownloadsChangeObserver(Downloads.CONTENT_URI,
				uri);
		mContext.getContentResolver().registerContentObserver(
				Downloads.CONTENT_URI, true, mDownloadsObserver);
	}

	/**
	 * The ContentObserver
	 */
	private DownloadsChangeObserver mDownloadsObserver;

	/**
	 * The DownloadsChangeObserver.When the Media Object downloaded
	 * changed,should notify the Activity to do something,such as update the
	 * download progressbar.
	 * 
	 * @author Percy.Peng
	 * @see DownloadProgressListener#onChange
	 */
	private class DownloadsChangeObserver extends ContentObserver {
		private Uri uri;

		public DownloadsChangeObserver(Uri uri, Uri insertUri) {
			super(new Handler());
			this.uri = insertUri;

			Utils.log(TAG, "DownloadsChangeObserver,uri=" + uri + ",insertUri="
					+ insertUri);
		}

		@Override
		public void onChange(boolean selfChange) {
			Utils.log(TAG, "DownloadsChangeObserver,onChange");
			Cursor c = ((Activity) mContext).managedQuery(uri, sProjection,
					null, null, null);

			if (null == c) {
				return;
			}

			// Call the listener,then can get the details and show in the
			// Activity which call it.
			if (null != mDownloadProgressListener) {
				mDownloadProgressListener.onChange(c);
			}

		}
	}

	/**
	 * Used to pass the Download Progress do the Activity which call it through
	 * the {@link DownloadProgressListener#onChange(Cursor)}
	 * 
	 * @author Percy.Peng
	 */
	public interface DownloadProgressListener {
		/**
		 * Almost the same to {@link DownloadsChangeObserver#onChange} Call it
		 * when the data change.
		 * 
		 * @param c
		 * @see DownloadsChangeObserver#onChange(boolean)
		 */
		public void onChange(Cursor c);
	}
}