Implemented export worker

res/values/strings.xml

@@ -147,6 +147,12 @@
     <string name="search_label">Search</string>
     <string name="found_in_title_label">Found in title</string>
     <string name="choose_file_to_import_label">Choose file to import</string>
+    <string name="opml_export_label">OPML export</string>
+    <string name="exporting_label">Exporting...</string>
+    <string name="opml_export_error_no_feeds">You have no feeds</string>
+    <string name="export_error_label">Export error</string>
+    <string name="opml_export_success_title">Opml export successful.</string>
+    <string name="opml_export_success_sum">The .opml file was written to:\u0020</string>
     
 
 </resources>

src/de/danoeh/antennapod/PodcastApp.java

@@ -21,6 +21,7 @@ public class PodcastApp extends Application implements
 
 	private static final String TAG = "PodcastApp";
 	public static final String PREF_NAME = "AntennapodPrefs";
+	public static final String EXPORT_DIR = "export/";
 
 	public static final String PREF_PAUSE_ON_HEADSET_DISCONNECT = "prefPauseOnHeadsetDisconnect";
 	public static final String PREF_FOLLOW_QUEUE = "prefFollowQueue";

src/de/danoeh/antennapod/asynctask/OpmlExportWorker.java

@@ -0,0 +1,104 @@
+package de.danoeh.antennapod.asynctask;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+
+import android.annotation.SuppressLint;
+import android.app.AlertDialog;
+import android.app.ProgressDialog;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.os.AsyncTask;
+import android.util.Log;
+import de.danoeh.antennapod.PodcastApp;
+import de.danoeh.antennapod.R;
+import de.danoeh.antennapod.feed.FeedManager;
+import de.danoeh.antennapod.opml.OpmlWriter;
+
+/** Writes an OPML file into the export directory in the background. */
+public class OpmlExportWorker extends AsyncTask<Void, Void, Void> {
+	private static final String TAG = "OpmlExportWorker";
+	private static final String DEFAULT_OUTPUT_NAME = "AntennaPod-Feeds.opml";
+	private Context context;
+	private File output;
+
+	private ProgressDialog progDialog;
+	private Exception exception;
+
+	public OpmlExportWorker(Context context, File output) {
+		this.context = context;
+		this.output = output;
+	}
+
+	public OpmlExportWorker(Context context) {
+		this.context = context;
+	}
+
+	@Override
+	protected Void doInBackground(Void... params) {
+		OpmlWriter opmlWriter = new OpmlWriter();
+		if (output == null) {
+			output = new File(
+					context.getExternalFilesDir(PodcastApp.EXPORT_DIR),
+					DEFAULT_OUTPUT_NAME);
+			if (output.exists()) {
+				Log.w(TAG, "Overwriting previously exported file.");
+				output.delete();
+			}
+		}
+		try {
+			FileWriter writer = new FileWriter(output);
+			opmlWriter.writeDocument(FeedManager.getInstance().getFeeds(),
+					writer);
+			writer.close();
+		} catch (IOException e) {
+			e.printStackTrace();
+			exception = e;
+		}
+		return null;
+	}
+
+	@Override
+	protected void onPostExecute(Void result) {
+		progDialog.dismiss();
+		AlertDialog.Builder alert = new AlertDialog.Builder(context)
+				.setNeutralButton(android.R.string.ok,
+						new DialogInterface.OnClickListener() {
+
+							@Override
+							public void onClick(DialogInterface dialog,
+									int which) {
+								dialog.dismiss();
+							}
+						});
+		if (exception != null) {
+			alert.setTitle(R.string.export_error_label);
+			alert.setMessage(exception.getMessage());
+		} else {
+			alert.setTitle(R.string.opml_export_success_title);
+			alert.setMessage(context
+					.getString(R.string.opml_export_success_sum)
+					+ output.toString());
+		}
+		alert.create().show();
+	}
+
+	@Override
+	protected void onPreExecute() {
+		progDialog = new ProgressDialog(context);
+		progDialog.setMessage(context.getString(R.string.exporting_label));
+		progDialog.setIndeterminate(true);
+		progDialog.show();
+	}
+
+	@SuppressLint("NewApi")
+	public void executeAsync() {
+		if (android.os.Build.VERSION.SDK_INT > android.os.Build.VERSION_CODES.GINGERBREAD_MR1) {
+			executeOnExecutor(THREAD_POOL_EXECUTOR);
+		} else {
+			execute();
+		}
+	}
+
+}