Added auto refresh to the activity

OnResume creates an AsyncTask which keeps running
until cancelled. It requests server updates with
a delay of two seconds between each update.

OnPause cancels the AsyncTask.

To handle multiselect gracefully, the fragment requests
the auto refresh to be paused. This pause is remembered
between resets, as long as the multiselect mode is active.
Once the users selects an action or exits multiselect,
the auto refresh resumes.

There are probably several things I haven't thought of,
and there should be a user setting for this maybe.

Signed-off-by: Jonas Kalderstam <jonas@kalderstam.se>

core/src/org/transdroid/core/gui/TorrentsActivity.java

@@ -103,6 +103,7 @@ import android.app.SearchManager;
 import android.content.ContentResolver;
 import android.content.Intent;
 import android.net.Uri;
+import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Bundle;
 import android.view.View;
@@ -170,6 +171,11 @@ public class TorrentsActivity extends SherlockFragmentActivity implements OnNavi
 	@FragmentById(resName = "torrent_details")
 	protected DetailsFragment fragmentDetails;
 	
+	// Auto refresh task. Could be replaced by @Background(id="task-id")
+	private AsyncTask<Void, Void, Void> autoRefreshTask;
+	// Fragment uses this to pause the refresh across restarts
+	public boolean stopRefresh = false;
+
 	@Override
 	public void onCreate(Bundle savedInstanceState) {
 		// Set the theme according to the user preference
@@ -274,6 +280,8 @@ public class TorrentsActivity extends SherlockFragmentActivity implements OnNavi
 	@Override
 	protected void onResume() {
 		super.onResume();
+		// Start auto refresh
+		startAutoRefresh();
 
 		// Refresh server settings
 		navigationSpinnerAdapter.updateServers(applicationSettings.getAllServerSettings());
@@ -301,6 +309,54 @@ public class TorrentsActivity extends SherlockFragmentActivity implements OnNavi
 		}
 	}
 	
+
+	@TargetApi(Build.VERSION_CODES.HONEYCOMB)
+	public void startAutoRefresh() {
+		// Check if already running
+		if (autoRefreshTask != null || stopRefresh)
+			return;
+		
+		autoRefreshTask = new AsyncTask<Void, Void, Void>() {
+			@Override
+			protected Void doInBackground(Void... params) {
+				while (!isCancelled()) {
+					// X seconds seems reasonable if someone actually wants real time updates
+					try {
+						Thread.sleep(2000);
+					} catch (InterruptedException e) {
+						// Ignore
+					}
+					// Just in case it was cancelled during sleep
+					if (isCancelled())
+						return null;
+						
+					refreshTorrents();
+					if (Daemon.supportsStats(currentConnection.getType()))
+						getAdditionalStats();
+				}
+				return null;
+			}
+			
+		};
+		// Executes serially by default on Honeycomb, was parallel before
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
+			autoRefreshTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, null);
+		else
+			autoRefreshTask.execute();
+	}
+	
+	public void stopAutoRefresh() {
+		if (autoRefreshTask != null)
+			autoRefreshTask.cancel(true);
+		autoRefreshTask = null;
+	}
+	
+	@Override
+	protected void onPause() {
+		stopAutoRefresh();
+		super.onPause();
+	}
+
 	@Override
 	protected void onDestroy() {
 		Crouton.cancelAllCroutons();

core/src/org/transdroid/core/gui/TorrentsFragment.java

@@ -261,6 +261,9 @@ public class TorrentsFragment extends SherlockFragment implements OnLabelPickedL
 				menu.findItem(R.id.action_stop).setVisible(Daemon.supportsStoppingStarting(daemonType));
 				menu.findItem(R.id.action_setlabel).setVisible(Daemon.supportsSetLabel(daemonType));
 			}
+			// Pause autorefresh
+			((TorrentsActivity) getActivity()).stopRefresh = true;
+			((TorrentsActivity) getActivity()).stopAutoRefresh();
 			return true;
 		}
 
@@ -329,6 +332,9 @@ public class TorrentsFragment extends SherlockFragment implements OnLabelPickedL
 
 		@Override
 		public void onDestroyActionMode(ActionMode mode) {
+			// Resume autorefresh
+			((TorrentsActivity) getActivity()).stopRefresh = false;
+			((TorrentsActivity) getActivity()).startAutoRefresh();
 			selectionManagerMode.onDestroyActionMode(mode);
 		}