Java tutorial
/* * Copyright (C) 2010 Paul Watts (paulcwatts@gmail.com) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package can.yrt.onebusaway; import com.actionbarsherlock.app.SherlockFragmentActivity; import com.actionbarsherlock.view.MenuItem; import can.yrt.oba.provider.ObaContract; import android.content.ContentResolver; import android.database.ContentObserver; import android.database.Cursor; import android.os.Bundle; import android.os.Handler; import android.support.v4.app.FragmentManager; import android.support.v4.app.LoaderManager; import android.support.v4.content.CursorLoader; import android.support.v4.content.Loader; import android.support.v4.widget.SimpleCursorAdapter; import android.view.ContextMenu; import android.view.ContextMenu.ContextMenuInfo; import android.view.View; import android.widget.AdapterView.AdapterContextMenuInfo; import android.widget.ListView; import android.widget.TextView; public class TripListActivity extends SherlockFragmentActivity { // private static final String TAG = "TripListActivity"; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); UIHelp.setupActionBar(this); FragmentManager fm = getSupportFragmentManager(); // Create the list fragment and add it as our sole content. if (fm.findFragmentById(android.R.id.content) == null) { TripListFragment list = new TripListFragment(); fm.beginTransaction().add(android.R.id.content, list).commit(); } } @Override public boolean onOptionsItemSelected(MenuItem item) { if (item.getItemId() == android.R.id.home) { NavHelp.goHome(this); return true; } return false; } public static final class TripListFragment extends ListFragment implements LoaderManager.LoaderCallbacks<Cursor> { private static final String[] PROJECTION = { ObaContract.Trips._ID, ObaContract.Trips.NAME, ObaContract.Trips.HEADSIGN, ObaContract.Trips.DEPARTURE, ObaContract.Trips.ROUTE_ID, ObaContract.Trips.STOP_ID }; private static final int COL_ID = 0; private static final int COL_NAME = 1; private static final int COL_HEADSIGN = 2; private static final int COL_DEPARTURE = 3; private static final int COL_ROUTE_ID = 4; private static final int COL_STOP_ID = 5; private static final Handler mHandler = new Handler(); private class Observer extends ContentObserver { Observer() { super(mHandler); } @Override public boolean deliverSelfNotifications() { return false; } public void onChange(boolean selfChange) { if (isAdded()) { getLoaderManager().restartLoader(0, null, TripListFragment.this); } } } private SimpleCursorAdapter mAdapter; private Observer mObserver; @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); // Set empty text setEmptyText(getString(R.string.trip_list_notrips)); registerForContextMenu(getListView()); // Create our generic adapter mAdapter = newAdapter(); setListAdapter(mAdapter); ContentResolver cr = getActivity().getContentResolver(); mObserver = new Observer(); cr.registerContentObserver(ObaContract.Trips.CONTENT_URI, true, mObserver); // Prepare the loader getLoaderManager().initLoader(0, null, this); } @Override public void onDestroy() { if (mObserver != null) { ContentResolver cr = getActivity().getContentResolver(); cr.unregisterContentObserver(mObserver); mObserver = null; } super.onDestroy(); } @Override public Loader<Cursor> onCreateLoader(int id, Bundle args) { return new CursorLoader(getActivity(), ObaContract.Trips.CONTENT_URI, PROJECTION, null, null, ObaContract.Trips.NAME + " asc"); } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor data) { mAdapter.swapCursor(data); } @Override public void onLoaderReset(Loader<Cursor> loader) { mAdapter.swapCursor(null); } private SimpleCursorAdapter newAdapter() { final String[] from = { ObaContract.Trips.NAME, ObaContract.Trips.HEADSIGN, ObaContract.Trips.DEPARTURE, ObaContract.Trips.ROUTE_ID }; final int[] to = { R.id.name, R.id.headsign, R.id.departure_time, R.id.route_name }; SimpleCursorAdapter simpleAdapter = new SimpleCursorAdapter(getActivity(), R.layout.trip_list_listitem, null, from, to, 0); simpleAdapter.setViewBinder(new SimpleCursorAdapter.ViewBinder() { public boolean setViewValue(View view, Cursor cursor, int columnIndex) { if (columnIndex == COL_NAME) { TextView text = (TextView) view; String name = cursor.getString(columnIndex); if (name.length() == 0) { name = getString(R.string.trip_info_noname); } text.setText(name); return true; } else if (columnIndex == COL_HEADSIGN) { String headSign = cursor.getString(columnIndex); TextView text = (TextView) view; text.setText(MyTextUtils.toTitleCase(headSign)); return true; } else if (columnIndex == COL_DEPARTURE) { TextView text = (TextView) view; text.setText(TripInfoActivity.getDepartureTime(getActivity(), ObaContract.Trips.convertDBToTime(cursor.getInt(columnIndex)))); return true; } else if (columnIndex == COL_ROUTE_ID) { // // Translate the Route ID into the Route Name by looking // it up in the Routes table. // TextView text = (TextView) view; final String routeId = cursor.getString(columnIndex); final String routeName = TripService.getRouteShortName(getActivity(), routeId); if (routeName != null) { text.setText(getString(R.string.trip_info_route, routeName)); } return true; } return false; } }); return simpleAdapter; } @Override public void onListItemClick(ListView l, View v, int position, long id) { String[] ids = getIds(l, position); TripInfoActivity.start(getActivity(), ids[0], ids[1]); } private static final int CONTEXT_MENU_DEFAULT = 1; private static final int CONTEXT_MENU_DELETE = 2; private static final int CONTEXT_MENU_SHOWSTOP = 3; private static final int CONTEXT_MENU_SHOWROUTE = 4; @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); AdapterContextMenuInfo info = (AdapterContextMenuInfo) menuInfo; final TextView text = (TextView) info.targetView.findViewById(R.id.name); menu.setHeaderTitle(text.getText()); menu.add(0, CONTEXT_MENU_DEFAULT, 0, R.string.trip_list_context_edit); menu.add(0, CONTEXT_MENU_DELETE, 0, R.string.trip_list_context_delete); menu.add(0, CONTEXT_MENU_SHOWSTOP, 0, R.string.trip_list_context_showstop); menu.add(0, CONTEXT_MENU_SHOWROUTE, 0, R.string.trip_list_context_showroute); } @Override public boolean onContextItemSelected(android.view.MenuItem item) { AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo(); switch (item.getItemId()) { case CONTEXT_MENU_DEFAULT: // Fake a click onListItemClick(getListView(), info.targetView, info.position, info.id); return true; case CONTEXT_MENU_DELETE: deleteTrip(getListView(), info.position); return true; case CONTEXT_MENU_SHOWSTOP: goToStop(getListView(), info.position); return true; case CONTEXT_MENU_SHOWROUTE: goToRoute(getListView(), info.position); return true; default: return super.onContextItemSelected(item); } } private void deleteTrip(ListView l, int position) { String[] ids = getIds(l, position); // TODO: Confirmation dialog? ContentResolver cr = getActivity().getContentResolver(); cr.delete(ObaContract.Trips.buildUri(ids[0], ids[1]), null, null); TripService.scheduleAll(getActivity()); getLoaderManager().getLoader(0).onContentChanged(); } private void goToStop(ListView l, int position) { String[] ids = getIds(l, position); ArrivalsListActivity.start(getActivity(), ids[1]); } private void goToRoute(ListView l, int position) { String[] ids = getIds(l, position); RouteInfoActivity.start(getActivity(), ids[2]); } private String[] getIds(ListView l, int position) { // Get the cursor and fetch the stop ID from that. SimpleCursorAdapter cursorAdapter = (SimpleCursorAdapter) l.getAdapter(); final Cursor c = cursorAdapter.getCursor(); c.moveToPosition(position - l.getHeaderViewsCount()); final String[] result = new String[] { c.getString(COL_ID), c.getString(COL_STOP_ID), c.getString(COL_ROUTE_ID) }; return result; } } }