Java tutorial
/* * Copyright 2008 Google Inc. * * 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 com.google.gwt.gdata.sample.hellogdata.client; import com.google.gwt.accounts.client.AuthSubStatus; import com.google.gwt.accounts.client.User; import com.google.gwt.gdata.client.GData; import com.google.gwt.gdata.client.GDataSystemPackage; import com.google.gwt.gdata.client.calendar.CalendarEventEntry; import com.google.gwt.gdata.client.calendar.CalendarEventFeed; import com.google.gwt.gdata.client.calendar.CalendarEventFeedCallback; import com.google.gwt.gdata.client.calendar.CalendarEventQuery; import com.google.gwt.gdata.client.calendar.CalendarService; import com.google.gwt.gdata.client.impl.CallErrorException; import com.google.gwt.user.client.ui.FlexTable; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.Label; /** * The following example demonstrates how to perform a full text * query for events. */ public class CalendarQueryEventsFullTextDemo extends GDataDemo { /** * This method is used by the main sample app to obtain * information on this sample and a sample instance. * * @return An instance of this demo. */ public static GDataDemoInfo init() { return new GDataDemoInfo() { @Override public GDataDemo createInstance() { return new CalendarQueryEventsFullTextDemo(); } @Override public String getDescription() { return "<p>This sample demonstrates how to perform a full " + "text query to retrieve events. The full text query serves as " + "a filter against all event entries of the private/full feed " + "and return those events that contain the specified text in " + "the event title and/or description.</p>"; } @Override public String getName() { return "Calendar - Querying events full-text"; } }; } private CalendarService service; private FlexTable mainPanel; private final String scope = "http://www.google.com/calendar/feeds/"; /** * Setup the Calendar service and create the main content panel. * If the user is not logged on to Calendar display a message, * otherwise start the demo by querying the user's calendar events. */ public CalendarQueryEventsFullTextDemo() { mainPanel = new FlexTable(); initWidget(mainPanel); if (!GData.isLoaded(GDataSystemPackage.CALENDAR)) { showStatus("Loading the GData Calendar package...", false); GData.loadGDataApi(GDATA_API_KEY, new Runnable() { public void run() { startDemo(); } }, GDataSystemPackage.CALENDAR); } else { startDemo(); } } /** * Retrieves an events feed using a Query object. * In GData, feed URIs can contain querystring parameters. The * GData query objects aid in building parameterized feed URIs. * Upon successfully receiving the events feed, the event entries * are displayed to the user via the showData method. * The FullTextQuery parameter is used to search for events * containing a specific text string. * * @param eventsFeedUri The uri of the events feed */ private void queryEvents(String eventsFeedUri) { showStatus("Querying for events...", false); CalendarEventQuery query = CalendarEventQuery.newInstance(eventsFeedUri); query.setFullTextQuery("GWT-Calendar-Client"); service.getEventsFeed(query, new CalendarEventFeedCallback() { public void onFailure(CallErrorException caught) { showStatus("An error occurred while retrieving the Event feed: " + caught.getMessage(), true); } public void onSuccess(CalendarEventFeed result) { CalendarEventEntry[] entries = (CalendarEventEntry[]) result.getEntries(); if (entries.length == 0) { showStatus("No events found containing the text 'GWT-Calendar-Client'.", false); } else { showData(entries); } } }); } /** * Displays a set of Calendar event entries in a tabular fashion with * the help of a GWT FlexTable widget. The data fields Title, URL * and Updated are displayed. * * @param entries The Calendar event entries to display. */ private void showData(CalendarEventEntry[] entries) { mainPanel.clear(); String[] labels = new String[] { "Title", "URL", "Updated" }; mainPanel.insertRow(0); for (int i = 0; i < labels.length; i++) { mainPanel.addCell(0); mainPanel.setWidget(0, i, new Label(labels[i])); mainPanel.getFlexCellFormatter().setStyleName(0, i, "hm-tableheader"); } for (int i = 0; i < entries.length; i++) { CalendarEventEntry entry = entries[i]; int row = mainPanel.insertRow(i + 1); mainPanel.addCell(row); mainPanel.setWidget(row, 0, new Label(entry.getTitle().getText())); mainPanel.addCell(row); String link = entry.getHtmlLink().getHref(); mainPanel.setWidget(row, 1, new HTML("<a href=\"" + link + "\">" + link + "</a>")); mainPanel.addCell(row); mainPanel.setWidget(row, 2, new Label(entry.getUpdated().getValue().getDate().toString())); } } /** * Displays a status message to the user. * * @param message The message to display. * @param isError Indicates whether the status is an error status. */ private void showStatus(String message, boolean isError) { mainPanel.clear(); mainPanel.insertRow(0); mainPanel.addCell(0); Label msg = new Label(message); if (isError) { msg.setStylePrimaryName("hm-error"); } mainPanel.setWidget(0, 0, msg); } /** * Starts this demo. */ private void startDemo() { service = CalendarService.newInstance("HelloGData_Calendar_QueryEventsFullTextDemo_v2.0"); if (User.getStatus(scope) == AuthSubStatus.LOGGED_IN) { queryEvents("http://www.google.com/calendar/feeds/default/private/full"); } else { showStatus("You are not logged on to Google Calendar.", true); } } }