Google Web Toolkit Solutions: More Cool & Useful Stuff

408 Pages·2007·10.8 MB·English

by  David Geary

Solution 1: Drag and Drop i
Google™ Web Toolkit
Solutions
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Google™ Web Toolkit
Solutions
More Cool & Useful Stuff
David Geary
with Rob Gordon
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Library of Congress Cataloging-in-Publication Data:
Geary, David M.
Google Web toolkit solutions : more cool & useful stuff / David Geary with Rob Gordon.
p. cm.
ISBN 0-13-234481-5 (pbk. : alk. paper) 1. Ajax (Web site development technology) 2. Java (Computer
program language) 3. Google. I. Gordon, Rob. II. Title.
TK5105.8885.A52G43 2007
006.7’6—dc22
2007021607
Copyright © 2008 Pearson Education, Inc.
All rights reserved. Printed in the United States of America. This publication is protected by copyright, and
permission must be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval
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likewise. For information regarding permissions, write to:
Pearson Education, Inc
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Fax [phone]
ISBN-13: 978-0-13-234481-4
ISBN-10: 0-13-234481-5
Text printed in the United States on recycled paper at RR Donnelley in Crawfordsville, Indiana
First printing November 2007
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Development Editors Editorial Assistant
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Chris Zahn Interior Designer
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Kristy Hart Senior Compositor
Indexer Gloria Schurick
Heather McNeill
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vii
Contents
Foreword xiii
Preface xvi
Acknowledgments xviii
About the Authors xix
Solution 1 GWT Fundamentals and Beyond 1
In This Book 1
Stuff You’re Going to Learn 3
Introduction to GWT Widgets 4
Anatomy of a GWT Application 7
User Interfaces Composed with GWT Panels 8
The Root Panel 10
The user.client.ui API 11
Widget Styling with CSS Styles 12
Event-Driven Programming with GWT 14
Internationalization and Localization 18
Implementing the Four Steps for GWT Internationalization 19
Using GWT’s i18nCreator Command 22
A New “View” in Your GWT Web Application 23
GWT’s History Mechanism 26
Adding the History Class and History Listeners 27
Handling the Browser’s Back Button 30
GWT’s Peers: DOM Elements 32
Use of Deferred Commands to Give Widgets Keyboard Focus 32
Remote Procedure Call Implementation 34
Custom Widget Use 40
Custom Widget Packaging in GWT Modules 43
The Complete Login Application 47
Stuff We Covered in This Solution 52
viii Google Web Toolkit Solutions
Solution 2 JavaScript Integration 53
Stuff You’re Going to Learn 53
The Script.aculo.us JavaScript Library Integration 54
Importing a JavaScript File in Your HTMLFile 61
Importing a JavaScript File in Your GWT Configuration File 63
A JavaScript Calendar Integration 64
Stuff We Covered in This Solution 69
Solution 3 Custom Widget Implementation 71
Stuff You’re Going to Learn 71
Composite Custom Widgets 72
Composite Widgets and Pass-Through Methods 88
Event Handlers 89
The Text Box’s Keyboard Listener 89
The List Box’s Keyboard Listener 90
The List Box’s Click Listener 90
Firing Change Events 90
Implementing the HasText and HasName Interfaces 90
Incorporating the Script.aculo.us Blind Down Effect 91
A Low-Level Custom Widget 95
Using the DOM Class in a Low-Level Custom Widget 99
Setting Default CSS Styles for a Custom Widget 99
Parameterizing Script.aculo.us Effects in a Custom Widget 99
Stuff We Covered in This Solution 100
Solution 4 Viewports and Maps 103
Stuff You’re Going to Learn 103
Viewports 104
A General-Purpose Viewport Widget 105
The Map Application’s Files and Directories 106
The Viewport Implementation 107
Using an Instance of AbsolutePanel to Place Widgets at
Pixel Locations 110
Dragging the View Inside the Viewport 110
ix
Using a Focus Panel to React to Mouse Events 110
Using an Event Preview to Inhibit the Browser’s Default Reaction
to Mouse Events 111
Capturing Events 111
Clipping the Viewport’s View 111
Changing the Mouse Cursor with CSS Styles 112
Adding a Default CSS Style Name for a Custom Widget 112
The Viewport’s Use of a Focus Panel: Revisited 115
A Viewport’s View with Animated Gestures 117
The Final Version of the Viewport 120
Incorporating the Drag Gesture 129
Animating Scrolling in Response to the Drag Gesture 129
Animating Scrolling in the Same Direction as the Drag Gesture 129
Varying the Speed of the Scrolling Animation 130
Stuff We Covered in This Solution 131
Solution 5 Access to Online Web Services 133
Stuff You’re Going to Learn 133
Yahoo! Maps Web Service 134
Exploring the Example Application 134
Summarizing the Map Application’s Files and Directories 138
Implementing the YahooMaps Application 139
Access to Yahoo!’s Web Service 146
Zoom! 151
Stuff We Covered in This Solution 164
Solution 6 Drag and Drop 167
Stuff You’re Going to Learn 167
The Drag-and-Drop Example Application 168
The Drag-and-Drop Module 170
Inheriting the Drag-and-Drop Module in an Application’s
Configuration File 172
Implementation of the Drag-and-Drop Application 173
Using the Music Player and Shopping Cart Panel Components 174
Using Drag Sources and Drop Targets 176