Chapter 1. GWT
Figure 1.1. Gmail was launched on April 1, 2004, and was one of the early web applications to influence the new paradigm of web applications that work like a traditional desktop application.
Figure 1.2. This is an artist’s rendering of what the GWT compiler is responsible for. This figure doesn’t cover everything the compiler does, but it does provide a high-level overview of how Java code (on the left) is compiled into JavaScript code.
Figure 1.3. An example of a user-built AddressBook widget. It’s made up of at least eight different types of widgets and dozens of instances. Some of the widgets are used for layout, like the VerticalPanel, and others will react based on user events, like the Button.
Figure 1.4. An event bus is like a messaging channel or a pipe. A producer puts an event onto the bus, and any number of recipients can handle it. Producers and recipients are decoupled from each other because they connect to the message bus and not to each other.
Figure 1.5. GWT provides a number of tools for passing data between the server and browser. This includes Ajax-style communication for passing XML and JSON data, HTML forms for form data, and GWT-RPC for passing serialized Java objects.
Figure 1.6. GWT’s DatePicker widget, using three different locale settings. From left to right are calendars for Northern Sami, Russia, and Japan.