GChart is implemented as the GWT module com.googlecode.gchart.GChart, packaged into the file gchart.jar. For detailed installation instructions see Installing GChart
With the release of Client-side GChart 2.1, chart updates became 10 times faster for many common usage scenarios. But you will have to replace every GChart.Point in your code with GChart.Curve.Point (it's easy). See GChart 2.1 Performance, Features, Incompatibilities and Bugfixes for complete details.
The latest v2.2 release provides faster line charts via the new LINE symbol type and the ability to precisely control the space allocated for title, footnotes, axis labels, and legend. But the size of your charts will change. For more info about these and other 2.2 features see the Client-side GChart 2.2 Release Notes.
For a quasi-serious discussion of the fundamental principles behind GChart's design see The GChart Manifest.
To see the simpler charts below live, visit the GChart Paint Test page, which contains the over 100 charts used to test GChart. You will see the first few Chart Gallery charts within 10 seconds or so, but it can take over a minute for the full test, so be prepared to wait if you don't want to miss a single chart (trust me, it's not that exciting, especially in IE6 quirks mode).
If you see a test chart that piques your interest on this paint test page, you may want to visit the svn repository for this test to look at its source code.
Note: To facilitate their reuse in GChart's paint test, as of version 2.1, these examples no longer include a built-in call to GChart.update. You must add such a call, for example, using the typical GChart boilerplate code shown below:
GChart gchart = new GChartExample00(); RootPanel.get().add(gchart); gchart.update(); // without this line, no chart appears
The instructions below were tested using The Eclipse Platform Version 3.3.0, and GWT version 1.4.61.These steps assume you already have a working Eclipse-based GWT project, into which you want to add a few GChart charts. To create a new working GWT project within Eclipse, simply follow the Eclipse-specific instructions in the Getting Started section of the GWT Developer Guide.
Just as for a normal Java JAR, you need to tell Eclipse where to find gchart.jar. One way to do this is to right click on your GWT project's name in the Eclipse Project Explorer, select Build Path, then Add External Archives, and then navigate to the folder you unzipped GChart into and click on the gchart.jar it contains.
<inherits name='com.googlecode.gchart.GChart'/>
That's it. You can now add classes to your project such as those shown in the Chart Gallery, and then make those charts appear in the browser via the typical GChart boilerplate code shown earlier.
The above steps are all that you need to do to add GChart if you are doing everything interactively within Eclipse. However, as Ian Petersen and Isaac Truett explained in response to my question on the GWT forum (thanks!), additional steps (that involve editing your project's *-compile.cmd and *-shell.cmd scripts to add appropriate references to gchart.jar) are required if you are planning to invoke these scripts within, say, an ant-based automated build. Fortunately, if you are already using an automated ant-based build for your GWT projects, you likely don't need any of these instructions.
@author John C. Gunther @author May B. Yew @version 2.2 (tested with GWT 1.4.62 in Firefox 2, IE 7 and IE 6 quirks mode)