The primary intent of the Debug Panel for the Google Web Toolkit (GWT) is to provide the developer of a GWT application performance data about the application as well as tools to debug the client side application code. Web applications built with GWT run mainly in the client's environment, over which the developer has little control or access. The Debug Panel provides tools to the developer to help lift the shroud over the client environment to help diagnose problems, help tune and improve performance as well as assist with application testing.
Here is a sample screenshot of the Debug Panel in action:
Here, the Debug Panel shows us the statistics of an invocation of the EchoService as well as the startup times. It is clear from the example that RPC finished quickly. It shows that the slowest component was waiting for the server to respond at 121ms. While serializing the request and deserializing the response both took 19ms, updating the UI with the data returned from the server only took 2ms. These are the kinds of numbers you would want to see!
Here is another example screenshot of the Debug Panel:
Check out an online example of the Debug Panel, check out the example's source to see how easy it is to use or check out the Google Code project for more information.
Pascal Muetschard, Software Engineering Team