Progress Bar

Hi,

i'm new to vaadin, and found the framework really nice. The documentation is also very good, but now i have a question about the progress bar, because this component, is not really good documented.
In my application i must execute server side thread, that takes some seconds till half a minute or more.
To do this, i have used the ProgressBar in the indeterminated mode and place it in a separate window. But now my question, is there a better possibility to use the default progressBar, which is showing during page loading in the top right corner.

Thank you in advance.