Export JDR - best way to react to the async operation

The "Export a JBoss Diagnostics Report" is an asynchronous operation, meaning that clicking on the button will send the request to Hawkular, which will forward to the target server. Once the report is done, the target server sends the resulting ZIP back to Hawkular, which sends it back to the user who requested it on the UI.

This interaction might take a long time (from a few seconds to a dozen of minutes).

Right now, clicking on the button doesn't give any feedback (is it missing a toast?), and once the report is done, the UI just shows a File Dialog, for the user to open/save the file.

I think this is not the optimal experience. So, I'm opening this JIRA to get ideas on how to improve this. My first thought would be to:

• When clicking on the "Export a JBoss Diagnostics Report" action, a toast tells the user that the request has been made and that it might take a while.
• Add a spinner or alike to the bottom right corner of the screen, with some transparency.
• Once the file is ready for download, replace the spinner with another icon, without transparency.
• Clicking on such icon would result in the File Dialog window.

rhn-support-eclayton, gcardoso_jira, mithomps1@redhat.com, alexandrem_jira, khala-1, pilhuhn, what are your opinions?