Code review comment for lp:~vanvugt/mir/hidden

>> Gerry's concern about clicking on an icon which appears to do nothing is actually an old problem
>> that we can't avoid. This already happens if either the app crashes, or if the app chooses to not
>> create a surface. It's not a new problem with this branch.

I think it is. First lets look at the two problems you outline:

1. An app crashes. In this case we can remove its launcher icon. If the app is just frozen either it has never submitted its first buffer (in which case the launcher icon will never reach the opened state) or we always have a buffer available to render....so the launcher icon can always do something.
2. If an app chooses not to create a surface it will be in the Launching state...until it times out and is killed. If it just never creates a surface, then I suppose its not an app you launch from the launcher.

This branch introduces a new scenario:
3. An app is open and the launcher icon in the "launched" state, but all the surfaces are hidden. Not only is this a sort of violation of the app model (the app is consuming resources with windows that the user cant see?) but introduces this inconsistency where the launcher icon does nothing.