[Interest] How to make modal dialog?

[Igor Mironchik]

Hi,

Is it possible to implement next feature? ...

If main window of application is active then some dialog, let's call its 
Dialog, will apear on some event, let's call its Event, in the 
application. But if main window is not active (minimized) and Event 
occures in app then Dialog shouldn't be shown on desktop. But when main 
window again maximized this Dialog should be shown.

I know that I can just store some flag and if application is not active 
I set this flag to true and don't display Dialog and when main window 
will be shown again I can just check this flag and if it set I can show 
Dialog...

But may be there is better solution?

Thank you.