Don't allow export when there's no pattern
Currently the export button is always active, and there's an error dialog when you click it right after opening the app:
This is not ideal for a few reasons (confusing user flow, dialog with an "OK" button, unnecessary extra UI and strings), and could be streamlined by just making the button insensitive while the pattern is empty.
Hi @bertob, thanks so much for raising this issue! I think, in addition to what you mentioned, Drum Machine can sometimes get confused and recognize an empty pattern as unsaved changes. This is fixed in #55, but the other side of it, exactly what you're describing in here, still needs to be addressed. A high-quality PR from anyone interested in tackling this would be greatly appreciated. :)