Emit message when greyed out icons are pressed

[jidanni]

Pressing greyed out icons should may a message 'adding waypoints is disabled for this layer' etc., instead of just doing nothing.
Else the user, who has never seen what the non-greyed out version of a particular icon looks like,
thinks they can still press it.

[rnorris]

I think this is by design of the underlying GUI GTK toolkit behaviour (and AFAIK all GUI toolkits behave this way included Qt, WinForms, WxWidgets), so the top level program doesn't get notified about such events.

Can you identify an existing program - preferably a 'popular/mainstream' one - that offers such feedback?

[jidanni]

All I know is that emacs would at least beep in such situations. But of course emacs isn't inside a browser.

[rnorris]

Ah, I always turn off beeps!

I noticed the other day using VMWare Workstation (on Windows) - that it does respond to clicks on (at least some) inactive buttons on the toolbar - with some kind of dialog warning message. But none of the inactive menu entries did.

However, I still don't think that is possible with the GTK framework. But I've not researched that definitively.

Alternatively, what might be easier to achieve, is changing the tooltip message as appropriate.