Re: libsigc++ question

[klaus triendl <klaus triendl eu>]

Andreas Volz schrieb:
> I've a main loop where I catch all keyboard input. In that input class
> there's a signal that all interested widgets could connect. This works
> so far. Now if the main loop gets a key press than a signal is emit and
> all connected widgets are informed.
>
> But what if I only like to emit the signal for a group of connected
> widgets? With emit() it seems all signal handlers are informed. Maybe
> there's a way in the libsigc++ API to signal only some with a special
> property set.
>
> For example it's same as in Gtkmm. Only widgets that have the input
> focus receive the keyboard input and all other widgets not. How does
> that work?

I don't know of the gtkmm implementation. But I think you have 2 
possibilities at the sigc level:
- filter the signal in your signal handler
- save a copy of the slot that you connect to the signal and set its 
blocking state (see 
<http://libsigc.sourceforge.net/libsigc2/docs/reference/html/classsigc_1_1slot__base.html#69042c2e2b0e5449fbf8203e862192a7>)


Klaus