Hi, everyone.

For some GdkEvent like signal/event, we may want a behavior that connected handlers or overrided methods could use its return value to determine if the processing should be stopped, like "key-press-event" in GtkWidget.

To implement this behavior we should provide a param in g_signal_new() (http://library.gnome.org/devel/gobject/stable/gobject-Signals.html#g-signal-new), accumulator, it works as a callback function, and can stop emission by return false.

Code generated by valac only use null as the accumulator, and there may be no other way to install a new signal in vala, at present.

So will it be possible to privide accumulator support? Maybe by some [Signal] properties?

Thanks.