_gtkWidgetCB
_gtkWidgetCB defines a generic callback to any Widgets object. Almost 100% of GTK+ signals can be defined by this way.
** Warning ** : this function works fine but the developer should be rigourous when it is used. He/She should read the GTK+ documentation for each asked signal.If you are NOT an advanced GTK developer, you are strongly recommended to use the specific functions in sub classes, even if they are much less.
Prototype : fun [* $ u0 I S u1] *
- * : a widget object (a window, a text, a button, ... or other)
- $ : the callback (like @function_name). The developer is responsable of its prototype.
The callback takes these arguments :- the widget object,
- the user parameter,
- the signal (its name),
- if any, other arguments depending of the signal, see GTK documentation for that.
- u0 : an user parameter, at your convenience, for the callback.
- I : the propagate mask : SIGNAL_PROPAGATE or SIGNAL_NOPROPAGATE.
- S : the signal (it is its GTK name, strictly. For example : "clicked").
- u1 : not used yet. It should be always nil.
- Return * : the same widget or nil if an error occurs.