Re: Making Signal For A Widget.

["B. Souliotis" <bill beta-cae gr>]

Gustavo J. A. M. Carneiro wrote:

> A Ter, 2003-06-03 às 13:03, B. Souliotis escreveu:
>  
>
> > I would like to make a signal for a particular widget that will be 
> > emmited when you press the
> > first mouse button.
> > I don't want to use the
> > g_signal_connect(G_OBJECT(widget),"button_press_event",G_CALLBACK(callback),NULL);
> > for the widget Because i want the callback to called only when i press 
> > the First mouse button.
> >
> > So I would like to make something like "clicked" signal for the gtk_button.
> > IN gtkbutton.c is called
> > g_signal_new("clicked",....);
> > but i don't undarstand how this signal is emmited only when the button 
> > pressed.
> > So can anyone tell me how you pass the events to g_signal_new that will 
> > emmit the new signal.
> >    
>
>         What you want to do is:
>         1. register a new signal with signal_id = g_signal_new(...), but only
> once per app!
>         2. for each instance of the widget,
> g_signal_connect(widget,"button_press_event", callback, NULL)
>         3. In the 'callback' function, check if the first button has been
> pressed..
>         4. ..if so, g_signal_emit(signal_id, ...)
>
>         Actually doing what I say becomes more complicated if you are not used
> to such things.  Also, this is usually done by creating a new widget
> class deriving from the first widget, but this is also a lot of work...
>         Good luck.
As far as i know if you make a new widget class i can put in the 
structure of new widget
something like
widget->button1_pressed = callback_1_pressed

after make the signal

signal_id = g_signal_connect(widget,"button1_pressed",callback, NULL);

and in  callback_1_pressed(GtkWidgetNewClass *)
i'll emit the signal with
g_signal_emit(signal_id,......);

The same thing exactly is doing the GtkButtonClass
with the clicked signal.
But I could not Understand how the signal is emitted only for the first button.
So the question is how the signal_id is connected with a specific event like Button1_pressed
without using other signals like g_signal_connect(widget,"button_press_event", callback, NULL)
and after emiting the specific signal that you want.

Thanks 
In advance
Bill Souliotis