Re: Re: Howto make a gtkbutton send a "changed" signal?

["Till Harbaum" <lists harbaum org>]

Hi,

First of all: Thanks. Your reply indeed solved my problem. Thanks.

Other than that: Why is this silly? (You see, i didn't agree, but did 
continue to read ...)

My reasoning is: A gtkentry for me is just "something that contains 
some text which may change". Now in this particular setup
is text entry a problem (as the device doesn't always have a keyboard).
So i build something based on a button which changes its label 
by some "input magic" that kicks into place when the user clicks
the button. And whenever the user does this i want it to trigger the
same behaviour the original gtkentry did. 

If you think this is silly: What do you think is the non-silly way
to solve this?

Thanks again,
  Till

----- original Nachricht --------

Betreff: Re: Howto make a gtkbutton send a "changed" signal?
Gesendet: Di, 01. Dez 2009
Von: David Ne?as<yeti physics muni cz>

> On Tue, Dec 01, 2009 at 09:59:07AM +0100, Till Harbaum wrote:
> > i am changing the UI of an existing app for mobile usage in a way that i
> replace
> > some gtkentry's with some gtkbuttons which the use some alternate input
> method.
> > I want to keep as much of the application as it is and one of the things
> the app expects
> > is that this particular widget emits a "changed" event whenever its
> contents changes.
> > So i'd like to enable my gtkbutton to emit a "changed" event, but i don't
> find any examples
> > on how to achieve that. How do i "attach" a new signal to an existing
> widget type?
>
> If you agree that what you are trying to do is silly and you are
> desperate, you are allowed to read on.
>
> I'm not sure what it means `contents changed' for a button.  So I
> respond to "clicked".  But you can emit the signal in response to
> "notify::label" (i.e. the change of the label) or whatever it means
> `contents changed' for you.
>
> Yeti
>
> ----------------------------------------------------------
> #include <gtk/gtk.h>
>
> static void
> emit(GObject *object, gpointer user_data)
> {
>     guint id = GPOINTER_TO_UINT(user_data);
>     g_signal_emit(object, id, 0);
> }
>
> static void
> changed(GObject *object)
> {
>     g_print("signal \"changed\" emitted on instance %p (%s)\n",
>             object, G_OBJECT_TYPE_NAME(object));
> }
>
> int
> main(int argc, char *argv[])
> {
>     GtkWidget *window, *button;
>     guint id;
>
>     gtk_init(&argc, &argv);
>     window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
>     g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
>
>     id = g_signal_new("changed", GTK_TYPE_BUTTON,
>                       G_SIGNAL_RUN_FIRST, 0, NULL, NULL,
>                       g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);
>
>     button = gtk_button_new_with_label("Click Me!");
>     g_signal_connect(button, "clicked", G_CALLBACK(emit),
> GUINT_TO_POINTER(id));
>     g_signal_connect(button, "changed", G_CALLBACK(changed), NULL);
>     gtk_container_add(GTK_CONTAINER(window), button);
>     gtk_widget_show_all(window);
>
>     gtk_main();
>
>     return 0;
> }
> ----------------------------------------------------------

--- original Nachricht Ende ----