Re: [gtkmm] How to set a button back to its released(?) state?

[Paul Davis <pbd op net>]

> I'm writing an application where there are two buttons.  If one of the
> buttons is in the released (default) state, the other has to be made
> non-sensitive _and_ released, too.  In time it would for example like
> this (P = pressed, R = released, S = sensitive, N = non-sensitive)

   [ ... ]
  
>    if (button.get_active())
>        button.clicked();
>
> does it, with the side effect that it triggers the clicked signal,
> which I don't necessarely want to happen.

use button.set_active().

or use Gtk::RadioButtons.

or if like me, you consider their visual appearance completely
appalling, you could try this. i'll just include the header for
now. You'd need to use set_sensitive() at some point as well.  this is
gtkmm 1.2 code, btw.

/*
    Copyright (C) 2001 Paul Davis 

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    $Id: grouped_buttons.h,v 1.3 2002/06/01 03:32:47 trutkin Exp $
*/

#ifndef __gtkmmext_grouped_buttons_h__
#define __gtkmmext_grouped_buttons_h__

#include <vector>
#include <sigc++/signal_system.h>

using namespace std;

namespace Gtk {
	class ToggleButton;
};

class GroupedButtons : public SigC::Object
{
  public:
	GroupedButtons (unsigned int nbuttons, unsigned int first_active);
	GroupedButtons (vector<Gtk::ToggleButton *>&);
	
	Gtk::ToggleButton& button (unsigned int which) {
		return *buttons[which];
	}

  private:
	vector<Gtk::ToggleButton *> buttons;
	unsigned int current_active;
	void one_clicked (unsigned int which);
};

#endif /* __gtkmmext_grouped_buttons_h__ */

#include <gtk--.h>

#include "grouped_buttons.h"

GroupedButtons::GroupedButtons (vector<Gtk::ToggleButton *>& buttonset)
{
	unsigned int n = 0;

	buttons = buttonset;

	for (vector<Gtk::ToggleButton *>::iterator i = buttons.begin(); i != buttons.end(); i++, n++) {
		if ((*i)->get_active()) {
			current_active = n;
		}
		(*i)->clicked.connect (bind (slot (this, &GroupedButtons::one_clicked), n));
	}
}

GroupedButtons::GroupedButtons (unsigned int nbuttons, unsigned int first_active)
{
	buttons.reserve (nbuttons);
	current_active = first_active;

	for (unsigned int n = 0; n < nbuttons; n++) {

		Gtk::ToggleButton *button;
		
		button = manage (new (Gtk::ToggleButton));
		
		if (n == current_active) {
			button->set_active (true);
		} 

		button->clicked.connect (bind (slot (this, &GroupedButtons::one_clicked), n));
		buttons.push_back (button);
	}
}

static gint
reactivate_button (void *arg)
{
	Gtk::ToggleButton *b = (Gtk::ToggleButton *) arg;
	b->set_active (true);
	return FALSE;
}

void
GroupedButtons::one_clicked (unsigned int which)
{
	if (buttons[which]->get_active()) {

		if (which != current_active) {
			unsigned int old = current_active;
			current_active = which;
			buttons[old]->set_active (false);
		}

	} else if (which == current_active) {

		/* Someobody tried to unset the current active
		   button by clicking on it. This caused
		   set_active (false) to be called. We don't
		   allow that, so just reactivate it.

		   Don't try this right here, because of some
		   design glitches with GTK+ toggle buttons.
		   Setting the button back to active from
		   within the signal emission that marked
		   it as inactive causes a segfault ...
		*/

		gtk_idle_add (reactivate_button, buttons[which]);
	}
}