Change Color of checkbutton

["Andrew E. Makeev" <andrew solvo ru>]

Hello.

I have question - how to change color of checkbutton background properly
(background of small square where check-sign is placed)?

Look at this function:

void CustomCheckBox::set_background( const Gdk::Color& color )
{
    if( Gtk::Widget* w = get_focus_widget() )
    {
        static Glib::RefPtr< Gtk::RcStyle > default_style( 0 );
        const Glib::RefPtr< Gtk::RcStyle > modifier_style =
            w->get_modifier_style();
        if( !default_style )
        {
            default_style = modifier_style->copy();
            default_style->reference();
        }

        if( color != Gdk::Color() )
        {
            modifier_style->set_color_flags( Gtk::STATE_NORMAL,
Gtk::RC_BG );
            modifier_style->set_bg( Gtk::STATE_NORMAL, color );
            w->modify_style( modifier_style );

// this row used only for checkbutton, otherwise set_bg has no effect
            w->get_style()->set_white( color );
// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        }
        else
        {
            w->modify_style( default_style );
        }
    }
}

It works well for any widget except checkbutton. Of course I am using
Gtk::RcStyle::set_base() for widgets that derived from Entry. The
problem with checkbutton is that it won't change background just on
widget creation, some later (when window "completelly" shown) it works
well.

I tried to override on_style_changed() method to call set_background
from there on widget creation - no luck.

Any help would be appreciated.

thanks in advance,
-andrew