Re: GtkRadioMenuItem set active problem

[Jeff Franks <jcf tpg com au>]

Owen Taylor wrote:
> Jeff Franks <jcf tpg com au> writes:
>
> > Hi,
> >
> > I've come across a problem with GtkRadioMenuItem. The only way to set
> > the active item in a group is to call 'gtk_check_menu_item_set_active'
> > which also emits an 'activate' signal. This is ok when a program is up
> > and running but when you are initializing a program, emitting an
> > 'activate' signal can be undesireable. When adding a group of
> > radiomenuitems all you really want to do is let GtkRadioMenuItem know
> > which way to draw its indicator. Since
> > 'gtk_radio_menu_item_draw_indicator' checks 'GtkCheckMenuItem::active'
> > before drawing the indicator wouldn't it be reasonable to let
> > GtkRadioMenuItem have a way to set/unset this flag without emitting an
> > 'activate signal. The best place for this might be as extra parameter
> > in the 'gtk_radio_menu_item_new' functions.
>
> I don't see this is being any different from a toggle button,
> where gtk_toggle_button_set_active() emits ::toggled.
>
> Generally, in response to any sort of change notification, instead of
> assuming that a change happened, you should get the current state and
> compare it against your internal state.
>     
I was testing GtkRadioMenuItem. While initializiing the main window I was
adding a submenu of 4 radiomenutiems. I wanted the previously saved option
to be restored when the menu was displayed. As I added the menuitems if the
menutitem being added matched the previously saved item I set it to active
by calling 'gtk_check_menu_item_set_active'. This emitted an activate signal
during program initialization which tried to activate partially initialized
code. All I wanted during initialization was to let the radiomenuitems know
which one should be drawn active. You can't check the internal state here
because it is the default GtkRadioMenuItem state. Remember the program is
being initialized and is not yet up and running. I accomplished what I wanted
to by directly setting the GtkCheckMenuItem::active flag for each item and
everthing works ok. 
    
Since radiomenuitems operate as a group isn't it reasonable, during initialization
of a group and before the group is visible, that you can somehow tell the
group which item should be drawn in the active state without having an activate
signal emitted.
    
I guess this situation arose because I was writng in C++ using libsig++ and
had directly linked the activation to a response using 'bind' during the
initialization.
    
Jeff.