Re: Optional keybindings

[Tim Janik <timj gtk org>]

On Tue, 15 Jan 2002, Owen Taylor wrote:

> As was discussed some earlier, here is a patch to allow keybindings to be
> optional: if the action signal for a keybinding has a boolean return value
> and returns FALSE, then it is as if that binding didn't exist.
> 
> This is needed in particular to fix a problem with activateable
> widgets in notebooks. If you hit "space" with the focus on one, then
> the space propagates up until it hits the notebook, which has a
> binding for "Space" and eats the keystroke. (I think we also need
> such binding for GtkPaned)
> 
> The notebook patch using this is attached; it makes bindings that should
> only have an effect when the focus is on the tabs return FALSE if the
> focus is on the child.
> 
> There are no compatibility problems with the binding change since action
> signals with a boolean return were not previously allowed in this context.
> 
> It is a newly exported public API, but I don't see any way around
> this ... we need the functionality internal to GTK+, and we can't hide it
> since it is a matter of use of existing function calls than adding new
> ones.

this needs a proper entry in Changes-2.0, as it is changing the return type
of three signals which existed in 1.2 already. users who emit those signals
from their code may get a segfault or similar for not passing a return
value location.

for a semi-related item, since we're talking about the notebook here,
i was recently prompted by someone on irc (think the xchat maintainer),
he suggested we change:

  void (*GtkNotebook::switch_page) (GtkNotebook     *notebook,
                                    GtkNotebookPage *page,
                                    guint            page_num);
to
  void (*GtkNotebook::switch_page) (GtkNotebook     *notebook,
                                    GtkWidget       *page_child,
                                    guint            page_num);

since GtkNotebookPage* is now opaque, and we don't have any accessors
for it, it's basically useless. 
and i have to admit that using
  widget = gtk_notebook_get_nth_page (notebook,
                                      gtk_notebook_get_current_page (notebook));
within a GtkNotebook::switch_page handler is rather awkward.
so since GtkNotebookPage* is currently useless anyways, this change
would have exactly zero impact on current code, and i think we
should make it, for "fixing" the uselessness of a pointer ;)

> 
> Regards,
>                                         Owen
> 

---
ciaoTJ