Re: [Scwm-devs] Re: event question

[Greg B. <gj...@cs...>]

I see your point.  But you can think of the first level event map as
containing bindings for "j" -> literal "j" to be passed to the
application (that's the way Emacs treats them -- X's implementation
makes it a little bit trickier to view things that way, but I think it
can still make sense conceptually).  FWIW, the closest place I came to
multi-key mappings is stuff like my H-p "shove-window" binding that pops
up a little visualization of a keyboard, grabs the keyboard, and lets
you hit another key.  I like this UI a bunch and it does exactly what I
expect and want.

Thanks,
Greg

Scott Lenser <sl...@cs...> writes:

> > I'd use Emacs as a guide.  Try hitting something like C-c C-2 and you'll
> > see it complain "C-c C-@" is undefined.  Scwm could do that using a
> > popup message box for a user configurable amount of time.  Neither of
> > the keystrokes get inserted into the buffer.  (Just as Scwm wouldn't
> > send either to the application.)  The upshot of that is that prefix keys
> > should be non-app keys, but that's good sense, anyway.
> > 
> > Thanks,
> > Greg
> > 
> 
> I don't think the situation is entirely analogous since there is no question
> of emacs passing the event on to the app.  In any case, I think that is the
> most reasonable behavior.
> 
> There is an interesting side effect to this behavior.  If we follow the emacs
> model of event maps are a single event deep and prefixes are handled by
> going down to another event map, then the event maps act differently.
> 
> Consider, bindings like so:
> 
> event_map
>   M-F1 => event_map
>             M => maximize window
>             m => minimize window
>             i => iconify window
> 
> Now, if the user types "M-F1 j", a message displays saying this is not bound
> and nothing else happens.  If the user type "j", then this gets sent on to
> the application.  So in the first level event map, unbound events gets passed
> through.  In the second level event map, unbound events cause a message to
> be displayed.  The implementation in X calls is likely to be different too.
> The first level event map will need to install a bunch of passive X grabs to
> get its keys, but the second one will probably be handled with at least the
> keyboard grabbed.  I suppose this distinction could be made when the event map
> gets installed and thus hidden from the user.  It does create some interesting
> problems, though.
> 
> - Scott