RE: Arrow keys as accellerators?

["Ian Puleston" <ian underpressuredivers com>]

FYI, and just in case anyone else needs to do this too, I figured out a way
to get the up/down keys working as accelerators for scrolling my scrolled
window. The up/down keys that GTK won't let me use are GDK_Up/GDK_Down, so
instead I registered the accelerators as GDK_uparrow/GDK_downarrow:

  closure = g_cclosure_new(G_CALLBACK(accelKeyHandler), "up", NULL);
  gtk_accel_group_connect(accelGrp, GDK_uparrow, 0, 0, closure);
  closure = g_cclosure_new(G_CALLBACK(accelKeyHandler), "down", NULL);
  gtk_accel_group_connect(accelGrp, GDK_downarrow, 0, 0, closure);

Then I installed an event handler for the "key_press_event" on the main
window and had this check for GDK_Up/GDK_Down and activate the above
accelerators like this (note that I only intercept these keys when my
scrolled window is showing):

gboolean winKeyHandler(GtkWidget *topWin, GdkEvent *event, gpointer data)
{
    gboolean ret = FALSE;

    if (viewWinShowingNow() && event->type == GDK_KEY_PRESS)
    {
        GdkEventKey *keyEvnt = (GdkEventKey*)event;

        switch (keyEvnt->keyval)
        {
        case GDK_Up:
            gtk_accel_groups_activate(G_OBJECT(topWin), GDK_uparrow, 0);
            ret = TRUE;
            break;
        case GDK_Down:
            gtk_accel_groups_activate(G_OBJECT(topWin), GDK_downarrow, 0);
            ret = TRUE;
            break;
        }
    }

    return ret;
}

> -----Original Message-----
> From: Paul Davis [mailto:paul linuxaudiosystems com]
> Sent: Monday, April 10, 2006 6:53 PM
> To: Ian Puleston
> Cc: gtk-list gnome org
> Subject: Re: Arrow keys as accellerators?
> 
> On Mon, 2006-04-10 at 17:59 -0700, Ian Puleston wrote:
> > Hi,
> >
> > I've trying to install accelerator keys for a scrolled window to get the
> > page-up, page-down, up-arrow and down-arrow keys to act as short-cuts
> for
> > the vertical scroll bar. I install them as follows:
> >
> >     accelGrp = gtk_accel_group_new();
> >     gtk_window_add_accel_group(GTK_WINDOW(mainWin), accelGrp);
> >     closure = g_cclosure_new(G_CALLBACK(accelKeyHandler), "up", NULL);
> >     gtk_accel_group_connect(accelGrp, GDK_uparrow, 0, 0, closure);
> >     closure = g_cclosure_new(G_CALLBACK(accelKeyHandler), "page-up",
> NULL);
> >     gtk_accel_group_connect(accelGrp, GDK_Page_Up, 0, 0, closure);
> >       ....
> >
> > This works fine for the page-up and page-down keys, but the up-arrow and
> > down-arrow keys do not get intercepted and passed to the key handler
> > function. I'm guessing that this is because they are used for movement
> > around the buttons on the window. So:
> >
> > 1. Is there some way to unbind the up/down arrow keys from the button
> > navigation so that they can be used as accelerators?
> 
> no, this is disallowed in the source code. explicitly. if this isn't
> objectionable enough, KP_{Up,Right,Left,Down} are also prevented from
> being used as accelerators.
>