RE: [gtk-list] entry input verification [Was: Uppercase only ent

[Trog <trog gtk org>]

On 29-Feb-2000 Ralf Corsepius wrote:
> On a related subject (It might be an FAQ, but ...):

[NOTE to self] write a FAQ entry for this.

> 
> I am looking for a method to provide input verification on
> GtkEntry/GtkEditable, e.g. I am looking for an GtkEditable which
> shall only
> accept a subset of characters (eg. those that match a regular
> expression, or
> integers only) as text input.
> 
> [Actually, I  looking for something similar to Motif's
> XmNmodifyVerifyCallback
> for XmTextFieldWidgets]
> 
> The approach you outline above doesn't seem to work in my case,
> because the
> insert_text signal does't seem to allow changing the size of the
> inserted
> text.
> Implementing it with the changed signal seems to be possible, but
> seems to be
> rather ineffective and also seems to suffer from the "infinite
> loop" issue
> (changed being called because invoking "set_text" ).

Attach to the "key_press_event" event of the entry widget:

gtk_signal_connect(GTK_OBJECT(entry),
                   "key_press_event"
                   GTK_SIGNAL_FUNC(entry_key_press),
                   data);

Then the callback function goes along the lines:

gint entry_key_press (GtkWidget *widget,
                      GdkEventKey *event,
                      gpointer     data)
{
  switch (event->keyval) {
  case GDK_F1:
   gtk_signal_emit_stop_by_name(GTK_OBJECT(widget),"key_press_event");
   gtk_editable_insert_text( GTK_EDITABLE(widget), "hello",
                             5,&GTK_EDITABLE(widget)->current_pos);
   return TRUE;

  case GDK_F2:
   gtk_signal_emit_stop_by_name(GTK_OBJECT(widget),"key_press_event");
   gtk_editable_insert_text( GTK_EDITABLE(widget), "world",
                             5,&GTK_EDITABLE(widget)->current_pos);
   return TRUE;
  }

  return FALSE;
}

I think that covers what you need. Well, you should get the idea
anyway.

-tony











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