Re: How "Tab" brings widgets into focus

[muppet <scott asofyet org>]

On Jul 18, 2007, at 9:02 AM, varun_shrivastava wrote:

> so which of the GtkWidget "focus" signal handler is being called  
> the default
> one or the overridden one in GtkContainer class.

An overridden handler always gets called, and has the option to chain  
up to the default.

gtk_container_focus() handles two cases: 1) the container itself can  
take focus, and 2) the container cannot take focus, but perhaps its  
children can.  The point of overriding this method for a container,  
then, is to pass the focus on to a child.

set-focus-child is a container-specific method to allow container  
implementations to control which child of the container has or will  
get focus.  In gtk_container_focus_move(), the focus_child is used as  
the start point for finding the next item in the focus chain.

For example:

   focus chain:   A, B, C, D
   focus child:  B

   gtk_container_focus_move(forward) will see that the current focus  
child is B, and focus C next.


So, set-focus-child is not involved in the call chain resulting from  
the user hitting the Tab key, but instead can be used by a widget to  
control programmatically what widget in a specific container will get  
focus when the user does hit the Tab key.


--
me, while driving the car: Okay, girls, what do you want for lunch?
yvonne: I wan' noo-tulls!
zella: I want lavaloli!  Can we go to the lavaloli store?
me: Um, where *is* the ravioli store?
zella: At the lavaloli store!
yvonne: I want noo-tulls!  Let's go to the noo-tull store!