wxruby users - Apr 2007 - how to simulate key_down event(when event.get_key_code()==Wx::K_DOWN) in ListCtrl or TreeCtrl?

I want to simulate vi(vim) like operations in ListCtrl or TreeCtrl,
that is, for example, when user pressed a ''j'' on keyboard,the
selected
item change into the next one item, just like user press a
Wx::K_DOWN(arrow key down on keyboard) .
but not jump to some item started with a "J" charater.

    evt_tree_key_down(TreeTest_Ctrl) { | e | on_tree_key_down(e) }
...
  def on_tree_key_down(event)
    keycode = event.get_key_code()
    case keycode
    when 74 # ''j'' ''s keycode
       #what should I write here? ...............
    end
  end

that''s the basic, when I know how to write, i will organize the
program''s struct.

thanks!
cy

yang cao wrote:
> I want to simulate vi(vim) like operations in ListCtrl or TreeCtrl,
> that is, for example, when user pressed a ''j'' on
keyboard,the selected
> item change into the next one item, just like user press a
> Wx::K_DOWN(arrow key down on keyboard) .
Perhaps something like this?

    case event.get_key_code
    when ?j # correct ASCII code for ''j''
      curr_sel = get_selection # what''s currently selected?
      return unless curr_sel
      if sib = get_next_sibling(curr_sel)
        select_item(sib)
      end
    end

This only scrolls down through the TreeCtrl if the current item has 
another sibling - you''d need to decide whether ''j''
should move down into
the current item''s children, or up into its parent''s siblings
if it
doesn''t. get_item_parent and get_children (which is in WxSugar) should
help.

alex