From: Lyle Johnson <lyle@...>
Date: 2003-02-11T15:37:45+09:00
Subject: Re: Does FX/Ruby have some standard icons?

Harry Ohlsen wrote:

> I'm trying to be vaguely clever, by only expanding tree items when 
> someone double clicks on them, thus improving perceived performance (in 
> terms of startup time).
> 
> However, I'd like the user to know whether an item has children.  Ie, 
> whether it makes sense to double click on an item.
> 
> Hence, I'd like to put two different icons next to the tree nodes, 
> depending upon whether they have children in the data.  FOX won't know 
> about the children yet, since they won't be added to the tree list until 
> the double click, so it doesn't display a "+" sign.

You are talking about two different issues with regards to how tree 
items are drawn.

The first issue is whether the boxes with the +/- signs appear to the 
left of (non-leaf) tree items. Two different options for the FXTreeList 
widget control affect this. For root-level tree items, if you pass in 
the TREELIST_ROOT_BOXES option you'll see these boxes; if not, you 
won't. For other (non-root) tree items, the TREELIST_SHOWS_BOXES option 
serves the same purpose.

The second issue (and independent of the first) is which icon(s) are 
displayed when a tree item is open or closed. If you're using, for 
example, FXTreeList#addItemLast to append child items to a parent node, 
you can pass the "open" and "closed" icons as the third and fourth 
arguments to addItemLast:

     treeList.addItemLast(parentItem, "Item Text", openIcon, closedIcon)

for the other methods on FXTreeList, see the API docs here:

     http://www.fxruby.org/doc/api

So for the application you've described, it sounds like you'd want to 
turn off display of all of the "boxes", then use custom icons for the 
leaf and non-leaf items, as appropriate.

> Are there any "standard" icons, or do I need to actually have my own 
> images, in order to add icons?

You'll need to provide your own icons. Any of the icons used for tree 
lists in the FXRuby examples (e.g. splitter.rb) are fair game, if that 
helps.