>Hi Dezider,
>You have already answered yourself I think. Then do something like this :
>- Just create first level + one dummy node for nodes deeper than one

Another approach: have different icons for directories and files (and no dummy node). So if user clicks on a directory, check if it's filled already; if it isn't apply the technique (lock screen, add nodes on the level below, expand, unlock screen); if it is filled, just DoDefault().

It simply amounts to knowing if a node is expandable or not - in Cetin's method, it is if it has a dummy node. In mine, it is if it's a directory. BTW, if you're building from Adir(), beware of . and .. directories - they will be included in the array, and you'll have to skip them - you don't need them since you already have higher level nodes.