How to sort data as I want in a VirtualExplorerTreeview (VirtualShellTools)

Question

Hello

This is probably a very "dumb" question for whoever knows VirtualShellTools but I only started using it and couldn't find my answer in the demos' code. Please note that I'm also unfamiliar with virtualtreeview.

I use a VirtualExplorerTreeview to display a directory structure, linked with a VirtualExplorerListview to display a certain type of files in the selected directory as well as specific informations about them

I've been able to point them at the right place, link them as I wanted, filter everything in the listview, and looking at the demos I have a pretty good idea about how to add my own columns and draw it to display my custom data.

My issue lies with the Treeview: I would like to sort the directories displayed in the order I want; specifically, I want "My Docs" and other folder to appears first, then drives, then removable media. Looking in the TNamespace property I found how to distinguish them (Directory and Removable properties), but I don't know how to implement my own sort/what event I need. I tried CompareNode but that doesn't even seem to be called.

Answer 1

If you want to do everything yourself, then set toUserSort in the TVirtualExplorerTree.TreeOptions.VETMiscOptions property. That causes the control to just use the DoCompare method inherited from the virtual tree view, and that should call the OnCompareNodes event handler.

A better way is to provide a custom TShellSortHelper. Make a descendant of that class and override whichever methods you need. Create an instance of that class and assign it to the tree's SortHelper property. (The tree takes ownership of the helper; free the old one, but not the new one.) If the items are being sorted on a column that that class doesn't know how to compare, then handle the tree's OnCustomColumnCompare event.

To help you figure out exactly which methods you need to override or events you need to handle, set a breakpoint in TCustomVirtualExplorerTree.DoCompare and step through to see what gets called in various situations.

Answer 2

Thanks Rob,

I just learned of this site. To be honest it seems you understand (well.. recall) my code better than I do. I would not have remembered about using the SortHelper!

Jim www.mustangpeak.net