lazarus/examples/treeview
..
README.txt
treeview.ex-meta
tv_add_remove_u1.lfm
tv_add_remove_u1.pas
TV_Add_Remove_U1.dfm
TV_Add_Remove.dpr
tv_add_remove.lpi
TV_Add_Remove.res

This demo was written by Andre .v.d. Merwe and marked public domain.
Quickly converted to Lazarus and FPC by Tom Lisjac <vlx@users.sourceforge.net>

The original source and an *excellent* tutorial on the TTreeview
component can be found here:

https://web.archive.org/web/20180423180227/http://users.iafrica.com/d/da/dart/Delphi/TTreeView/TreeView.html

(The original site at http://users.iafrica.com/d/da/dart/Delphi/TTreeView/TreeView.html
is not available any more).