How can I hide a TVirtualStringTree node?

Question

if I'm not mistaken it's not possible to have invisible nodes in a TVirtualStringTree treeview, as there are no enabled, visible or other properties to do so. Am I right about this?

If yes, how did I manage to have a non visible node?

Structure of my tree:

• One Node
• Another node
  • Subnode 1
  • Subnode 2
  • ...
  • Subnode 15
  • Subnode 16 (which is not visible!)
• Yet another node
  • Subnode 1 from yet another node
  • Subnode 2 from yet another node

I can find Subnode 16 when I do a FirstNode/GetNextNode loop over the whole tree and let me print out the text for the first column. I can also inspect the node and see that he's got a previous sibling but no next sibling for instance and the node height is 18.

So how did I do this?

Answer 1

if I'm not mistaken it's not possible to have invisible nodes in a TVirtualStringTree treeview, as there are no enabled, visible or other properties to do so. Am I right about this?

You are wrong, it is possible to have both invisible and disabled nodes. To switch visible state of the node use

vtree.IsVisible[Node] := boolean;

to enable / disable node use

vtree.IsDisabled[Node] := boolean;

You can also initialize node to disabled state in tree's OnInitNode event with adding ivsDisabled to InitialStates parameter.

Answer 2

In Addition to ains answer, to recurse the tree you can use the following functions:

To recurse ALL nodes

Tree.GetFirst();
Tree.GetNext();
Tree.GetPrevious();

To recurse only VISIBLE nodes:

Tree.GetFirstVisible();
Tree.GetNextVisible();
Tree.GetPreviousVisible();