Freeing TListView.data

[OmniCog]

I am trying to extend the TTreeView class.

How do I ensure that the memory of the object (it will always be an object) that is assigned to TreeNode.data is freed whenever a node is deleted in statements such as TV.Items.Clear?

I understand something like:
TNodeData(TV.Selected.Data).Free;
TV.Selected.Delete;

wil do but what if CustomTV.Items.clear is called or when the application is terminated? I can't even override TTreeCustomView.Clear or TTNode.Delete methods.

Any help is appreciated

David

 

[whosrdaddy]

indeed, expanding the TTreeView component to accomplish this task is not as easy as it would seem.
I would add a TObjectList somewhere and add the objects from the Treeview to the objectlist also.

Like this

uses contnrs,...
...
var MyObjects : TObjectList
// somewhere in init code
 MyObjects:=TObjectList.Create(True);

// create object , here is some psuedocode
 NodeData:=TNodeData.Create;
// add object to objectlist
 MyObjects.Add(NodeData);
// set treenode pointer towards our object 
 TreeNode.Data:=NodeData;

// object deletion, deleting the object from the TobjectList will free the object
MyObjects.Delete(MyObjects.IndexOf(TV.Selected.Data));
// delete Treeview node
TV.Selected.Delete;

cheers,
Daddy

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