Add the possibility to grab the tree item and drag it across the tree zone.
When dragging the TreeItem onto another one -> make the target the ParentNode
When dragging the TreeItem out of the ParentNode -> make it a leaf if no ChildNode left
When dragging the ParentNode -> move all the ChildNodes with it
Add the possibility to grab the tree item and drag it across the tree zone.
When dragging the TreeItem onto another one -> make the target the ParentNode
When dragging the TreeItem out of the ParentNode -> make it a leaf if no ChildNode left
When dragging the ParentNode -> move all the ChildNodes with it