Add items after a given item
int PtGenTreeAddAfter( PtWidget_t *tree, PtGenTreeItem_t *items, PtGenTreeItem_t *brother );
This function inserts a list of trees linked with the brother field. PtGenTreeAddAfter() assumes that items points to a list of trees. The tree variable points to a PtGenTree widget. The new items are added to the specified tree below the specified brother.
This function may be called with a NULL tree argument, as long as brother points to an item that isn't attached to any tree widget.