Author: Tomas Rutkauskas

Can someone tell me where I can look to get some help implementing scrolling while 
a drag operation is in effect.

Answer:
1   
2   procedure TfrmajNewsEditor.ajNewsTreeViewDragOver(Sender, Source: TObject;
3     X, Y: Integer; State: TDragState; var Accept: boolean);
4   const
5     cScrollOffset = 5;
6   var
7     Node: TTreeNode;
8   begin
9     Accept := true; {Always accept}
10    Node := fajNewsTreeView.TopItem; {Get the top node as a reference}
11    if (y < cScrollOffset) then {Are we dragging at the top of the treeview?}
12      SendMessage(fajNewsTreeView.Handle, WM_VSCROLL, SB_LINEUP, 0)
13        {We'll scroll the treeview}
14    else if (y > fajNewsTreeView.Height - cScrollOffset) then {Dragging at the 
15  bottom?}
16      SendMessage(fajNewsTreeView.Handle, WM_VSCROLL, SB_LINEDOWN, 0); {Do a scroll}
17    if (Node <> fajNewsTreeView.TopItem) then {Did we scroll? We'll need to redraw.}
18      fajNewsTreeView.Refresh; {The treeview gets in a mess if we don't.}
19  end;