unit Unit1;
interface
uses
  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, Grids, Outline;
type
  TForm1 = class(TForm)
    Outline1: TOutline;
    Outline2: TOutline;
    procedure OutlineDragDrop(Sender, Source: TObject; X, Y: Integer);
    procedure OutlineMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure OutlineDragOver(Sender, Source: TObject; X, Y: Integer;
      State: TDragState; var Accept: Boolean);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.OutlineDragDrop(Sender, Source: TObject; X, Y: Integer);
begin
  with Sender as TOutline do
  begin
    AddChild(GetItem(x, y),
      TOutline(Source).Items[TOutline(Source).SelectedItem].Text);
  end;
end;
procedure TForm1.OutlineMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if Button = mbLeft then
    with Sender as TOutline do
    begin
      if GetItem(x, y) >= 0 then
        BeginDrag(False);
    end;
end;
procedure TForm1.OutlineDragOver(Sender, Source: TObject; X, Y: Integer;
  State: TDragState; var Accept: Boolean);
begin
  if (Source is TOutline) and (TOutline(Source).GetItem(x, y) <>
    TOutline(Source).SelectedItem) then
    Accept := True
  else
    Accept := False;
end;
end.