Перемещение формы

Code:

...

private

  procedure WMWINDOWPOSCHANGING

           (Var Msg: TWMWINDOWPOSCHANGING);

            message WM_WINDOWPOSCHANGING;

...

procedure TfrMain.WMWINDOWPOSCHANGING

         (var Msg: TWMWINDOWPOSCHANGING);

const

Docked: Boolean = FALSE;

var

rWorkArea: TRect;

StickAt : Word;

begin

StickAt := StrToInt(edStickAt.Text);

SystemParametersInfo

    (SPI_GETWORKAREA, 0, @rWorkArea, 0);

with Msg.WindowPos^ do begin

   if chkLeft.Checked then

    if x <= rWorkArea.Left + StickAt then begin

     x := rWorkArea.Left;

     Docked := TRUE;

    end;

   if chkRight.Checked then

    if x + cx >= rWorkArea.Right - StickAt then begin

     x := rWorkArea.Right - cx;

     Docked := TRUE;

    end;

   if chkTop.Checked then

    if y <= rWorkArea.Top + StickAt then begin

     y := rWorkArea.Top;

     Docked := TRUE;

    end;

   if chkBottom.Checked then

    if y + cy >= rWorkArea.Bottom - StickAt then begin

     y := rWorkArea.Bottom - cy;

     Docked := TRUE;

    end;

   if Docked then begin

     with rWorkArea do begin

     // не должна вылезать за пределы экрана

     if x < Left then x := Left;

     if x + cx > Right then x := Right - cx;

     if y < Top then y := Top;

     if y + cy > Bottom then y := Bottom - cy;

     end; {ширина rWorkArea}

   end; {}

end; {с Msg.WindowPos^}

inherited;

end;

end.