[MDI] Child form to use whole client area?

Question

Hello

I'd like to show an MDI child window that will use the whole client area, ie. the grey part no the right-side of the taskpane, and have the child window show its titlebar and borders:

http://img149.imageshack.us/img149/3204/delphimdichildwindowwit.jpg

Here's the code, which doesn't work as planned:

procedure TForm1.RzGroup1Items0Click(Sender: TObject);
var
  Form2 : TForm2;
begin
  Form2 := TForm2.Create(Application);

  //BAD : doesn't start at 0,0, and triggers horizontal scrollbar
  Form2.Align := alClient;

  //BAD : doesn't show titlebar and borders
  Form2.WindowState := wsMaximized;

  //BAD : window exceeds width -> horizontal scrollbar shown
  Form2.top     := 0;
  Form2.Left    := 0;
  Form2.Width   := Self.ClientWidth;
  Form2.Height  := Self.ClientHeight;
end;

Is there a way to do this, besides computing the coordinates myself (eg. ClientWidth, etc.)?

Thank you.

Answer 1

The following code will give you the rect of the MDI client area. Please note that fighting MDI is hard.

Form2.BoundsRect := GetMDIClientAreaBoundsRect(Form1);

function GetMDIClientAreaBoundsRect(MDIForm: TForm): TRect;
begin
  if MDIForm.FormStyle = fsMDIForm then begin
    if not Windows.GetClientRect(MDIForm.ClientHandle, Result) then
      RaiseLastOSError;
  end
  else
    raise Exception.Create('MDIForm is not an MDI form');
end;

Answer 2

The quickest way to do that would be the TILE command.

var
  wFrm : TChildMDI;
begin
  wFrm := TChildMDI.create(self);
  wFrm.Show;
  Tile;
end;

TILE is a method of TForm and if you only have 1 MDI child window it will do exactly what you want. With more that 1 it will then arrange all the visible child windows to fit in a similar layout.

Ryan.