Author: Tomas Rutkauskas

I am working on a project that must keep the 640x480 pixel screen size. I would 
like to make it MDI. I've designed a small form with a menu and a tool bar (like 
Delphi's IDE). The user will click on this IDE like form and a new window will be 
display. Here is the problem: When the user maximizes this window, it goes to (0,0) 
thus hiding IDE form.

Answer:

Handle WM_GETMINMAXINFO, that allows you to specify position and size of the 
maximized window:


private
1   { Private declarations }
2   
3   procedure WMGetMinMaxInfo(var msg: TWMGetMinmaxInfo); message WM_GETMINMAXINFO;
4   
5   procedure TForm2.WMGetMinMaxInfo(var msg: TWMGetMinmaxInfo);
6   var
7     r: TRect;
8   begin
9     inherited;
10    SystemParametersInfo(SPI_GETWORKAREA, 0, @r, 0);
11    r.top := Application.Mainform.Height + Application.Mainform.Top;
12    with msg.MinMaxInfo^.ptMaxSize do
13    begin
14      x := r.right - r.left;
15      y := r.bottom - r.top;
16    end;
17    msg.Minmaxinfo^.ptmaxPosition := r.TopLeft;
18  end;



This code will make the form use the full available screen area (minus taskbar) under the main form, you will need to modify it to limit it to a maximum of 640x480.