Ribbon control bug? (causes cutoff in vista)

Question

I've found that when I take a simple form containing only a ribbon bar and a status bar, it's cutoff. The control you see above the status bar was later removed. The same cutoff occurs whatever control happens to be present. Later I removed the status bar & put a memo control there instead with the same result.

without ribbon bar:
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with ribbon bar:
_{(source: xrw.bc.ca)}

i've illustrated this with some drawing 2, 4, and 8 pixels from the edge.

<sub>(source: xrw.bc.ca)

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as Chris Lively says below, there's clearly been a miscalculation of the sizes. how can i correct this?

Thank you for your comments!

Answer 1

I misunderstood the problem with my previous answer.

There is a workaround to this miscalculation problem I've been able to come up with (quickly).

You can use a custom messagehandler for WM_SYSCOMMAND with the SC_MAXIMIZE wParam parameter. You can then resize your form using the following:

type
  TForm1 = class(TForm)
    // other stuff
    procedure WMSyscommand(var Msg: TWMSYSCOMMAND); message WM_SYSCOMMAND;



procedure TForm1.WMSysCommand(var Msg: TWMSYSCOMMAND);
var
  R: TRect;
begin
  // Test for SC_MAXIMIZE. If found...
  if Msg.CmdType = SC_MAXIMIZE then
  begin
    SystemParametersInfo(SPI_GETWORKAREA, 0, @R, 0);
    Top := R.Top;
    Left := R.Left;
    Width := R.Right - R.Left;
    Height := R.Bottom - R.Top;
    Msg.Result := 0; // Message handled
  end
  else
    DefaultHandler(Msg);
end;

The code above (tested on Vista 32-bit Home Premium with Aero/Glass enabled) works fine.

Answer 2

The solution proposed by Ken White has a few issues:

• Maximize button stays active, can use resize handles on maximised window
• Unable to restore window back to previous size.

So I propose the following:

// add to form object
procedure WMGetMinMaxInfo(var mmInfo : TWMGETMINMAXINFO); message WM_GETMINMAXINFO;

// implementation
procedure TfrmMain.WMGetMinMaxInfo(var mmInfo: TWMGETMINMAXINFO);
var
  R: TRect;
begin
  with mmInfo.MinMaxInfo^ do
  begin
    SystemParametersInfo(SPI_GETWORKAREA, 0, @R, 0);
    ptMaxPosition.X := R.Left;
    ptMaxPosition.Y := R.Top;
    ptMaxSize.X     := R.Right - R.Left;
    ptMaxSize.Y     :=  R.Bottom - R.Top-1;
  end;
end;

Not ideal, as I have to (for some reason) adjust the maxHeight by -1 in order for the default handler to not re-assert itself and move the window to -8,-8,... But it works for me.