Fade all other windows of an application when a dialog is shown?

Question

How to dim / fade all other windows of an application in Delphi 2009.

Form has an AlphaBlend property, but it controls only transparency level. But it would be nice if

Answer 1

I have done something similar for showing a modal form trying to keep the implementation as simple as possible. I don't know if this will fit your needs, but here it is:

function ShowModalDimmed(Form: TForm; Centered: Boolean = true): TModalResult;
var
  Back: TForm;
begin
  Back := TForm.Create(nil);
  try
    Back.Position := poDesigned;
    Back.BorderStyle := bsNone;
    Back.AlphaBlend := true;
    Back.AlphaBlendValue := 192;
    Back.Color := clBlack;
    Back.SetBounds(0, 0, Screen.Width, Screen.Height);
    Back.Show;
    if Centered then begin
      Form.Left := (Back.ClientWidth - Form.Width) div 2;
      Form.Top := (Back.ClientHeight - Form.Height) div 2;
    end;
    result := Form.ShowModal;
  finally
    Back.Free;
  end;
end;