procedure TForm1.Demo_TgtPDFSquareAnnot;
var
  gtPDFSquareAnnot1: TgtPDFSquareAnnot;
  gtPDFEngine1: TgtPDFEngine;
begin
  gtPDFEngine1 := TgtPDFEngine.Create(Nil);

  // Create a square annotation
  gtPDFSquareAnnot1 := TgtPDFSquareAnnot.Create;
  gtPDFSquareAnnot1.Rect := gtRect(1, 1, 2, 2);
  gtPDFSquareAnnot1.DifferRect := gtRect(0.3, 0.3, 0.1, 0.1);
  gtPDFSquareAnnot1.InteriorColor := clYellow;
  gtPDFSquareAnnot1.BorderStyle := brInset;
  gtPDFSquareAnnot1.BorderWidth := 3;
  gtPDFSquareAnnot1.BorderColor := clRed;
  gtPDFSquareAnnot1.Cloudy := True;
  gtPDFSquareAnnot1.CloudIntensity := 2;
  gtPDFSquareAnnot1.Contents := 'This is a square annotation';
  gtPDFSquareAnnot1.Title := 'eDocEngine Demos';
  gtPDFSquareAnnot1.Subject := 'Square Annotation Demo';

  with gtPDFEngine1 do
  begin
    Preferences.ShowSetupDialog := False;
    Preferences.OpenAfterCreate := True;
    FileName := 'square_annotation.pdf';

    BeginDoc; // Create a PDF document
    // Add the annotation to the current page
    AddAnnotItem(gtPDFSquareAnnot1);
    EndDoc; // Save the PDF document
  end;
end;