procedure TForm1.Demo_TgtPDFTextAnnotation;
var
  gtPDFTextAnnot1: TgtPDFTextAnnot;
  gtPDFEngine1: TgtPDFEngine;
begin
  gtPDFEngine1 := TgtPDFEngine.Create(Nil);

  // Create a text annotation
  gtPDFTextAnnot1 := TgtPDFTextAnnot.Create;
  gtPDFTextAnnot1.Rect := gtRect(1, 1, 3, 2);
  gtPDFTextAnnot1.Name := tnNote;
  gtPDFTextAnnot1.Open := True;
  gtPDFTextAnnot1.BorderColor := clRed;
  gtPDFTextAnnot1.Contents := 'This is a note.';
  gtPDFTextAnnot1.Subject := 'Review by John Doe';
  gtPDFTextAnnot1.Title := 'Sample Doc';

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

    BeginDoc; // Create a PDF document
    Rectangle(1, 1, 3, 2, False);
    TextOut(1, 0.8, 'What is this?');
    // Add the annotation to the current page
    AddAnnotItem(gtPDFTextAnnot1);
    EndDoc; // Save the PDF document
  end;
end;