Lazarus Pascal Requires Chilkat v11.7.0+

PDF Object Streams: generate, preserve or disable

See more PDF Optimization Examples

Demonstrates the objectStreams option. An object stream packs many small objects (dictionaries, not stream data) into one compressed stream, which is usually a worthwhile saving in a document with many pages or tags. "generate" (the default) packs them and writes a cross-reference stream; "preserve" keeps the file as it is -- packed if it already was, not packed if it was not; "disable" writes every object on its own with a classic cross-reference table, which is what a PDF 1.4 reader needs. Object streams require PDF 1.5 and are skipped for PDF/A-1. Lazarus Pascal

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.FileAccess,
  Chilkat.Pdf,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  fac: TFileAccess;
  json: TJsonObject;
  jsonOut: TJsonObject;
  pdf1: TPdf;
  pdf2: TPdf;
  pdf3: TPdf;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  //  The PDF used in this example is available at grand_canyon_hiking_guide.pdf

  fac := TFileAccess.Create;
  json := TJsonObject.Create;
  jsonOut := TJsonObject.Create;

  //  generate: pack the objects (the default).
  pdf1 := TPdf.Create;
  success := pdf1.LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');
  if (success = False) then
    begin
      WriteLn(pdf1.LastErrorText);
      Exit;
    end;
  json.UpdateString('objectStreams','generate');
  success := pdf1.Optimize('optimize',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf1.LastErrorText);
      Exit;
    end;
  success := pdf1.WriteFile('qa_output/grand_canyon_objstm_generate.pdf');
  if (success = False) then
    begin
      WriteLn(pdf1.LastErrorText);
      Exit;
    end;
  WriteLn('generate: ' + fac.FileSize('qa_output/grand_canyon_objstm_generate.pdf') + ' bytes, objects packed: ' + jsonOut.IntOf('actions.objectStreams.count'));

  //  disable: every object on its own, with a classic cross-reference table.
  pdf2 := TPdf.Create;
  success := pdf2.LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');
  if (success = False) then
    begin
      WriteLn(pdf2.LastErrorText);
      Exit;
    end;
  json.UpdateString('objectStreams','disable');
  success := pdf2.Optimize('optimize',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf2.LastErrorText);
      Exit;
    end;
  success := pdf2.WriteFile('qa_output/grand_canyon_objstm_disable.pdf');
  if (success = False) then
    begin
      WriteLn(pdf2.LastErrorText);
      Exit;
    end;
  WriteLn('disable:  ' + fac.FileSize('qa_output/grand_canyon_objstm_disable.pdf') + ' bytes');

  //  preserve: leave the file's own structure alone.  Use it when the output must stay readable by
  //  whatever reads the input today.
  pdf3 := TPdf.Create;
  success := pdf3.LoadFile('qa_data/pdf/grand_canyon_hiking_guide.pdf');
  if (success = False) then
    begin
      WriteLn(pdf3.LastErrorText);
      Exit;
    end;
  json.UpdateString('objectStreams','preserve');
  success := pdf3.Optimize('optimize',json,jsonOut);
  if (success = False) then
    begin
      WriteLn(pdf3.LastErrorText);
      Exit;
    end;
  success := pdf3.WriteFile('qa_output/grand_canyon_objstm_preserve.pdf');
  if (success = False) then
    begin
      WriteLn(pdf3.LastErrorText);
      Exit;
    end;
  WriteLn('preserve: ' + fac.FileSize('qa_output/grand_canyon_objstm_preserve.pdf') + ' bytes');


  fac.Free;
  json.Free;
  jsonOut.Free;
  pdf1.Free;
  pdf2.Free;
  pdf3.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.