Delphi DLL

PDF Signatures with Built-in SVG Graphics

See more PDF Signatures Examples

This example demonstrates the built-in SVG graphics that can be applied to the appearance when signing a PDF.

Note: This example requires Chilkat v9.5.0.85 or greater.

Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Pdf, Cert, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
pdf: HCkPdf;
json: HCkJsonObject;
cert: HCkCert;

begin
success := False;

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

pdf := CkPdf_Create();

// Load a PDF to be signed.
// The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
success := CkPdf_LoadFile(pdf,'qa_data/pdf/hello.pdf');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

// Options for signing are specified in JSON.
json := CkJsonObject_Create();

// In most cases, the signingCertificateV2 and signingTime attributes are required.
CkJsonObject_UpdateInt(json,'signingCertificateV2',1);
CkJsonObject_UpdateInt(json,'signingTime',1);

// Specify the location/position, scale, and content of the signature's appearance.
CkJsonObject_UpdateInt(json,'page',1);
CkJsonObject_UpdateString(json,'appearance.y','top');
CkJsonObject_UpdateString(json,'appearance.x','left');
CkJsonObject_UpdateString(json,'appearance.fontScale','10.0');
CkJsonObject_UpdateString(json,'appearance.text[0]','Digitally signed by: cert_cn');
CkJsonObject_UpdateString(json,'appearance.text[1]','current_dt');
CkJsonObject_UpdateString(json,'appearance.text[2]','The crazy brown fox jumps over the lazy dog.');

// In addition to the above, this example adds a built-in SVG graphic to the appearance.
// The built-in SVG graphic is specified by a name, such as "green-check-grey-circle".
// The full list of graphic names and images are shown below.
CkJsonObject_UpdateString(json,'appearance.image','green-check-grey-circle');

// The graphic can be placed "left", "center", or "right".
// If "center", then the graphic is displayed behind the text.
CkJsonObject_UpdateString(json,'appearance.imagePlacement','left');

// The graphic's opacity can range from 1 to 100.
// Centered graphics look best with less opacity (50 or less).
// In this example, we'll keep the opacity at 100.
CkJsonObject_UpdateString(json,'appearance.imageOpacity','100');

// Here's an example of the signature's appearance if we centered the SVG graphic with an opacity of 40%
// (image:https://example-code.com/images/centered_svg.jpg/endImage)

// Load the signing certificate. (Use your own certificate.)
cert := CkCert_Create();
success := CkCert_LoadPfxFile(cert,'qa_data/pfx/myPdfSigningCert.pfx','secret');
if (success = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

// Tell the pdf object to use the certificate for signing.
success := CkPdf_SetSigningCert(pdf,cert);
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

success := CkPdf_SignPdf(pdf,json,'qa_output/hello_signed.pdf');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPdf__lastErrorText(pdf));
    Exit;
  end;

Memo1.Lines.Add('The PDF has been successfully cryptographically signed.');

// The appearance of the signature appears in Adobe Acrobat as shown here:

// (image:https://example-code.com/images/pdf_signature_green_check_grey_circle.jpg/endImage)

// The SVG icon graphics are embedded within the Chilkat library, 
// and were graciously provided by uxwing - Free SVG Icons 
// 
// The uxwing licensing terms are reproduced here and can be verified at uxwing licensing

// Icons from uxwing.com are free (see https://uxwing.com/license/)
// 	- All icons on UXWing free to download, and use personal, commercial projects.
// 	- Attribution and Credit is NOT required, however, any credit will be much appreciated.
// 	- There is no limit to the number of times you can use.
// 	- You may modify the resources according to your requirements.

// The set of SVG names and the corresponding graphics are shown below.
// 
// For example, if we specify "green-check-green-circle"
CkJsonObject_UpdateString(json,'appearance.image','green-check-green-circle');
// We get:
// (image:https://example-code.com/images/green-check-green-circle.jpg/endImage)

// "application-approved"
// (image:https://example-code.com/images/application-approved.jpg/endImage)

// "application-rejected"
// (image:https://example-code.com/images/application-rejected.jpg/endImage)

// "document-accepted"
// (image:https://example-code.com/images/document-accepted.jpg/endImage)

// "approved"
// (image:https://example-code.com/images/approved.jpg/endImage)

// "blue-check-mark"
// (image:https://example-code.com/images/blue-check-mark.jpg/endImage)

// "green-check-mark"
// (image:https://example-code.com/images/green-check-mark.jpg/endImage)

// "green-check-grey-circle"
// (image:https://example-code.com/images/green-check-grey-circle.jpg/endImage)

// "red-x-red-circle"
// (image:https://example-code.com/images/red-x-red-circle.jpg/endImage)

// "rejected"
// (image:https://example-code.com/images/rejected.jpg/endImage)

// "result-failure"
// (image:https://example-code.com/images/result-failure.jpg/endImage)

// "result-pass"
// (image:https://example-code.com/images/result-pass.jpg/endImage)

// "signature"
// (image:https://example-code.com/images/signature.jpg/endImage)

// "document-check"
// (image:https://example-code.com/images/document-check.jpg/endImage)

// "document-x"
// (image:https://example-code.com/images/document-x.jpg/endImage)

// "red-x-grey-circle"
// (image:https://example-code.com/images/red-x-grey-circle.jpg/endImage)

CkPdf_Dispose(pdf);
CkJsonObject_Dispose(json);
CkCert_Dispose(cert);

end;