(DataFlex) PDF Signature Appearance Width and Height

See more PDF Signatures Examples

This example explains how the width and height of the signature appearance rectangle box is determined.

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoPdf
    Boolean iSuccess
    Variant vJson
    Handle hoJson
    Variant vJAppearance
    Handle hoJAppearance
    Variant vCert
    Handle hoCert
    String sTemp1

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

    Get Create (RefClass(cComChilkatPdf)) To hoPdf
    If (Not(IsComObjectCreated(hoPdf))) Begin
        Send CreateComObject of hoPdf
    End

    // Load a PDF to be signed.
    // The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf
    Get ComLoadFile Of hoPdf "qa_data/pdf/hello.pdf" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPdf To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Options for signing are specified in JSON.
    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End

    // In most cases, the signingCertificateV2 and signingTime attributes are required.
    Get ComUpdateInt Of hoJson "signingCertificateV2" 1 To iSuccess
    Get ComUpdateInt Of hoJson "signingTime" 1 To iSuccess

    // Put the signature on page 1, top left
    Get ComUpdateInt Of hoJson "page" 1 To iSuccess
    Get ComUpdateString Of hoJson "appearance.y" "top" To iSuccess
    Get ComUpdateString Of hoJson "appearance.x" "left" To iSuccess

    // Add some text.
    Get ComUpdateString Of hoJson "appearance.text[0]" "Digitally signed by: cert_cn" To iSuccess
    Get ComUpdateString Of hoJson "appearance.text[1]" "current_dt" To iSuccess

    // Add a built-in SVG graphic to the right.
    Get ComUpdateString Of hoJson "appearance.image" "blue-check-mark" To iSuccess
    Get ComUpdateString Of hoJson "appearance.imagePlacement" "right" To iSuccess
    Get ComUpdateString Of hoJson "appearance.imageOpacity" "100" To iSuccess

    // There are 4 ways the width and height of the signature rectangle can be specified.
    // 1) The width and height (in points) are both explicitly specified.
    //    User space coordinates use "points" where 72 points equals 1 inch.
    //    For example (3 inches wide and 1 inch high)
    //    The fontScale is automatically chose to fit.  In addition, if a graphic (JPG or built-in SVG) is included,
    //    it is automatically scaled such that the text + graphic fit together in the specified rectangle.
    //    Note: When both height and width are explicitly specified, the resultant signature appearance rectangle
    //    will match one of the dimensions, but the other dimension will be equal or smaller.  This is because the text
    //    must be proportionally scaled.
    Get ComUpdateInt Of hoJson "appearance.width" (72 * 3) To iSuccess
    Get ComUpdateInt Of hoJson "appearance.height" 72 To iSuccess

    // The signature would have this appearance. In this case, the height is actually less than 1 inch because
    // if Chilkat chose a fontScale to fill the height, the resulting text's width would be too long for the desired width. 
    

    // 2) The width is explicitly specified, but we use the keyword "auto" for height.
    //    In this case, the fontScale is chosen to achieve the desired width,
    //    and the height will be whatever the result of the chosen font scale.
    //    In this example, the width is 4 inches, and the height is "auto".
    Get ComUpdateInt Of hoJson "appearance.width" (72 * 4) To iSuccess
    Get ComUpdateString Of hoJson "appearance.height" "auto" To iSuccess

    // The signature would have this appearance: 
    

    // 3) The height is explicitly specified, but we use the keyword "auto" for width.
    //    In this case, the fontScale is chosen to achieve the desired height,
    //    and the width will be whatever the result of the chosen font scale.
    //    In this example, the height is 1 inch (72 points) and the width is "auto".
    Get ComUpdateString Of hoJson "appearance.width" "auto" To iSuccess
    Get ComUpdateInt Of hoJson "appearance.height" 72 To iSuccess

    // The signature would have this appearance.
    

    // 4) Finally, we don't need to specify width/height at all.  Instead, we can choose a fontScale
    //    and the dimensions of the PDF signature appearance's rectangle will be the result of using the
    //    specified fontScale.

    Get ComObjectOf Of hoJson "appearance" To vJAppearance
    If (IsComObject(vJAppearance)) Begin
        Get Create (RefClass(cComChilkatJsonObject)) To hoJAppearance
        Set pvComObject Of hoJAppearance To vJAppearance
    End
    Get ComDelete Of hoJAppearance "width" To iSuccess
    Get ComDelete Of hoJAppearance "height" To iSuccess
    Send Destroy of hoJAppearance
    Get ComUpdateString Of hoJson "appearance.fontScale" "10.0" To iSuccess

    // With fontScale = "10.0"
    

    // Load the signing certificate. (Use your own certificate.)
    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End
    Get ComLoadPfxFile Of hoCert "qa_data/pfx/myPdfSigningCert.pfx" "pfx_password" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Tell the pdf object to use the certificate for signing.
    Get pvComObject of hoCert to vCert
    Get ComSetSigningCert Of hoPdf vCert To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPdf To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get pvComObject of hoJson to vJson
    Get ComSignPdf Of hoPdf vJson "qa_output/hello_signed.pdf" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPdf To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "The PDF has been successfully cryptographically signed."


End_Procedure