C Requires Chilkat v11.7.0+

Add a CONFIDENTIAL Watermark to Every Page of a PDF

See more PDF Watermark Examples

Demonstrates the simplest watermark: a line of text across every page. "rotation" set to diagonal runs the text from the bottom-left corner to the top-right, computed for each page size, and "scale" with fit page sizes it to fill 80 percent of the page. The watermark is stored as a marked artifact by default, which means viewers show it, text extraction leaves it out, and it can be found and removed again later. Nothing is written until WriteFile is called. C

#include <C_CkPdf.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPdf pdf;
    HCkJsonObject json;
    HCkJsonObject jsonOut;

    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 long_report.pdf

    pdf = CkPdf_Create();
    success = CkPdf_LoadFile(pdf,"qa_data/pdf/long_report.pdf");
    if (success == FALSE) {
        printf("%s\n",CkPdf_lastErrorText(pdf));
        CkPdf_Dispose(pdf);
        return;
    }

    json = CkJsonObject_Create();
    CkJsonObject_UpdateString(json,"type","text");
    CkJsonObject_UpdateString(json,"text","CONFIDENTIAL");

    //  An id of your own choosing, so that the watermark can be found and removed later.  One is
    //  generated when you do not give one.
    CkJsonObject_UpdateString(json,"id","confidential");

    CkJsonObject_UpdateString(json,"color","#C00000");
    CkJsonObject_UpdateNumber(json,"opacity","0.25");
    CkJsonObject_UpdateString(json,"rotation","diagonal");
    CkJsonObject_UpdateString(json,"scale.fit","page");
    CkJsonObject_UpdateNumber(json,"scale.fitPercent","80");

    jsonOut = CkJsonObject_Create();
    success = CkPdf_Watermark(pdf,"add",json,jsonOut);
    if (success == FALSE) {
        printf("%s\n",CkPdf_lastErrorText(pdf));
        CkPdf_Dispose(pdf);
        CkJsonObject_Dispose(json);
        CkJsonObject_Dispose(jsonOut);
        return;
    }

    //  The id, and the pages it was stamped on.  "pages" defaults to all.
    printf("id: %s\n",CkJsonObject_stringOf(jsonOut,"id"));
    printf("pages: %s\n",CkJsonObject_stringOf(jsonOut,"pages"));

    success = CkPdf_WriteFile(pdf,"qa_output/report_confidential.pdf");
    if (success == FALSE) {
        printf("%s\n",CkPdf_lastErrorText(pdf));
        CkPdf_Dispose(pdf);
        CkJsonObject_Dispose(json);
        CkJsonObject_Dispose(jsonOut);
        return;
    }

    //  Sample output:

    //  id: confidential
    //  pages: 1-3


    CkPdf_Dispose(pdf);
    CkJsonObject_Dispose(json);
    CkJsonObject_Dispose(jsonOut);

    }