C Requires Chilkat v11.7.0+

Tile a Watermark Across a PDF Page

See more PDF Watermark Examples

Demonstrates a tiled watermark, which repeats the stamp over the whole page instead of placing it once. Tiling overrides position.align; tile.spacingX and spacingY set the gaps, and tile.stagger offsets alternate rows by half a tile so the pattern does not line up in columns. A faint tiled stamp carrying the name or address is the usual way to mark a document so that a leaked copy can be traced back, and zOrder back keeps it behind the text where it does not hinder reading. 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");

    //  {date:FORMAT} is replaced per page when the watermark is added.  The other placeholders are
    //  {page}, {pages} and {filename}; {{ gives a literal brace.
    CkJsonObject_UpdateString(json,"text","jdoe@example.com  {date:yyyy-MM-dd}");
    CkJsonObject_UpdateString(json,"id","trace");
    CkJsonObject_UpdateString(json,"zOrder","back");
    CkJsonObject_UpdateNumber(json,"font.size","14");
    CkJsonObject_UpdateNumber(json,"opacity","0.15");
    CkJsonObject_UpdateNumber(json,"rotation","30");

    CkJsonObject_UpdateBool(json,"tile.enabled",TRUE);
    CkJsonObject_UpdateNumber(json,"tile.spacingX","60");
    CkJsonObject_UpdateNumber(json,"tile.spacingY","80");
    CkJsonObject_UpdateBool(json,"tile.stagger",TRUE);

    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;
    }

    printf("id: %s pages: %s\n",CkJsonObject_stringOf(jsonOut,"id"),CkJsonObject_stringOf(jsonOut,"pages"));

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

    //  Sample output:

    //  id: trace pages: 1-3


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

    }