Sample code for 30+ languages & platforms
Unicode 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.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkPdfW.h>
#include <C_CkJsonObjectW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPdfW pdf;
    HCkJsonObjectW json;
    HCkJsonObjectW 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 = CkPdfW_Create();
    success = CkPdfW_LoadFile(pdf,L"qa_data/pdf/long_report.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        return;
    }

    json = CkJsonObjectW_Create();
    CkJsonObjectW_UpdateString(json,L"type",L"text");

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

    CkJsonObjectW_UpdateBool(json,L"tile.enabled",TRUE);
    CkJsonObjectW_UpdateNumber(json,L"tile.spacingX",L"60");
    CkJsonObjectW_UpdateNumber(json,L"tile.spacingY",L"80");
    CkJsonObjectW_UpdateBool(json,L"tile.stagger",TRUE);

    jsonOut = CkJsonObjectW_Create();
    success = CkPdfW_Watermark(pdf,L"add",json,jsonOut);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    wprintf(L"id: %s pages: %s\n",CkJsonObjectW_stringOf(jsonOut,L"id"),CkJsonObjectW_stringOf(jsonOut,L"pages"));

    success = CkPdfW_WriteFile(pdf,L"qa_output/report_traced.pdf");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPdfW_lastErrorText(pdf));
        CkPdfW_Dispose(pdf);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(jsonOut);
        return;
    }

    //  Sample output:

    //  id: trace pages: 1-3


    CkPdfW_Dispose(pdf);
    CkJsonObjectW_Dispose(json);
    CkJsonObjectW_Dispose(jsonOut);

    }