PDFbox - how can i add content to a layer?

Question

I'm using pdfbox 2.0.8 - need to create a layer and add some graphic there.

I started from How do I make modifications to existing layer(Optional Content Group) in pdf?

which however is based on 1.8. I tried to adapt to 2.0 and managed to create the layer, but it is completely unclear how then you can create a new resource and add it to the layer - i.e. how the props.putMapping(resourceName, layer); which was in 1.8 has to be rewritten

Please add the code that you used, and link to the source and result PDF. — Tilman Hausherr, Mar 26 '18 at 18:46
instead of `props.putMapping(resourceName, layer);` use `props.getCOSObject().setItem(resourceName, layer);` — Tilman Hausherr, Mar 26 '18 at 19:28

score 1 · Answer 1 · answered Apr 04 '18 at 22:40

Equivalent to the PDFBox 1.8 code in the answer referenced by the OP is the following code:

void addTextToLayer(PDDocument document, int pageNumber, String layerName, float x, float y, String text) throws IOException
{
    PDDocumentCatalog catalog = document.getDocumentCatalog();
    PDOptionalContentProperties ocprops = catalog.getOCProperties();
    if (ocprops == null)
    {
        ocprops = new PDOptionalContentProperties();
        catalog.setOCProperties(ocprops);
    }
    PDOptionalContentGroup layer = null;
    if (ocprops.hasGroup(layerName))
    {
        layer = ocprops.getGroup(layerName);
    }
    else
    {
        layer = new PDOptionalContentGroup(layerName);
        ocprops.addGroup(layer);
    }

    PDPage page = (PDPage) document.getPage(pageNumber);

    PDResources resources = page.getResources();
    if (resources == null)
    {
        resources = new PDResources();
        page.setResources(resources);
    }

    PDFont font = PDType1Font.HELVETICA;

    PDPageContentStream contentStream = new PDPageContentStream(document, page, AppendMode.APPEND, true, true);
    contentStream.beginMarkedContent(COSName.OC, layer);
    contentStream.beginText();
    contentStream.setFont(font, 12);
    contentStream.newLineAtOffset(x, y);
    contentStream.showText(text);
    contentStream.endText();
    contentStream.endMarkedContent();

    contentStream.close();
}

(AddContentToOCG)

which can be used like this:

PDDocument document = new PDDocument();
PDPage page = new PDPage();
document.addPage(page);

addTextToLayer(document, 0, "MyLayer", 30, 600, "Text in new layer 'MyLayer'");
addTextToLayer(document, 0, "MyOtherLayer", 230, 550, "Text in new layer 'MyOtherLayer'");
addTextToLayer(document, 0, "MyLayer", 30, 500, "Text in existing layer 'MyLayer'");
addTextToLayer(document, 0, "MyOtherLayer", 230, 450, "Text in existing layer 'MyOtherLayer'");

document.save(new File(RESULT_FOLDER, "TextInOCGs.pdf"));
document.close();

(AddContentToOCG test testAddContentToNewOrExistingOCG)

PDFbox - how can i add content to a layer?

1 Answers1