Put a Button on PDF with PDFBox 2.x

Question

I hope somebody can help me with my Problem with Buttons and Textfields on a PDF created with PdfBox 2.x.

I tried to put a Button on my Page, which sets a Date in a

Answer 1

The second solution (merging) won't work because PDFBox can't change the JS code. The first solution (which you don't show) I tried to recreate, one problem IMHO is that there is only 1 date function which is in OpenAction. You need each function in the JavaScript name tree (you might even work without by having all in the field but I didn't test that):

public static void main(String[] args) throws IOException
{
    String dest = "SO52807807.pdf";

    Map map = new HashMap<>();
    DecimalFormat DFMM = new DecimalFormat("00");

    try (PDDocument doc = new PDDocument())
    {
        PDDocumentNameDictionary documentNameDictionary = new PDDocumentNameDictionary(doc.getDocumentCatalog());
        PDJavascriptNameTreeNode javascriptNameTreeNode = new PDJavascriptNameTreeNode();
        documentNameDictionary.setJavascript(javascriptNameTreeNode);

        COSDictionary acroFormDict = new COSDictionary();
        acroFormDict
                .setBoolean(COSName.getPDFName("NeedAppearances"), true);
        acroFormDict.setItem(COSName.FIELDS, new COSArray());

        PDAcroForm acroForm = new PDAcroForm(doc, acroFormDict);
        doc.getDocumentCatalog().setAcroForm(acroForm);

        for (int i = 0; i < 4; i++)
        {
            PDPage page = new PDPage();
            doc.addPage(page);

            PDAnnotationAdditionalActions buttonAction1 = null;
            PDActionJavaScript javascript = null;
            PDActionJavaScript tfJs = null;

            String iStr = DFMM.format(i);

            PDFont font = PDType1Font.HELVETICA;
            PDResources resources = new PDResources();
            resources.put(COSName.getPDFName("Helv"), font);
            acroForm.setDefaultResources(resources);

            PDAppearanceStream pdAppearanceStream = new PDAppearanceStream(doc);
            pdAppearanceStream.setResources(resources);

            PDTextField textField = new PDTextField(acroForm);
            textField.setPartialName("SampleField-" + iStr);

            String defaultAppearance = "/Helv 24 Tf 0 0 0 rg";
            textField.setDefaultAppearance(defaultAppearance);

            textField.setMultiline(true);

            acroForm.getFields().add(textField);

            PDAnnotationWidget fieldwidget = textField.getWidgets().get(0);
            PDRectangle rect = new PDRectangle(50, 600, 300, 70);
            fieldwidget.setRectangle(rect);
            fieldwidget.setPage(page);

            textField.setValue("Click to get Date");

            PDAppearanceCharacteristicsDictionary fieldAppearance = new PDAppearanceCharacteristicsDictionary(
                    new COSDictionary());
            fieldAppearance.setBorderColour(new PDColor(
                    new float[]
                    {
                        0, 0, 0
                    }, PDDeviceRGB.INSTANCE));
            fieldAppearance.setBackground(new PDColor(new float[]
            {
                1, 1, 1
            },
                    PDDeviceRGB.INSTANCE));
            fieldwidget.setAppearanceCharacteristics(fieldAppearance);

            fieldwidget.setPrinted(true);

            page.getAnnotations().add(fieldwidget);

            COSDictionary cosDict1 = new COSDictionary();
            COSArray buttonRect1 = new COSArray();
            buttonRect1.add(new COSFloat(50));
            buttonRect1.add(new COSFloat(575));
            buttonRect1.add(new COSFloat(150));
            buttonRect1.add(new COSFloat(550));

            cosDict1.setItem(COSName.RECT, buttonRect1);
            cosDict1.setItem(COSName.FT, COSName.getPDFName("Btn")); // Field
            // Type
            cosDict1.setItem(COSName.TYPE, COSName.ANNOT);
            cosDict1.setItem(COSName.SUBTYPE, COSName.getPDFName("Widget"));
            cosDict1.setItem(COSName.T, new COSString("Datum anzeigen"));
            cosDict1.setItem(COSName.DA,
                    new COSString("/F0 6 Tf 0 g 1 1 1 rg "));

            PDPushButton button1 = new PDPushButton(acroForm);
            javascript = new PDActionJavaScript("function date" + iStr
                    + "() {var fld" + iStr + " = this.getField('SampleField-"
                    + iStr + "'); fld" + iStr
                    + ".value = util.printd('dd mmmm yyyy',new Date());}");

            //doc.getDocumentCatalog().setOpenAction(javascript);
            map.put("date" + iStr, javascript);

            tfJs = new PDActionJavaScript("date" + iStr + "();");
            buttonAction1 = new PDAnnotationAdditionalActions();

            buttonAction1.setU(tfJs);
            button1.getWidgets().get(0).setActions(buttonAction1);

            button1.getCOSObject().addAll(cosDict1);
            acroForm.getFields().add(button1);

            PDAnnotationWidget buttonWidget1 = button1.getWidgets().get(0);

            PDAppearanceCharacteristicsDictionary buttonFieldAppearance = new PDAppearanceCharacteristicsDictionary(
                    new COSDictionary());
            COSArray borderColorArray = new COSArray();
            borderColorArray.add(new COSFloat((float) (141f / 255f)));
            borderColorArray.add(new COSFloat((float) (179f / 255f)));
            borderColorArray.add(new COSFloat((float) (226f / 255f)));
            PDColor blue = new PDColor(borderColorArray, PDDeviceRGB.INSTANCE);
            buttonFieldAppearance.setBorderColour(blue);
            buttonFieldAppearance.setBackground(blue);
            buttonFieldAppearance.setNormalCaption("Felder löschen");

            buttonWidget1.setAppearanceCharacteristics(buttonFieldAppearance);
            page.getAnnotations().add(buttonWidget1);

        }
        javascriptNameTreeNode.setNames(map);
        doc.getDocumentCatalog().setNames(documentNameDictionary);
        File file = new File(dest);
        file.getParentFile().mkdirs();
        doc.save(dest);
    }
}

Update 20.10.2018: I made two more changes in the code: 1) the font name in the defaultAppearance must be the same font name as in the default resources ("Helv"). 2) the value of the field must be set AFTER the widget is assigned, not before. (makes sense if you think about it - the widget is about the visual).. Not doing that could mean trouble when displaying with non Adobe viewers.

Update: 25.5.2019: IMHO the code is a bit clunky because most dictionary elements don't have to be set. A better version to create a button can be found in this answer.