java - 如何为复选框添加边框并使其始终可见

Question

当我创建我的 PDF 时，复选框最初没有出现。单击它 (onBlur) 后，会出现某种可见的阴影，当它聚焦时，它就不再可见了。我怎样才能让它始终可见？以及如何添加某种边框(无需使用矩形类手动添加)？

public class CheckBoxWriter  {

    public static void main(String[] args) throws IOException {

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

        // just a rectangle to be able to locate the checkbox
        PDPageContentStream contentStream = new PDPageContentStream(document, page, AppendMode.APPEND, false);
        contentStream.addRect(100, 100, 50, 50);
        contentStream.setLineWidth(1);
        contentStream.setNonStrokingColor(Color.WHITE);
        contentStream.setStrokingColor(Color.BLACK);
        contentStream.stroke();
        contentStream.close();

        PDAcroForm acroForm = new PDAcroForm(document);
        PDCheckBox checkBox = new PDCheckBox(acroForm);
        checkBox.setPartialName("xxx");

        PDAnnotationWidget widget = new PDAnnotationWidget();
        widget.setRectangle(new PDRectangle(100, 100, 10, 10));
        widget.setAnnotationFlags(4);
        widget.setPage(page);
        widget.setParent(checkBox);

        List<PDAnnotationWidget> widgets = new ArrayList<>();
        widgets.add(widget);
        page.getAnnotations().add(widget);
        checkBox.setWidgets(widgets);

        acroForm.getFields().add(checkBox);
        document.getDocumentCatalog().setAcroForm(acroForm);

        File file = new File("test.pdf");

        document.save(file);
        document.close();
    }
}

Answer 1

试试这个 - 它为复选框创建外观流，即"is"和“关闭”显示的内容流。我还修改了您使用小部件的方式，使文件更简单。您使用的策略(小部件与字段分开)只有在一个字段有多个小部件时才有用。

要了解运算符的作用(那是胡言乱语)，请查看 PDF specification , 搜索“运算符摘要”。

public static void main(String[] args) throws IOException
{
    PDDocument document = new PDDocument();
    PDPage page = new PDPage();
    document.addPage(page);

    // just a rectangle to be able to locate the checkbox
    PDPageContentStream contentStream = new PDPageContentStream(document, page, AppendMode.APPEND, false);
    contentStream.addRect(100, 100, 50, 50);
    contentStream.setLineWidth(1);
    contentStream.setNonStrokingColor(Color.WHITE);
    contentStream.setStrokingColor(Color.BLACK);
    contentStream.stroke();
    contentStream.close();

    PDAcroForm acroForm = new PDAcroForm(document);
    PDCheckBox checkBox = new PDCheckBox(acroForm);
    checkBox.setPartialName("xxx");


    //PDAnnotationWidget widget = new PDAnnotationWidget();
    PDAnnotationWidget widget = checkBox.getWidgets().get(0);
    widget.setRectangle(new PDRectangle(100, 100, 10, 10));
    widget.setAnnotationFlags(4);
    widget.setPage(page);
    //widget.setParent(checkBox);

    // inspired by annot 92 of file from PDFBOX-563
    // annot 172 has "checkmark" instead, but more more complex, needs ZaDb

    String offNString = "1 g\n"
            + "0 0 9.5 9.5 re\n"
            + "f\n"
            + "0.5 0.5 9.5 9.5 re\n"
            + "s";
    String offDString = "0.75 g\n"
            + "0 0 9.5 9.5 re\n"
            + "f\n"
            + "0.5 0.5 9.5 9.5 re\n"
            + "s";
    String yesNString = "1 g\n"
            + "0 0 9 9.5 re\n"
            + "f\n"
            + "0.5 0.5 9.5 9.5 re\n"
            + "s\n"
            + "q\n"
            + "  1 1 9 9 re\n"
            + "  W\n"
            + "  n\n"
            + "  2 8 m\n"
            + "  8 2 l\n"
            + "  8 8 m\n"
            + "  2 2 l\n"
            + "  s\n"
            + "Q";
    String yesDString = "0.75 g\n"
            + "0 0 9 9.5 re\n"
            + "f\n"
            + "0.5 0.5 9.5 9.5 re\n"
            + "s\n"
            + "q\n"
            + "  1 1 9 9 re\n"
            + "  W\n"
            + "  n\n"
            + "  2 8 m\n"
            + "  8 2 l\n"
            + "  8 8 m\n"
            + "  2 2 l\n"
            + "  s\n"
            + "Q";

    COSDictionary apNDict = new COSDictionary();
    COSStream offNStream = new COSStream();
    offNStream.setItem(COSName.BBOX, new PDRectangle(10, 10));
    offNStream.setItem(COSName.FORMTYPE, COSInteger.ONE);
    offNStream.setItem(COSName.TYPE, COSName.XOBJECT);
    offNStream.setItem(COSName.SUBTYPE, COSName.FORM);
    offNStream.setItem(COSName.MATRIX, new Matrix().toCOSArray());
    offNStream.setItem(COSName.RESOURCES, new COSDictionary());
    OutputStream os = offNStream.createOutputStream();
    os.write(offNString.getBytes());
    os.close();
    apNDict.setItem(COSName.Off, offNStream);

    COSStream yesNStream = new COSStream();
    yesNStream.setItem(COSName.BBOX, new PDRectangle(10, 10));
    yesNStream.setItem(COSName.FORMTYPE, COSInteger.ONE);
    yesNStream.setItem(COSName.TYPE, COSName.XOBJECT);
    yesNStream.setItem(COSName.SUBTYPE, COSName.FORM);
    yesNStream.setItem(COSName.MATRIX, new Matrix().toCOSArray());
    yesNStream.setItem(COSName.RESOURCES, new COSDictionary());
    os = yesNStream.createOutputStream();
    os.write(yesNString.getBytes());
    os.close();
    apNDict.setItem(COSName.getPDFName("Yes"), yesNStream);

    COSDictionary apDDict = new COSDictionary();
    COSStream offDStream = new COSStream();
    offDStream.setItem(COSName.BBOX, new PDRectangle(16, 16));
    offDStream.setItem(COSName.FORMTYPE, COSInteger.ONE);
    offDStream.setItem(COSName.TYPE, COSName.XOBJECT);
    offDStream.setItem(COSName.SUBTYPE, COSName.FORM);
    offDStream.setItem(COSName.MATRIX, new Matrix().toCOSArray());
    offDStream.setItem(COSName.RESOURCES, new COSDictionary());
    os = offDStream.createOutputStream();
    os.write(offDString.getBytes());
    os.close();
    apDDict.setItem(COSName.Off, offDStream);

    COSStream yesDStream = new COSStream();
    yesDStream.setItem(COSName.BBOX, new PDRectangle(16, 16));
    yesDStream.setItem(COSName.FORMTYPE, COSInteger.ONE);
    yesDStream.setItem(COSName.TYPE, COSName.XOBJECT);
    yesDStream.setItem(COSName.SUBTYPE, COSName.FORM);
    yesDStream.setItem(COSName.MATRIX, new Matrix().toCOSArray());
    yesDStream.setItem(COSName.RESOURCES, new COSDictionary());
    os = yesDStream.createOutputStream();
    os.write(yesDString.getBytes());
    os.close();
    apDDict.setItem(COSName.getPDFName("Yes"), yesDStream);

    PDAppearanceDictionary appearance = new PDAppearanceDictionary();
    PDAppearanceEntry appearanceNEntry = new PDAppearanceEntry(apNDict);
    appearance.setNormalAppearance(appearanceNEntry);

    // push appearance doesn't look nice enough, has weird effect when pushing
//        PDAppearanceEntry appearanceDEntry = new PDAppearanceEntry(apDDict);
//        appearance.setDownAppearance(appearanceDEntry);

    widget.setAppearance(appearance);

    // MK (appearance characteristics dictionary)
    COSDictionary acdDict = new COSDictionary();
    acdDict.setItem(COSName.CA, new COSString("8")); // 8 is X, 4 is checkmark
    COSArray bcArray = new COSArray();
    bcArray.add(COSInteger.ZERO);
    acdDict.setItem(COSName.BC, bcArray);
    COSArray bgArray = new COSArray();
    bgArray.add(COSInteger.ONE);
    acdDict.setItem(COSName.BG, bgArray);
    PDAppearanceCharacteristicsDictionary acd = new PDAppearanceCharacteristicsDictionary(acdDict);
    widget.setAppearanceCharacteristics(acd);

//        List<PDAnnotationWidget> widgets = new ArrayList<>();
//        widgets.add(widget);
    page.getAnnotations().add(widget);
//        checkBox.setWidgets(widgets);

    checkBox.setValue("Yes");

    acroForm.getFields().add(checkBox);
    document.getDocumentCatalog().setAcroForm(acroForm);

    File file = new File("checkbox.pdf");

    document.save(file);
    document.close();
}

2019 年 1 月 17 日更新:我创建了此代码的更灵活版本(动态计算、支持颜色和不同内容)并将其添加到 source code repository .