如何将边框添加到复选框并使其始终可见 [英] How to add a border to a checkbox and make it always visible

问题描述

当我创建PDF时，该复选框最初没有出现。单击它（onBlur）后，可以看到某种阴影，当聚焦时，它不再可见。
如何使其始终可见？以及如何添加某种边框（无需使用矩形类手动完成）？

When I create my PDF the checkbox at first doesn't have any appearence. After I click on it (onBlur) there is some kind of shade visible and when it is focussed it isn't visible anymore. How can I make it always visible? And how can I add some kind of border (without doing it manually with a rectangle class)?

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();
    }
}

推荐答案

尝试此-它为复选框创建外观流，即为是和关显示的内容流。我还修改了使用小部件的方式，从而使文件更简单。仅当您为一个字段使用多个小部件时，您使用的策略（与该字段分开的小部件）才有用。

Try this - it creates appearance streams for the check box, i.e. content streams for the "Yes" and "Off" display. I also modified the way you used the widgets, so that the file is simpler. The strategy you used (widget separate from the field) is useful only if you have several widgets for one field.

要查看操作员的工作（那是胡言乱语），请查看 PDF规范，搜索运算符摘要。

To see what the operators do (that's the gibberish), have a look at the PDF specification, search for "operator summary".

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();
}

更新17.1.2019：我为该代码创建了一个更灵活的版本（动态计算，支持颜色和不同的内容）并将其添加到源代码存储库。

Update 17.1.2019: I've created a more flexible version of this code (dynamic calculations, support colors and different contents) and added it to the source code repository.

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