Tab character is not visible in the PDF generated as glyph substitution not working

[PallaviSaini]

Bug
Tab character is not visible in the PDF generated.
This is due to glyph substitutions are not done for tab character as per the TTF file.
Below is link to typography specs:
https://docs.microsoft.com/en-us/typography/opentype/spec/gsub

Below is code to Reproduce
package test;

import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

import org.apache.poi.util.IOUtils;
import org.apache.poi.xwpf.converter.pdf.PdfConverter;
import org.apache.poi.xwpf.converter.pdf.PdfOptions;
import org.apache.poi.xwpf.usermodel.XWPFDocument;

import fr.opensagres.xdocreport.core.XDocReportException;
import fr.opensagres.xdocreport.document.IXDocReport;
import fr.opensagres.xdocreport.document.registry.XDocReportRegistry;
import fr.opensagres.xdocreport.template.IContext;
import fr.opensagres.xdocreport.template.TemplateEngineKind;
import fr.opensagres.xdocreport.template.formatter.FieldsMetadata;
/**
*

• @author pallavi.saini

*/
public class OpenPdf {

public static void main(String[] args) throws XDocReportException, IOException {
	PdfOptions options = PdfOptions.create();
	String templatePath = "D:\\Workspace\\ThankYouNote_Template.docx";
	URL url = new File(templatePath).toURI().toURL();
	InputStream inputStream = url.openStream();
	IXDocReport xdocReport = XDocReportRegistry.getRegistry().loadReport(inputStream, null,
            TemplateEngineKind.Freemarker, false);
	FieldsMetadata metadata = xdocReport.createFieldsMetadata();
    metadata.setTemplateEngineKind("Freemarker");
    xdocReport.setFieldsMetadata(metadata);
	IContext context = xdocReport.createContext();
	context.put("name", "RAJ\tVIHAR");
	ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
	xdocReport.process(context, outputStream);

	XWPFDocument document = new XWPFDocument(new ByteArrayInputStream(outputStream.toByteArray()));
	ByteArrayOutputStream out = new ByteArrayOutputStream();
	PdfConverter.getInstance().convert(document, out, options);
	writeToPdfFile(out.toByteArray(), "D:\\Workspace\\ThankYouNote_Template.pdf");

}

private static void writeToPdfFile(byte[] fileContent, String path) {

	BufferedOutputStream bs = null;
	FileOutputStream fs = null;
	try {

		fs = new FileOutputStream(new File(path));
		bs = new BufferedOutputStream(fs);
		bs.write(fileContent);
		bs.close();
		bs = null;
	} catch (Exception e) {
		e.printStackTrace();
	} finally {
		IOUtils.closeQuietly(fs);
	}

}

}

Expected behavior
The text should be visible as "Raj Vihar" instead of "RajVihar". The rendered text in PDF should have a tab character in it.

Screenshot of current behaviour

System:

• OS: Windows
• Used Font: Times New Roman

[Wugengxian]

@asturio @PallaviSaini This issue is caused by that when we use \t, PdfChunk will change font to font-fallback/LiberationSans-Regular.ttf. But this font can not support \t, when it meet \t in bytesArray it will ignore it and don't encode it. So my solution is that when we use \t, use default font which actually support \t.
related code:

OpenPDF/openpdf/src/main/java/com/lowagie/text/pdf/PdfChunk.java

Lines 212 to 224 in bff6520

	// Check if the chunk content is text
	if (chunk.getContent().chars().allMatch(c -> (c >= 0x20 && c <= 0xFF))) {
	// translation of the font-family to a PDF font-family
	baseFont = f.getCalculatedBaseFont(false);
	} else {
	// translation to the embeddable free font
	try {
	baseFont = BaseFont.createFont("font-fallback/LiberationSans-Regular.ttf",
	BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
	} catch (IOException e) {
	throw new RuntimeException(e);
	}
	}

\t not in the matrix:

OpenPDF/openpdf/src/main/java/com/lowagie/text/pdf/FopGlyphProcessor.java

Lines 42 to 45 in bff6520

	if (metrics == null){
	textLength--;
	continue;
	}

I have fix it solution. In the futher, I will study how to let other fonts to encode \t and give a better solution.
Test Code:

public class TabTest {
    public static void main(String[] args) throws FileNotFoundException, DocumentException {
        Document document = new Document(PageSize.A4.rotate(), 10, 10, 10, 10);
        Document.compress = false;
        try {
            PdfWriter.getInstance(document,
                    new FileOutputStream("TabsTable.pdf"));
            document.open();
            Chunk a = new Chunk("data\\ttable");
            a.setFont(new Font(BaseFont.createFont("font-fallback/LiberationSans-Regular.ttf",
                    BaseFont.IDENTITY_H, BaseFont.EMBEDDED)));
            document.add(a);
        } catch (Exception de) {
            de.printStackTrace();
        }
        document.close();
    }
}

[asturio]

Thanks for the contribution!