您如何正确使用pdpagecontentstream :: settextrise？

Question

使用PDFBox，给定的数据如下：[g]荣耀是[d]上帝[em] [c]父亲，\ n [g]和[a]基督[d]儿子代码>，我正在创建一个吉他和弦表：

我的方法是通过歌曲中的每个字符迭代并检查针对地图的当前索引。字符索引，我们“跳到”上方的线，写和弦，然后跳下来。

方法setTextrise看起来很有希望，但仍然不正确地处理水平间距：

这是一个SSCCE（需要PDFBox库），该SSCCE（需要PDFBox库）在上面产生PDF：

public static void main(String[] args) {
    try {
        
        String extracted_text = "Capo 1\n\n1\n[G]Glory be to [D]God [Em]the [C]Father,\n[G]And to [A]Christ the [D]Son,\n[B7]Glory to the [Em]Holy [C]Spirit—\n[D-D7]Ever [ G]One.\n\n2\nAs we view the vast creation,\nPlanned with wondrous skill,\nSo our hearts would move to worship,\nAnd be still.\n\n3\nBut, our God, how great Thy yearning\nTo have sons who love\nIn the Son e’en now to praise Thee,\nLove to prove!\n\n4\n’Twas Thy thought in revelation,\nTo present to men\nSecrets of Thine own affections,\nTheirs to win.\n\n5\nSo in Christ, through His redemption\n(Vanquished evil powers!)\nThou hast brought, in new creation,\nWorshippers!\n\n6\nGlory be to God the Father,\nAnd to Christ the Son,\nGlory to the Holy Spirit—\nEver One.\n".replaceAll("\n", "\r");
        
        String[] lines = extracted_text.split("\\r");
        
        ArrayList<SongLine> songlines = new ArrayList<>();
        for(String s : lines) {
            LinkedHashMap<Integer, String> chords = new LinkedHashMap();
            StringBuilder line = new StringBuilder();
            StringBuilder currentchord = null;
            int index = 0;
            for(char c : s.toCharArray()) {
                if(currentchord != null) {
                    if(c == ']') {
                        chords.put(index, currentchord.toString());
                        currentchord = null;
                    } else {
                        currentchord.append(c);
                    }
                } else {
                    if(c == '[') {
                        currentchord = new StringBuilder();
                    } else {
                        line.append(c);
                        index++;
                    }
                }
            }
            
            SongLine sl = new SongLine();
            if(chords.size() > 0)
                sl.char_index_to_chords = chords;
            sl.line = line.toString();
            
            songlines.add(sl);
        }
        
        try (PDDocument doc = new PDDocument()) {
            PDPage page = new PDPage();
            PDPageContentStream pcs = new PDPageContentStream(doc, page);
            int firstLineX = 25;
            int firstLineY = 700;
            boolean first = true;

            float leading = 14.5f;
            pcs.beginText();
            pcs.newLineAtOffset(firstLineX, firstLineY);
            pcs.setFont(PDType1Font.TIMES_ROMAN, 12);
            pcs.setLeading(leading);
            for(SongLine line : songlines) {
                if(line.char_index_to_chords != null)
                    System.out.println(line.char_index_to_chords.toString());
                System.out.println(line.line);
                if(!first) {
                    pcs.newLine();
                }
                first = false;
                if(line.char_index_to_chords != null) {
                    pcs.newLine();
                }
                for(int i = 0; i < line.line.length(); i++) {
                    pcs.showText(String.valueOf(line.line.charAt(i)));
                    if(line.char_index_to_chords != null && line.char_index_to_chords.containsKey(i)) {
                        
                        pcs.setTextRise(12);
                        pcs.showText(line.char_index_to_chords.get(i));
                        pcs.setTextRise(0);
                    }
                }
            }
            pcs.endText();
            pcs.close();
            doc.addPage(page);
            String path = "0001.pdf";
            doc.save(path);
            
            Desktop.getDesktop().open(new File(path));
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}


static class SongLine {
    Map<Integer, String> char_index_to_chords;
    String line;
}

您会在PDFBox中做什么创建与和弦对齐的文本（例如第一个图像中）？

Answer 1

我得到了它。答案不是setTextrise，而是newlineatoffset在使用getsTringWidth计算字体大小：

for(SongLine line : songlines) {
    if(!first) {
        pcs.newLine();
    }
    first = false;
    if(line.char_index_to_chords != null) {
        float offset = 0;
        for(Entry<Integer, String> entry : line.char_index_to_chords.entrySet()) {
            float offsetX = font.getStringWidth(line.char_index_to_leading_lyrics.get(entry.getKey())) / (float)1000 * fontSize;
            pcs.newLineAtOffset(offsetX, 0);
            offset += offsetX;
            pcs.showText(entry.getValue());
        }
        pcs.newLineAtOffset(-offset, -leading);
    }
    pcs.showText(line.line);
}