jsPDF对齐文本

问题描述

我正在尝试对 jsPDF 库进行一些更改，以使文本合理.

I'm trying to apply some changes on jsPDF library to be able to justify text.

我很难找到 Tw (字距)的正确值.

I'm having trouble to find the right value for Tw (word spacing).

在 jspdf.js (L:1413)我添加了以下代码:

In jspdf.js (L:1413) I have added this code:

if (align) {
    ...
    else if (align === 'justify') {
       left = x;
    }
    else {
        throw new Error('Unrecognized alignment option, use "center" or "right".');
    }
    prevX = x;
    text = '(' + da[0];

    let pdfPageWidth = this.internal.pageSize.width;
    let wordSpacing;
    if( align === 'justify' ) {
        let fontSize = this.internal.getFontSize();
        let nWords = da[0].trim().split(/\s+/).length;
        let textWidth = this.getStringUnitWidth(da[0].replace(/\s+/g, '')) / this.internal.scaleFactor;
        wordSpacing = (Math.max(0, (pdfPageWidth - textWidth) / Math.max(1, nWords - 1));
        wordSpacing += ' Tw\n';
        text = wordSpacing + text;
    }
    ...
}

想法是通过执行(pageWidth-textWidth)/numberOfWords -1来提取空间宽度.我无法获得正确的单词空间.

The idea was to extract the space width by doing (pageWidth - textWidth) / numberOfWords -1. I can't get the correct word space.

输出示例

BT
/F1 16 Tf
18.4 TL
0 g
28.35 756.85 Td
19.00357142857142 Tw
(And a little bit it adélkfjalké.) Tj
ET

是否存在编码问题?

感谢您的帮助.

推荐答案

经过多次尝试，我发现了有效的代码解决方案:D.它也可以将文本数组用作参数.

After many tries I have found the working code solution :D. It works also with array of text as param.

        } else if (align === 'justify') {
          left = x;
        }
        else {
          throw new Error(
            'Unrecognized alignment option, use "center" or "right".'
          );
        }
        prevX = x;
        text = '(' + da[0];

        var pdfPageWidth = this.internal.pageSize.width;
        var wordSpacing;
        var fontSize = this.internal.getFontSize();
        if( align === 'justify' ) {
          var nWords = da[0].trim().split(/\s+/).length;
          var textWidth = this.getStringUnitWidth(da[0]) * fontSize / k;

          wordSpacing = (Math.max(0, ((pdfPageWidth - x - marginRight) - textWidth) / Math.max(1, nWords - 1))) * k;
          // Do not justify if wordSpacing is too high
          wordSpacing = ( wordSpacing > 50 ? 0 : wordSpacing ) + ' Tw\n';

          text = wordSpacing + text;
        }

        for (var i = 1, len = da.length; i < len; i++) {
          var delta = maxLineLength - lineWidths[i];
          if (align === "center") delta /= 2;
          if (align === "justify") { // TODO: improve code duplication
            delta = 0;
            var nWords = da[i].trim().split(/\s+/).length;
            var textWidth = this.getStringUnitWidth(da[i]) * fontSize / k;

            wordSpacing = (Math.max(0, ((pdfPageWidth - x - marginRight) - textWidth) / Math.max(1, nWords - 1))) * k;
            // Do not justify if wordSpacing is too high
            wordSpacing = ( wordSpacing > 50 ? 0 : wordSpacing ) + ' Tw\n';
            text += ") Tj\n" + ((left - prevX) + delta) + " -" + leading + " Td\n" + wordSpacing + "(" + da[i];
          } else {
            // T* = x-offset leading Td ( text )
            text += ") Tj\n" + ((left - prevX) + delta) + " -" + leading + " Td (" + da[i];
          }
          prevX = left + delta;
        }
      } else {
        text = ' 0 Tw\n (' + da.join(") Tj\nT* (");
      }

这是我的 PR

这篇关于jsPDF对齐文本的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！