在 TextView 中显示正确缩进和解析的源代码 [英] Show source code in TextView correctly indented and parsed

问题描述

是否可以逐字模式或类似方式解析 HTML 代码，以便最终可能出现的源代码片段(包含在 pre 和 code HTML 标记之间)能正常显示吗?

我想做的是以用户友好的模式显示源代码(易于与文本的其余部分区分开，保持缩进等)，就像 Stack Overflow 一样:)

Html.fromHtml() 似乎只支持 减少的 HTML 标签子集.

解决方案

最后我自己预解析了收到的 HTML 代码，因为 Html.fromHtml 不支持 pre 和 code 标签，y 用我的自定义格式替换它们，并预先解析这些标签内的代码，用 <br/> 替换 "\n" 和  .

然后我把结果发送到Html.fromHtml，结果就好了:

公共类 HtmlParser {公共静态跨度解析(字符串文本){if (text == null) 返回 null；文本 = 解析源代码(文本)；Spanned textSpanned = Html.fromHtml(text);返回 textSpanned;}私有静态字符串解析源代码(字符串文本){如果 (text.indexOf(ORIGINAL_PATTERN_BEGIN) <0) 返回文本；StringBuilder 结果 = new StringBuilder();int开始；打算;int beginIndexToProcess = 0;而 (text.indexOf(ORIGINAL_PATTERN_BEGIN) >= 0) {begin = text.indexOf(ORIGINAL_PATTERN_BEGIN);end = text.indexOf(ORIGINAL_PATTERN_END);String code = parseCodeSegment(text, begin, end);result.append(text.substring(beginIndexToProcess, begin));result.append(PARSED_PATTERN_BEGIN);结果.追加(代码)；result.append(PARSED_PATTERN_END);//在原文中替换以查找下一次出现text = text.replaceFirst(ORIGINAL_PATTERN_BEGIN, PARSED_PATTERN_BEGIN);text = text.replaceFirst(ORIGINAL_PATTERN_END，PARSED_PATTERN_END);//更新要处理的字符串索引beginIndexToProcess = text.lastIndexOf(PARSED_PATTERN_END) + PARSED_PATTERN_END.length();}//添加字符串的其余部分result.append(text.substring(beginIndexToProcess, text.length()));返回 result.toString();}私有静态字符串 parseCodeSegment(String text, int begin, int end) {String code = text.substring(begin + ORIGINAL_PATTERN_BEGIN.length(), end);code = code.replace(" ", "&nbsp;");code = code.replace("\n","
");返回码；}private static final String ORIGINAL_PATTERN_BEGIN = "
";private static final String ORIGINAL_PATTERN_END = "</code></pre>";private static final String PARSED_PATTERN_BEGIN = "<font color=\"#888888\"><tt>";private static final String PARSED_PATTERN_END = "</tt></font>";}
Is it possible to parse HTML code in a verbatim mode or something similar so that the source code fragments that eventually may appear (enclosed between pre and code HTML tags) can be displayed properly?

What I want to do is show source code in a user-friendly mode (easy to distinguish from the rest of the text, keep indentation, etc.), as Stack Overflow does :)

It seems that Html.fromHtml() supports only a reduced subset of HTML tags.
解决方案
Finally I preparsed by myself the HTML code received, since Html.fromHtml does not support the pre and code tags, y replaced them with my custom format and pre-parsed the code inside those tags replacing "\n" with <br/> and " " with &nbsp;.

Then I send the results to Html.fromHtml, and the result is just fine:
public class HtmlParser {
    public static Spanned parse(String text) {
        if (text == null) return null;

        text = parseSourceCode(text);

        Spanned textSpanned = Html.fromHtml(text);
        return textSpanned;
    }

    private static String parseSourceCode(String text) {
        if (text.indexOf(ORIGINAL_PATTERN_BEGIN) < 0) return text;

        StringBuilder result = new StringBuilder();
        int begin;
        int end;
        int beginIndexToProcess = 0;

        while (text.indexOf(ORIGINAL_PATTERN_BEGIN) >= 0) {
            begin = text.indexOf(ORIGINAL_PATTERN_BEGIN);
            end = text.indexOf(ORIGINAL_PATTERN_END);

            String code = parseCodeSegment(text, begin, end);

            result.append(text.substring(beginIndexToProcess, begin));
            result.append(PARSED_PATTERN_BEGIN);
            result.append(code);
            result.append(PARSED_PATTERN_END);

            //replace in the original text to find the next appearance
            text = text.replaceFirst(ORIGINAL_PATTERN_BEGIN, PARSED_PATTERN_BEGIN);
            text = text.replaceFirst(ORIGINAL_PATTERN_END, PARSED_PATTERN_END);

            //update the string index to process
            beginIndexToProcess = text.lastIndexOf(PARSED_PATTERN_END) + PARSED_PATTERN_END.length();
        }

        //add the rest of the string
        result.append(text.substring(beginIndexToProcess, text.length()));

        return result.toString();
    }

    private static String parseCodeSegment(String text, int begin, int end) {
        String code = text.substring(begin + ORIGINAL_PATTERN_BEGIN.length(), end);
        code = code.replace(" ", "&nbsp;");
        code = code.replace("\n","<br/>");
        return code;
    }

    private static final String ORIGINAL_PATTERN_BEGIN = "<pre><code>";
    private static final String ORIGINAL_PATTERN_END = "</code></pre>";

    private static final String PARSED_PATTERN_BEGIN = "<font color=\"#888888\"><tt>";
    private static final String PARSED_PATTERN_END = "</tt></font>";
}


                        
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