基于Qscintilla实现自定义语法编辑器

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前提条件：

• 官网下载Qscintilla库，并使用QtCreator构建出静态库。

• 将Qsci文件夹和生成的库拷到准备使用的项目文件下

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正文

1. 实现自己的customqscintilla

    // 自动缩进
    editor->setTabWidth(4);
    editor->setIndentationWidth(4);
    editor->setIndentationsUseTabs(false);
    editor->setAutoIndent(true);
   
    // 当前行高亮
    editor->setCaretLineVisible(true);
    editor->setCaretLineBackgroundColor(QColor("#E8E8FF"));
    editor->setCaretWidth(3);
   
    // 词法分析器
    auto textLexer = new QsciLexerMat(editor);
    editor->setLexer(textLexer);
   
    // 行号
    editor->setMarginLineNumbers(1, true);
    editor->setMarginWidth(1, "000");
   
    // 代码折叠
    editor->setFolding(QsciScintilla::BoxedTreeFoldStyle);
    editor->setMarginSensitivity(2, true); // 确保可以点击边距进行折叠
    editor->setMarginType(2, QsciScintilla::SymbolMargin);
   
    auto api = new QsciAPIs(textLexer);
    // 读取关键字文件
    if (!api->load("C:/Users/12117/Desktop/QtWidgetsApplication1/QtWidgetsApplication1/QtWidgetsApplication1/apis.txt"))
    {
        QMessageBox::warning(this, "Warning", "Load Failed");
    }
    else
    {
        api->prepare();
    }
   
    // 自动补全
    editor->setAutoCompletionSource(QsciScintilla::AcsAll);
    editor->setAutoCompletionCaseSensitivity(true);
    editor->setAutoCompletionReplaceWord(true);
    editor->setAutoCompletionUseSingle(QsciScintilla::AcusNever);
    editor->setAutoCompletionThreshold(1)
   

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2. 继承QsciLexerCustom实现自己的自定义词法分析器

    class QsciLexerMat : public QsciLexerCustom
    {
    Q_OBJECT
   
    public:
      QsciLexerMat(QObject* parent);
      ~QsciLexerMat();
   
   
    virtual void styleText(int start, int end);
    virtual const char* language() const;
    virtual QString description(int style) const;
    QColor defaultColor(int style) const;
    virtual const char* keywords(int set) const;
   
   
    enum {
    	SCE_C_DEFAULT = 0,
    	SCE_C_COMMENTLINE,
    	SCE_C_STRING,
    	SCE_C_NUMBER,
    	SCE_C_KEYWORD,
    	SCE_C_IDENTIFIER
    };
   };  
   

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3. 重点实现styleText函数（以下代码仅作示例）

    ///----省略----////
    auto handleString = [&]() {
        QChar delimiter = text[pos];
        styleBuffer[pos] = SCE_C_STRING;
        ++pos;
        while (pos < length) {
            if (text[pos] == '\\') { // 转义字符
                if (pos + 1 < length) {
                    styleBuffer[pos] = SCE_C_STRING;
                    styleBuffer[pos + 1] = SCE_C_STRING;
                    pos += 2;
                }
                else {
                    break;
                }
            }
            else if (pos < length && text[pos] == delimiter) {
                styleBuffer[pos] = SCE_C_STRING;
                ++pos;
                inString = false;
                break;
            }
            else if (pos < length) {
                styleBuffer[pos] = SCE_C_STRING;
                ++pos;
            }
            else {
                break;
            }
        }
        };  
    ///----省略----////
    while (pos < length) {
    QChar ch = text.at(pos);
   
    // 处理字符串，注释，关键字和标识符，数字
    if (!inString && (ch == '\'' || ch == '"')) {
        inString = true;
        handleString();
        continue;
    }  
   
    ////----省略----////  
   
    // 应用样式  
      startStyling(start);
      int currentBytePos = start;
      int currentStyle = -1;
      int count = 0;
      QTextCodec* codec = QTextCodec::codecForName("UTF-8");
      if (!codec) {
          qWarning("Failed to get UTF-8 codec");
          return;
      }
   
      QByteArray byteArray;
      for (int i = 0; i < styleBuffer.size(); ++i) {
          if (styleBuffer[i] != currentStyle) {
              if (count > 0) {
                  byteArray = codec->fromUnicode(text.mid(i - count, count));
                  setStyling(byteArray.length(), currentStyle); // 设置相同样式的字符
                  currentBytePos += byteArray.length();
              }
              currentStyle = styleBuffer[i];
              count = 0;
          }
          count++;
      }
      if (count > 0) {
          byteArray = codec->fromUnicode(text.mid(text.length() - count, count));
          setStyling(byteArray.length(), currentStyle); // 设置最后一段相同样式的字符
          currentBytePos += byteArray.length();
      }