1 //语法高亮---QSyntaxHighlighter  2 //highlighter.h  3 class Highlighter : public QSyntaxHighlighter    //定义一个类继承自QSyntaxHightliaghter  4 {  5     Q_OBJECT                                         //Qt宏定义，使用Qt元编程  6   7 public:  8     Highlighter(QTextDocument *parent = 0);      //构造函数，传递一个QTextDocument对象给其父类  9  10 protected: 11     void highlightBlock(const QString &text) Q_DECL_OVERRIDE;    //块高亮使用的函数，自动调用 12  13 private: 14     struct HighlightingRule                    //语法规则结构体，包含正则表达式模式串和匹配的样式 15     { 16         QRegExp pattern; 17         QTextCharFormat format; 18     }; 19     QVector
     
       highlightingRules;    //规则的集合，可以定义多个高亮规则 20  21     QRegExp commentStartExpression;                //注释的高亮，使用highliangBlock()匹配，下文提到 22     QRegExp commentEndExpression; 23  24     QTextCharFormat keywordFormat;                //高亮样式，关键词，一下顾名思义 25     QTextCharFormat classFormat; 26     QTextCharFormat singleLineCommentFormat; 27     QTextCharFormat multiLineCommentFormat; 28     QTextCharFormat quotationFormat; 29     QTextCharFormat functionFormat; 30 }; 31  32 //highlighter.c 33 #include "highlighter.h" 34  35 Highlighter::Highlighter(QTextDocument *parent)    //构造函数，主要是对词语的高亮 36     : QSyntaxHighlighter(parent) 37 { 38     HighlightingRule rule;                            //高亮规则 39  40     keywordFormat.setForeground(Qt::darkBlue);    //设定关键词的高亮样式 41     keywordFormat.setFontWeight(QFont::Bold); 42     QStringList keywordPatterns;                    //关键词集合,关键都以正则表达式表示 43     keywordPatterns << "\\bchar\\b" << "\\bclass\\b" << "\\bconst\\b" 44                     << "\\bdouble\\b" << "\\benum\\b" << "\\bexplicit\\b" 45                     << "\\bfriend\\b" << "\\binline\\b" << "\\bint\\b" 46                     << "\\blong\\b" << "\\bnamespace\\b" << "\\boperator\\b" 47                     << "\\bprivate\\b" << "\\bprotected\\b" << "\\bpublic\\b" 48                     << "\\bshort\\b" << "\\bsignals\\b" << "\\bsigned\\b" 49                     << "\\bslots\\b" << "\\bstatic\\b" << "\\bstruct\\b" 50                     << "\\btemplate\\b" << "\\btypedef\\b" << "\\btypename\\b" 51                     << "\\bunion\\b" << "\\bunsigned\\b" << "\\bvirtual\\b" 52                     << "\\bvoid\\b" << "\\bvolatile\\b"; 53     foreach (const QString &pattern, keywordPatterns) {    //添加各个关键词到高亮规则中 54         rule.pattern = QRegExp(pattern); 55         rule.format = keywordFormat; 56         highlightingRules.append(rule); 57     } 58  59     classFormat.setFontWeight(QFont::Bold);        //添加Qt的类到高亮规则中 60     classFormat.setForeground(Qt::darkMagenta); 61     rule.pattern = QRegExp("\\bQ[A-Za-z]+\\b"); 62     rule.format = classFormat; 63     highlightingRules.append(rule); 64  65     singleLineCommentFormat.setForeground(Qt::red);    //单行注释 66     rule.pattern = QRegExp("//[^\n]*"); 67     rule.format = singleLineCommentFormat; 68     highlightingRules.append(rule); 69  70     multiLineCommentFormat.setForeground(Qt::red);    //多行注释，只设定了样式，具体匹配在highlightBlock中设置 71  72  73     quotationFormat.setForeground(Qt::darkGreen);    //字符串 74     rule.pattern = QRegExp("\".*\""); 75     rule.format = quotationFormat; 76     highlightingRules.append(rule); 77  78  79     functionFormat.setFontItalic(true);        //函数 80     functionFormat.setForeground(Qt::blue); 81     rule.pattern = QRegExp("\\b[A-Za-z0-9_]+(?=\\()"); 82     rule.format = functionFormat; 83     highlightingRules.append(rule); 84  85  86     commentStartExpression = QRegExp("/\\*");        //多行注释的匹配正则表达式 87     commentEndExpression = QRegExp("\\*/"); 88 } 89  90  91 void Highlighter::highlightBlock(const QString &text)    //应用高亮规则，也用于区块的高亮，比如多行注释 92 { 93     foreach (const HighlightingRule &rule, highlightingRules) {    //文本采用高亮规则 94         QRegExp expression(rule.pattern); 95         int index = expression.indexIn(text); 96         while (index >= 0) { 97             int length = expression.matchedLength(); 98             setFormat(index, length, rule.format); 99             index = expression.indexIn(text, index + length);100         }101     }102 103     setCurrentBlockState(0);        //以下是多行注释的匹配104 105     int startIndex = 0;106     if (previousBlockState() != 1)107         startIndex = commentStartExpression.indexIn(text);108 109     while (startIndex >= 0) {110         int endIndex = commentEndExpression.indexIn(text, startIndex);111         int commentLength;112         if (endIndex == -1) {113             setCurrentBlockState(1);114             commentLength = text.length() - startIndex;115         } else {116             commentLength = endIndex - startIndex117                             + commentEndExpression.matchedLength();118         }119         setFormat(startIndex, commentLength, multiLineCommentFormat);120         startIndex = commentStartExpression.indexIn(text, startIndex + commentLength);121     }122 }123 //used in editor124 void MainWindow::setupEditor()    125 {126     QFont font;127     font.setFamily("Courier");128     font.setFixedPitch(true);129     font.setPointSize(10);130 131     editor = new QTextEdit;132     editor->setFont(font);133 134     highlighter = new Highlighter(editor->document());   //调用方法，新建对象并传递document135 136     QFile file("mainwindow.h");137     if (file.open(QFile::ReadOnly | QFile::Text))138         editor->setPlainText(file.readAll());139 }
     

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