//! [0]
QTextEdit *editor = new QTextEdit;
MyHighlighter *highlighter = new MyHighlighter(editor->document());
//! [0]


//! [1]
void MyHighlighter::highlightBlock(const QString &text)
{
    QTextCharFormat myClassFormat;
    myClassFormat.setFontWeight(QFont::Bold);
    myClassFormat.setForeground(Qt::darkMagenta);
    QString pattern = "\\bMy[A-Za-z]+\\b";

    QRegExp expression(pattern);
    int index = text.indexOf(expression);
    while (index >= 0) {
        int length = expression.matchedLength();
        setFormat(index, length, myClassFormat);
        index = text.indexOf(expression, index + length);
    }
}
//! [1]


//! [2]
QTextCharFormat multiLineCommentFormat;
multiLineCommentFormat.setForeground(Qt::red);

QRegExp startExpression("/\\*");
QRegExp endExpression("\\*/");

setCurrentBlockState(0);

int startIndex = 0;
if (previousBlockState() != 1)
    startIndex = text.indexOf(startExpression);

while (startIndex >= 0) {
   int endIndex = text.indexOf(endExpression, startIndex);
   int commentLength;
   if (endIndex == -1) {
       setCurrentBlockState(1);
       commentLength = text.length() - startIndex;
   } else {
       commentLength = endIndex - startIndex
                       + endExpression.matchedLength();
   }
   setFormat(startIndex, commentLength, multiLineCommentFormat);
   startIndex = text.indexOf(startExpression,
                             startIndex + commentLength);
}
//! [2]


//! [3]
void MyHighlighter::highlightBlock(const QString &text)
{
    QTextCharFormat myClassFormat;
    myClassFormat.setFontWeight(QFont::Bold);
    myClassFormat.setForeground(Qt::darkMagenta);
    QString pattern = "\\bMy[A-Za-z]+\\b";

    QRegExp expression(pattern);
    int index = text.indexOf(expression);
    while (index >= 0) {
        int length = expression.matchedLength();
        setFormat(index, length, myClassFormat);
        index = text.indexOf(expression, index + length);
     }
 }
//! [3]


//! [4]
struct ParenthesisInfo
{
    QChar char;
    int position;
};

struct BlockData : public QTextBlockUserData
{
    QVector<ParenthesisInfo> parentheses;
};
//! [4]