Custom syntax highlighting using QScintilla with Qt/C++

Question

I am trying to implement custom syntax highlighting in Qt (C++) using QScintilla, however, the documentation is somehow poor. I googled and only found a tutorial for PyQt (qscintilla.com). I am using C++ not Python.

So where can I start? I have noticed that there is a class QSciLexCustom but it looks really confusing for me.

Actually, my custom syntax is quite similar to C++ and one of the different features is using $ before a variable.

Answer 1

You can subclass QsciLexerCustom and implement a styleText() function:

class MyCustomLexer: public QsciLexerCustom
{
public:
    MyCustomLexer(QsciScintilla *parent);

    void styleText(int start, int end);

    QString description(int style) const;
    const char *language() const;

    QsciScintilla *parent_; 
};

MyCustomLexer::MyCustomLexer(QsciScintilla *parent)
{
    setColor(QColor("#000000"), 1);
    setFont(QFont("Consolas", 18), 1);
}

void MyCustomLexer::styleText(int start, int end)
{
    QString lexerText = parent_->text(start, end);
    ...

    startStyling(...);
    setStyling(..., 1); // set to style 1
}

QString MyCustomLexer::description(int style) const
{
    switch (style)
    {
    case 0:
        return tr("Default");   
...
}

const char *MyCustomLexer::language() const
{
    return "MyCustomLexer";
}