#ifndef CODEEDITOR_H

#define CODEEDITOR_H

#include <QSyntaxHighlighter>

#include <QPlainTextEdit>

#include <QObject>

#include <QRegularExpression>

class QPaintEvent;

class QResizeEvent;

class QSize;

class QWidget;

class LineNumberArea;

class Highlighter : public QSyntaxHighlighter {

Q_OBJECT

public:

explicit Highlighter(QTextDocument *parent);

protected:

void highlightBlock(const QString &text) override;

private:

struct HighlightingRule {

QRegularExpression pattern;

QTextCharFormat format;

};

QVector<HighlightingRule> highlightingRules;

QRegularExpression commentStartExpression;

QRegularExpression commentEndExpression;

QTextCharFormat keywordFormat;

QTextCharFormat classFormat;

QTextCharFormat singleLineCommentFormat;

QTextCharFormat multiLineCommentFormat;

QTextCharFormat quotationFormat;

QTextCharFormat functionFormat;

};

class CodeEditor : public QPlainTextEdit {

Q_OBJECT

public:

explicit CodeEditor(QWidget *parent);

void lineNumberAreaPaintEvent(QPaintEvent *event);

int lineNumberAreaWidth();

void setErrorLine(int errorLine);

protected:

void resizeEvent(QResizeEvent *event) override;

private slots:

void updateLineNumberAreaWidth(int newBlockCount);

void highlightCurrentLine();

void updateLineNumberArea(const QRect &, int);

private:

QWidget *lineNumberArea;

Highlighter *highlighter;

int mErrorPosition;

};

class LineNumberArea : public QWidget {

public:

explicit LineNumberArea(CodeEditor *editor) : QWidget(editor) {

codeEditor = editor;

}

QSize sizeHint() const override {

return QSize(codeEditor->lineNumberAreaWidth(), 0);

}

protected:

void paintEvent(QPaintEvent *event) override {

codeEditor->lineNumberAreaPaintEvent(event);

}

private:

CodeEditor *codeEditor;

};

#endif // CODEEDITOR_H