logger.hh

#ifndef LOGGER_HH
#define LOGGER_HH
 
#include <QFile>
#include <QTextStream>
#include <QList>
#include <QMutex>

#define logDebug() LogMessage(LogMessage::DEBUG, __FILE__, __LINE__)
#define logInfo()  LogMessage(LogMessage::INFO, __FILE__, __LINE__)
#define logWarn()  LogMessage(LogMessage::WARNING, __FILE__, __LINE__)
#define logError() LogMessage(LogMessage::ERROR, __FILE__, __LINE__)
#ifdef __cpp_lib_stacktrace
#include <stacktrace>
#define logFatal() LogMessage(LogMessage::FATAL, __FILE__, __LINE__) << \
  QString::fromStdString(std::to_string(std::stacktrace::current()))
#else
#define logFatal() LogMessage(LogMessage::FATAL, __FILE__, __LINE__)
#endif

class LogMessage: public QTextStream
{
public:
  typedef enum {
    DEBUG,    
    INFO,     
    WARNING,  
    ERROR,    
    FATAL     
  } Level;
 
public:
  LogMessage(Level level, const QString &file, int line, const QString &message="");
  LogMessage(const LogMessage &other);
  virtual ~LogMessage();

  Level level() const;
  const QString &file() const;
  int line() const;
  const QString &message() const;
 
protected:
  Level _level;
  QString _file;
  int _line;
  QString _message;
};
 

class LogHandler: public QObject
{
  Q_OBJECT
 
public:
  explicit LogHandler(QObject *parent=nullptr);
  virtual ~LogHandler();
  virtual void handle(const LogMessage &message) = 0;
};
 

class Logger: public QObject
{
  Q_OBJECT
 
protected:
  Logger();
 
public:
  virtual ~Logger();

  void log(const LogMessage &msg);
  void addHandler(LogHandler *handler);
  void remHandler(LogHandler *handler);
 
protected slots:
  void onHandlerDeleted(QObject *obj);
 
public:
  static Logger &get();
 
protected:
  static Logger *_instance;
  QList<LogHandler *> _handler;
  QMutex _lock;
};
 

class StreamLogHandler: public LogHandler
{
  Q_OBJECT
 
public:
  StreamLogHandler(QTextStream &stream, LogMessage::Level minLevel=LogMessage::DEBUG, bool color=false, QObject *parent=nullptr);

  LogMessage::Level minLevel() const;
  void setMinLevel(LogMessage::Level minLevel);
 
  void handle(const LogMessage &message);
 
protected:
  QTextStream &_stream;
  LogMessage::Level _minLevel;
  bool _color;
};
 

class FileLogHandler: public LogHandler
{
  Q_OBJECT
 
public:
  FileLogHandler(const QString &file, LogMessage::Level minLevel=LogMessage::DEBUG, QObject *parent=nullptr);

  virtual ~FileLogHandler();

  LogMessage::Level minLevel() const;
  void setMinLevel(LogMessage::Level minLevel);
 
  void handle(const LogMessage &message);
 
protected:
  QFile _file;
  QTextStream _stream;
  LogMessage::Level _minLevel;
};
 
#endif // LOGGER_HH