QGIS/python/core/qgslogger.sip

/**QgsLogger is a class to print debug/warning/error messages to the console. The advantage of this class over std::cout, std::cerr & co. is that the output can be controlled with environment variables:

QGIS_DEBUG is an int describing what debug messages are written to the console. If the debug level of a message is <= QGIS_DEBUG, the message is written to the console. It the variable QGIS_DEBUG is not defined, it defaults to 1 for debug mode and to 0 for release mode

QGIS_DEBUG_FILE may contain a file name. Only the messages from this file are printed (provided they have the right debuglevel). If QGIS_DEBUG_FILE is not set, messages from all files are printed
*/

class QgsLogger
{
%TypeHeaderCode
#include <qgslogger.h>
%End

  public:

    /**Goes to qDebug.
    @param msg the message to be printed
    @param debuglevel
    @param file file name where the message comes from
    @param function function where the message comes from
    @param line place in file where the message comes from*/
    static void debug( const QString& msg, int debuglevel = 1, const char* file = NULL, const char* function = NULL, int line = -1 );

    /**Similar to the previous method, but prints a variable int-value pair*/
    static void debug( const QString& var, int val, int debuglevel = 1, const char* file = NULL, const char* function = NULL, int line = -1 );

    /**Similar to the previous method, but prints a variable double-value pair*/
    // @note not available in python bindings
    // static void debug( const QString& var, double val, int debuglevel = 1, const char* file = NULL, const char* function = NULL, int line = -1 );

    /**Prints out a variable/value pair for types with overloaded operator<<*/
    // @note not available in python bindings
    //template <typename T> static void debug(const QString& var, T val, const char* file = 0, const char* function = 0,
    //     int line = -1, int debuglevel = 1);

    /**Goes to qWarning*/
    static void warning( const QString& msg );

    /**Goes to qCritical*/
    static void critical( const QString& msg );

    /**Goes to qFatal*/
    static void fatal( const QString& msg );

    /**Reads the environment variable QGIS_DEBUG and converts it to int. If QGIS_DEBUG is not set,
     the function returns 1 if QGISDEBUG is defined and 0 if not*/
    static int debugLevel();

    /** Logs the message passed in to the logfile defined in QGIS_LOG_FILE if any. **/
    static void logMessageToFile( QString theMessage );

    /**Reads the environment variable QGIS_LOG_FILE. Returns NULL if the variable is not set,
     * otherwise returns a file name for writing log messages to.*/
    static const QString logFile();
};