assimp/include/Logger.h

/*
Open Asset Import Library (ASSIMP)
----------------------------------------------------------------------

Copyright (c) 2006-2008, ASSIMP Development Team
All rights reserved.

Redistribution and use of this software in source and binary forms, 
with or without modification, are permitted provided that the 
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* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
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* Neither the name of the ASSIMP team, nor the names of its
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  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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----------------------------------------------------------------------
*/

/** @file Logger.h
 *  @brief Abstract base class 'Logger', base of the logging system. 
 */

#ifndef INCLUDED_AI_LOGGER_H
#define INCLUDED_AI_LOGGER_H

#include "aiTypes.h"
namespace Assimp	{

class LogStream;

// ----------------------------------------------------------------------------------
/**	@class	Logger
 *	@brief	Abstract interface for logger implementations.
 *  Assimp provides a default implementation ('DefaultLogger').
 */
class ASSIMP_API Logger : public Intern::AllocateFromAssimpHeap
{
public:
	/**	@enum	LogSeverity
	 *	@brief	Log severity to describe the granularity of logging.
	 *
	 *  This is a general property of a Logger instance, NORMAL means
	 *  that debug messages are rejected immediately.
	 */
	enum LogSeverity
	{
		NORMAL,		//!< Normal granularity of logging
		VERBOSE		//!< Debug infos will be logged, too
	};

	/**	@enum	ErrorSeverity
	 *	@brief	Description for severity of a log message.
	 *
	 *  Every LogStream has a bitwise combination of these flags.
	 *  A LogStream doesn't receive any messages of a specific type
	 *  if it doesn't specify the corresponding ErrorSeverity flag.
	 */
	enum ErrorSeverity
	{
		DEBUGGING	= 1,	//!< Debug log message
		INFO		= 2, 	//!< Info log message
		WARN		= 4,	//!< Warn log message
		ERR			= 8		//!< Error log message
	};

	/** @brief Maximum length for log messages
	 */
	static const size_t MAX_LOG_MESSAGE_LENGTH = 1024;

public:
	/** @brief	Virtual destructor */
	virtual ~Logger();

	/** @brief	Writes a debug message
	 *	 @param	message		Debug message
	 */
	void debug(const std::string &message);

	/** @brief	Writes a info message
	 *	 @param	message		Info message
	 */
	void info(const std::string &message);

	/** @brief	Writes a warning message
	 *	 @param	message		Warn message
	 */
	void warn(const std::string &message);

	/** @brief	Writes an error message
	 *	 @param	message		Error message
	 */
	void error(const std::string &message);

	/** @brief	Set a new log severity.
	 *	 @param	log_severity	New severity for logging
	 */
	virtual void setLogSeverity(LogSeverity log_severity) = 0;

	/** @brief	Attach a new logstream
	 *
	 *  The logger takes ownership of the stream and is responsible
	 *  for its destruction (which is done when the logger itself 
	 *  is destroyed). Call detachStream to detach a stream and to
	 *  gain ownership of it again.
	 *	 @param	pStream	 Logstream to attach
	 *  @param severity  Message filter, specified which types of log
	 *    messages are dispatched to the stream. Provide a bitwise
	 *    combination of the ErrorSeverity flags.
	 */
	virtual void attachStream(LogStream *pStream, 
		unsigned int severity = DEBUGGING | ERR | WARN | INFO) = 0;

	/** @brief	Detach a still attached stream from the logger (or 
	 *          modify the filter flags bits)
	 *	 @param	pStream	Logstream instance for detaching
	 *  @param severity Provide a bitwise combination of the ErrorSeverity
	 *    flags. This value is &~ed with the current flags of the stream,
	 *    if the result is 0 the stream is detached from the Logger and
	 *    the caller retakes the possession of the stream.
	 */
	virtual void detatchStream(LogStream *pStream, 
		unsigned int severity = DEBUGGING | ERR | WARN | INFO) = 0;

protected:
	/**	@brief	Default constructor	*/
	Logger();

	/**  @brief Called as a request to write a specific debug message
	 *	 @param	message		Debug message. Never longer than
	 *     MAX_LOG_MESSAGE_LENGTH characters (exluding the '0').
	 *   @note  The message string is only valid until the scope of
	 *     the function is left.
	 */
	virtual void OnDebug(const char* message)= 0;

	/**  @brief Called as a request to write a specific info message
	 *	 @param	message		Info message. Never longer than
	 *     MAX_LOG_MESSAGE_LENGTH characters (exluding the '0').
	 *   @note  The message string is only valid until the scope of
	 *     the function is left.
	 */
	virtual void OnInfo(const char* message) = 0;

	/**  @brief Called as a request to write a specific warn message
	 *	 @param	message		Warn message. Never longer than
	 *     MAX_LOG_MESSAGE_LENGTH characters (exluding the '0').
	 *   @note  The message string is only valid until the scope of
	 *     the function is left.
	 */
	virtual void OnWarn(const char* essage) = 0;

	/**  @brief Called as a request to write a specific error message
	 *	 @param	message		Error message. Never longer than
	 *     MAX_LOG_MESSAGE_LENGTH characters (exluding the '0').
	 *   @note  The message string is only valid until the scope of
	 *     the function is left.
	 */
	virtual void OnError(const char* message) = 0;
};

// ----------------------------------------------------------------------------------
//	Default constructor
inline Logger::Logger()
{
	//	empty
}

// ----------------------------------------------------------------------------------
//	Virtual destructor
inline  Logger::~Logger()
{
	// empty
}
// ----------------------------------------------------------------------------------

} // Namespace Assimp

#endif // !! INCLUDED_AI_LOGGER_H