JUCE/modules/juce_core/logging/juce_Logger.h

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2016 - ROLI Ltd.

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

   -----------------------------------------------------------------------------

   To release a closed-source product which uses other parts of JUCE not
   licensed under the ISC terms, commercial licenses are available: visit
   www.juce.com for more information.

  ==============================================================================
*/

#pragma once


//==============================================================================
/**
    Acts as an application-wide logging class.

    A subclass of Logger can be created and passed into the Logger::setCurrentLogger
    method and this will then be used by all calls to writeToLog.

    The logger class also contains methods for writing messages to the debugger's
    output stream.

    @see FileLogger
*/
class JUCE_API  Logger
{
public:
    //==============================================================================
    /** Destructor. */
    virtual ~Logger();

    //==============================================================================
    /** Sets the current logging class to use.

        Note that the object passed in will not be owned or deleted by the logger, so
        the caller must make sure that it is not deleted while still being used.
        A null pointer can be passed-in to reset the system to the default logger.
    */
    static void JUCE_CALLTYPE setCurrentLogger (Logger* newLogger) noexcept;

    /** Returns the current logger, or nullptr if no custom logger has been set. */
    static Logger* JUCE_CALLTYPE getCurrentLogger() noexcept;

    /** Writes a string to the current logger.

        This will pass the string to the logger's logMessage() method if a logger
        has been set.

        @see logMessage
    */
    static void JUCE_CALLTYPE writeToLog (const String& message);


    //==============================================================================
    /** Writes a message to the standard error stream.

        This can be called directly, or by using the DBG() macro in
        juce_PlatformDefs.h (which will avoid calling the method in non-debug builds).
    */
    static void JUCE_CALLTYPE outputDebugString (const String& text);


protected:
    //==============================================================================
    Logger();

    /** This is overloaded by subclasses to implement custom logging behaviour.
        @see setCurrentLogger
    */
    virtual void logMessage (const String& message) = 0;

private:
    static Logger* currentLogger;
};