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

   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.

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

#ifndef JUCE_MESSAGELISTENER_H_INCLUDED
#define JUCE_MESSAGELISTENER_H_INCLUDED


//==============================================================================
/**
    MessageListener subclasses can post and receive Message objects.

    @see Message, MessageManager, ActionListener, ChangeListener
*/
class JUCE_API  MessageListener
{
public:
    //==============================================================================
    MessageListener() noexcept;

    /** Destructor. */
    virtual ~MessageListener();

    //==============================================================================
    /** This is the callback method that receives incoming messages.

        This is called by the MessageManager from its dispatch loop.

        @see postMessage
    */
    virtual void handleMessage (const Message& message) = 0;

    //==============================================================================
    /** Sends a message to the message queue, for asynchronous delivery to this listener
        later on.

        This method can be called safely by any thread.

        @param message      the message object to send - this will be deleted
                            automatically by the message queue, so make sure it's
                            allocated on the heap, not the stack!
        @see handleMessage
    */
    void postMessage (Message* message) const;

private:
    WeakReference<MessageListener>::Master masterReference;
    friend class WeakReference<MessageListener>;
};


#endif   // JUCE_MESSAGELISTENER_H_INCLUDED
