/* ============================================================================== This file is part of the JUCE library. Copyright (c) 2022 - Raw Material Software Limited JUCE is an open source library subject to commercial or open-source licensing. The code included in this file is provided 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. JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE DISCLAIMED. ============================================================================== */ namespace juce { //============================================================================== /** A message that invokes a callback method when it gets delivered. You can use this class to fire off actions that you want to be performed later on the message thread. To use it, create a subclass of CallbackMessage which implements the messageCallback() method, then call post() to dispatch it. The event thread will then invoke your messageCallback() method later on, and will automatically delete the message object afterwards. Always create a new instance of a CallbackMessage on the heap, as it will be deleted automatically after the message has been delivered. Note that this class was essential back in the days before C++11, but in modern times you may prefer to use MessageManager::callAsync() with a lambda. @see MessageManager::callAsync, MessageListener, ActionListener, ChangeListener @tags{Events} */ class JUCE_API CallbackMessage : public MessageManager::MessageBase { public: //============================================================================== CallbackMessage() = default; /** Destructor. */ ~CallbackMessage() override = default; //============================================================================== /** Called when the message is delivered. You should implement this method and make it do whatever action you want to perform. Note that like all other messages, this object will be deleted immediately after this method has been invoked. */ void messageCallback() override = 0; private: // Avoid the leak-detector because for plugins, the host can unload our DLL with undelivered // messages still in the system event queue. These aren't harmful, but can cause annoying assertions. JUCE_DECLARE_NON_COPYABLE (CallbackMessage) }; } // namespace juce