git subrepo clone --branch=sono6good https://github.com/essej/JUCE.git deps/juce

subrepo:
  subdir:   "deps/juce"
  merged:   "b13f9084e"
upstream:
  origin:   "https://github.com/essej/JUCE.git"
  branch:   "sono6good"
  commit:   "b13f9084e"
git-subrepo:
  version:  "0.4.3"
  origin:   "https://github.com/ingydotnet/git-subrepo.git"
  commit:   "2f68596"

deps/juce/modules/juce_events/messages/juce_CallbackMessage.h

@@ -0,0 +1,74 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2020 - 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