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/broadcasters/juce_ChangeBroadcaster.h

@@ -0,0 +1,105 @@
+/*
+  ==============================================================================
+
+   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
+{
+
+//==============================================================================
+/**
+    Holds a list of ChangeListeners, and sends messages to them when instructed.
+
+    @see ChangeListener
+
+    @tags{Events}
+*/
+class JUCE_API  ChangeBroadcaster
+{
+public:
+    //==============================================================================
+    /** Creates an ChangeBroadcaster. */
+    ChangeBroadcaster() noexcept;
+
+    /** Destructor. */
+    virtual ~ChangeBroadcaster();
+
+    //==============================================================================
+    /** Registers a listener to receive change callbacks from this broadcaster.
+        Trying to add a listener that's already on the list will have no effect.
+    */
+    void addChangeListener (ChangeListener* listener);
+
+    /** Unregisters a listener from the list.
+        If the listener isn't on the list, this won't have any effect.
+    */
+    void removeChangeListener (ChangeListener* listener);
+
+    /** Removes all listeners from the list. */
+    void removeAllChangeListeners();
+
+    //==============================================================================
+    /** Causes an asynchronous change message to be sent to all the registered listeners.
+
+        The message will be delivered asynchronously by the main message thread, so this
+        method will return immediately. To call the listeners synchronously use
+        sendSynchronousChangeMessage().
+    */
+    void sendChangeMessage();
+
+    /** Sends a synchronous change message to all the registered listeners.
+
+        This will immediately call all the listeners that are registered. For thread-safety
+        reasons, you must only call this method on the main message thread.
+
+        @see dispatchPendingMessages
+    */
+    void sendSynchronousChangeMessage();
+
+    /** If a change message has been sent but not yet dispatched, this will call
+        sendSynchronousChangeMessage() to make the callback immediately.
+
+        For thread-safety reasons, you must only call this method on the main message thread.
+    */
+    void dispatchPendingMessages();
+
+private:
+    //==============================================================================
+    class ChangeBroadcasterCallback  : public AsyncUpdater
+    {
+    public:
+        ChangeBroadcasterCallback();
+        void handleAsyncUpdate() override;
+
+        ChangeBroadcaster* owner;
+    };
+
+    friend class ChangeBroadcasterCallback;
+    ChangeBroadcasterCallback broadcastCallback;
+    ListenerList <ChangeListener> changeListeners;
+
+    std::atomic<bool> anyListeners { false };
+
+    void callListeners();
+
+    JUCE_DECLARE_NON_COPYABLE (ChangeBroadcaster)
+};
+
+} // namespace juce