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_AsyncUpdater.h

@@ -0,0 +1,110 @@
+/*
+  ==============================================================================
+
+   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
+{
+
+//==============================================================================
+/**
+    Has a callback method that is triggered asynchronously.
+
+    This object allows an asynchronous callback function to be triggered, for
+    tasks such as coalescing multiple updates into a single callback later on.
+
+    Basically, one or more calls to the triggerAsyncUpdate() will result in the
+    message thread calling handleAsyncUpdate() as soon as it can.
+
+    @tags{Events}
+*/
+class JUCE_API  AsyncUpdater
+{
+public:
+    //==============================================================================
+    /** Creates an AsyncUpdater object. */
+    AsyncUpdater();
+
+    /** Destructor.
+        If there are any pending callbacks when the object is deleted, these are lost.
+    */
+    virtual ~AsyncUpdater();
+
+    //==============================================================================
+    /** Causes the callback to be triggered at a later time.
+
+        This method returns immediately, after which a callback to the
+        handleAsyncUpdate() method will be made by the message thread as
+        soon as possible.
+
+        If an update callback is already pending but hasn't happened yet, calling
+        this method will have no effect.
+
+        It's thread-safe to call this method from any thread, BUT beware of calling
+        it from a real-time (e.g. audio) thread, because it involves posting a message
+        to the system queue, which means it may block (and in general will do on
+        most OSes).
+    */
+    void triggerAsyncUpdate();
+
+    /** This will stop any pending updates from happening.
+
+        If called after triggerAsyncUpdate() and before the handleAsyncUpdate()
+        callback happens, this will cancel the handleAsyncUpdate() callback.
+
+        Note that this method simply cancels the next callback - if a callback is already
+        in progress on a different thread, this won't block until the callback finishes, so
+        there's no guarantee that the callback isn't still running when the method returns.
+    */
+    void cancelPendingUpdate() noexcept;
+
+    /** If an update has been triggered and is pending, this will invoke it
+        synchronously.
+
+        Use this as a kind of "flush" operation - if an update is pending, the
+        handleAsyncUpdate() method will be called immediately; if no update is
+        pending, then nothing will be done.
+
+        Because this may invoke the callback, this method must only be called on
+        the main event thread.
+    */
+    void handleUpdateNowIfNeeded();
+
+    /** Returns true if there's an update callback in the pipeline. */
+    bool isUpdatePending() const noexcept;
+
+    //==============================================================================
+    /** Called back to do whatever your class needs to do.
+
+        This method is called by the message thread at the next convenient time
+        after the triggerAsyncUpdate() method has been called.
+    */
+    virtual void handleAsyncUpdate() = 0;
+
+private:
+    //==============================================================================
+    class AsyncUpdaterMessage;
+    friend class ReferenceCountedObjectPtr<AsyncUpdaterMessage>;
+    ReferenceCountedObjectPtr<AsyncUpdaterMessage> activeMessage;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AsyncUpdater)
+};
+
+} // namespace juce