fix macOS build (following Projucer changes made in Windows, which removed /Applications/JUCE/modules from its headers). move JUCE headers under source control, so that Windows and macOS can both build against same version of JUCE. remove AUv3 target (I think it's an iOS thing, so it will never work with this macOS fluidsynth dylib).

modules/juce_audio_utils/gui/juce_AudioThumbnailCache.h

@@ -0,0 +1,120 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE library.
+   Copyright (c) 2017 - ROLI Ltd.
+
+   JUCE is an open source library subject to commercial or open-source
+   licensing.
+
+   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
+   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
+   27th April 2017).
+
+   End User License Agreement: www.juce.com/juce-5-licence
+   Privacy Policy: www.juce.com/juce-5-privacy-policy
+
+   Or: You may also use this code under the terms of the GPL v3 (see
+   www.gnu.org/licenses).
+
+   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
+{
+
+//==============================================================================
+/**
+    An instance of this class is used to manage multiple AudioThumbnail objects.
+
+    The cache runs a single background thread that is shared by all the thumbnails
+    that need it, and it maintains a set of low-res previews in memory, to avoid
+    having to re-scan audio files too often.
+
+    @see AudioThumbnail
+
+    @tags{Audio}
+*/
+class JUCE_API  AudioThumbnailCache
+{
+public:
+    //==============================================================================
+    /** Creates a cache object.
+
+        The maxNumThumbsToStore parameter lets you specify how many previews should
+        be kept in memory at once.
+    */
+    explicit AudioThumbnailCache (int maxNumThumbsToStore);
+
+    /** Destructor. */
+    virtual ~AudioThumbnailCache();
+
+    //==============================================================================
+    /** Clears out any stored thumbnails. */
+    void clear();
+
+    /** Reloads the specified thumb if this cache contains the appropriate stored
+        data.
+
+        This is called automatically by the AudioThumbnail class, so you shouldn't
+        normally need to call it directly.
+    */
+    bool loadThumb (AudioThumbnailBase& thumb, int64 hashCode);
+
+    /** Stores the cachable data from the specified thumb in this cache.
+
+        This is called automatically by the AudioThumbnail class, so you shouldn't
+        normally need to call it directly.
+    */
+    void storeThumb (const AudioThumbnailBase& thumb, int64 hashCode);
+
+    /** Tells the cache to forget about the thumb with the given hashcode. */
+    void removeThumb (int64 hashCode);
+
+    //==============================================================================
+    /** Attempts to re-load a saved cache of thumbnails from a stream.
+        The cache data must have been written by the writeToStream() method.
+        This will replace all currently-loaded thumbnails with the new data.
+    */
+    bool readFromStream (InputStream& source);
+
+    /** Writes all currently-loaded cache data to a stream.
+        The resulting data can be re-loaded with readFromStream().
+    */
+    void writeToStream (OutputStream& stream);
+
+    /** Returns the thread that client thumbnails can use. */
+    TimeSliceThread& getTimeSliceThread() noexcept      { return thread; }
+
+protected:
+    /** This can be overridden to provide a custom callback for saving thumbnails
+        once they have finished being loaded.
+    */
+    virtual void saveNewlyFinishedThumbnail (const AudioThumbnailBase&, int64 hashCode);
+
+    /** This can be overridden to provide a custom callback for loading thumbnails
+        from pre-saved files to save the cache the trouble of having to create them.
+    */
+    virtual bool loadNewThumb (AudioThumbnailBase&, int64 hashCode);
+
+private:
+    //==============================================================================
+    TimeSliceThread thread;
+
+    class ThumbnailCacheEntry;
+    friend struct ContainerDeletePolicy<ThumbnailCacheEntry>;
+    OwnedArray<ThumbnailCacheEntry> thumbs;
+    CriticalSection lock;
+    int maxNumThumbsToStore;
+
+    ThumbnailCacheEntry* findThumbFor (int64 hash) const;
+    int findOldestThumb() const;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AudioThumbnailCache)
+};
+
+} // namespace juce