FijkVolumeCallback typedef Null safety
Volume changed callback func.
value is the value of volume, and has been mapped into range
true value of
ui indicates that Android/iOS system volume changed UI is shown for this volume change event
streamType shows track\stream type for this volume change, this value is always FijkVolume.STREAM_MUSIC in this version
typedef FijkVolumeCallback = void Function(FijkVolumeEvent value);