• Members:
• static void OnError(DfMp3& mp3, uint16_t errorCode)
• static void OnPlayFinished(DfMp3& mp3, DfMp3_PlaySources source, uint16_t track)
• static void OnPlaySourceOnline(DfMp3& mp3, DfMp3_PlaySources source)
• static void OnPlaySourceInserted(DfMp3& mp3, DfMp3_PlaySources source)
• static void OnPlaySourceRemoved(DfMp3& mp3, DfMp3_PlaySources source)