the proper way to detect the current bar?

Question

I am working on a sequencer app based on the SequencerDemo app, using AKAppleSequencer. It's been great so far, but now I need to add a new function to highlight the current bar.

Is there any delegate I can use to keep track of the bar that's currently being played? What is the proper way to handle this? Any help is much appreciated.

Answer 1

I ended up using AKMIDICallbackInstrument as per suggestion by @c_booth. And I added midi notes (2 beats per bar) to a separate (dedicated) track just to track the transport.

I put the following in init:

callbackInstr = AKMIDICallbackInstrument(
        midiInputName: "midiCallBack",
        callback: { status, noteNumber, velocity in
            let statusType = AKMIDIStatus(byte: status)?.type
            if(statusType == AKMIDIStatusType.noteOn){
                self.sequencerCallback()
            }
    })

and I'm tracking the sequencer.currentPosition.musicTimeStamp in sequencerCallback()

it seems to be working.