Simple Bitwig Helper for endless controllers

util.js

/**
 * @var int max
 * @var callback nextCallback
 * @var callback prevCallback
 */
function EndlessScroller(max, nextCallback, prevCallback) {
    var lastValue = null;
    var maxValue = max;

    return function(value) {
        if(lastValue==maxValue && value == 0) {
            lastValue = value;
            nextCallback();
            return;
        }
        if(lastValue == 0 && value == maxValue) {
            lastValue = value;
            prevCallback();
            return;
        }

        if(value > lastValue) {
            lastValue = value;
            nextCallback();
            return;
        }
        if(value < lastValue) {
            lastValue = value;
            prevCallback();
        }
    }
}


// short usage
// full example at https://github.com/woodworker/bitwig-controller/blob/master/CME/CME-UF5.control.js

var PROGRAMM_CHANGER = 192;

// create the endless scroller with 127 as max value
var trackSelector = EndlessScroller(127, function(){
    cursorTrack.selectNext();
}, function() {
    cursorTrack.selectPrevious();
});


function onMidi(status, data1, data2) {
    if(status == PROGRAMM_CHANGER) {
        trackSelector(data1);
        return;
    }
}