Function attachWheelEventHandler

src/plots/cartesian/dragbox.js:1335–1353

(element, handler)

// still seems to be some confusion about onwheel vs onmousewheel...
function attachWheelEventHandler(element, handler) {
    if(!supportsPassive) {
        if(element.onwheel !== undefined) element.onwheel = handler;
        else if(element.onmousewheel !== undefined) element.onmousewheel = handler;
        else if(!element.isAddedWheelEvent) {
            element.isAddedWheelEvent = true;
            element.addEventListener('wheel', handler, {passive: false});
        }
    } else {
        var wheelEventName = element.onwheel !== undefined ? 'wheel' : 'mousewheel';

        if(element._onwheel) {
            element.removeEventListener(wheelEventName, element._onwheel);
        }
        element._onwheel = handler;

        element.addEventListener(wheelEventName, handler, {passive: false});
    }
}

function hashValues(hash) {
    var out = [];