Trigger mouse event programmatically. Useful to simulate mouse wheel events.

triggerMouseEvent.js

/**
 * Simulate a mouse event to a given DOM element
 * @param {string, WebElement} elem
 * @param {string} evtName Event name
 * @param {object} eventInitProps Properties to set on the mouse event
 */
function triggerMouseEvent(elem, evtName, eventInitProps) {
    return browser.executeScript(function(_elem, _evtName, _eventInitProps) {
        var $ = window.jQuery;
        elem = $(_elem);
        var evt = document.createEvent('MouseEvents'); // not using "new WheelEvent()" because it doesn't work on IE9 yet.
        var evtGroupName = _evtName + '.protractor';
        evt.initEvent(_evtName, true, true);

        $.extend(evt, _eventInitProps);

        elem.one(evtGroupName, function(e) { // create wheel event handler to do the vertical scroll programmatically
            var originalEvent = e.originalEvent;

            //DEBUG
            // console.log('internal ' + e.type + ' handler: deltaY=', originalEvent.deltaY, ' detail=', originalEvent.detail, ' wheelDelta =', originalEvent.wheelDelta);

            if (!e.isDefaultPrevented() && !originalEvent.shiftKey) {
                var curElem = $(this);
                curElem.scrollTop(curElem.scrollTop() + originalEvent.deltaY);
            }
        });
        elem.each(function() {
                this.dispatchEvent(evt);
            })
            .unbind(evtGroupName);
    }, elem.getWebElement ? elem.getWebElement() : elem, evtName, eventInitProps);
}

browser is not defined