clicker.js

/**
 * The clicker gremlin clicks anywhere on the visible area of the document
 *
 * The clicker gremlin triggers mouse events (click, dblclick, mousedown,
 * mouseup, mouseover, mouseover, mouseover, mousemove, and mouseout) on 
 * random targets displayed on the viewport.
 *
 * By default, the clicker gremlin activity is showed by a red circle.
 *
 *   var clickerGremlin = gremlins.species.clicker();
 *   horde.gremlin(clickerGremlin);
 *
 * The clicker gremlin can be customized as follows:
 *
 *   clickerGremlin.clickTypes(['click', 'mouseover']); // the mouse event types to trigger
 *   clickerGremlin.positionSelector(function() { // find a random pair of coordinates to click });
 *   clickerGremlin.showAction(function(x, y) { // show the gremlin activity on screen });
 *   clickerGremlin.canClick(function(element) { return true }); // to limit where the gremlin can click
 *   clickerGremlin.maxNbTries(5); // How many times the gremlin must look for a clickable element before quitting
 *   clickerGremlin.logger(loggerObject); // inject a logger
 *   clickerGremlin.randomizer(randomizerObject); // inject a randomizer
 *
 * Example usage:
 *
 *   horde.gremlin(gremlins.species.clicker()
 *     .clickTypes(['click'])
 *     .positionSelector(function() {
 *        // only click inside the foo element area
 *        var $el = $('#foo');
 *        var offset = $el.offset();
 *        return [
 *          parseInt(Math.random() * $el.outerWidth() + offset.left),
 *          parseInt(Math.random() * $el.outerHeight() + offset.top)
 *        ];
 *     })
 *     .canClick(function(element) {
 *       // only click elements in bar
 *       return $(element).parents('#bar').length;
 *       // when canClick returns false, the gremlin will look for another
 *       // element to click on until maxNbTries is reached
 *     })
 *     . showAction(function(x, y) {
 *       // do nothing (hide the gremlin action on screen)
 *     })
 *   );
 */
define(function(require) {
    "use strict";

    var configurable = require('../utils/configurable');
    var Chance = require('../vendor/chance');
    var RandomizerRequiredException = require('../exceptions/randomizerRequired');

    return function() {

        var document = window.document,
            body = document.body;

        var defaultClickTypes = ['click', 'click', 'click', 'click', 'click', 'click', 'dblclick', 'dblclick', 'mousedown', 'mouseup', 'mouseover', 'mouseover', 'mouseover', 'mousemove', 'mouseout'];

        function defaultPositionSelector() {
            return [
                config.randomizer.natural({ max: document.documentElement.clientWidth - 1 }),
                config.randomizer.natural({ max: document.documentElement.clientHeight - 1 })
            ];
        }

        function defaultShowAction(x, y) {
            var clickSignal = document.createElement('div');
            clickSignal.style.zIndex = 2000;
            clickSignal.style.border = "3px solid red";
            clickSignal.style['border-radius'] = '50%'; // Chrome
            clickSignal.style.borderRadius = '50%';     // Mozilla
            clickSignal.style.width = "40px";
            clickSignal.style.height = "40px";
            clickSignal.style['box-sizing'] = 'border-box';
            clickSignal.style.position = "absolute";
            clickSignal.style.webkitTransition = 'opacity 1s ease-out';
            clickSignal.style.mozTransition = 'opacity 1s ease-out';
            clickSignal.style.transition = 'opacity 1s ease-out';
            clickSignal.style.left = (x - 20 ) + 'px';
            clickSignal.style.top = (y - 20 )+ 'px';
            var element = body.appendChild(clickSignal);
            setTimeout(function() {
                body.removeChild(element);
            }, 1000);
            setTimeout(function() {
                element.style.opacity = 0;
            }, 50);
        }

        function defaultCanClick() {
            return true;
        }

        /**
         * @mixin
         */
        var config = {
            clickTypes:       defaultClickTypes,
            positionSelector: defaultPositionSelector,
            showAction:       defaultShowAction,
            canClick:         defaultCanClick,
            maxNbTries:       10,
            logger:           null,
            randomizer:       null
        };

        /**
         * @mixes config
         */
        function clickerGremlin() {
            if (!config.randomizer) {
                throw new RandomizerRequiredException();
            }
            var position, posX, posY, targetElement, nbTries = 0;
            do {
                position = config.positionSelector();
                posX = position[0];
                posY = position[1];
                targetElement = document.elementFromPoint(posX, posY);
                nbTries++;
                if (nbTries > config.maxNbTries) return false;
            } while (!targetElement || !config.canClick(targetElement));

            var evt = document.createEvent("MouseEvents");
            var clickType = config.randomizer.pick(config.clickTypes);
            evt.initMouseEvent(clickType, true, true, window, 0, 0, 0, posX, posY, false, false, false, false, 0, null);
            targetElement.dispatchEvent(evt);

            if (typeof config.showAction == 'function') {
                config.showAction(posX, posY, clickType);
            }

            if (config.logger && typeof config.logger.log == 'function') {
                config.logger.log('gremlin', 'clicker   ', clickType, 'at', posX, posY);
            }
        }

        configurable(clickerGremlin, config);

        return clickerGremlin;
    };
});