Coursera EXT - Quiz option cross-out

Coursera Extension -- enables the user to temporary disable some quiz answers/options (eg. the obvious incorrect ones)

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(У мене вже є менеджер скриптів, дайте мені встановити його!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name            Coursera EXT - Quiz option cross-out
// @description     Coursera Extension -- enables the user to temporary disable some quiz answers/options (eg. the obvious incorrect ones)
// @namespace       http://sepczuk.com/
// @version         0.10
// @include         https://*.coursera.org/*/quiz/attempt*
// @match           https://*.coursera.org/*/quiz/attempt*
// @include         https://*.coursera.org/*/exam/attempt*
// @match           https://*.coursera.org/*/exam/attempt*
// @copyright       2013, Damian Sepczuk, damian at sepczuk period delme com
// ==/UserScript==

function mainWrapper(){
    var debug = !false;
    var US_SHORT_NAME = 'CourseraEXT-QACO';
    var US_VERSION = 0.01;
    
  	function debugLog(msg) {
        if (!debug) return;
        console.log(US_SHORT_NAME + ": " + msg);
  	}
    
    function disableQuizOption(qo) {
        $(qo).css('opacity','.3').prop('disabled', true)
        	.children('.cext-toggle-this-one').html('○').end()
            .children('input').prop('disabled', true).next().css('text-decoration', 'line-through').css('cursor','default');
    }
    
    function enableQuizOption(qo) {
        $(qo).css('opacity','').prop('disabled', false)
        	.children('.cext-toggle-this-one').html('●').end()
        	.children('input').prop('disabled', false).next().css('text-decoration', '').css('cursor','pointer');
    }
    
    function toggleQuizOption(qo) {
        if ($(qo).prop('disabled') === true) {
            enableQuizOption(qo);
        } else {
            disableQuizOption(qo);
        }
    }
    
    function main(){
        debugLog("Running main!");
        var stylesheetText = (function(){/*!HTML!
        <style type="text/css">
        .cext-choose-this-one {
            font-size: 140%;
            font-family: monospace;
            margin-right: 2px;
            cursor: cell;
            vertical-align: top;
            color: #aaa;
        }
        
        .course-disabled-quiz-option {
        	opacity: .3;
            pointer-events: none;            
        }

        .cext-toggle-this-one {
            font-size: 130%;
            font-family: monospace;
            margin-right: 7px;
            cursor: pointer;
            vertical-align: top;
            color: #aaa;
            line-height: 17px;
        }
        
        .cext-toggle-question {
        	line-height: 0px;
			color: #999;
			position: absolute;
			left: -40px;
            top: 20px;
        }
        
        .course-quiz-question-number {
        	position: relative;
        	cursor: pointer;
            background-color: rgb(234, 234, 234);
            padding-left: 10px;
        }
        </style>
        */}).toString().slice(21,-3);
        
        $(stylesheetText).appendTo('head');
        
        var chooseThisOne = $('<span class="cext-choose-this-one">&#9758;</span>').click(function(){
            var quizOption = this.parentElement;
            var allButMe = $(quizOption).parent().children().not(quizOption);
			var otherEnabled = allButMe.filter(':not([disabled])');
            var amIEnabled = $(quizOption).prop('disabled') !== true;
            
            if (otherEnabled.length === 0) {
                enableQuizOption(allButMe);
            } else {
                disableQuizOption(otherEnabled);
                enableQuizOption(quizOption);
                
                if($(quizOption).children('input').attr('type')==='radio') {
                    $(quizOption).children('input').click();
                }
            }
        });
        
        var toggleThisOne = $('<span class="cext-toggle-this-one">&#9679;</span>').click(function(){
            toggleQuizOption(this.parentElement);
        });
        
        var toggleQuestion = $('<span class="cext-toggle-question">&#9679;</span>');
        
        $('.course-quiz-option').prepend(toggleThisOne).prepend(chooseThisOne);
        $('.course-quiz-question-number').prepend(toggleQuestion).toggle(
        function(){
            $(this).parent().css('opacity', '.3');
            $(this).children('.cext-toggle-question').html('&#9675;');
        },
        function(){
            $(this).parent().css('opacity', '');
            $(this).children('.cext-toggle-question').html('&#9679;');
        });
        
        $('.course-quiz-submit-button-container input[type=submit]').click(function(){
            enableQuizOption($('.course-quiz-option'));
        });
    };

    main();
};


if (!document.xmlVersion) {
    var script = document.createElement('script');
    script.appendChild(document.createTextNode('('+ mainWrapper +')();'));
    document.documentElement.appendChild(script);
}