Merge pull request #1315 from edx/anton/fix-caltulator-a11y

Add a11y to the calculator

lms/static/coffee/fixtures/calculator.html

 <ul>
   <li class="calc-main">
-    <a href="#" class="calc">Calculator</a>
+    <a href="#" class="calc" title="Open Calculator" role="button" aria-controls="calculator_wrapper" aria-expanded="false">Open Calculator</a>
     <div id="calculator_wrapper">
       <form id="calculator">
         <div class="input-wrapper">
-          <input type="text" id="calculator_input" />
+          <input type="text" id="calculator_input" tabindex="-1" />
           <div class="help-wrapper">
-            <a href="#">Hints</a>
-            <dl class="help"></dl>
+            <a id="calculator_hint" href="#" role="button" aria-haspopup="true" aria-controls="calculator_input_help" aria-expanded="false" tabindex="-1">Hints</a>
+            <dl id="calculator_input_help" class="help"></dl>
           </div>
         </div>
-        <input id="calculator_button" type="submit" value="="/>
-        <input type="text" id="calculator_output" readonly />
+        <input id="calculator_button" type="submit" title="Calculate" arial-label="Calculate" value="=" tabindex="-1" />
+        <input type="text" id="calculator_output" readonly tabindex="-1" />
       </form>
     </div>
   </li>

lms/static/coffee/spec/calculator_spec.coffee

@@ -9,8 +9,10 @@ describe 'Calculator', ->
 
     it 'bind the help button', ->
       # These events are bind by $.hover()
-      expect($('div.help-wrapper a')).toHandleWith 'mouseover', @calculator.helpToggle
-      expect($('div.help-wrapper a')).toHandleWith 'mouseout', @calculator.helpToggle
+      expect($('div.help-wrapper a')).toHandle 'mouseover'
+      expect($('div.help-wrapper a')).toHandle 'mouseout'
+      expect($('div.help-wrapper')).toHandle 'focusin'
+      expect($('div.help-wrapper')).toHandle 'focusout'
 
     it 'prevent default behavior on help button', ->
       $('div.help-wrapper a').click (e) ->
@@ -49,12 +51,14 @@ describe 'Calculator', ->
       @calculator.toggle(jQuery.Event("click"))
       expect($('.calc')).not.toHaveClass('closed')
 
-  describe 'helpToggle', ->
-    it 'toggle the help overlay', ->
-      @calculator.helpToggle()
+  describe 'helpShow', ->
+    it 'show the help overlay', ->
+      @calculator.helpShow()
       expect($('.help')).toHaveClass('shown')
 
-      @calculator.helpToggle()
+  describe 'helpHide', ->
+    it 'show the help overlay', ->
+      @calculator.helpHide()
       expect($('.help')).not.toHaveClass('shown')
 
   describe 'calculate', ->

lms/static/coffee/src/calculator.coffee

@@ -3,26 +3,70 @@ class @Calculator
     $('.calc').click @toggle
     $('form#calculator').submit(@calculate).submit (e) ->
       e.preventDefault()
-    $('div.help-wrapper a').hover(@helpToggle).click (e) ->
+    $('div.help-wrapper a')
+      .hover(
+        $.proxy(@helpShow, @),
+        $.proxy(@helpHide, @)
+      )
+      .click (e) ->
         e.preventDefault()
+      $('div.help-wrapper')
+        .focusin($.proxy @helpOnFocus, @)
+        .focusout($.proxy @helpOnBlur, @)
 
   toggle: (event) ->
     event.preventDefault()
+    $calc = $('.calc')
+    $calcWrapper = $('#calculator_wrapper')
+    text = gettext('Open Calculator')
+    isExpanded = false
+
     $('div.calc-main').toggleClass 'open'
-    if $('.calc.closed').length
-      $('.calc').attr 'aria-label', 'Open Calculator'
+    if $calc.hasClass('closed')
+      $calcWrapper
+        .find('input, a, dt, dd')
+        .attr 'tabindex', -1
     else
-      $('.calc').attr 'aria-label', 'Close Calculator'
+      text = gettext('Close Calculator')
+      isExpanded = true
+
+      $calcWrapper
+        .find('input, a, dt, dd')
+        .attr 'tabindex', 0
       # TODO: Investigate why doing this without the timeout causes it to jump
       # down to the bottom of the page. I suspect it's because it's putting the
       # focus on the text field before it transitions onto the page.
-      setTimeout (-> $('#calculator_wrapper #calculator_input').focus()), 100
+      setTimeout (-> $calcWrapper.find('#calculator_input').focus()), 100
+
+    $calc
+      .attr
+        'title': text
+        'aria-expanded': isExpanded
+      .text text
+
+    $calc.toggleClass 'closed'
+
+  helpOnFocus: (e) ->
+    e.preventDefault()
+    @isFocusedHelp = true
+    @helpShow()
+
+  helpOnBlur: (e) ->
+    e.preventDefault()
+    @isFocusedHelp = false
+    @helpHide()
 
-    $('.calc').toggleClass 'closed'
+  helpShow: ->
+    $('.help').addClass 'shown'
+    $('#calculator_hint').attr 'aria-expanded', true
 
-  helpToggle: ->
-    $('.help').toggleClass 'shown'
+  helpHide: ->
+    if not @isFocusedHelp
+      $('.help').removeClass 'shown'
+      $('#calculator_hint').attr 'aria-expanded', false
 
   calculate: ->
     $.getWithPrefix '/calculate', { equation: $('#calculator_input').val() }, (data) ->
-      $('#calculator_output').val(data.result)
+      $('#calculator_output')
+        .val(data.result)
+        .focus()

lms/static/sass/course/layout/_calculator.scss

@@ -117,6 +117,7 @@ div.calc-main {
             height: 35px;
             @include hide-text;
             width: 35px;
+             display: block;
           }
 
           dl {
@@ -124,8 +125,6 @@ div.calc-main {
             border-radius: 3px;
             box-shadow: 0 0 3px #999;
             color: #333;
-            display: none;
-            line-height: lh();
             opacity: 0;
             padding: 10px;
             position: absolute;
@@ -133,10 +132,15 @@ div.calc-main {
             top: -122px;
             @include transition(none);
             width: 600px;
+            height: 0;
+            overflow: hidden;
+            pointer-events: none;
 
             &.shown {
-              display: block;
-              opacity: 1.0;
+              height: auto;
+              opacity: 1;
+              overflow: visible;
+              pointer-events: auto;
             }
 
             dt {

lms/templates/courseware/courseware.html

@@ -208,24 +208,23 @@ ${fragment.foot_html()}
 
 % if course.show_calculator:
     <div class="calc-main">
-        <a aria-label="${_('Open Calculator')}" href="#" class="calc">${_("Calculator")}</a>
-
+        <a title="${_('Open Calculator')}" href="#" role="button" aria-controls="calculator_wrapper" aria-expanded="false" class="calc">${_("Open Calculator")}</a>
         <div id="calculator_wrapper">
             <form id="calculator">
                 <div class="input-wrapper">
-                    <input type="text" id="calculator_input" title="Calculator Input Field" />
+                    <input type="text" id="calculator_input" title="${_('Calculator Input Field')}" tabindex="-1" />
 
                     <div class="help-wrapper">
-                        <a href="#">${_("Hints")}</a>
-                        <dl class="help">
-                            <dt>${_("Suffixes:")}</dt>
-                            <dd> %kMGTcmunp</dd>
-                            <dt>${_("Operations:")}</dt>
-                            <dd>^ * / + - ()</dd>
-                            <dt>${_("Functions:")}</dt>
-                            <dd>sin, cos, tan, sqrt, log10, log2, ln, arccos, arcsin, arctan, abs </dd>
-                            <dt>${_("Constants")}</dt>
-                            <dd>e, pi</dd>
+                        <a id="calculator_hint" href="#" role="button" aria-haspopup="true" aria-controls="calculator_input_help" aria-expanded="false" tabindex="-1">${_("Hints")}</a>
+                        <dl id="calculator_input_help" class="help">
+                            <dt tabindex="-1">${_("Suffixes:")}</dt>
+                            <dd tabindex="-1"> %kMGTcmunp</dd>
+                            <dt tabindex="-1">${_("Operations:")}</dt>
+                            <dd tabindex="-1">^ * / + - ()</dd>
+                            <dt tabindex="-1">${_("Functions:")}</dt>
+                            <dd tabindex="-1">sin, cos, tan, sqrt, log10, log2, ln, arccos, arcsin, arctan, abs </dd>
+                            <dt tabindex="-1">${_("Constants")}</dt>
+                            <dd tabindex="-1">e, pi</dd>
 
                             <!-- Students won't know what parallel means at this time.  Complex numbers aren't well tested in the courseware, so we would prefer to not expose them.  If you read the comments in the source, feel free to use them. If you run into a bug, please let us know. But we can't officially support them right now.
 
@@ -233,8 +232,8 @@ ${fragment.foot_html()}
                         </dl>
                     </div>
                 </div>
-                <input id="calculator_button" type="submit" title="Calculate" value="="/>
-                <input type="text" id="calculator_output" title="Calculator Output Field" readonly />
+                <input id="calculator_button" type="submit" title="${_('Calculate')}" value="=" arial-label="${_('Calculate')}" value="=" tabindex="-1" />
+                <input type="text" id="calculator_output" title="${_('Calculator Output Field')}" readonly tabindex="-1" />
             </form>
 
         </div>