jQuery tooltip: accessibility friendly

index.html

<div class="button-list namespace">
  <h2>$('selector').tooltip()</h2>
  <ul>
    <li>
      <span>Lorem Ipsum Dolar Sit</span>
      <button type="button">+
        <span class="tooltip" role="tooltip">Hello World again and again and again and again.</span>
      </button>
    </li>
    <li>
      <span>Lorem Ipsum Dolar Sit</span>
      <button type="button">+
        <span class="tooltip" role="tooltip">Hello World</span>
      </button>
    </li>
    <li>
      <span>Lorem Ipsum Dolar Sit</span>
      <button type="button">+
        <span class="tooltip" role="tooltip">Hello World</span>
      </button>
    </li>
    <li>
      <span>Lorem Ipsum Dolar Sit</span>
      <button type="button">+
        <span class="tooltip" role="tooltip">Hello World</span>
      </button>
    </li>
    <li>
      <span>Lorem Ipsum Dolar Sit</span>
      <button type="button">+
        <span class="tooltip" role="tooltip">Hello World</span>
      </button>
    </li>
  </ul>
</div>

jQuery-tooltip:-accessibility-friendly.markdown

jQuery tooltip: accessibility friendly

Purpose: provide a tooltip that meets the following requirements:

1. Is accessible to screen readers
2. Is accessible to sighted keyboard users
3. Shows on hover and on focus
4. Doesn't obstruct other clickable elements
5. Gracefully degrades to IE8

A Pen by Gerald on CodePen.

License.

script.js

// Fully accessible tooltip jQuery plugin with delegation.
// Ideal for view containers that may re-render content.
(function ($) {
  $.fn.tooltip = function() {
    this
    
      // Delegate to tooltip, Hide if tooltip receives mouse or is clicked (tooltip may stick if parent has focus)
      .on('mouseenter click', '.tooltip', function (e) {
          e.stopPropagation();
          $(this).removeClass('isVisible');
      })

      // Delegate to parent of tooltip, Show tooltip if parent receives mouse or focus
      .on('mouseenter focus', ':has(>.tooltip)', function () {
          $(this)
              .find('.tooltip')
              .addClass('isVisible');
      })

      // Delegate to parent of tooltip, Hide tooltip if parent loses mouse or focus
      .on('mouseleave blur', ':has(>.tooltip)', function () {
          $(this)
              .find('.tooltip')
              .removeClass('isVisible');
      });
    return this;
  };
}(jQuery));

// Bind event listener to container element
$('.namespace').tooltip();

style.css

html {
  font-size: 62.5%;
}

body {
  font-family: Calibri, Candara, Segoe, 'Segoe UI', Optima, Arial, sans-serif;
  font-size: 1.6em;
}

h2 {
    font-size: 2.4rem;
    line-height: 1;
    margin: 0 0 1em;
}

div {
  display: inline-block;
  margin: 1rem;
  padding: 1rem;
  border: 1px solid #bcbec0;
  border-radius: 3px;
}

ul {
  display: inline-block;
  margin: 0;
  padding: 0;
  list-style: none;
}

li {
  padding: .2em;
  border-top: 1px solid #ccc;
}

li:first-child {
  border-top: none;
}

button {
  position: relative;
}

/* Predefine tooltip styles, content; Hide by default */
.tooltip {
  position: absolute;
  box-sizing: border-box;
  z-index: 2;
  top: 110%;
  top: calc(100% + 5px);
  left: 50%;
  overflow: hidden;
  clip: rect(0,0,0,0);
  width: 1px;
  height: 1px;
  padding: 10px 15px;
  -webkit-transform: translateX(-50%);
    -ms-transform: translateX(-50%);
      transform: translateX(-50%);
  transition: opacity .3s ease-in .3s;
  font-family: Helvetica, Arial, sans-serif;
  font-size: 14px;
  font-size: 1.4rem;
  text-align: center;
  white-space: pre;
  opacity: 0;
  color: #fff;
  border: 1px solid #6d6e71;
  border-top-color: #373739;
  background-color: #373739;
}

/* Up arrow */
.tooltip:after {
  position: absolute;
  top: -10px;
  left: 50%;
  display: block;
  width: 0;
  height: 0;
  margin-left: -10px;
  content: ' ';
  pointer-events: none;
  border-right: 10px solid transparent;
  border-bottom: 10px solid #373739;
  border-left: 10px solid transparent;
}

/* Toggled by jQuery for show/hide */
.tooltip.isVisible {
  overflow: visible;
  clip: auto;
  width: auto;
  height: auto;
  opacity: 1;
}