Add example of select-only combobox (pull w3c#1396)

Resolves issue w3c#1026 by adding a new select-only combobox example.

Co-authored-by: Valerie Young <valerie@bocoup.com>
Co-authored-by: Matt King <a11yThinker@gmail.com>
Co-authored-by: Carolyn MacLeod <Carolyn_MacLeod@ca.ibm.com>

aria-practices.html

@@ -790,6 +790,7 @@ <h3>Combobox</h3>
       <section class="notoc">
         <h4>Examples</h4>
         <ul>
+          <li><a href="examples/combobox/combobox-select-only.html">Select-Only Combobox</a>: A single-select combobox with no text input that is functionally similar to an HTML <code>select</code> element.</li>
           <li><a href="examples/combobox/combobox-autocomplete-both.html">Editable Combobox with Both List and Inline Autocomplete</a>: An editable combobox that demonstrates the autocomplete behavior known as <q>list with inline autocomplete</q>.</li>
           <li><a href="examples/combobox/combobox-autocomplete-list.html">Editable Combobox with List Autocomplete</a>: An editable combobox that demonstrates the autocomplete behavior known as <q>list with manual selection</q>.</li>
           <li><a href="examples/combobox/combobox-autocomplete-none.html">Editable Combobox Without Autocomplete</a>: An editable combobox that demonstrates the behavior associated with <code>aria-autocomplete=none</code>.</li>

examples/combobox/combobox-autocomplete-both.html

@@ -39,6 +39,7 @@ <h1>Editable Combobox With Both List and Inline Autocomplete Example</h1>
     </p>
     <p>Similar examples include:</p>
     <ul>
+      <li><a href="examples/combobox/combobox-select-only.html">Select-Only Combobox</a>: A single-select combobox with no text input that is functionally similar to an HTML <code>select</code> element.</li>
       <li><a href="combobox-autocomplete-list.html">Editable Combobox with List Autocomplete</a>: An editable combobox that demonstrates the autocomplete behavior known as <q>list with manual selection</q>.</li>
       <li><a href="combobox-autocomplete-none.html">Editable Combobox Without Autocomplete</a>: An editable combobox that demonstrates the behavior associated with <code>aria-autocomplete=none</code>.</li>
       <li><a href="grid-combo.html">Editable Combobox with Grid Popup</a>: An editable combobox that presents suggestions in a grid, enabling users to navigate descriptive information about each suggestion.</li>

examples/combobox/combobox-autocomplete-list.html

@@ -39,6 +39,7 @@ <h1>Editable Combobox With List Autocomplete Example</h1>
     </p>
     <p>Similar examples include:</p>
     <ul>
+      <li><a href="examples/combobox/combobox-select-only.html">Select-Only Combobox</a>: A single-select combobox with no text input that is functionally similar to an HTML <code>select</code> element.</li>
       <li><a href="combobox-autocomplete-both.html">Editable Combobox with Both List and Inline Autocomplete</a>: An editable combobox that demonstrates the autocomplete behavior known as <q>list with inline autocomplete</q>.</li>
       <li><a href="combobox-autocomplete-none.html">Editable Combobox Without Autocomplete</a>: An editable combobox that demonstrates the behavior associated with <code>aria-autocomplete=none</code>.</li>
       <li><a href="grid-combo.html">Editable Combobox with Grid Popup</a>: An editable combobox that presents suggestions in a grid, enabling users to navigate descriptive information about each suggestion.</li>

examples/combobox/combobox-autocomplete-none.html

@@ -36,6 +36,7 @@ <h1>Editable Combobox without Autocomplete Example</h1>
     </p>
     <p>Similar examples include: </p>
     <ul>
+      <li><a href="examples/combobox/combobox-select-only.html">Select-Only Combobox</a>: A single-select combobox with no text input that is functionally similar to an HTML <code>select</code> element.</li>
       <li><a href="combobox-autocomplete-both.html">Editable Combobox with Both List and Inline Autocomplete</a>: An editable combobox that demonstrates the autocomplete behavior known as <q>list with inline autocomplete</q>.</li>
       <li><a href="combobox-autocomplete-list.html">Editable Combobox with List Autocomplete</a>: An editable combobox that demonstrates the autocomplete behavior known as <q>list with manual selection</q>.</li>
       <li><a href="grid-combo.html">Editable Combobox with Grid Popup</a>: An editable combobox that presents suggestions in a grid, enabling users to navigate descriptive information about each suggestion.</li>

examples/combobox/css/select-only.css

@@ -0,0 +1,103 @@
+.combo *,
+.combo *::before,
+.combo *::after {
+  box-sizing: border-box;
+}
+
+.combo {
+  display: block;
+  margin-bottom: 1.5em;
+  max-width: 400px;
+  position: relative;
+}
+
+.combo::after {
+  border-bottom: 2px solid rgba(0, 0, 0, 0.75);
+  border-right: 2px solid rgba(0, 0, 0, 0.75);
+  content: '';
+  display: block;
+  height: 12px;
+  pointer-events: none;
+  position: absolute;
+  right: 16px;
+  top: 50%;
+  transform: translate(0, -65%) rotate(45deg);
+  width: 12px;
+}
+
+.combo-input {
+  background-color: #f5f5f5;
+  border: 2px solid rgba(0, 0, 0, 0.75);
+  border-radius: 4px;
+  display: block;
+  font-size: 1em;
+  min-height: calc(1.4em + 26px);
+  padding: 12px 16px 14px;
+  text-align: left;
+  width: 100%;
+}
+
+.open .combo-input {
+  border-radius: 4px 4px 0 0;
+}
+
+.combo-input:focus {
+  border-color: #0067b8;
+  box-shadow: 0 0 4px 2px #0067b8;
+  outline: 4px solid transparent;
+}
+
+.combo-label {
+  display: block;
+  font-size: 20px;
+  font-weight: 100;
+  margin-bottom: 0.25em;
+}
+
+.combo-menu {
+  background-color: #f5f5f5;
+  border: 1px solid rgba(0, 0, 0, 0.75);
+  border-radius: 0 0 4px 4px;
+  display: none;
+  max-height: 300px;
+  overflow-y:scroll;
+  left: 0;
+  position: absolute;
+  top: 100%;
+  width: 100%;
+  z-index: 100;
+}
+
+.open .combo-menu {
+  display: block;
+}
+
+.combo-option {
+  padding: 10px 12px 12px;
+}
+
+.combo-option:hover {
+  background-color: rgba(0, 0, 0, 0.1);
+}
+
+.combo-option.option-current {
+  outline: 3px solid #0067b8;
+  outline-offset: -3px;
+}
+
+.combo-option[aria-selected="true"] {
+  padding-right: 30px;
+  position: relative;
+}
+
+.combo-option[aria-selected="true"]::after {
+  border-bottom: 2px solid #000;
+  border-right: 2px solid #000;
+  content: '';
+  height: 16px;
+  position: absolute;
+  right: 15px;
+  top: 50%;
+  transform: translate(0, -50%) rotate(45deg);
+  width: 8px;
+}

examples/combobox/grid-combo.html

@@ -44,6 +44,7 @@ <h1>Editable Combobox with Grid Popup Example</h1>
     </p>
     <p>Similar examples include: </p>
     <ul>
+      <li><a href="examples/combobox/combobox-select-only.html">Select-Only Combobox</a>: A single-select combobox with no text input that is functionally similar to an HTML <code>select</code> element.</li>
       <li><a href="combobox-autocomplete-both.html">Editable Combobox with Both List and Inline Autocomplete</a>: An editable combobox that demonstrates the autocomplete behavior known as <q>list with inline autocomplete</q>.</li>
       <li><a href="combobox-autocomplete-list.html">Editable Combobox with List Autocomplete</a>: An editable combobox that demonstrates the autocomplete behavior known as <q>list with manual selection</q>.</li>
       <li><a href="combobox-autocomplete-none.html">Editable Combobox Without Autocomplete</a>: An editable combobox that demonstrates the behavior associated with <code>aria-autocomplete=none</code>.</li>