Dropdown lists or selects present a list of options but the only way to show list items is to click on the disclosure icon.
This feature would provide a programmatic way to open the list.
Example:
<select id="myList">
<options>
<option>1</option>
<option>2</option>
<option>3</option>
</option>
</select>
function showListItems() {
document.getElementById("myList").open();
}
Use Case
Percival is writing an icons plugin. He has grid of icons and each has a list of sizes that can be inserted. When the user clicks on the icon they like he wants to show the options in his dropdown list. He’s set an dropdown list 1px wide in the upper corner of the icon group. When the user clicks on the icon he opens and shows the dropdown list items.