systrace/catapult/third_party/polymer/components/paper-listbox/paper-listbox.html

<!--
@license
Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-->

<link rel="import" href="../polymer/polymer.html">
<link rel="import" href="../iron-menu-behavior/iron-menu-behavior.html">
<link rel="import" href="../paper-styles/default-theme.html">

<!--
Material design: [Menus](https://www.google.com/design/spec/components/menus.html)

`<paper-listbox>` implements an accessible listbox control with Material Design styling. The focused item
is highlighted, and the selected item has bolded text.

    <paper-listbox>
      <paper-item>Item 1</paper-item>
      <paper-item>Item 2</paper-item>
    </paper-listbox>

An initial selection can be specified with the `selected` attribute.

    <paper-listbox selected="0">
      <paper-item>Item 1</paper-item>
      <paper-item>Item 2</paper-item>
    </paper-listbox>

Make a multi-select listbox with the `multi` attribute. Items in a multi-select listbox can be deselected,
and multiple item can be selected.

    <paper-listbox multi>
      <paper-item>Item 1</paper-item>
      <paper-item>Item 2</paper-item>
    </paper-listbox>

### Styling

The following custom properties and mixins are available for styling:

Custom property | Description | Default
----------------|-------------|----------
`--paper-listbox-background-color`   | Menu background color                                            | `--primary-background-color`
`--paper-listbox-color`              | Menu foreground color                                            | `--primary-text-color`
`--paper-listbox`                    | Mixin applied to the listbox                                        | `{}`

### Accessibility

`<paper-listbox>` has `role="listbox"` by default. A multi-select listbox will also have
`aria-multiselectable` set. It implements key bindings to navigate through the listbox with the up and
down arrow keys, esc to exit the listbox, and enter to activate a listbox item. Typing the first letter
of a listbox item will also focus it.

@group Paper Elements
@element paper-listbox
@hero hero.svg
@demo demo/index.html
-->

<dom-module id="paper-listbox">
  <template>
    <style>
      :host {
        display: block;
        padding: 8px 0;

        background: var(--paper-listbox-background-color, --primary-background-color);
        color: var(--paper-listbox-color, --primary-text-color);

        @apply(--paper-listbox);
      }
    </style>

    <content></content>
  </template>

  <script>
    (function() {
      Polymer({
        is: 'paper-listbox',

        behaviors: [
          Polymer.IronMenuBehavior
        ],

        hostAttributes: {
          role: 'listbox'
        }
      });
    })();
  </script>
</dom-module>