@polymer/paper-listbox
Version:
Implements an accessible material design listbox
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Markdown
[](https://www.npmjs.com/package/@polymer/paper-listbox)
[](https://travis-ci.org/PolymerElements/paper-listbox)
[](https://webcomponents.org/element/@polymer/paper-listbox)
## <paper-listbox>
`<paper-listbox>` implements an accessible listbox control with Material Design styling. The focused item
is highlighted, and the selected item has bolded text.
```html
<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.
```html
<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.
```html
<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.
See: [Documentation](https://www.webcomponents.org/element/@polymer/paper-listbox),
[Demo](https://www.webcomponents.org/element/@polymer/paper-listbox/demo/demo/index.html).
## Usage
### Installation
```
npm install --save @polymer/paper-listbox
```
### In an html file
```html
<html>
<head>
<script type="module">
import '@polymer/paper-listbox/paper-listbox.js';
</script>
</head>
<body>
<paper-listbox>
<div role="option">item 1</div>
<div role="option">item 2</div>
<div role="option">item 3</div>
</paper-listbox>
</body>
</html>
```
### In a Polymer 3 element
```js
import {PolymerElement, html} from '@polymer/polymer';
import '@polymer/paper-listbox/paper-listbox.js';
class SampleElement extends PolymerElement {
static get template() {
return html`
<paper-listbox>
<div role="option">item 1</div>
<div role="option">item 2</div>
<div role="option">item 3</div>
</paper-listbox>
`;
}
}
customElements.define('sample-element', SampleElement);
```
## Contributing
If you want to send a PR to this element, here are
the instructions for running the tests and demo locally:
### Installation
```sh
git clone https://github.com/PolymerElements/paper-listbox
cd paper-listbox
npm install
npm install -g polymer-cli
```
### Running the demo locally
```sh
polymer serve --npm
open http://127.0.0.1:<port>/demo/
```
### Running the tests
```sh
polymer test --npm
```