isabella232 / iron-a11y-keys-behavior

A behavior that enables keybindings for greater a11y

<iron-a11y-keys-behavior>

Polymer.IronA11yKeysBehavior provides a normalized interface for processing keyboard commands that pertain to WAI-ARIA best practices. The element takes care of browser differences with respect to Keyboard events and uses an expressive syntax to filter key presses.

See: Documentation, Demo.

Usage

Installation

npm install --save @polymer/iron-a11y-keys-behavior

In a Polymer 3 element

import {PolymerElement, html} from '@polymer/polymer';
import {mixinBehaviors} from '@polymer/polymer/lib/legacy/class.js';
import {IronA11yKeysBehavior} from '@polymer/iron-a11y-keys-behavior/iron-a11y-keys-behavior.js';

class SampleElement extends  extends mixinBehaviors([IronA11yKeysBehavior], PolymerElement) {
  static get template() {
    return html`
      <pre>[[pressed]]</pre>
    `;
  }

  static get properties() {
    return {
      pressed: {type: String, readOnly: true, value: ''},
      keyBindings: {
        'space': '_onKeydown', // same as 'space:keydown'
        'shift+tab': '_onKeydown',
        'enter:keypress': '_onKeypress',
        'esc:keyup': '_onKeyup'
      }
    }
  }

  function _onKeydown: function(event) {
    console.log(event.detail.combo); // KEY+MODIFIER, e.g. "shift+tab"
    console.log(event.detail.key); // KEY only, e.g. "tab"
    console.log(event.detail.event); // EVENT, e.g. "keydown"
    console.log(event.detail.keyboardEvent); // the original KeyboardEvent
  }
}
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

git clone https://github.com/PolymerElements/iron-a11y-keys-behavior
cd iron-a11y-keys-behavior
npm install
npm install -g polymer-cli

Running the demo locally

polymer serve --npm
open http://127.0.0.1:<port>/demo/

Running the tests

polymer test --npm