paper-spinner.js

/**
@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
*/
import '@polymer/polymer/polymer-legacy.js';
import '@polymer/paper-styles/color.js';
import './paper-spinner-styles.js';

import {Polymer} from '@polymer/polymer/lib/legacy/polymer-fn.js';
import {html} from '@polymer/polymer/lib/utils/html-tag.js';

import {PaperSpinnerBehavior} from './paper-spinner-behavior.js';

/**
Material design: [Progress &
activity](https://www.google.com/design/spec/components/progress-activity.html)

Element providing a multiple color material design circular spinner.

    <paper-spinner active></paper-spinner>

The default spinner cycles between four layers of colors; by default they are
blue, red, yellow and green. It can be customized to cycle between four
different colors. Use <paper-spinner-lite> for single color spinners.

### Accessibility

Alt attribute should be set to provide adequate context for accessibility. If
not provided, it defaults to 'loading'. Empty alt can be provided to mark the
element as decorative if alternative content is provided in another form (e.g. a
text block following the spinner).

    <paper-spinner alt="Loading contacts list" active></paper-spinner>

### Styling

The following custom properties and mixins are available for styling:

Custom property | Description | Default
----------------|-------------|----------
`--paper-spinner-layer-1-color` | Color of the first spinner rotation | `--google-blue-500`
`--paper-spinner-layer-2-color` | Color of the second spinner rotation | `--google-red-500`
`--paper-spinner-layer-3-color` | Color of the third spinner rotation | `--google-yellow-500`
`--paper-spinner-layer-4-color` | Color of the fourth spinner rotation | `--google-green-500`
`--paper-spinner-stroke-width` | The width of the spinner stroke | 3px

@element paper-spinner
@demo demo/index.html
*/
Polymer({
  /** @override */
  _template: html`
    <style include="paper-spinner-styles"></style>

    <div id="spinnerContainer" class-name="[[__computeContainerClasses(active, __coolingDown)]]" on-animationend="__reset" on-webkit-animation-end="__reset">
      <div class="spinner-layer layer-1">
        <div class="circle-clipper left">
          <div class="circle"></div>
        </div>
        <div class="circle-clipper right">
          <div class="circle"></div>
        </div>
      </div>

      <div class="spinner-layer layer-2">
        <div class="circle-clipper left">
          <div class="circle"></div>
        </div>
        <div class="circle-clipper right">
          <div class="circle"></div>
        </div>
      </div>

      <div class="spinner-layer layer-3">
        <div class="circle-clipper left">
          <div class="circle"></div>
        </div>
        <div class="circle-clipper right">
          <div class="circle"></div>
        </div>
      </div>

      <div class="spinner-layer layer-4">
        <div class="circle-clipper left">
          <div class="circle"></div>
        </div>
        <div class="circle-clipper right">
          <div class="circle"></div>
        </div>
      </div>
    </div>
  `,

  is: 'paper-spinner',

  behaviors: [PaperSpinnerBehavior],

  /** @override */
  registered() {
    this._template.setAttribute('strip-whitespace', '');
  }
});