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+<!--
+@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">
+
+<!--
+`iron-a11y-announcer` is a singleton element that is intended to add a11y
+to features that require on-demand announcement from screen readers. In
+order to make use of the announcer, it is best to request its availability
+in the announcing element.
+
+Example:
+
+    Polymer({
+
+      is: 'x-chatty',
+
+      attached: function() {
+        // This will create the singleton element if it has not
+        // been created yet:
+        Polymer.IronA11yAnnouncer.requestAvailability();
+      }
+    });
+
+After the `iron-a11y-announcer` has been made available, elements can
+make announces by firing bubbling `iron-announce` events.
+
+Example:
+
+    this.fire('iron-announce', {
+      text: 'This is an announcement!'
+    }, { bubbles: true });
+
+Note: announcements are only audible if you have a screen reader enabled.
+
+@group Iron Elements
+@demo demo/index.html
+-->
+
+<dom-module id="iron-a11y-announcer">
+  <template>
+    <style>
+      :host {
+        display: inline-block;
+        position: fixed;
+        clip: rect(0px,0px,0px,0px);
+      }
+    </style>
+    <div aria-live$="[[mode]]">[[_text]]</div>
+  </template>
+</dom-module>
+<script>
+'use strict';
+(function() {
+  'use strict';
+  Polymer.IronA11yAnnouncer = Polymer({
+    is: 'iron-a11y-announcer',
+
+    properties: {
+
+      /**
+        * The value of mode is used to set the `aria-live` attribute
+        * for the element that will be announced. Valid values are: `off`,
+        * `polite` and `assertive`.
+        */
+      mode: {
+        type: String,
+        value: 'polite'
+      },
+
+      _text: {
+        type: String,
+        value: ''
+      }
+    },
+
+    created: function() {
+      if (!Polymer.IronA11yAnnouncer.instance) {
+        Polymer.IronA11yAnnouncer.instance = this;
+      }
+
+      document.body.addEventListener('iron-announce', this._onIronAnnounce.bind(this));
+    },
+
+    /**
+      * Cause a text string to be announced by screen readers.
+      *
+      * @param {string} text The text that should be announced.
+      */
+    announce: function(text) {
+      this._text = '';
+      this.async(function() {
+        this._text = text;
+      }, 100);
+    },
+
+    _onIronAnnounce: function(event) {
+      if (event.detail && event.detail.text) {
+        this.announce(event.detail.text);
+      }
+    }
+  });
+
+  Polymer.IronA11yAnnouncer.instance = null;
+
+  Polymer.IronA11yAnnouncer.requestAvailability = function() {
+    if (!Polymer.IronA11yAnnouncer.instance) {
+      Polymer.IronA11yAnnouncer.instance = document.createElement('iron-a11y-announcer');
+    }
+
+    document.body.appendChild(Polymer.IronA11yAnnouncer.instance);
+  };
+})();
+
+</script>