W3C home > Mailing lists > Public > public-dap-commits@w3.org > February 2013

dap commit: add Overview.html

From: Mercurial notifier <cvsmail@w3.org>
Date: Fri, 01 Feb 2013 08:43:44 +0000
Message-Id: <E1U1CDo-00025c-Lm@mcbain.w3.org>
To: public-dap-commits@w3.org
changeset:   370:ffdaef94ac31
tag:         tip
user:        Anssi Kostiainen <anssi.kostiainen@nokia.com>
date:        Fri Feb 01 10:43:20 2013 +0200
files:       battery/Overview.html
description:
add Overview.html


diff -r 662d11531e98 -r ffdaef94ac31 battery/Overview.html
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/battery/Overview.html	Fri Feb 01 10:43:20 2013 +0200
@@ -0,0 +1,911 @@
+<!DOCTYPE html>
+<html lang="en" dir="ltr"><head>
+    <title>Battery Status API</title>
+    <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
+    
+    
+  <style>/*****************************************************************
+ * ReSpec 3 CSS
+ * Robin Berjon - http://berjon.com/
+ *****************************************************************/
+
+/* --- INLINES --- */
+em.rfc2119 { 
+    text-transform:     lowercase;
+    font-variant:       small-caps;
+    font-style:         normal;
+    color:              #900;
+}
+
+h1 acronym, h2 acronym, h3 acronym, h4 acronym, h5 acronym, h6 acronym, a acronym,
+h1 abbr, h2 abbr, h3 abbr, h4 abbr, h5 abbr, h6 abbr, a abbr {
+    border: none;
+}
+
+dfn {
+    font-weight:    bold;
+}
+
+a.internalDFN {
+    color:  inherit;
+    border-bottom:  1px solid #99c;
+    text-decoration:    none;
+}
+
+a.externalDFN {
+    color:  inherit;
+    border-bottom:  1px dotted #ccc;
+    text-decoration:    none;
+}
+
+a.bibref {
+    text-decoration:    none;
+}
+
+cite .bibref {
+    font-style: normal;
+}
+
+code {
+    color:  #ff4500;
+}
+
+
+/* --- --- */
+ol.algorithm { counter-reset:numsection; list-style-type: none; }
+ol.algorithm li { margin: 0.5em 0; }
+ol.algorithm li:before { font-weight: bold; counter-increment: numsection; content: counters(numsection, ".") ") "; }
+
+/* --- TOC --- */
+.toc a, .tof a {
+    text-decoration:    none;
+}
+
+a .secno, a .figno {
+    color:  #000;
+}
+
+ul.tof, ol.tof {
+    list-style: none outside none;
+}
+
+.caption {
+    margin-top: 0.5em;
+    font-style:   italic;
+}
+
+/* --- TABLE --- */
+table.simple {
+    border-spacing: 0;
+    border-collapse:    collapse;
+    border-bottom:  3px solid #005a9c;
+}
+
+.simple th {
+    background: #005a9c;
+    color:  #fff;
+    padding:    3px 5px;
+    text-align: left;
+}
+
+.simple th[scope="row"] {
+    background: inherit;
+    color:  inherit;
+    border-top: 1px solid #ddd;
+}
+
+.simple td {
+    padding:    3px 10px;
+    border-top: 1px solid #ddd;
+}
+
+.simple tr:nth-child(even) {
+    background: #f0f6ff;
+}
+
+/* --- DL --- */
+.section dd > p:first-child {
+    margin-top: 0;
+}
+
+.section dd > p:last-child {
+    margin-bottom: 0;
+}
+
+.section dd {
+    margin-bottom:  1em;
+}
+
+.section dl.attrs dd, .section dl.eldef dd {
+    margin-bottom:  0;
+}
+</style><style>/* --- EXAMPLES --- */
+div.example-title {
+    min-width: 7.5em;
+    color: #b9ab2d;
+}
+div.example-title span {
+    text-transform: uppercase;   
+}
+aside.example, div.example, div.illegal-example {
+    padding: 0.5em;
+    margin: 1em 0;
+    position: relative;
+    clear: both;
+}
+div.illegal-example { color: red }
+div.illegal-example p { color: black }
+aside.example, div.example {
+    padding: .5em;
+    border-left-width: .5em;
+    border-left-style: solid;
+    border-color: #e0cb52;
+    background: #fcfaee;    
+}
+
+aside.example div.example {
+    border-left-width: .1em;
+    border-color: #999;
+    background: #fff;
+}
+aside.example div.example div.example-title {
+    color: #999;
+}
+</style><style>/* --- ISSUES/NOTES --- */
+div.issue-title, div.note-title {
+    padding-right:  1em;
+    min-width: 7.5em;
+    color: #b9ab2d;
+}
+div.issue-title { color: #e05252; }
+div.note-title { color: #52e052; }
+div.issue-title span, div.note-title span {
+    text-transform: uppercase;
+}
+div.note, div.issue {
+    margin-top: 1em;
+    margin-bottom: 1em;
+}
+.note > p:first-child, .issue > p:first-child { margin-top: 0 }
+.issue, .note {
+    padding: .5em;
+    border-left-width: .5em;
+    border-left-style: solid;
+}
+div.issue, div.note {
+    padding: 0.5em;
+    margin: 1em 0;
+    position: relative;
+    clear: both;
+}
+span.note, span.issue { padding: .1em .5em .15em; }
+
+.issue {
+    border-color: #e05252;
+    background: #fbe9e9;
+}
+.note {
+    border-color: #52e052;
+    background: #e9fbe9;
+}
+
+
+</style><style>/* HIGHLIGHTS */
+code.prettyprint {
+    color:  inherit;
+}
+
+/* this from google-code-prettify */
+.pln{color:#000}@media screen{.str{color:#080}.kwd{color:#008}.com{color:#800}.typ{color:#606}.lit{color:#066}.pun,.opn,.clo{color:#660}.tag{color:#008}.atn{color:#606}.atv{color:#080}.dec,.var{color:#606}.fun{color:red}}@media print,projection{.str{color:#060}.kwd{color:#006;font-weight:bold}.com{color:#600;font-style:italic}.typ{color:#404;font-weight:bold}.lit{color:#044}.pun,.opn,.clo{color:#440}.tag{color:#006;font-weight:bold}.atn{color:#404}.atv{color:#060}}ol.linenums{margin-top:0;margin-bottom:0}li.L0,li.L1,li.L2,li.L3,li.L5,li.L6,li.L7,li.L8{list-style-type:none}li.L1,li.L3,li.L5,li.L7,li.L9{background:#eee}
+</style><style>/* --- WEB IDL --- */
+pre.idl {
+    border-top: 1px solid #90b8de;
+    border-bottom: 1px solid #90b8de;
+    padding:    1em;
+    line-height:    120%;
+}
+
+pre.idl::before {
+    content:    "WebIDL";
+    display:    block;
+    width:      150px;
+    background: #90b8de;
+    color:  #fff;
+    font-family:    initial;
+    padding:    3px;
+    font-weight:    bold;
+    margin: -1em 0 1em -1em;
+}
+
+.idlType {
+    color:  #ff4500;
+    font-weight:    bold;
+    text-decoration:    none;
+}
+
+/*.idlModule*/
+/*.idlModuleID*/
+/*.idlInterface*/
+.idlInterfaceID, .idlDictionaryID, .idlCallbackID, .idlEnumID {
+    font-weight:    bold;
+    color:  #005a9c;
+}
+
+.idlSuperclass {
+    font-style: italic;
+    color:  #005a9c;
+}
+
+/*.idlAttribute*/
+.idlAttrType, .idlFieldType, .idlMemberType {
+    color:  #005a9c;
+}
+.idlAttrName, .idlFieldName, .idlMemberName {
+    color:  #ff4500;
+}
+.idlAttrName a, .idlFieldName a, .idlMemberName a {
+    color:  #ff4500;
+    border-bottom:  1px dotted #ff4500;
+    text-decoration: none;
+}
+
+/*.idlMethod*/
+.idlMethType, .idlCallbackType {
+    color:  #005a9c;
+}
+.idlMethName {
+    color:  #ff4500;
+}
+.idlMethName a {
+    color:  #ff4500;
+    border-bottom:  1px dotted #ff4500;
+    text-decoration: none;
+}
+
+/*.idlParam*/
+.idlParamType {
+    color:  #005a9c;
+}
+.idlParamName, .idlDefaultValue {
+    font-style: italic;
+}
+
+.extAttr {
+    color:  #666;
+}
+
+/*.idlConst*/
+.idlConstType {
+    color:  #005a9c;
+}
+.idlConstName {
+    color:  #ff4500;
+}
+.idlConstName a {
+    color:  #ff4500;
+    border-bottom:  1px dotted #ff4500;
+    text-decoration: none;
+}
+
+/*.idlException*/
+.idlExceptionID {
+    font-weight:    bold;
+    color:  #c00;
+}
+
+.idlTypedefID, .idlTypedefType {
+    color:  #005a9c;
+}
+
+.idlRaises, .idlRaises a.idlType, .idlRaises a.idlType code, .excName a, .excName a code {
+    color:  #c00;
+    font-weight:    normal;
+}
+
+.excName a {
+    font-family:    monospace;
+}
+
+.idlRaises a.idlType, .excName a.idlType {
+    border-bottom:  1px dotted #c00;
+}
+
+.excGetSetTrue, .excGetSetFalse, .prmNullTrue, .prmNullFalse, .prmOptTrue, .prmOptFalse {
+    width:  45px;
+    text-align: center;
+}
+.excGetSetTrue, .prmNullTrue, .prmOptTrue { color:  #0c0; }
+.excGetSetFalse, .prmNullFalse, .prmOptFalse { color:  #c00; }
+
+.idlImplements a {
+    font-weight:    bold;
+}
+
+dl.attributes, dl.methods, dl.constants, dl.fields, dl.dictionary-members {
+    margin-left:    2em;
+}
+
+.attributes dt, .methods dt, .constants dt, .fields dt, .dictionary-members dt {
+    font-weight:    normal;
+}
+
+.attributes dt code, .methods dt code, .constants dt code, .fields dt code, .dictionary-members dt code {
+    font-weight:    bold;
+    color:  #000;
+    font-family:    monospace;
+}
+
+.attributes dt code, .fields dt code, .dictionary-members dt code {
+    background:  #ffffd2;
+}
+
+.attributes dt .idlAttrType code, .fields dt .idlFieldType code, .dictionary-members dt .idlMemberType code {
+    color:  #005a9c;
+    background:  transparent;
+    font-family:    inherit;
+    font-weight:    normal;
+    font-style: italic;
+}
+
+.methods dt code {
+    background:  #d9e6f8;
+}
+
+.constants dt code {
+    background:  #ddffd2;
+}
+
+.attributes dd, .methods dd, .constants dd, .fields dd, .dictionary-members dd {
+    margin-bottom:  1em;
+}
+
+table.parameters, table.exceptions {
+    border-spacing: 0;
+    border-collapse:    collapse;
+    margin: 0.5em 0;
+    width:  100%;
+}
+table.parameters { border-bottom:  1px solid #90b8de; }
+table.exceptions { border-bottom:  1px solid #deb890; }
+
+.parameters th, .exceptions th {
+    color:  #fff;
+    padding:    3px 5px;
+    text-align: left;
+    font-family:    initial;
+    font-weight:    normal;
+    text-shadow:    #666 1px 1px 0;
+}
+.parameters th { background: #90b8de; }
+.exceptions th { background: #deb890; }
+
+.parameters td, .exceptions td {
+    padding:    3px 10px;
+    border-top: 1px solid #ddd;
+    vertical-align: top;
+}
+
+.parameters tr:first-child td, .exceptions tr:first-child td {
+    border-top: none;
+}
+
+.parameters td.prmName, .exceptions td.excName, .exceptions td.excCodeName {
+    width:  100px;
+}
+
+.parameters td.prmType {
+    width:  120px;
+}
+
+table.exceptions table {
+    border-spacing: 0;
+    border-collapse:    collapse;
+    width:  100%;
+}
+</style><link rel="stylesheet" href="https://www.w3.org/StyleSheets/TR/W3C-ED"></head>
+  <body><div class="head">
+  <p>
+    
+      <a href="http://www.w3.org/"><img width="72" height="48" src="https://www.w3.org/Icons/w3c_home" alt="W3C"></a>
+    
+  </p>
+  <h1 class="title" id="title">Battery Status API</h1>
+  
+  <h2 id="w3c-editor-s-draft-01-february-2013"><abbr title="World Wide Web Consortium">W3C</abbr> Editor's Draft 01 February 2013</h2>
+  <dl>
+    
+      <dt>This version:</dt>
+      <dd><a href="http://dvcs.w3.org/hg/dap/raw-file/default/battery/Overview.html">http://dvcs.w3.org/hg/dap/raw-file/default/battery/Overview.html</a></dd>
+      <dt>Latest published version:</dt>
+      <dd><a href="http://www.w3.org/TR/battery-status/">http://www.w3.org/TR/battery-status/</a></dd>
+    
+    
+      <dt>Latest editor's draft:</dt>
+      <dd><a href="http://dvcs.w3.org/hg/dap/raw-file/default/battery/Overview.html">http://dvcs.w3.org/hg/dap/raw-file/default/battery/Overview.html</a></dd>
+    
+    
+      <dt>Test suite:</dt>
+      <dd><a href="http://w3c-test.org/dap/battery/tests/">http://w3c-test.org/dap/battery/tests/</a></dd>
+    
+    
+    
+      
+    
+    
+    
+    <dt>Editors:</dt>
+    <dd><span>Anssi Kostiainen</span>, <a href="http://nokia.com/">Nokia</a></dd>
+<dd><span>Mounir Lamouri</span>, <a href="http://mozilla.org/">Mozilla</a></dd>
+
+    
+  </dl>
+  
+  
+  
+  
+    
+      <p class="copyright">
+        <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 
+        2013
+        
+        <a href="http://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> 
+        (<a href="http://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>,
+        <a href="http://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>,
+        <a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved.
+        <abbr title="World Wide Web Consortium">W3C</abbr> <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
+        <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and
+        <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.
+      </p>
+    
+  
+  <hr>
+</div>
+    <section id="abstract" class="introductory"><h2>Abstract</h2><p>
+      This specification defines an API that provides information about the
+      battery status of the hosting device.
+    </p></section><section id="sotd" class="introductory"><h2>Status of This Document</h2>
+  
+    
+      
+        <p>
+          <em>This section describes the status of this document at the time of its publication. Other
+          documents may supersede this document. A list of current <abbr title="World Wide Web Consortium">W3C</abbr> publications and the latest revision
+          of this technical report can be found in the <a href="http://www.w3.org/TR/"><abbr title="World Wide Web Consortium">W3C</abbr> technical reports
+          index</a> at http://www.w3.org/TR/.</em>
+        </p>
+        
+      <p>
+        The functionality described in this specification was initially
+        specified as part of the
+        <a href="http://www.w3.org/TR/system-info-api/">System Information
+        API</a> but has been extracted in order to be more readily available,
+        more straightforward to implement, and in order to produce a
+        specification that could be implemented on its own merits without
+        interference with other, often unrelated, features.
+      </p>
+    
+        <p>
+          This document was published by the <a href="http://www.w3.org/2009/dap/">Device APIs Working Group</a> as an Editor's Draft.
+          
+          
+          If you wish to make comments regarding this document, please send them to 
+          <a href="mailto:public-device-apis@w3.org">public-device-apis@w3.org</a> 
+          (<a href="mailto:public-device-apis-request@w3.org?subject=subscribe">subscribe</a>,
+          <a href="http://lists.w3.org/Archives/Public/public-device-apis/">archives</a>).
+          
+          
+          
+          
+        All comments are welcome.
+        
+        
+          </p><p>
+            Publication as an Editor's Draft does not imply endorsement by the <abbr title="World Wide Web Consortium">W3C</abbr> Membership.
+            This is a draft document and may be updated, replaced or obsoleted by other documents at 
+            any time. It is inappropriate to cite this document as other than work in progress.
+          </p>
+        
+        
+        <p>
+          
+            This document was produced by a group operating under the 
+            <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February 2004 <abbr title="World Wide Web Consortium">W3C</abbr> Patent Policy</a>.
+          
+          
+          
+            
+              <abbr title="World Wide Web Consortium">W3C</abbr> maintains a <a href="http://www.w3.org/2004/01/pp-impl/43696/status" rel="disclosure">public list of any patent disclosures</a> 
+            
+            made in connection with the deliverables of the group; that page also includes instructions for 
+            disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains
+            <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential Claim(s)</a> must disclose the
+            information in accordance with <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
+            6 of the <abbr title="World Wide Web Consortium">W3C</abbr> Patent Policy</a>.
+          
+          
+        </p>
+        
+      
+    
+  
+</section><section id="toc"><h2 class="introductory">Table of Contents</h2><ul class="toc"><li class="tocline"><a href="#introduction" class="tocxref"><span class="secno">1. </span>Introduction</a></li><li class="tocline"><a href="#conformance" class="tocxref"><span class="secno">2. </span>Conformance</a></li><li class="tocline"><a href="#terminology" class="tocxref"><span class="secno">3. </span>Terminology</a></li><li class="tocline"><a href="#security-and-privacy-considerations" class="tocxref"><span class="secno">4. </span>Security and privacy considerations</a></li><li class="tocline"><a href="#navigatorbattery-interface" class="tocxref"><span class="secno">5. </span><span class="formerLink"><code>NavigatorBattery</code></span> Interface</a><ul class="toc"><li class="tocline"><a href="#attributes" class="tocxref"><span class="secno">5.1 </span>Attributes</a></li></ul></li><li class="tocline"><a href="#batterymanager-interface" class="tocxref"><span class="secno">6. </span><span class="formerLink"><code>BatteryManager</code></span> Interface</a><ul class="toc"><li class="tocline"><a href="#attributes-1" class="tocxref"><span class="secno">6.1 </span>Attributes</a></li><li class="tocline"><a href="#event-handlers" class="tocxref"><span class="secno">6.2 </span>Event handlers</a></li></ul></li><li class="tocline"><a href="#examples" class="tocxref"><span class="secno">7. </span>Examples</a></li><li class="tocline"><a href="#acknowledgements" class="tocxref"><span class="secno">A. </span>Acknowledgements</a></li><li class="tocline"><a href="#references" class="tocxref"><span class="secno">B. </span>References</a><ul class="toc"><li class="tocline"><a href="#normative-references" class="tocxref"><span class="secno">B.1 </span>Normative references</a></li></ul></li></ul></section>
+    
+    
+    
+    <section class="informative" id="introduction">
+      <!--OddPage--><h2><span class="secno">1. </span>Introduction</h2><p><em>This section is non-normative.</em></p>
+      <p>
+        The Battery Status API specification defines a means for web
+        developers to programmatically determine the battery status of the
+        hosting device. Without knowing the battery status of a device, a web
+        developer must design the web application with an assumption of
+        sufficient battery level for the task at hand. This means the battery
+        of a device may exhaust faster than desired because web developers are
+        unable to make decisions based on the battery status. Given knowledge
+        of the battery status, web developers are able to craft web content and
+        applications which are power-efficient, thereby leading to improved
+        user experience.
+     </p>
+     <p>
+        The Battery Status API can be used to defer or scale back work when
+        the device is not charging in or is low on battery. An archetype of an
+        advanced web application, a web-based email client, may check the
+        server for new email every few seconds if the device is charging,
+        but do so less frequently if the device is not charging or is low on
+        battery. Another example is a web-based word processor which could
+        monitor the battery level and save changes before the battery runs
+        out to prevent data loss.
+      </p>
+      <p>
+        The following example shows how a web-based email client could check
+        for new emails every ten seconds without knowledge of the battery
+        status:
+      </p>
+      <div class="example"><div class="example-title"><span>Example 1</span></div><pre class="example highlight prettyprint"><span class="dec">&lt;!DOCTYPE html&gt;</span><span class="pln">
+</span><span class="tag">&lt;html&gt;</span><span class="pln">
+</span><span class="tag">&lt;head&gt;</span><span class="pln">
+  </span><span class="tag">&lt;title&gt;</span><span class="pln">Email Client</span><span class="tag">&lt;/title&gt;</span><span class="pln">
+  </span><span class="tag">&lt;script&gt;</span><span class="pln">
+    </span><span class="kwd">var</span><span class="pln"> mail </span><span class="pun">=</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      INTERVAL_DEFAULT</span><span class="pun">:</span><span class="pln"> </span><span class="lit">1000</span><span class="pln"> </span><span class="pun">*</span><span class="pln"> </span><span class="lit">10</span><span class="pun">,</span><span class="pln">
+      interval</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">,</span><span class="pln">
+      timer</span><span class="pun">:</span><span class="pln"> </span><span class="lit">0</span><span class="pun">,</span><span class="pln">
+
+      check</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+        console</span><span class="pun">.</span><span class="pln">log</span><span class="pun">(</span><span class="str">'Checking the server for new emails using an interval of '</span><span class="pln"> </span><span class="pun">+</span><span class="pln"> 
+                    </span><span class="pun">(</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">interval </span><span class="pun">/</span><span class="pln"> </span><span class="lit">1000</span><span class="pun">)</span><span class="pln"> </span><span class="pun">+</span><span class="pln"> </span><span class="str">' seconds.'</span><span class="pun">);</span><span class="pln">
+      </span><span class="pun">},</span><span class="pln">
+      
+      setTimer</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">(</span><span class="pln">interval</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+        </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">interval </span><span class="pun">===</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">interval</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="kwd">return</span><span class="pun">;</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
+        </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">timer </span><span class="pun">!==</span><span class="pln"> </span><span class="lit">0</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> clearTimeout</span><span class="pun">(</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">timer</span><span class="pun">);</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
+        </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">interval</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">timer </span><span class="pun">=</span><span class="pln"> setInterval</span><span class="pun">(</span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">check</span><span class="pun">();</span><span class="pln"> </span><span class="pun">},</span><span class="pln"> interval</span><span class="pun">);</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
+        mail</span><span class="pun">.</span><span class="pln">interval </span><span class="pun">=</span><span class="pln"> interval</span><span class="pun">;</span><span class="pln">
+      </span><span class="pun">}</span><span class="pln">
+    </span><span class="pun">};</span><span class="pln">
+
+    window</span><span class="pun">.</span><span class="pln">addEventListener</span><span class="pun">(</span><span class="str">'load'</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      mail</span><span class="pun">.</span><span class="pln">setTimer</span><span class="pun">(!</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">interval </span><span class="pun">?</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">INTERVAL_DEFAULT </span><span class="pun">:</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">interval</span><span class="pun">);</span><span class="pln">
+    </span><span class="pun">},</span><span class="pln"> </span><span class="kwd">false</span><span class="pun">);</span><span class="pln">
+  </span><span class="tag">&lt;/script&gt;</span><span class="pln">
+</span><span class="tag">&lt;/head&gt;</span><span class="pln">
+</span><span class="tag">&lt;body&gt;&lt;/body&gt;</span><span class="pln">
+</span><span class="tag">&lt;/html&gt;</span></pre></div>
+      <p>
+        The script will always check for emails every ten seconds, even if the
+        battery level is critically low and the device is not charging.
+        This is an example of poor resource management.
+      </p>
+      <p>
+        Using the <a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a> interface, the web application is, for
+        example, able to throttle checking for emails if the device is low on
+        battery, stop checking for emails if the battery is critically low and
+        resume normal operation when the battery is charging:
+      </p>
+      <div class="example"><div class="example-title"><span>Example 2</span></div><pre class="example highlight prettyprint"><span class="dec">&lt;!DOCTYPE html&gt;</span><span class="pln">
+</span><span class="tag">&lt;html&gt;</span><span class="pln">
+</span><span class="tag">&lt;head&gt;</span><span class="pln">
+  </span><span class="tag">&lt;title&gt;</span><span class="pln">Battery-aware Email Client</span><span class="tag">&lt;/title&gt;</span><span class="pln">
+  </span><span class="tag">&lt;script&gt;</span><span class="pln">
+    </span><span class="kwd">var</span><span class="pln"> mail </span><span class="pun">=</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      INTERVAL_BATTERY_LOW</span><span class="pun">:</span><span class="pln"> </span><span class="lit">1000</span><span class="pln"> </span><span class="pun">*</span><span class="pln"> </span><span class="lit">60</span><span class="pln"> </span><span class="pun">*</span><span class="pln"> </span><span class="lit">10</span><span class="pun">,</span><span class="pln">
+      INTERVAL_DEFAULT</span><span class="pun">:</span><span class="pln"> </span><span class="lit">1000</span><span class="pln"> </span><span class="pun">*</span><span class="pln"> </span><span class="lit">10</span><span class="pun">,</span><span class="pln">
+      interval</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">,</span><span class="pln">
+      timer</span><span class="pun">:</span><span class="pln"> </span><span class="lit">0</span><span class="pun">,</span><span class="pln">
+      
+      check</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+        console</span><span class="pun">.</span><span class="pln">log</span><span class="pun">(</span><span class="str">'Checking the server for new emails using an interval of '</span><span class="pln"> </span><span class="pun">+</span><span class="pln"> 
+                    </span><span class="pun">(</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">interval </span><span class="pun">/</span><span class="pln"> </span><span class="lit">1000</span><span class="pun">)</span><span class="pln"> </span><span class="pun">+</span><span class="pln"> </span><span class="str">' seconds.'</span><span class="pun">);</span><span class="pln">
+      </span><span class="pun">},</span><span class="pln">
+      
+      setTimer</span><span class="pun">:</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">(</span><span class="pln">interval</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+        </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">interval </span><span class="pun">===</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">interval</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="kwd">return</span><span class="pun">;</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
+        </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">timer </span><span class="pun">!==</span><span class="pln"> </span><span class="lit">0</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> clearTimeout</span><span class="pun">(</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">timer</span><span class="pun">);</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
+        </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">interval</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">timer </span><span class="pun">=</span><span class="pln"> setInterval</span><span class="pun">(</span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">check</span><span class="pun">();</span><span class="pln"> </span><span class="pun">},</span><span class="pln"> interval</span><span class="pun">);</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
+        mail</span><span class="pun">.</span><span class="pln">interval </span><span class="pun">=</span><span class="pln"> interval</span><span class="pun">;</span><span class="pln">
+      </span><span class="pun">}</span><span class="pln">
+    </span><span class="pun">};</span><span class="pln">
+    
+    window</span><span class="pun">.</span><span class="pln">addEventListener</span><span class="pun">(</span><span class="str">'load'</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      mail</span><span class="pun">.</span><span class="pln">setTimer</span><span class="pun">(!</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">interval </span><span class="pun">?</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">INTERVAL_DEFAULT </span><span class="pun">:</span><span class="pln"> mail</span><span class="pun">.</span><span class="pln">interval</span><span class="pun">);</span><span class="pln">
+    </span><span class="pun">},</span><span class="pln"> </span><span class="kwd">false</span><span class="pun">);</span><span class="pln">
+    
+    </span><span class="kwd">var</span><span class="pln"> battery </span><span class="pun">=</span><span class="pln"> navigator</span><span class="pun">.</span><span class="pln">battery</span><span class="pun">;</span><span class="pln">
+    
+    battery</span><span class="pun">.</span><span class="pln">addEventListener</span><span class="pun">(</span><span class="str">'dischargingtimechange'</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">battery</span><span class="pun">.</span><span class="pln">dischargingTime </span><span class="pun">&lt;</span><span class="pln"> </span><span class="lit">60</span><span class="pln"> </span><span class="pun">*</span><span class="pln"> </span><span class="lit">30</span><span class="pln"> </span><span class="pun">||</span><span class="pln"> battery</span><span class="pun">.</span><span class="pln">level </span><span class="pun">&lt;</span><span class="pln"> </span><span class="lit">0.1</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+        mail</span><span class="pun">.</span><span class="pln">setTimer</span><span class="pun">(</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">INTERVAL_BATTERY_LOW</span><span class="pun">);</span><span class="pln">
+        console</span><span class="pun">.</span><span class="pln">log</span><span class="pun">(</span><span class="str">'30 minutes remaining or level below 10%, checking the server less frequently.'</span><span class="pun">);</span><span class="pln">
+      </span><span class="pun">}</span><span class="pln"> </span><span class="kwd">else</span><span class="pln"> </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">battery</span><span class="pun">.</span><span class="pln">dischargingTime </span><span class="pun">&lt;</span><span class="pln"> </span><span class="lit">60</span><span class="pln"> </span><span class="pun">*</span><span class="pln"> </span><span class="lit">10</span><span class="pln"> </span><span class="pun">||</span><span class="pln"> battery</span><span class="pun">.</span><span class="pln">level </span><span class="pun">&lt;</span><span class="pln"> </span><span class="lit">0.05</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+        mail</span><span class="pun">.</span><span class="pln">setTimer</span><span class="pun">(</span><span class="kwd">null</span><span class="pun">);</span><span class="pln">
+        console</span><span class="pun">.</span><span class="pln">log</span><span class="pun">(</span><span class="str">'10 minutes remaining or level below 5%, stop checking the server.'</span><span class="pun">);</span><span class="pln">
+      </span><span class="pun">}</span><span class="pln">
+    </span><span class="pun">},</span><span class="pln"> </span><span class="kwd">false</span><span class="pun">);</span><span class="pln">
+    
+    battery</span><span class="pun">.</span><span class="pln">addEventListener</span><span class="pun">(</span><span class="str">'chargingchange'</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">battery</span><span class="pun">.</span><span class="pln">charging</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+        mail</span><span class="pun">.</span><span class="pln">setTimer</span><span class="pun">(</span><span class="pln">mail</span><span class="pun">.</span><span class="pln">INTERVAL_DEFAULT</span><span class="pun">);</span><span class="pln">
+        console</span><span class="pun">.</span><span class="pln">log</span><span class="pun">(</span><span class="str">'Battery is charging, checking the server normally.'</span><span class="pun">);</span><span class="pln">
+      </span><span class="pun">}</span><span class="pln">
+    </span><span class="pun">},</span><span class="pln"> </span><span class="kwd">false</span><span class="pun">);</span><span class="pln">
+  </span><span class="tag">&lt;/script&gt;</span><span class="pln">
+</span><span class="tag">&lt;/head&gt;</span><span class="pln">
+</span><span class="tag">&lt;body&gt;&lt;/body&gt;</span><span class="pln">
+</span><span class="tag">&lt;/html&gt;</span></pre></div>
+    </section>
+    
+    <section id="conformance"><!--OddPage--><h2><span class="secno">2. </span>Conformance</h2>
+<p>
+  As well as sections marked as non-normative, all authoring guidelines, diagrams, examples,
+  and notes in this specification are non-normative. Everything else in this specification is
+  normative.
+</p>
+<p>
+  The key words <em class="rfc2119" title="must">must</em>, <em class="rfc2119" title="must not">must not</em>, <em class="rfc2119" title="required">required</em>, <em class="rfc2119" title="should">should</em>, <em class="rfc2119" title="should not">should not</em>, <em class="rfc2119" title="recommended">recommended</em>, <em class="rfc2119" title="may">may</em>,
+  and <em class="rfc2119" title="optional">optional</em> in this specification are to be interpreted as described in [<cite><a class="bibref" href="#bib-RFC2119">RFC2119</a></cite>].
+</p>
+
+      <p>
+        This specification defines conformance criteria that apply to a single
+        product: the <dfn id="dfn-user-agent">user agent</dfn> that implements the
+        interfaces that it contains.
+      </p>
+      <p>
+        Implementations that use ECMAScript to implement the APIs defined in
+        this specification must implement them in a manner consistent with the
+        ECMAScript Bindings defined in the Web IDL specification [<cite><a class="bibref" href="#bib-WEBIDL">WEBIDL</a></cite>],
+        as this specification uses that specification and terminology.
+      </p>
+    </section>
+    <section id="terminology">
+      <!--OddPage--><h2><span class="secno">3. </span>Terminology</h2>
+      <p>
+        The <code><a href="http://dev.w3.org/html5/spec/webappapis.html#eventhandler">
+        EventHandler</a></code> interface represents a callback used for event
+        handlers as defined in [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>].
+      </p>
+      <p>
+        The concepts <dfn id="dfn-queue-a-task"><a href="http://dev.w3.org/html5/spec/webappapis.html#queue-a-task">
+        queue a task</a></dfn> and
+        <dfn id="dfn-fires-a-simple-event"><a href="http://dev.w3.org/html5/spec/webappapis.html#fire-a-simple-event">
+        fires a simple event</a></dfn> are defined in [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>].
+      </p>
+      <p>
+        The terms <dfn id="dfn-event-handlers"><a href="http://dev.w3.org/html5/spec/webappapis.html#event-handlers">
+        event handlers</a></dfn> and
+        <dfn id="dfn-event-handler-event-types"><a href="http://dev.w3.org/html5/spec/webappapis.html#event-handler-event-type">
+        event handler event types</a></dfn> are defined in [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>].
+      </p>
+    </section>
+    <section id="security-and-privacy-considerations">
+      <!--OddPage--><h2><span class="secno">4. </span>Security and privacy considerations</h2>
+      <p>
+        The API defined in this specification is used to determine the battery
+        status of the hosting device. The information disclosed has minimal
+        impact on privacy or fingerprinting, and therefore is exposed without
+        permission grants. For example, authors cannot directly know if there
+        is a battery or not in the hosting device.
+      </p>
+    </section>
+    <section id="navigatorbattery-interface">
+      <!--OddPage--><h2><span class="secno">5. </span><a href="#idl-def-NavigatorBattery" class="idlType"><code>NavigatorBattery</code></a> Interface</h2>
+      <p>
+        The <a href="#idl-def-NavigatorBattery" class="idlType"><code>NavigatorBattery</code></a> interface is exposed on the 
+        <code>Navigator</code> object.
+      </p>
+      <pre class="idl"><span class="idlImplements"><a>Navigator</a> implements <a href="#idl-def-NavigatorBattery" class="idlType"><code>NavigatorBattery</code></a>;</span></pre><div class="idlImplementsDesc"><p>All instances of the <code><a>Navigator</a></code> type are defined to also implement the <a href="#idl-def-NavigatorBattery" class="idlType"><code>NavigatorBattery</code></a> interface.</p></div>
+      <pre class="idl"><span class="idlInterface" id="idl-def-NavigatorBattery">[<span class="extAttr">NoInterfaceObject</span>]
+interface <span class="idlInterfaceID">NavigatorBattery</span> {
+<span class="idlAttribute">    readonly attribute <span class="idlAttrType"><a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a></span> <span class="idlAttrName"><a href="#widl-NavigatorBattery-battery">battery</a></span>;</span>
+};</span></pre><section id="attributes"><h3><span class="secno">5.1 </span>Attributes</h3><dl class="attributes"><dt id="widl-NavigatorBattery-battery"><code>battery</code> of type <span class="idlAttrType"><a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a></span>, readonly</dt><dd>
+          The object that exposes the battery status information.
+        </dd></dl></section>
+    </section>
+    
+    <section id="batterymanager-interface">
+      <!--OddPage--><h2><span class="secno">6. </span><a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a> Interface</h2>
+      <pre class="idl"><span class="idlInterface" id="idl-def-BatteryManager">[<span class="extAttr">NoInterfaceObject</span>]
+interface <span class="idlInterfaceID">BatteryManager</span> : <span class="idlSuperclass"><a>EventTarget</a></span> {
+<span class="idlAttribute">    readonly attribute <span class="idlAttrType"><a>boolean</a></span>             <span class="idlAttrName"><a href="#widl-BatteryManager-charging">charging</a></span>;</span>
+<span class="idlAttribute">    readonly attribute <span class="idlAttrType"><a>unrestricted double</a></span> <span class="idlAttrName"><a href="#widl-BatteryManager-chargingTime">chargingTime</a></span>;</span>
+<span class="idlAttribute">    readonly attribute <span class="idlAttrType"><a>unrestricted double</a></span> <span class="idlAttrName"><a href="#widl-BatteryManager-dischargingTime">dischargingTime</a></span>;</span>
+<span class="idlAttribute">    readonly attribute <span class="idlAttrType"><a>double</a></span>              <span class="idlAttrName"><a href="#widl-BatteryManager-level">level</a></span>;</span>
+<span class="idlAttribute">             attribute <span class="idlAttrType"><a>EventHandler</a></span>        <span class="idlAttrName"><a href="#widl-BatteryManager-onchargingchange">onchargingchange</a></span>;</span>
+<span class="idlAttribute">             attribute <span class="idlAttrType"><a>EventHandler</a></span>        <span class="idlAttrName"><a href="#widl-BatteryManager-onchargingtimechange">onchargingtimechange</a></span>;</span>
+<span class="idlAttribute">             attribute <span class="idlAttrType"><a>EventHandler</a></span>        <span class="idlAttrName"><a href="#widl-BatteryManager-ondischargingtimechange">ondischargingtimechange</a></span>;</span>
+<span class="idlAttribute">             attribute <span class="idlAttrType"><a>EventHandler</a></span>        <span class="idlAttrName"><a href="#widl-BatteryManager-onlevelchange">onlevelchange</a></span>;</span>
+};</span></pre><section id="attributes-1"><h3><span class="secno">6.1 </span>Attributes</h3><dl class="attributes"><dt id="widl-BatteryManager-charging"><code>charging</code> of type <span class="idlAttrType"><a>boolean</a></span>, readonly</dt><dd>
+          Represents if the system's battery is charging.
+        </dd><dt id="widl-BatteryManager-chargingTime"><code>chargingTime</code> of type <span class="idlAttrType"><a>unrestricted double</a></span>, readonly</dt><dd>
+          Represents the time remaining in seconds until the system's battery
+          is fully charged.
+        </dd><dt id="widl-BatteryManager-dischargingTime"><code>dischargingTime</code> of type <span class="idlAttrType"><a>unrestricted double</a></span>, readonly</dt><dd>
+          Represents the time remaining in seconds until the system's battery
+          is completely discharged and the system is about to be suspended.
+        </dd><dt id="widl-BatteryManager-level"><code>level</code> of type <span class="idlAttrType"><a>double</a></span>, readonly</dt><dd>
+          Represents the current battery level scaled from 0 to 1.0.
+        </dd><dt id="widl-BatteryManager-onchargingchange"><code>onchargingchange</code> of type <span class="idlAttrType"><a>EventHandler</a></span></dt><dd>
+        </dd><dt id="widl-BatteryManager-onchargingtimechange"><code>onchargingtimechange</code> of type <span class="idlAttrType"><a>EventHandler</a></span></dt><dd>
+        </dd><dt id="widl-BatteryManager-ondischargingtimechange"><code>ondischargingtimechange</code> of type <span class="idlAttrType"><a>EventHandler</a></span></dt><dd>
+        </dd><dt id="widl-BatteryManager-onlevelchange"><code>onlevelchange</code> of type <span class="idlAttrType"><a>EventHandler</a></span></dt><dd>
+        </dd></dl></section>
+      <p>
+        When a <code>BatteryManager</code> object is created,
+        <code>charging</code> <em class="rfc2119" title="must">must</em> be set to true, <code>chargingTime</code>
+        to 0, <code>level</code> to 1.0 and <code>dischargingTime</code> to
+        the value positive Infinity, if the implementation is unable to report
+        the battery's charging state, charging time, level or remaining time
+        respectively.
+      </p>
+      <p>
+        The <code>charging</code> attribute <em class="rfc2119" title="must">must</em> be set to false if the battery
+        is discharging, and set to true, if the battery is charging, the
+        implementation is unable to report the state, or there is no battery
+        attached to the system, or otherwise. When the battery charging state
+        is updated, the <a href="#dfn-user-agent" class="internalDFN">user agent</a> <em class="rfc2119" title="must">must</em> <a href="#dfn-queue-a-task" class="internalDFN">queue a task</a> which sets
+        the <code>charging</code> attribute's value and <a href="#dfn-fires-a-simple-event" class="internalDFN">fires a simple
+        event</a> named <code><a href="#dfn-chargingchange" class="internalDFN">chargingchange</a></code> at the
+        <a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a> object.
+      </p>
+      <p>
+        The <code>chargingTime</code> attribute <em class="rfc2119" title="must">must</em> be set to 0, if the
+        battery is full or there is no battery attached to the system, and to
+        the value positive Infinity if the battery is discharging, the
+        implementation is unable to report the remaining charging time, or
+        otherwise. When the battery charging time is updated, the <a href="#dfn-user-agent" class="internalDFN">user
+        agent</a> <em class="rfc2119" title="must">must</em> <a href="#dfn-queue-a-task" class="internalDFN">queue a task</a> which sets the
+        <code>chargingTime</code> attribute's value and <a href="#dfn-fires-a-simple-event" class="internalDFN">fires a simple
+        event</a> named <code><a href="#dfn-chargingtimechange" class="internalDFN">chargingtimechange</a></code> at the
+        <a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a> object.
+      </p>
+      <p>
+        The <code>dischargingTime</code> attribute <em class="rfc2119" title="must">must</em> be set to the value
+        positive Infinity, if the battery is charging, the implementation is
+        unable to report the remaining discharging time, there is no battery
+        attached to the system, or otherwise. When the battery discharging time
+        is updated, the <a href="#dfn-user-agent" class="internalDFN">user agent</a> <em class="rfc2119" title="must">must</em> <a href="#dfn-queue-a-task" class="internalDFN">queue a task</a> which sets
+        the <code>dischargingTime</code> attribute's value and <a href="#dfn-fires-a-simple-event" class="internalDFN">fires a
+        simple event </a> named <code><a href="#dfn-dischargingtimechange" class="internalDFN">dischargingtimechange</a></code> at the
+        <a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a> object.
+      </p>
+      <p>
+        The <code>level</code> attribute <em class="rfc2119" title="must">must</em> be set to 0 if the system's
+        battery is depleted and the system is about to be suspended, and to
+        1.0 if the battery is full, the implementation is unable to report the
+        battery's level, or there is no battery attached to the system. When
+        the battery level is updated, the <a href="#dfn-user-agent" class="internalDFN">user agent</a> <em class="rfc2119" title="must">must</em> <a href="#dfn-queue-a-task" class="internalDFN">queue a
+        task</a> which sets the <code>level</code> attribute's value and
+        <a href="#dfn-fires-a-simple-event" class="internalDFN">fires a simple event</a> named <code><a href="#dfn-levelchange" class="internalDFN">levelchange</a></code> at
+        the <a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a> object.
+      </p>
+      <div class="note"><div class="note-title"><span>Note</span></div><div class="">
+        The definition of how often the <code><a href="#dfn-chargingtimechange" class="internalDFN">chargingtimechange</a></code>,
+        <code><a href="#dfn-dischargingtimechange" class="internalDFN">dischargingtimechange</a></code>, and <code><a href="#dfn-levelchange" class="internalDFN">levelchange</a>
+        </code> events are fired is left to the implementation.
+      </div></div>
+      <section id="event-handlers">
+        <h3><span class="secno">6.2 </span>Event handlers</h3>
+        <p>
+          The following are the <a href="#dfn-event-handlers" class="internalDFN">event handlers</a> (and their corresponding
+          <a href="#dfn-event-handler-event-types" class="internalDFN">event handler event types</a>) that <em class="rfc2119" title="must">must</em> be supported as
+          attributes by the <a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a> object:
+        </p>
+        <table class="simple">
+          <thead>
+            <tr>
+              <th>event handler</th>
+              <th>event handler event type</th>
+            </tr>
+          </thead>
+          <tbody>
+            <tr>
+              <td><strong><code>onchargingchange</code></strong></td>
+              <td><code><dfn id="dfn-chargingchange">chargingchange</dfn></code></td>
+            </tr>
+            <tr>
+              <td><strong><code>onchargingtimechange</code></strong></td>
+              <td><code><dfn id="dfn-chargingtimechange">chargingtimechange</dfn></code></td>
+            </tr>
+            <tr>
+              <td><strong><code>ondischargingtimechange</code></strong></td>
+              <td><code><dfn id="dfn-dischargingtimechange">dischargingtimechange</dfn></code></td>
+            </tr>
+            <tr>
+              <td><strong><code>onlevelchange</code></strong></td>
+              <td><code><dfn id="dfn-levelchange">levelchange</dfn></code></td>
+            </tr>
+          </tbody>
+        </table>
+      </section>
+    </section>
+
+    <section class="informative" id="examples">
+      <!--OddPage--><h2><span class="secno">7. </span>Examples</h2><p><em>This section is non-normative.</em></p>
+      <p>
+        This trivial example writes the battery level to the console each time
+        the level changes:
+      </p>
+      <div class="example"><div class="example-title"><span>Example 3</span></div><pre class="example highlight prettyprint"><span class="pln">navigator</span><span class="pun">.</span><span class="pln">battery</span><span class="pun">.</span><span class="pln">onlevelchange </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+  console</span><span class="pun">.</span><span class="pln">log</span><span class="pun">(</span><span class="pln">navigator</span><span class="pun">.</span><span class="pln">battery</span><span class="pun">.</span><span class="pln">level</span><span class="pun">);</span><span class="pln">
+</span><span class="pun">};</span></pre></div>
+      <p>
+        Alternatively, the same using the <code>addEventListener()</code>
+        method:
+      </p>
+      <div class="example"><div class="example-title"><span>Example 4</span></div><pre class="example highlight prettyprint"><span class="pln">navigator</span><span class="pun">.</span><span class="pln">battery</span><span class="pun">.</span><span class="pln">addEventListener</span><span class="pun">(</span><span class="str">'levelchange'</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+  console</span><span class="pun">.</span><span class="pln">log</span><span class="pun">(</span><span class="pln">navigator</span><span class="pun">.</span><span class="pln">battery</span><span class="pun">.</span><span class="pln">level</span><span class="pun">);</span><span class="pln">
+</span><span class="pun">},</span><span class="pln"> </span><span class="kwd">false</span><span class="pun">);</span></pre></div>
+      <p>
+        The following example updates the indicators to show the charging
+        state, level and time remaining in minutes:
+      </p>
+      <div class="example"><div class="example-title"><span>Example 5</span></div><pre class="example highlight prettyprint"><span class="dec">&lt;!DOCTYPE html&gt;</span><span class="pln">
+</span><span class="tag">&lt;html&gt;</span><span class="pln">
+</span><span class="tag">&lt;head&gt;</span><span class="pln">
+  </span><span class="tag">&lt;title&gt;</span><span class="pln">Battery Status API Example</span><span class="tag">&lt;/title&gt;</span><span class="pln">
+  </span><span class="tag">&lt;script&gt;</span><span class="pln">
+    </span><span class="kwd">var</span><span class="pln"> battery </span><span class="pun">=</span><span class="pln"> navigator</span><span class="pun">.</span><span class="pln">battery</span><span class="pun">;</span><span class="pln">
+    
+    battery</span><span class="pun">.</span><span class="pln">onchargingchange </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      document</span><span class="pun">.</span><span class="pln">querySelector</span><span class="pun">(</span><span class="str">'#charging'</span><span class="pun">).</span><span class="pln">textContent </span><span class="pun">=</span><span class="pln"> battery</span><span class="pun">.</span><span class="pln">charging </span><span class="pun">?</span><span class="pln"> </span><span class="str">'charging'</span><span class="pln"> </span><span class="pun">:</span><span class="pln"> </span><span class="str">'not charging'</span><span class="pun">;</span><span class="pln">
+    </span><span class="pun">};</span><span class="pln">
+
+    battery</span><span class="pun">.</span><span class="pln">onlevelchange </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      document</span><span class="pun">.</span><span class="pln">querySelector</span><span class="pun">(</span><span class="str">'#level'</span><span class="pun">).</span><span class="pln">textContent </span><span class="pun">=</span><span class="pln"> battery</span><span class="pun">.</span><span class="pln">level</span><span class="pun">;</span><span class="pln">
+    </span><span class="pun">};</span><span class="pln">
+
+    battery</span><span class="pun">.</span><span class="pln">ondischargingtimechange </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">function</span><span class="pln"> </span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+      document</span><span class="pun">.</span><span class="pln">querySelector</span><span class="pun">(</span><span class="str">'#dischargingTime'</span><span class="pun">).</span><span class="pln">textContent </span><span class="pun">=</span><span class="pln"> battery</span><span class="pun">.</span><span class="pln">dischargingTime </span><span class="pun">/</span><span class="pln"> </span><span class="lit">60</span><span class="pun">;</span><span class="pln">
+    </span><span class="pun">};</span><span class="pln">
+  </span><span class="tag">&lt;/script&gt;</span><span class="pln">
+</span><span class="tag">&lt;/head&gt;</span><span class="pln">
+</span><span class="tag">&lt;body&gt;</span><span class="pln">
+  </span><span class="tag">&lt;div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"charging"</span><span class="tag">&gt;</span><span class="pln">(charging state unknown)</span><span class="tag">&lt;/div&gt;</span><span class="pln">
+  </span><span class="tag">&lt;div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"level"</span><span class="tag">&gt;</span><span class="pln">(battery level unknown)</span><span class="tag">&lt;/div&gt;</span><span class="pln">
+  </span><span class="tag">&lt;div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"dischargingTime"</span><span class="tag">&gt;</span><span class="pln">(discharging time unknown)</span><span class="tag">&lt;/div&gt;</span><span class="pln">
+</span><span class="tag">&lt;/body&gt;</span><span class="pln">
+</span><span class="tag">&lt;/html&gt;</span></pre></div>
+    </section>
+    <section class="appendix" id="acknowledgements">
+      <!--OddPage--><h2><span class="secno">A. </span>Acknowledgements</h2>
+      <p>
+        The group is deeply indebted to Mounir Lamouri, Jonas Sicking, and
+        the Mozilla WebAPI team in general for their invaluable feedback
+        based on prototype implementations. Many thanks to the people behind
+        the System Information API and Device Orientation Event specification
+        for the initial inspiration. Also thanks to the nice folks bringing us
+        the Page Visibility specification, which motivated the editor of this
+        specification to write the introduction chapter discussing some
+        real-world high value use cases that apply equally to this
+        specification. Special thanks to all the participants of the Device
+        APIs Working Group and others who have sent in substantial feedback
+        and comments, and made the Web a better place for everyone by
+        doing so.
+      </p>
+    </section>
+  
+
+<section id="references" class="appendix"><!--OddPage--><h2><span class="secno">B. </span>References</h2><section id="normative-references"><h3><span class="secno">B.1 </span>Normative references</h3><dl class="bibliography"><dt id="bib-HTML5">[HTML5]</dt><dd>Robin Berjon et al. <a href="http://www.w3.org/TR/html5/"><cite>HTML5.</cite></a> 17 December 2012. W3C Candidate Recommendation. URL: <a href="http://www.w3.org/TR/html5/">http://www.w3.org/TR/html5/</a>
+</dd><dt id="bib-RFC2119">[RFC2119]</dt><dd>S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key words for use in RFCs to Indicate Requirement Levels.</cite></a> March 1997. Internet RFC 2119.  URL: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a> 
+</dd><dt id="bib-WEBIDL">[WEBIDL]</dt><dd>Cameron McCormack. <a href="http://www.w3.org/TR/2011/WD-WebIDL-20110927/"><cite>Web IDL.</cite></a> 27 September 2011. W3C Working Draft. URL: <a href="http://www.w3.org/TR/2011/WD-WebIDL-20110927/">http://www.w3.org/TR/2011/WD-WebIDL-20110927/</a>
+</dd></dl></section></section></body></html>
\ No newline at end of file
Received on Friday, 1 February 2013 08:43:48 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 1 February 2013 08:43:48 GMT