--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/battery/CR2-diff.html Fri Nov 14 18:01:39 2014 +0200
@@ -0,0 +1,3574 @@
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+<style type='text/css'>
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+ font-size: smaller;
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+</style>
+</head>
+<body class="h-entry" role="document" id="respecDocument">
+<div class="head" role="contentinfo" id="respecHeader">
+<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 p-name" id="title" property="dcterms:title">
+Battery
+Status
+API
+</h1>
+<h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-12-08T22:00:00.000Z" id="w3c-candidate-recommendation-09-december-2014">
+<abbr title="World Wide Web Consortium">
+W3C
+</abbr>
+<del class="diff-old">Last
+Call
+Working
+Draft
+28
+August
+</del>
+<ins class="diff-chg">Candidate
+Recommendation
+</ins><time class="dt-published" datetime="2014-12-09"><ins class="diff-chg">
+09
+December
+</ins>
+2014
+</time>
+</h2>
+<dl>
+<dt>
+This
+version:
+</dt>
+<dd>
+<del class="diff-old">http://www.w3.org/TR/2014/WD-battery-status-20140828/
+</del>
+<a class="u-url" href="http://www.w3.org/TR/2014/CR-battery-status-20141209/">
+<ins class="diff-chg">http://www.w3.org/TR/2014/CR-battery-status-20141209/
+</ins>
+</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/battery-status/">
+http://w3c-test.org/battery-status/
+</a>
+</dd>
+<dt>
+Implementation
+report:
+</dt>
+<dd>
+<a href="http://www.w3.org/2009/dap/wiki/ImplementationStatus">
+http://www.w3.org/2009/dap/wiki/ImplementationStatus
+</a>
+</dd>
+<dt>
+Previous
+version:
+</dt>
+<dd>
+<del class="diff-old">http://www.w3.org/TR/2012/CR-battery-status-20120508/
+</del>
+<a rel="dcterms:replaces" href="http://www.w3.org/TR/2014/WD-battery-status-20140828/">
+<ins class="diff-chg">http://www.w3.org/TR/2014/WD-battery-status-20140828/
+</ins>
+</a>
+</dd>
+<dt>
+Editors:
+</dt>
+<dd class="p-author h-card vcard" rel="bibo:editor" inlist="">
+<span typeof="foaf:Person">
+<span property="foaf:name" class="p-name fn">
+Anssi
+Kostiainen
+</span>,
+<a rel="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://intel.com/">
+Intel
+</a>
+</span>
+</dd>
+<dd class="p-author h-card vcard" rel="bibo:editor" inlist="">
+<span typeof="foaf:Person">
+<span property="foaf:name" class="p-name fn">
+Mounir
+Lamouri
+</span>,
+<a rel="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://google.com/">
+Google
+Inc.
+</a>
+(previously
+Mozilla)
+</span>
+</dd>
+</dl>
+<p class="copyright">
+<a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">
+Copyright
+</a>
+©
+2014
+<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>,
+<a href="http://ev.buaa.edu.cn/">
+Beihang
+</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" property="dcterms:abstract" datatype typeof="bibo:Chapter" resource="#abstract" rel="bibo:Chapter">
+<h2 role="heading" id="h2_abstract">
+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" typeof="bibo:Chapter" resource="#sotd" rel="bibo:Chapter">
+<h2 role="heading" id="h2_sotd">
+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>
+<del class="diff-old">The
+following
+</del>
+<ins class="diff-chg">No
+substantial
+</ins>
+changes
+have
+been
+made
+since
+the
+<a href="http://www.w3.org/TR/2014/WD-battery-status-20140828/">
+<abbr title="World Wide Web Consortium">
+W3C
+</abbr>
+<del class="diff-old">Candidate
+Recommendation
+08
+May
+2012
+</del>
+<ins class="diff-chg">Last
+Call
+Working
+Draft
+28
+August
+2014
+</ins>
+</a>
+(
+<a href="CR2-diff.html">
+diff
+</a>
+<del class="diff-old">):
+</del>
+<ins class="diff-chg">).
+</ins>
+</p>
+<del class="diff-old">Expose
+BatteryManager
+via
+getBattery()
+returning
+a
+Promise
+instead
+of
+a
+synchronous
+accessor.
+(
+Section
+5
+)
+Clarify
+default
+values
+when
+a
+BatteryManager
+object
+is
+created
+and
+the
+implementation
+</del>
+<p>
+<ins class="diff-chg">The
+CR
+exit
+criterion
+</ins>
+is
+<del class="diff-old">unable
+to
+report
+the
+battery
+status
+information
+.
+(
+Section
+6
+)
+Specify
+the
+behavior
+when
+a
+host
+device
+has
+more
+than
+one
+battery.
+(
+Section
+6.1
+)
+</del>
+<ins class="diff-chg">two
+interoperable
+deployed
+implementations
+of
+each
+feature.
+No
+features
+are
+marked
+as
+'at-risk'.
+</ins></p>
+<p>
+This
+document
+was
+published
+by
+the
+<a href="http://www.w3.org/2009/dap/">
+Device
+APIs
+Working
+Group
+</a>
+as
+a
+<del class="diff-old">Last
+Call
+Working
+Draft.
+</del>
+<ins class="diff-chg">Candidate
+Recommendation.
+</ins>
+This
+document
+is
+intended
+to
+become
+a
+<abbr title="World Wide Web Consortium">
+W3C
+</abbr>
+Recommendation.
+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>
+).
+<del class="diff-old">The
+Last
+Call
+period
+ends
+02
+October
+2014.
+</del>
+<abbr title="World Wide Web Consortium">
+<ins class="diff-chg">W3C
+</ins></abbr><ins class="diff-chg">
+publishes
+a
+Candidate
+Recommendation
+to
+indicate
+that
+the
+document
+is
+believed
+to
+be
+stable
+and
+to
+encourage
+implementation
+by
+the
+developer
+community.
+This
+Candidate
+Recommendation
+is
+expected
+to
+advance
+to
+Proposed
+Recommendation
+no
+earlier
+than
+03
+February
+2015.
+</ins>
+All
+comments
+are
+welcome.
+</p>
+<p>
+Please
+see
+the
+Working
+Group's
+<a href="http://www.w3.org/2009/dap/wiki/ImplementationStatus">
+implementation
+report
+</a>.
+</p>
+<p>
+Publication
+as
+a
+<del class="diff-old">Last
+Call
+Working
+Draft
+</del>
+<ins class="diff-chg">Candidate
+Recommendation
+</ins>
+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
+<del class="diff-old">is
+a
+Last
+Call
+Working
+Draft
+and
+thus
+the
+Working
+Group
+has
+determined
+that
+this
+document
+has
+satisfied
+the
+relevant
+technical
+requirements
+and
+is
+sufficiently
+stable
+to
+advance
+through
+the
+Technical
+Recommendation
+process.
+This
+</del>
+document
+was
+produced
+by
+a
+group
+operating
+under
+the
+<a id="sotd_patent" about="" rel="w3p:patentRules" 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>
+<p>
+This
+document
+is
+governed
+by
+the
+<a id="w3c_process_revision" href="http://www.w3.org/2005/10/Process-20051014/">
+14
+October
+2005
+<abbr title="World Wide Web Consortium">
+W3C
+</abbr>
+Process
+Document
+</a>.
+</p>
+</section>
+<section id="toc">
+<h2 class="introductory" role="heading" id="h2_toc">
+Table
+of
+Contents
+</h2>
+<ul class="toc" role="directory" id="respecContents">
+<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="#the-navigator-interface" class="tocxref">
+<span class="secno">
+5.
+</span>
+The
+<span class="formerLink">
+<code>
+Navigator
+</code>
+</span>
+interface
+</a>
+</li>
+<li class="tocline">
+<a href="#the-batterymanager-interface" class="tocxref">
+<span class="secno">
+6.
+</span>
+The
+<span class="formerLink">
+<code>
+BatteryManager
+</code>
+</span>
+interface
+</a>
+<ul class="toc">
+<li class="tocline">
+<a href="#multiple-batteries" class="tocxref">
+<span class="secno">
+6.1
+</span>
+Multiple
+batteries
+</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">
+<h2 role="heading" id="h2_introduction">
+<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.
+Authors
+should
+be
+aware,
+however,
+that
+a
+naïve
+implementation
+of
+this
+API
+can
+negatively
+affect
+the
+battery
+life.
+</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>
+</section>
+<section id="conformance" typeof="bibo:Chapter" resource="#conformance" rel="bibo:Chapter">
+<h2 role="heading" id="h2_conformance">
+<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 id="respecRFC2119">
+The
+key
+words
+<em class="rfc2119" title="MUST">
+MUST
+</em>,
+<em class="rfc2119" title="MUST NOT">
+MUST
+NOT
+</em>,
+<del class="diff-old">REQUIRED
+,
+</del>
+<ins class="diff-chg">and
+</ins>
+<em class="rfc2119" title="SHOULD">
+SHOULD
+<del class="diff-old">,
+SHOULD
+NOT
+,
+RECOMMENDED
+,
+MAY
+,
+and
+OPTIONAL
+</del>
+</em>
+<del class="diff-old">in
+this
+specification
+</del>
+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">
+<h2 role="heading" id="h2_terminology">
+<span class="secno">
+3.
+</span>
+Terminology
+</h2>
+<p>
+The
+following
+concepts,
+terms
+and
+interfaces
+are
+defined
+in
+[
+<cite>
+<a class="bibref" href="#bib-HTML5">
+HTML5
+</a>
+</cite>
+]:
+</p>
+<ul>
+<li>
+<code>
+<a href="http://www.w3.org/html/wg/drafts/html/master/webappapis.html#navigator">
+Navigator
+</a>
+</code>
+</li>
+<li>
+<code>
+<a href="http://dev.w3.org/html5/spec/webappapis.html#eventhandler">
+EventHandler
+</a>
+</code>
+</li>
+<li>
+<dfn id="dfn-queue-a-task">
+<a href="http://dev.w3.org/html5/spec/webappapis.html#queue-a-task">
+queue
+a
+task
+</a>
+</dfn>
+</li>
+<li>
+<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>
+</li>
+<li>
+<dfn id="dfn-event-handlers">
+<a href="http://dev.w3.org/html5/spec/webappapis.html#event-handlers">
+event
+handlers
+</a>
+</dfn>
+</li>
+<li>
+<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>
+</li>
+<li>
+<dfn id="dfn-browsing-context">
+<a href="http://dev.w3.org/html5/spec/browsers.html#browsing-context">
+browsing
+context
+</a>
+</dfn>
+</li>
+</ul>
+<p>
+<a href="http://people.mozilla.org/~jorendorff/es6-draft.html#sec-promise-objects">
+<dfn id="dfn-promise">
+Promise
+</dfn>
+</a>
+objects
+are
+defined
+in
+[
+<cite>
+<a class="bibref" href="#bib-ECMASCRIPT">
+ECMASCRIPT
+</a>
+</cite>
+].
+</p>
+</section>
+<section class="informative" id="security-and-privacy-considerations">
+<h2 role="heading" id="h2_security-and-privacy-considerations">
+<span class="secno">
+4.
+</span>
+Security
+and
+privacy
+considerations
+</h2>
+<p>
+<em>
+This
+section
+is
+non-normative.
+</em>
+</p>
+<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,
+the
+user
+agent
+can
+obfuscate
+the
+exposed
+value
+in
+a
+way
+that
+authors
+cannot
+directly
+know
+if
+a
+hosting
+device
+has
+no
+battery,
+is
+charging
+or
+is
+exposing
+fake
+values.
+</p>
+</section>
+<section id="the-navigator-interface">
+<h2 role="heading" id="h2_the-navigator-interface">
+<span class="secno">
+5.
+</span>
+The
+<a href="#idl-def-Navigator" class="idlType">
+<code>
+Navigator
+</code>
+</a>
+interface
+</h2>
+<pre class="idl">
+<span class="idlInterface" id="idl-def-Navigator">partial interface <span class="idlInterfaceID">Navigator</span> {
+<span class="idlMethod"> <span class="idlMethType">Promise<<a href="#idl-def-BatteryManager" class="idlType"><code>BatteryManager</code></a>></span> <span class="idlMethName"><a href="#widl-Navigator-getBattery-Promise-BatteryManager">getBattery</a></span> ();</span>
+};</span>
+</pre>
+<p>
+For
+each
+<a href="#dfn-browsing-context" class="internalDFN">
+browsing
+context
+</a>,
+there
+is
+a
+<dfn id="dfn-battery-promise">
+battery
+promise
+</dfn>,
+which
+is
+initially
+set
+to
+<code>
+null
+</code>.
+It
+is
+a
+<a href="#dfn-promise" class="internalDFN">
+Promise
+</a>
+object
+which
+holds
+a
+<a href="#idl-def-BatteryManager" class="idlType">
+<code>
+BatteryManager
+</code>
+</a>.
+</p>
+<p>
+The
+<code id="widl-Navigator-getBattery-Promise-BatteryManager">
+getBattery()
+</code>
+method,
+when
+invoked,
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+run
+the
+following
+steps:
+</p>
+<ul>
+<li>
+If
+<a href="#dfn-battery-promise" class="internalDFN">
+battery
+promise
+</a>
+is
+not
+<code>
+null
+</code>,
+return
+<a href="#dfn-battery-promise" class="internalDFN">
+battery
+promise
+</a>
+and
+abort
+these
+steps.
+</li>
+<li>
+Otherwise,
+set
+<a href="#dfn-battery-promise" class="internalDFN">
+battery
+promise
+</a>
+to
+a
+newly
+created
+<a href="#dfn-promise" class="internalDFN">
+Promise
+</a>.
+</li>
+<li>
+Return
+<a href="#dfn-battery-promise" class="internalDFN">
+battery
+promise
+</a>
+and
+continue
+asynchronously.
+</li>
+<li>
+<a href="#dfn-create-a-new-batterymanager-object" class="internalDFN">
+Create
+a
+new
+<code>
+BatteryManager
+</code>
+object
+</a>,
+and
+let
+<var>
+battery
+</var>
+be
+that
+object.
+</li>
+<li>
+<dfn id="dfn-resolve">
+Resolve
+</dfn>
+<a href="#dfn-battery-promise" class="internalDFN">
+battery
+promise
+</a>
+with
+<var>
+battery
+</var>.
+</li>
+</ul>
+<p>
+The
+<a href="#dfn-user-agent" class="internalDFN">
+user
+agent
+</a>
+<em class="rfc2119" title="MUST NOT">
+MUST
+NOT
+</em>
+reject
+the
+<a href="#dfn-battery-promise" class="internalDFN">
+battery
+promise
+</a>.
+</p>
+</section>
+<section id="the-batterymanager-interface">
+<h2 role="heading" id="h2_the-batterymanager-interface">
+<span class="secno">
+6.
+</span>
+The
+<a href="#idl-def-BatteryManager" class="idlType">
+<code>
+BatteryManager
+</code>
+</a>
+interface
+</h2>
+<p>
+The
+<a href="#idl-def-BatteryManager" class="idlType">
+<code>
+BatteryManager
+</code>
+</a>
+interface
+represents
+the
+<dfn id="dfn-current-battery-status-information">
+current
+battery
+status
+information
+</dfn>
+of
+the
+hosting
+device.
+The
+<code>
+charging
+</code>
+attribute
+represents
+the
+charging
+state
+of
+the
+system's
+battery.
+The
+<code>
+chargingTime
+</code>
+attribute
+represents
+the
+time
+remaining
+in
+seconds
+until
+the
+system's
+battery
+is
+fully
+charged.
+The
+<code>
+dischargingTime
+</code>
+attribute
+represents
+the
+time
+remaining
+in
+seconds
+until
+the
+system's
+battery
+is
+completely
+discharged
+and
+the
+system
+is
+about
+to
+be
+suspended,
+and
+the
+<code>
+level
+</code>
+attribute
+represents
+the
+level
+of
+the
+system's
+battery.
+</p>
+<pre class="idl">
+<span class="idlInterface" id="idl-def-BatteryManager">interface <span class="idlInterfaceID">BatteryManager</span> : <span class="idlSuperclass">EventTarget</span> {
+<span class="idlAttribute"> readonly attribute <span class="idlAttrType">boolean</span> <span class="idlAttrName"><a href="#widl-BatteryManager-charging">charging</a></span>;</span>
+<span class="idlAttribute"> readonly attribute <span class="idlAttrType">unrestricted double</span> <span class="idlAttrName"><a href="#widl-BatteryManager-chargingTime">chargingTime</a></span>;</span>
+<span class="idlAttribute"> readonly attribute <span class="idlAttrType">unrestricted double</span> <span class="idlAttrName"><a href="#widl-BatteryManager-dischargingTime">dischargingTime</a></span>;</span>
+<span class="idlAttribute"> readonly attribute <span class="idlAttrType">double</span> <span class="idlAttrName"><a href="#widl-BatteryManager-level">level</a></span>;</span>
+<span class="idlAttribute"> attribute <span class="idlAttrType">EventHandler</span> <span class="idlAttrName"><a href="#widl-BatteryManager-onchargingchange">onchargingchange</a></span>;</span>
+<span class="idlAttribute"> attribute <span class="idlAttrType">EventHandler</span> <span class="idlAttrName"><a href="#widl-BatteryManager-onchargingtimechange">onchargingtimechange</a></span>;</span>
+<span class="idlAttribute"> attribute <span class="idlAttrType">EventHandler</span> <span class="idlAttrName"><a href="#widl-BatteryManager-ondischargingtimechange">ondischargingtimechange</a></span>;</span>
+<span class="idlAttribute"> attribute <span class="idlAttrType">EventHandler</span> <span class="idlAttrName"><a href="#widl-BatteryManager-onlevelchange">onlevelchange</a></span>;</span>
+};</span>
+</pre>
+<p>
+When
+the
+<a href="#dfn-user-agent" class="internalDFN">
+user
+agent
+</a>
+is
+to
+<dfn id="dfn-create-a-new-batterymanager-object">
+create
+a
+new
+<code>
+BatteryManager
+</code>
+object
+</dfn>,
+it
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+instantiate
+a
+new
+<a href="#idl-def-BatteryManager" class="idlType">
+<code>
+BatteryManager
+</code>
+</a>
+object
+and
+set
+its
+attributes'
+values
+to
+those
+that
+represent
+the
+<a href="#dfn-current-battery-status-information" class="internalDFN">
+current
+battery
+status
+information
+</a>,
+unless
+the
+<a href="#dfn-user-agent" class="internalDFN">
+user
+agent
+</a>
+is
+<a href="#dfn-unable-to-report-the-battery-status-information" class="internalDFN">
+unable
+to
+report
+the
+battery
+status
+information
+</a>,
+in
+which
+case
+the
+values
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+be
+set
+to
+<dfn id="dfn-default-values">
+default
+values
+</dfn>
+as
+follows:
+<code>
+charging
+</code>
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+be
+set
+to
+true,
+<code>
+chargingTime
+</code>
+<em class="rfc2119" title= "MUST">
+MUST
+</em>
+be
+set
+to
+0,
+<code>
+dischargingTime
+</code>
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+be
+set
+to
+positive
+Infinity,
+and
+<code>
+level
+</code>
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+be
+set
+to
+1.0.
+</p>
+<p>
+The
+<a href="#dfn-user-agent" class="internalDFN">
+user
+agent
+</a>
+is
+said
+to
+be
+<dfn id="dfn-unable-to-report-the-battery-status-information">
+unable
+to
+report
+the
+battery
+status
+information
+</dfn>,
+if
+it
+is
+not
+able
+to
+report
+the
+values
+for
+any
+of
+the
+attributes,
+for
+example,
+due
+to
+a
+user
+or
+system
+preference,
+setting,
+or
+limitation.
+</p>
+<div class="note">
+<div class="note-title" aria-level="1" role="heading" id="h_note_1">
+<span>
+Note
+</span>
+</div>
+<p class="">
+Implementations
+<a href="#dfn-unable-to-report-the-battery-status-information" class="internalDFN">
+unable
+to
+report
+the
+battery
+status
+information
+</a>
+emulate
+a
+fully
+charged
+and
+plugged
+in
+battery
+to
+reduce
+the
+potential
+for
+fingerprinting
+and
+prevent
+applications
+from
+degrading
+performance,
+if
+the
+battery
+status
+information
+is
+not
+made
+available,
+for
+example.
+</p>
+</div>
+<p>
+The
+<code id="widl-BatteryManager-charging">
+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 id="widl-BatteryManager-chargingTime">
+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 id="widl-BatteryManager-dischargingTime">
+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 id="widl-BatteryManager-level">
+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" aria-level="1" role="heading" id="h_note_2">
+<span>
+Note
+</span>
+</div>
+<p 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.
+</p>
+</div>
+<section id="multiple-batteries" typeof="bibo:Chapter" resource="#multiple-batteries" rel="bibo:Chapter">
+<h3 role="heading" id="h3_multiple-batteries">
+<span class="secno">
+6.1
+</span>
+Multiple
+batteries
+</h3>
+<p>
+If
+a
+hosting
+device
+contains
+more
+than
+one
+battery,
+<a href="#idl-def-BatteryManager" class="idlType">
+<code>
+BatteryManager
+</code>
+</a>
+<em class="rfc2119" title="SHOULD">
+SHOULD
+</em>
+expose
+an
+unified
+view
+of
+the
+batteries.
+</p>
+<p>
+The
+<code>
+charging
+</code>
+attribute
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+be
+set
+to
+true
+if
+at
+least
+one
+battery's
+<code>
+charging
+</code>
+state
+as
+described
+above
+is
+true.
+Otherwise,
+it
+<em class="rfc2119" title="MUST">
+MUST
+</em>
+be
+set
+to
+false.
+</p>
+<p>
+The
+<code>
+chargingTime
+</code>
+attribute
+can
+be
+set
+to
+the
+maximum
+charging
+time
+of
+the
+individual
+batteries
+if
+charging
+in
+parallel,
+and
+to
+the
+sum
+of
+the
+individual
+charging
+times
+if
+charging
+serially.
+</p>
+<p>
+The
+<code>
+dischargingTime
+</code>
+attribute
+can
+be
+set
+to
+the
+maximum
+discharging
+time
+of
+the
+individual
+batteries
+if
+discharging
+in
+parallel,
+and
+to
+the
+sum
+of
+individual
+discharging
+times
+if
+discharging
+serially.
+</p>
+<p>
+The
+<code>
+level
+</code>
+attribute
+can
+be
+set
+to
+the
+average
+of
+the
+levels
+of
+batteries
+of
+same
+capacity,
+or
+the
+weighted
+average
+of
+the
+battery
+level
+attributes
+for
+batteries
+of
+different
+capacities.
+</p>
+</section>
+<section id="event-handlers">
+<h3 role="heading" id="h3_event-handlers">
+<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 id="widl-BatteryManager-onchargingchange">
+onchargingchange
+</code>
+</strong>
+</td>
+<td>
+<code>
+<dfn id="dfn-chargingchange">
+chargingchange
+</dfn>
+</code>
+</td>
+</tr>
+<tr>
+<td>
+<strong>
+<code id="widl-BatteryManager-onchargingtimechange">
+onchargingtimechange
+</code>
+</strong>
+</td>
+<td>
+<code>
+<dfn id="dfn-chargingtimechange">
+chargingtimechange
+</dfn>
+</code>
+</td>
+</tr>
+<tr>
+<td>
+<strong>
+<code id="widl-BatteryManager-ondischargingtimechange">
+ondischargingtimechange
+</code>
+</strong>
+</td>
+<td>
+<code>
+<dfn id="dfn-dischargingtimechange">
+dischargingtimechange
+</dfn>
+</code>
+</td>
+</tr>
+<tr>
+<td>
+<strong>
+<code id="widl-BatteryManager-onlevelchange">
+onlevelchange
+</code>
+</strong>
+</td>
+<td>
+<code>
+<dfn id="dfn-levelchange">
+levelchange
+</dfn>
+</code>
+</td>
+</tr>
+</tbody>
+</table>
+</section>
+</section>
+<section class="informative" id="examples">
+<h2 role="heading" id="h2_examples">
+<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
+1
+</span>
+</div>
+<pre class="example highlight prettyprint prettyprinted">
+<span class="com">// We get the initial value when the promise resolves ...</span><span class="pln">
+navigator</span><span class="pun">.</span><span class="pln">getBattery</span><span class="pun">().</span><span class="kwd">then</span><span class="pun">(</span><span class="kwd">function</span><span class="pun">(</span><span class="pln">battery</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">battery</span><span class="pun">.</span><span class="pln">level</span><span class="pun">);</span><span class="pln">
+ </span><span class="com">// ... and any subsequent updates.</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="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="kwd">this</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="pun">});</span>
+</pre>
+</div>
+<p>
+Alternatively,
+the
+same
+using
+the
+<code>
+addEventListener()
+</code>
+method:
+</p>
+<div class="example">
+<div class="example-title">
+<span>
+Example
+2
+</span>
+</div>
+<pre class="example highlight prettyprint prettyprinted">
+<span class="pln">navigator</span><span class="pun">.</span><span class="pln">getBattery</span><span class="pun">().</span><span class="kwd">then</span><span class="pun">(</span><span class="kwd">function</span><span class="pun">(</span><span class="pln">battery</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">battery</span><span class="pun">.</span><span class="pln">level</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="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="kwd">this</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="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
+3
+</span>
+</div>
+<pre class="example highlight prettyprint prettyprinted">
+<span class="dec"><!DOCTYPE html></span><span class="pln">
+</span><span class="tag"><html></span><span class="pln">
+</span><span class="tag"><head></span><span class="pln">
+ </span><span class="tag"><title></span><span class="pln">Battery Status API Example</span><span class="tag"></title></span><span class="pln">
+ </span><span class="tag"><script></span><span class="pln">
+ window</span><span class="pun">.</span><span class="pln">onload </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">function</span><span class="pln"> updateBatteryStatus</span><span class="pun">(</span><span class="pln">battery</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">
+ 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">
+ 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">
+ navigator</span><span class="pun">.</span><span class="pln">getBattery</span><span class="pun">().</span><span class="pln">then</span><span class="pun">(</span><span class="kwd">function</span><span class="pun">(</span><span class="pln">battery</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
+ </span><span class="com">// Update the battery status initially when the promise resolves ...</span><span class="pln">
+ updateBatteryStatus</span><span class="pun">(</span><span class="pln">battery</span><span class="pun">);</span><span class="pln">
+ </span><span class="com">// .. and for any subsequent updates.</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">
+ updateBatteryStatus</span><span class="pun">(</span><span class="pln">battery</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">
+ updateBatteryStatus</span><span class="pun">(</span><span class="pln">battery</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">
+ updateBatteryStatus</span><span class="pun">(</span><span class="pln">battery</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="pun">};</span><span class="pln">
+ </span><span class="tag"></script></span><span class="pln">
+</span><span class="tag"></head></span><span class="pln">
+</span><span class="tag"><body></span><span class="pln">
+ </span><span class="tag"><div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"charging"</span><span class="tag">></span><span class="pln">(charging state unknown)</span><span class="tag"></div></span><span class="pln">
+ </span><span class="tag"><div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"level"</span><span class="tag">></span><span class="pln">(battery level unknown)</span><span class="tag"></div></span><span class="pln">
+ </span><span class="tag"><div</span><span class="pln"> </span><span class="atn">id</span><span class="pun">=</span><span class="atv">"dischargingTime"</span><span class="tag">></span><span class="pln">(discharging time unknown)</span><span class="tag"></div></span><span class="pln">
+</span><span class="tag"></body></span><span class="pln">
+</span><span class="tag"></html></span>
+</pre>
+</div>
+</section>
+<section class="appendix" id="acknowledgements">
+<h2 role="heading" id="h2_acknowledgements">
+<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" typeof="bibo:Chapter" resource="#references" rel="bibo:Chapter">
+<h2 role="heading" id="h2_references">
+<span class="secno">
+B.
+</span>
+References
+</h2>
+<section id="normative-references" typeof="bibo:Chapter" resource="#normative-references" rel="bibo:Chapter">
+<h3 role="heading" id="h3_normative-references">
+<span class="secno">
+B.1
+</span>
+Normative
+references
+</h3>
+<dl class="bibliography" about="">
+<dt id="bib-ECMASCRIPT">
+[ECMASCRIPT]
+</dt>
+<dd rel="dcterms:requires">
+<ins class="diff-chg">Allen
+Wirfs-Brock.
+</ins>
+<a href="http://people.mozilla.org/~jorendorff/es6-draft.html">
+<cite>
+ECMA-262
+ECMAScript
+Language
+Specification,
+Edition
+6
+</cite>
+</a>.
+Draft.
+URL:
+<a href="http://people.mozilla.org/~jorendorff/es6-draft.html">
+http://people.mozilla.org/~jorendorff/es6-draft.html
+</a>
+</dd>
+<dt id="bib-HTML5">
+[HTML5]
+</dt>
+<dd rel="dcterms:requires">
+Robin
+Berjon;
+Steve
+Faulkner;
+Travis
+Leithead;
+Erika
+Doyle
+Navara;
+Edward
+O'Connor;
+Silvia
+Pfeiffer.
+<a href="http://www.w3.org/TR/html5/">
+<cite>
+HTML5
+</cite>
+</a>.
+<del class="diff-old">17
+June
+</del>
+<ins class="diff-chg">28
+October
+</ins>
+2014.
+W3C
+<del class="diff-old">Last
+Call
+Working
+Draft.
+</del>
+<ins class="diff-chg">Recommendation.
+</ins>
+URL:
+<a href="http://www.w3.org/TR/html5/">
+http://www.w3.org/TR/html5/
+</a>
+</dd>
+<dt id="bib-RFC2119">
+[RFC2119]
+</dt>
+<dd rel="dcterms:requires">
+S.
+Bradner.
+<a href="https://tools.ietf.org/html/rfc2119">
+<cite>
+Key
+words
+for
+use
+in
+RFCs
+to
+Indicate
+Requirement
+Levels
+</cite>
+</a>.
+March
+1997.
+Best
+Current
+Practice.
+URL:
+<del class="diff-old">http://www.ietf.org/rfc/rfc2119.txt
+</del>
+<a href="https://tools.ietf.org/html/rfc2119">
+<ins class="diff-chg">https://tools.ietf.org/html/rfc2119
+</ins>
+</a>
+</dd>
+<dt id="bib-WEBIDL">
+[WEBIDL]
+</dt>
+<dd rel="dcterms:requires">
+Cameron
+McCormack.
+<a href="http://www.w3.org/TR/WebIDL/">
+<cite>
+Web
+IDL
+</cite>
+</a>.
+19
+April
+2012.
+W3C
+Candidate
+Recommendation.
+URL:
+<a href="http://www.w3.org/TR/WebIDL/">
+http://www.w3.org/TR/WebIDL/
+</a>
+</dd>
+</dl>
+</section>
+</section>
+</body>
+</html>
+