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index.html
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<!doctype html><html lang="en">
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<meta content="width=device-width, initial-scale=1, shrink-to-fit=no" name="viewport">
<title>Keyboard Lock</title>
<link href="https://www.w3.org/StyleSheets/TR/2016/cg-draft" rel="stylesheet" type="text/css">
<meta content="Bikeshed version e8cbf4ed2, updated Fri Sep 10 10:21:28 2021 -0700" name="generator">
<link href="https://wicg.github.io/keyboard-lock/" rel="canonical">
<meta content="17ec6f65673c69b0fdc7d49d16224762619ed77e" name="document-revision">
<style>/* style-autolinks */
.css.css, .property.property, .descriptor.descriptor {
color: var(--a-normal-text);
font-size: inherit;
font-family: inherit;
}
.css::before, .property::before, .descriptor::before {
content: "‘";
}
.css::after, .property::after, .descriptor::after {
content: "’";
}
.property, .descriptor {
/* Don't wrap property and descriptor names */
white-space: nowrap;
}
.type { /* CSS value <type> */
font-style: italic;
}
pre .property::before, pre .property::after {
content: "";
}
[data-link-type="property"]::before,
[data-link-type="propdesc"]::before,
[data-link-type="descriptor"]::before,
[data-link-type="value"]::before,
[data-link-type="function"]::before,
[data-link-type="at-rule"]::before,
[data-link-type="selector"]::before,
[data-link-type="maybe"]::before {
content: "‘";
}
[data-link-type="property"]::after,
[data-link-type="propdesc"]::after,
[data-link-type="descriptor"]::after,
[data-link-type="value"]::after,
[data-link-type="function"]::after,
[data-link-type="at-rule"]::after,
[data-link-type="selector"]::after,
[data-link-type="maybe"]::after {
content: "’";
}
[data-link-type].production::before,
[data-link-type].production::after,
.prod [data-link-type]::before,
.prod [data-link-type]::after {
content: "";
}
[data-link-type=element],
[data-link-type=element-attr] {
font-family: Menlo, Consolas, "DejaVu Sans Mono", monospace;
font-size: .9em;
}
[data-link-type=element]::before { content: "<" }
[data-link-type=element]::after { content: ">" }
[data-link-type=biblio] {
white-space: pre;
}</style>
<style>/* style-colors */
/* Any --*-text not paired with a --*-bg is assumed to have a transparent bg */
:root {
color-scheme: light dark;
--text: black;
--bg: white;
--unofficial-watermark: url(https://www.w3.org/StyleSheets/TR/2016/logos/UD-watermark);
--logo-bg: #1a5e9a;
--logo-active-bg: #c00;
--logo-text: white;
--tocnav-normal-text: #707070;
--tocnav-normal-bg: var(--bg);
--tocnav-hover-text: var(--tocnav-normal-text);
--tocnav-hover-bg: #f8f8f8;
--tocnav-active-text: #c00;
--tocnav-active-bg: var(--tocnav-normal-bg);
--tocsidebar-text: var(--text);
--tocsidebar-bg: #f7f8f9;
--tocsidebar-shadow: rgba(0,0,0,.1);
--tocsidebar-heading-text: hsla(203,20%,40%,.7);
--toclink-text: var(--text);
--toclink-underline: #3980b5;
--toclink-visited-text: var(--toclink-text);
--toclink-visited-underline: #054572;
--heading-text: #005a9c;
--hr-text: var(--text);
--algo-border: #def;
--del-text: red;
--del-bg: transparent;
--ins-text: #080;
--ins-bg: transparent;
--a-normal-text: #034575;
--a-normal-underline: #bbb;
--a-visited-text: var(--a-normal-text);
--a-visited-underline: #707070;
--a-hover-bg: rgba(75%, 75%, 75%, .25);
--a-active-text: #c00;
--a-active-underline: #c00;
--blockquote-border: silver;
--blockquote-bg: transparent;
--blockquote-text: currentcolor;
--issue-border: #e05252;
--issue-bg: #fbe9e9;
--issue-text: var(--text);
--issueheading-text: #831616;
--example-border: #e0cb52;
--example-bg: #fcfaee;
--example-text: var(--text);
--exampleheading-text: #574b0f;
--note-border: #52e052;
--note-bg: #e9fbe9;
--note-text: var(--text);
--noteheading-text: hsl(120, 70%, 30%);
--notesummary-underline: silver;
--assertion-border: #aaa;
--assertion-bg: #eee;
--assertion-text: black;
--advisement-border: orange;
--advisement-bg: #fec;
--advisement-text: var(--text);
--advisementheading-text: #b35f00;
--warning-border: red;
--warning-bg: hsla(40,100%,50%,0.95);
--warning-text: var(--text);
--amendment-border: #330099;
--amendment-bg: #F5F0FF;
--amendment-text: var(--text);
--amendmentheading-text: #220066;
--def-border: #8ccbf2;
--def-bg: #def;
--def-text: var(--text);
--defrow-border: #bbd7e9;
--datacell-border: silver;
--indexinfo-text: #707070;
--indextable-hover-text: black;
--indextable-hover-bg: #f7f8f9;
--outdatedspec-bg: rgba(0, 0, 0, .5);
--outdatedspec-text: black;
--outdated-bg: maroon;
--outdated-text: white;
--outdated-shadow: red;
--editedrec-bg: darkorange;
}</style>
<style>/* style-counters */
body {
counter-reset: example figure issue;
}
.issue {
counter-increment: issue;
}
.issue:not(.no-marker)::before {
content: "Issue " counter(issue);
}
.example {
counter-increment: example;
}
.example:not(.no-marker)::before {
content: "Example " counter(example);
}
.invalid.example:not(.no-marker)::before,
.illegal.example:not(.no-marker)::before {
content: "Invalid Example" counter(example);
}
figcaption {
counter-increment: figure;
}
figcaption:not(.no-marker)::before {
content: "Figure " counter(figure) " ";
}</style>
<style>/* style-dfn-panel */
:root {
--dfnpanel-bg: #ddd;
--dfnpanel-text: var(--text);
}
.dfn-panel {
position: absolute;
z-index: 35;
height: auto;
width: -webkit-fit-content;
width: fit-content;
max-width: 300px;
max-height: 500px;
overflow: auto;
padding: 0.5em 0.75em;
font: small Helvetica Neue, sans-serif, Droid Sans Fallback;
background: var(--dfnpanel-bg);
color: var(--dfnpanel-text);
border: outset 0.2em;
}
.dfn-panel:not(.on) { display: none; }
.dfn-panel * { margin: 0; padding: 0; text-indent: 0; }
.dfn-panel > b { display: block; }
.dfn-panel a { color: var(--dfnpanel-text); }
.dfn-panel a:not(:hover) { text-decoration: none !important; border-bottom: none !important; }
.dfn-panel > b + b { margin-top: 0.25em; }
.dfn-panel ul { padding: 0; }
.dfn-panel li { list-style: inside; }
.dfn-panel.activated {
display: inline-block;
position: fixed;
left: .5em;
bottom: 2em;
margin: 0 auto;
max-width: calc(100vw - 1.5em - .4em - .5em);
max-height: 30vh;
}
.dfn-paneled { cursor: pointer; }
</style>
<style>/* style-md-lists */
/* This is a weird hack for me not yet following the commonmark spec
regarding paragraph and lists. */
[data-md] > :first-child {
margin-top: 0;
}
[data-md] > :last-child {
margin-bottom: 0;
}</style>
<style>/* style-selflinks */
:root {
--selflink-text: white;
--selflink-bg: gray;
--selflink-hover-text: black;
}
.heading, .issue, .note, .example, li, dt {
position: relative;
}
a.self-link {
position: absolute;
top: 0;
left: calc(-1 * (3.5rem - 26px));
width: calc(3.5rem - 26px);
height: 2em;
text-align: center;
border: none;
transition: opacity .2s;
opacity: .5;
}
a.self-link:hover {
opacity: 1;
}
.heading > a.self-link {
font-size: 83%;
}
li > a.self-link {
left: calc(-1 * (3.5rem - 26px) - 2em);
}
dfn > a.self-link {
top: auto;
left: auto;
opacity: 0;
width: 1.5em;
height: 1.5em;
background: var(--selflink-bg);
color: var(--selflink-text);
font-style: normal;
transition: opacity .2s, background-color .2s, color .2s;
}
dfn:hover > a.self-link {
opacity: 1;
}
dfn > a.self-link:hover {
color: var(--selflink-hover-text);
}
a.self-link::before { content: "¶"; }
.heading > a.self-link::before { content: "§"; }
dfn > a.self-link::before { content: "#"; }
</style>
<style>/* style-syntax-highlighting */
pre.idl.highlight {
background: var(--borderedblock-bg, var(--def-bg));
}
code.highlight { padding: .1em; border-radius: .3em; }
pre.highlight, pre > code.highlight { display: block; padding: 1em; margin: .5em 0; overflow: auto; border-radius: 0; }
.highlight:not(.idl) { background: rgba(0, 0, 0, .03); }
c-[a] { color: #990055 } /* Keyword.Declaration */
c-[b] { color: #990055 } /* Keyword.Type */
c-[c] { color: #708090 } /* Comment */
c-[d] { color: #708090 } /* Comment.Multiline */
c-[e] { color: #0077aa } /* Name.Attribute */
c-[f] { color: #669900 } /* Name.Tag */
c-[g] { color: #222222 } /* Name.Variable */
c-[k] { color: #990055 } /* Keyword */
c-[l] { color: #000000 } /* Literal */
c-[m] { color: #000000 } /* Literal.Number */
c-[n] { color: #0077aa } /* Name */
c-[o] { color: #999999 } /* Operator */
c-[p] { color: #999999 } /* Punctuation */
c-[s] { color: #a67f59 } /* Literal.String */
c-[t] { color: #a67f59 } /* Literal.String.Single */
c-[u] { color: #a67f59 } /* Literal.String.Double */
c-[cp] { color: #708090 } /* Comment.Preproc */
c-[c1] { color: #708090 } /* Comment.Single */
c-[cs] { color: #708090 } /* Comment.Special */
c-[kc] { color: #990055 } /* Keyword.Constant */
c-[kn] { color: #990055 } /* Keyword.Namespace */
c-[kp] { color: #990055 } /* Keyword.Pseudo */
c-[kr] { color: #990055 } /* Keyword.Reserved */
c-[ld] { color: #000000 } /* Literal.Date */
c-[nc] { color: #0077aa } /* Name.Class */
c-[no] { color: #0077aa } /* Name.Constant */
c-[nd] { color: #0077aa } /* Name.Decorator */
c-[ni] { color: #0077aa } /* Name.Entity */
c-[ne] { color: #0077aa } /* Name.Exception */
c-[nf] { color: #0077aa } /* Name.Function */
c-[nl] { color: #0077aa } /* Name.Label */
c-[nn] { color: #0077aa } /* Name.Namespace */
c-[py] { color: #0077aa } /* Name.Property */
c-[ow] { color: #999999 } /* Operator.Word */
c-[mb] { color: #000000 } /* Literal.Number.Bin */
c-[mf] { color: #000000 } /* Literal.Number.Float */
c-[mh] { color: #000000 } /* Literal.Number.Hex */
c-[mi] { color: #000000 } /* Literal.Number.Integer */
c-[mo] { color: #000000 } /* Literal.Number.Oct */
c-[sb] { color: #a67f59 } /* Literal.String.Backtick */
c-[sc] { color: #a67f59 } /* Literal.String.Char */
c-[sd] { color: #a67f59 } /* Literal.String.Doc */
c-[se] { color: #a67f59 } /* Literal.String.Escape */
c-[sh] { color: #a67f59 } /* Literal.String.Heredoc */
c-[si] { color: #a67f59 } /* Literal.String.Interpol */
c-[sx] { color: #a67f59 } /* Literal.String.Other */
c-[sr] { color: #a67f59 } /* Literal.String.Regex */
c-[ss] { color: #a67f59 } /* Literal.String.Symbol */
c-[vc] { color: #0077aa } /* Name.Variable.Class */
c-[vg] { color: #0077aa } /* Name.Variable.Global */
c-[vi] { color: #0077aa } /* Name.Variable.Instance */
c-[il] { color: #000000 } /* Literal.Number.Integer.Long */
</style>
<style>/* style-var-click-highlighting */
var { cursor: pointer; }
var.selected0 { background-color: #F4D200; box-shadow: 0 0 0 2px #F4D200; }
var.selected1 { background-color: #FF87A2; box-shadow: 0 0 0 2px #FF87A2; }
var.selected2 { background-color: #96E885; box-shadow: 0 0 0 2px #96E885; }
var.selected3 { background-color: #3EEED2; box-shadow: 0 0 0 2px #3EEED2; }
var.selected4 { background-color: #EACFB6; box-shadow: 0 0 0 2px #EACFB6; }
var.selected5 { background-color: #82DDFF; box-shadow: 0 0 0 2px #82DDFF; }
var.selected6 { background-color: #FFBCF2; box-shadow: 0 0 0 2px #FFBCF2; }
</style>
<style>/* style-darkmode */
@media (prefers-color-scheme: dark) {
:root {
--text: #ddd;
--bg: black;
--unofficial-watermark: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='400' height='400'%3E%3Cg fill='%23100808' transform='translate(200 200) rotate(-45) translate(-200 -200)' stroke='%23100808' stroke-width='3'%3E%3Ctext x='50%25' y='220' style='font: bold 70px sans-serif; text-anchor: middle; letter-spacing: 6px;'%3EUNOFFICIAL%3C/text%3E%3Ctext x='50%25' y='305' style='font: bold 70px sans-serif; text-anchor: middle; letter-spacing: 6px;'%3EDRAFT%3C/text%3E%3C/g%3E%3C/svg%3E");
--logo-bg: #1a5e9a;
--logo-active-bg: #c00;
--logo-text: white;
--tocnav-normal-text: #999;
--tocnav-normal-bg: var(--bg);
--tocnav-hover-text: var(--tocnav-normal-text);
--tocnav-hover-bg: #080808;
--tocnav-active-text: #f44;
--tocnav-active-bg: var(--tocnav-normal-bg);
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<body class="h-entry">
<div class="head">
<p data-fill-with="logo"><a class="logo" href="https://www.w3.org/"> <img alt="W3C" height="48" src="https://www.w3.org/StyleSheets/TR/2016/logos/W3C" width="72"> </a> </p>
<h1>Keyboard Lock</h1>
<h2 class="no-num no-toc no-ref heading settled" id="profile-and-date"><span class="content">Draft Community Group Report, <time class="dt-updated" datetime="2021-10-06">6 October 2021</time></span></h2>
<div data-fill-with="spec-metadata">
<dl>
<dt>This version:
<dd><a class="u-url" href="https://wicg.github.io/keyboard-lock/">https://wicg.github.io/keyboard-lock/</a>
<dt>Issue Tracking:
<dd><a href="https://github.com/wicg/keyboard-lock/issues/">GitHub</a>
<dt class="editor">Editors:
<dd class="editor p-author h-card vcard"><span class="p-name fn"></span>
<dd class="editor p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:garykac@google.com">Gary Kacmarcik</a> (<span class="p-org org">Google</span>)
<dd class="editor p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:jamiewalch@google.com">Jamie Walch</a> (<span class="p-org org">Google</span>)
</dl>
</div>
<div data-fill-with="warning"></div>
<p class="copyright" data-fill-with="copyright"><a href="https://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 2021 <a href="https://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a href="https://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>, <a href="https://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>, <a href="httsp://www.keio.ac.jp/">Keio</a>, <a href="https://ev.buaa.edu.cn/">Beihang</a>). W3C <a href="https://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="https://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="https://www.w3.org/Consortium/Legal/2015/copyright-software-and-document" rel="license">permissive document license</a> rules apply. </p>
<hr title="Separator for header">
</div>
<div class="p-summary" data-fill-with="abstract">
<h2 class="no-num no-toc no-ref heading settled" id="abstract"><span class="content">Abstract</span></h2>
<p>This specification defines an API that allows websites to
capture keys that are normally reserved by the underlying host
operating system. It is intended to be used by web
applications that provide a fullscreen immersive experience
(like games or remote access apps).</p>
</div>
<h2 class="no-num no-toc no-ref heading settled" id="status"><span class="content">Status of this document</span></h2>
<div data-fill-with="status">
<p></p>
<p>This document is an editor’s draft proposed as a First Public Working Draft.</p>
</div>
<div data-fill-with="at-risk"></div>
<nav data-fill-with="table-of-contents" id="toc">
<h2 class="no-num no-toc no-ref" id="contents">Table of Contents</h2>
<ol class="toc" role="directory">
<li><a href="#introduction"><span class="secno">1</span> <span class="content">Introduction</span></a>
<li>
<a href="#API"><span class="secno">2</span> <span class="content">Keyboard Lock API</span></a>
<ol class="toc">
<li>
<a href="#navigator-interface"><span class="secno">2.1</span> <span class="content">Navigator Interface</span></a>
<ol class="toc">
<li><a href="#h-navigator-keyboard"><span class="secno">2.1.1</span> <span class="content"><span>keyboard</span></span></a>
</ol>
<li>
<a href="#keyboard-interface"><span class="secno">2.2</span> <span class="content">Keyboard Interface</span></a>
<ol class="toc">
<li><a href="#h-keyboard-lock"><span class="secno">2.2.1</span> <span class="content"><span>lock()</span></span></a>
<li><a href="#h-keyboard-unlock"><span class="secno">2.2.2</span> <span class="content"><span>unlock()</span></span></a>
</ol>
</ol>
<li>
<a href="#handling-events"><span class="secno">3</span> <span class="content">Handling Keyboard Key Presses</span></a>
<ol class="toc">
<li>
<a href="#key-press-handler"><span class="secno">3.1</span> <span class="content">System Key Press Handler</span></a>
<ol class="toc">
<li><a href="#registering"><span class="secno">3.1.1</span> <span class="content">Registering</span></a>
<li><a href="#unregistering"><span class="secno">3.1.2</span> <span class="content">Unregistering</span></a>
</ol>
<li><a href="#handling-keyboard-events"><span class="secno">3.2</span> <span class="content">Handling Keyboard Events</span></a>
</ol>
<li>
<a href="#interactions"><span class="secno">4</span> <span class="content">Integration With Other Web Platform APIs</span></a>
<ol class="toc">
<li><a href="#escape-key"><span class="secno">4.1</span> <span class="content">Special Considerations with the Escape Key</span></a>
<li><a href="#fullscreen-considerations"><span class="secno">4.2</span> <span class="content">Fullscreen Considerations</span></a>
</ol>
<li><a href="#pointerlock-considerations"><span class="secno">5</span> <span class="content">Pointer Lock Considerations</span></a>
<li><a href="#mobile"><span class="secno">6</span> <span class="content">Mobile Device Considerations</span></a>
<li><a href="#security"><span class="secno">7</span> <span class="content">Security Considerations</span></a>
<li><a href="#privacy"><span class="secno">8</span> <span class="content">Privacy Considerations</span></a>
<li><a href="#acknowledgements-contributors"><span class="secno">9</span> <span class="content">Acknowledgements</span></a>
<li>
<a href="#conformance"><span class="secno"></span> <span class="content">Conformance</span></a>
<ol class="toc">
<li><a href="#conventions"><span class="secno"></span> <span class="content">Document conventions</span></a>
<li><a href="#conformant-algorithms"><span class="secno"></span> <span class="content">Conformant Algorithms</span></a>
</ol>
<li>
<a href="#index"><span class="secno"></span> <span class="content">Index</span></a>
<ol class="toc">
<li><a href="#index-defined-here"><span class="secno"></span> <span class="content">Terms defined by this specification</span></a>
<li><a href="#index-defined-elsewhere"><span class="secno"></span> <span class="content">Terms defined by reference</span></a>
</ol>
<li>
<a href="#references"><span class="secno"></span> <span class="content">References</span></a>
<ol class="toc">
<li><a href="#normative"><span class="secno"></span> <span class="content">Normative References</span></a>
<li><a href="#informative"><span class="secno"></span> <span class="content">Informative References</span></a>
</ol>
<li><a href="#idl-index"><span class="secno"></span> <span class="content">IDL Index</span></a>
</ol>
</nav>
<main>
<h2 class="heading settled" data-level="1" id="introduction"><span class="secno">1. </span><span class="content">Introduction</span><a class="self-link" href="#introduction"></a></h2>
<p>Richly interactive web sites, games and remote
desktop/application streaming experiences want to provide an
immersive, full screen experience. To accomplish this, sites
need access to special keys and keyboard shortcuts while they
are in full screen mode so that they can be used for
navigation, menus or gaming functionality. Some examples of
the keys that may be required are Escape, Alt+Tab, Cmd+`, and
Ctrl+N.</p>
<p>By default, these keys are not available to the web application because
they are captured by the browser or the underlying operating
system. The Keyboard Lock API enables websites to capture and use
all available keys allowed by the OS.</p>
<h2 class="heading settled" data-level="2" id="API"><span class="secno">2. </span><span class="content">Keyboard Lock API</span><a class="self-link" href="#API"></a></h2>
<h3 class="heading settled" data-level="2.1" id="navigator-interface"><span class="secno">2.1. </span><span class="content">Navigator Interface</span><a class="self-link" href="#navigator-interface"></a></h3>
<pre class="idl highlight def" data-highlight="webidl"><c- b>partial</c-> <c- b>interface</c-> <a class="idl-code" data-link-type="interface" href="https://html.spec.whatwg.org/multipage/system-state.html#navigator" id="ref-for-navigator"><c- g>Navigator</c-></a> {
[<a class="idl-code" data-link-type="extended-attribute" href="https://heycam.github.io/webidl/#SecureContext" id="ref-for-SecureContext"><c- g>SecureContext</c-></a>, <a class="idl-code" data-link-type="extended-attribute" href="https://heycam.github.io/webidl/#SameObject" id="ref-for-SameObject"><c- g>SameObject</c-></a>] <c- b>readonly</c-> <c- b>attribute</c-> <a data-link-type="idl-name" href="#keyboard" id="ref-for-keyboard"><c- n>Keyboard</c-></a> <dfn class="idl-code" data-dfn-for="Navigator" data-dfn-type="attribute" data-export data-readonly data-type="Keyboard" id="dom-navigator-keyboard"><code><c- g>keyboard</c-></code><a class="self-link" href="#dom-navigator-keyboard"></a></dfn>;
};
</pre>
<div id="navigator-idl">
<div class="algorithm" data-algorithm="navigator-keyboard">
<h4 class="heading settled" data-level="2.1.1" id="h-navigator-keyboard"><span class="secno">2.1.1. </span><span class="content"><dfn class="dfn-paneled" data-dfn-for="Navigator" data-dfn-type="dfn" data-noexport id="navigator-keyboard">keyboard</dfn></span><a class="self-link" href="#h-navigator-keyboard"></a></h4>
The <a data-link-type="dfn" href="#navigator-keyboard" id="ref-for-navigator-keyboard">keyboard</a> attribute must return the <code class="idl"><a data-link-type="idl" href="https://html.spec.whatwg.org/multipage/system-state.html#navigator" id="ref-for-navigator①">Navigator</a></code>'s <code class="idl"><a data-link-type="idl" href="#keyboard" id="ref-for-keyboard①">Keyboard</a></code> object.
</div>
</div>
<h3 class="heading settled" data-level="2.2" id="keyboard-interface"><span class="secno">2.2. </span><span class="content">Keyboard Interface</span><a class="self-link" href="#keyboard-interface"></a></h3>
<pre class="idl highlight def" data-highlight="webidl">[<a class="idl-code" data-link-type="extended-attribute" href="https://heycam.github.io/webidl/#SecureContext" id="ref-for-SecureContext①"><c- g>SecureContext</c-></a>, <a class="idl-code" data-link-type="extended-attribute" href="https://heycam.github.io/webidl/#Exposed" id="ref-for-Exposed"><c- g>Exposed</c-></a>=<c- n>Window</c->]
<c- b>interface</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="interface" data-export id="keyboard"><code><c- g>Keyboard</c-></code></dfn> : <a data-link-type="idl-name" href="https://dom.spec.whatwg.org/#eventtarget" id="ref-for-eventtarget"><c- n>EventTarget</c-></a> {
<a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-promise" id="ref-for-idl-promise"><c- b>Promise</c-></a><<a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-undefined" id="ref-for-idl-undefined"><c- b>undefined</c-></a>> <dfn class="dfn-paneled idl-code" data-dfn-for="Keyboard" data-dfn-type="method" data-export data-lt="lock(keyCodes)|lock()" id="dom-keyboard-lock"><code><c- g>lock</c-></code></dfn>(<c- b>optional</c-> <a data-link-type="dfn" href="https://heycam.github.io/webidl/#idl-sequence" id="ref-for-idl-sequence"><c- b>sequence</c-></a><<a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString"><c- b>DOMString</c-></a>> <dfn class="dfn-paneled idl-code" data-dfn-for="Keyboard/lock(keyCodes), Keyboard/lock()" data-dfn-type="argument" data-export id="dom-keyboard-lock-keycodes-keycodes"><code><c- g>keyCodes</c-></code></dfn> = []);
<a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-undefined" id="ref-for-idl-undefined①"><c- b>undefined</c-></a> <dfn class="dfn-paneled idl-code" data-dfn-for="Keyboard" data-dfn-type="method" data-export data-lt="unlock()" id="dom-keyboard-unlock"><code><c- g>unlock</c-></code></dfn>();
};
</pre>
<div id="keyboard-idl">
<p>The keyboard object has <dfn class="dfn-paneled" data-dfn-for="Keyboard" data-dfn-type="dfn" data-noexport id="keyboard-enable-keyboard-lock">enable keyboard lock</dfn>, which is a
boolean that is set to true when Keyboard Lock is enabled.
By default, this is set to false.</p>
<p>The keyboard object has <dfn class="dfn-paneled" data-dfn-for="Keyboard" data-dfn-type="dfn" data-noexport id="keyboard-reserved-key-codes">reserved key codes</dfn>, which is a
set of DOMStrings, each of which is a valid <a data-link-type="dfn" href="http://www.w3.org/TR/uievents-code/#key-code-attribute-value" id="ref-for-key-code-attribute-value">key code attribute value</a> as defined in <a data-link-type="biblio" href="#biblio-uievents-code">[UIEvents-Code]</a>.
By default this set is empty (which would capture all keys
if <a data-link-type="dfn" href="#keyboard-enable-keyboard-lock" id="ref-for-keyboard-enable-keyboard-lock">enable keyboard lock</a> was enabled).</p>
<p>The keyboard object has a <dfn class="dfn-paneled" data-dfn-for="Keyboard" data-dfn-type="dfn" data-noexport id="keyboard-keyboard-lock-task-queue">keyboard lock task queue</dfn> which is
initialized to the result of <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/infrastructure.html#starting-a-new-parallel-queue" id="ref-for-starting-a-new-parallel-queue">starting a new parallel queue</a>.</p>
<p class="note" role="note"><span>Note:</span> The <code class="idl"><a data-link-type="idl" href="#keyboard" id="ref-for-keyboard②">Keyboard</a></code> interface inherits from <code class="idl"><a data-link-type="idl" href="https://dom.spec.whatwg.org/#eventtarget" id="ref-for-eventtarget①">EventTarget</a></code> because
it needs to be able to handle some keyboard-releated events like <a href="https://wicg.github.io/keyboard-map/#layoutchange-event"><code>layoutchange</code></a>.</p>
<div class="algorithm" data-algorithm="keyboard-lock">
<h4 class="heading settled" data-level="2.2.1" id="h-keyboard-lock"><span class="secno">2.2.1. </span><span class="content"><dfn data-dfn-for="Keyboard" data-dfn-type="dfn" data-export id="keyboard-lock">lock()<a class="self-link" href="#keyboard-lock"></a></dfn></span><a class="self-link" href="#h-keyboard-lock"></a></h4>
<p>When <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock" id="ref-for-dom-keyboard-lock">lock()</a></code> is called, the user agent must
run the following steps:</p>
<ol>
<li data-md>
<p>Let <var>p</var> be a new <a data-link-type="dfn" href="http://tc39.github.io/ecma262/#sec-promise-objects" id="ref-for-sec-promise-objects">Promise</a>.</p>
<li data-md>
<p>If not currently executing in the currently active <a data-link-type="dfn" href="https://html.spec.whatwg.org/#top-level-browsing-context" id="ref-for-top-level-browsing-context">top-level browsing context</a>, then</p>
<ol>
<li data-md>
<p>Reject <var>p</var> with an "<code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#invalidstateerror" id="ref-for-invalidstateerror">InvalidStateError</a></code>" <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-DOMException" id="ref-for-idl-DOMException">DOMException</a></code>.</p>
</ol>
<li data-md>
<p><a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/infrastructure.html#enqueue-the-following-steps" id="ref-for-enqueue-the-following-steps">Enqueue the following steps</a> to the <a data-link-type="dfn" href="#keyboard-keyboard-lock-task-queue" id="ref-for-keyboard-keyboard-lock-task-queue">keyboard lock task queue</a>:</p>
<ol>
<li data-md>
<p>Reset <a data-link-type="dfn" href="#keyboard-reserved-key-codes" id="ref-for-keyboard-reserved-key-codes">reserved key codes</a> to be an empty set.</p>
<li data-md>
<p>If the optional <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock-keycodes-keycodes" id="ref-for-dom-keyboard-lock-keycodes-keycodes">keyCodes</a></code> argument is present, run the
following substeps:</p>
<ol>
<li data-md>
<p><a data-link-type="dfn" href="https://infra.spec.whatwg.org/#list-iterate" id="ref-for-list-iterate">For each</a> string <var>key</var> in <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock-keycodes-keycodes" id="ref-for-dom-keyboard-lock-keycodes-keycodes①">keyCodes</a></code>:</p>
<ol>
<li data-md>
<p>If <var>key</var> is not a valid <a data-link-type="dfn" href="http://www.w3.org/TR/uievents-code/#key-code-attribute-value" id="ref-for-key-code-attribute-value①">key code attribute value</a>, then</p>
<ol>
<li data-md>
<p>Set <a data-link-type="dfn" href="#keyboard-enable-keyboard-lock" id="ref-for-keyboard-enable-keyboard-lock①">enable keyboard lock</a> to be false.</p>
<li data-md>
<p>Reject <var>p</var> with an "<code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#invalidaccesserror" id="ref-for-invalidaccesserror">InvalidAccessError</a></code>" <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-DOMException" id="ref-for-idl-DOMException①">DOMException</a></code>.</p>
</ol>
<li data-md>
<p><a data-link-type="dfn" href="https://infra.spec.whatwg.org/#set-append" id="ref-for-set-append">Append</a> <var>key</var> to <a data-link-type="dfn" href="#keyboard-reserved-key-codes" id="ref-for-keyboard-reserved-key-codes①">reserved key codes</a>.</p>
</ol>
</ol>
<li data-md>
<p>If <a data-link-type="dfn" href="#keyboard-enable-keyboard-lock" id="ref-for-keyboard-enable-keyboard-lock②">enable keyboard lock</a> is currently false, run the following
substeps:</p>
<ol>
<li data-md>
<p>Optionally, <a data-link-type="dfn" href="#register-a-system-key-press-handler" id="ref-for-register-a-system-key-press-handler">register a system key press handler</a>.</p>
<li data-md>
<p>Set <a data-link-type="dfn" href="#keyboard-enable-keyboard-lock" id="ref-for-keyboard-enable-keyboard-lock③">enable keyboard lock</a> to be true.</p>
</ol>
<li data-md>
<p>If there is a pending <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock" id="ref-for-dom-keyboard-lock①">lock()</a></code> task in the <a data-link-type="dfn" href="#keyboard-keyboard-lock-task-queue" id="ref-for-keyboard-keyboard-lock-task-queue①">keyboard lock task queue</a>, then</p>
<ol>
<li data-md>
<p>Set <a data-link-type="dfn" href="#keyboard-enable-keyboard-lock" id="ref-for-keyboard-enable-keyboard-lock④">enable keyboard lock</a> to be false.</p>
<li data-md>
<p>Reject the <var>p</var> with an "<code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#aborterror" id="ref-for-aborterror">AbortError</a></code>" DOMException.</p>
</ol>
<li data-md>
<p>Resolve <var>p</var>.</p>
</ol>
<li data-md>
<p>Return <var>p</var>.</p>
</ol>
<div></div>
<p class="note" role="note"><span>Note:</span> If <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock" id="ref-for-dom-keyboard-lock②">lock()</a></code> is called multiple times without an
intervening call to <code class="idl"><a data-link-type="idl" href="#dom-keyboard-unlock" id="ref-for-dom-keyboard-unlock">unlock()</a></code>, then only the <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock-keycodes-keycodes" id="ref-for-dom-keyboard-lock-keycodes-keycodes②">keyCodes</a></code> specified in the last request call will be in effect.
If a second call to <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock" id="ref-for-dom-keyboard-lock③">lock()</a></code> is made before the first one has finished,
then the first one will be rejected with "<code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#aborterror" id="ref-for-aborterror①">AbortError</a></code>".</p>
<div class="example" id="example-3c1370ba">
<a class="self-link" href="#example-3c1370ba"></a> To capture all keys, simply call <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock" id="ref-for-dom-keyboard-lock④">lock()</a></code> with no arguments:
<pre>navigator.keyboard.lock();
</pre>
</div>
<div class="example" id="example-5c32e45b">
<a class="self-link" href="#example-5c32e45b"></a> To capture the "W", "A", "S", and "D" keys, call <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock" id="ref-for-dom-keyboard-lock⑤">lock()</a></code> with
a list that contains the <a data-link-type="dfn" href="http://www.w3.org/TR/uievents-code/#key-code-attribute-value" id="ref-for-key-code-attribute-value②">key code attribute value</a> for each of these keys:
<pre>navigator.keyboard.lock(["KeyW", "KeyA", "KeyS", "KeyD"]);
</pre>
<p>This will capture these keys regardless of which modifiers are used with the
key press. Assuming a standard US QWERTY layout, registering <a data-link-type="dfn" href="http://www.w3.org/TR/uievents-code/#code-keyw" id="ref-for-code-keyw">KeyW</a> will
ensure that "W", Shift+"W", Control+"W", Control+Shift+"W", and all other key
modifier combinations with "W" will be sent to the app. Similarly for <a data-link-type="dfn" href="http://www.w3.org/TR/uievents-code/#code-keya" id="ref-for-code-keya">KeyA</a>, <a data-link-type="dfn" href="http://www.w3.org/TR/uievents-code/#code-keys" id="ref-for-code-keys">KeyS</a> and <a data-link-type="dfn" href="http://www.w3.org/TR/uievents-code/#code-keyd" id="ref-for-code-keyd">KeyD</a>.</p>
</div>
<div class="example" id="example-025aab28">
<a class="self-link" href="#example-025aab28"></a> Note that requesting a key is not a guarantee that all modified versions will
be made available to the app. As an example, consider <a data-link-type="dfn" href="http://www.w3.org/TR/uievents-code/#code-delete" id="ref-for-code-delete">Delete</a>
<pre>navigator.keyboard.lock(["Delete"]);
</pre>
<p>While this will make most Delete key presses available (e.g., Shift+Delete,
Control+Delete, Shift+Control+Delete), on Windows it will not make available
the “secure attention sequence” Control+Alt+Delete.</p>
</div>
</div>
<div class="algorithm" data-algorithm="keyboard-unlock">
<h4 class="heading settled" data-level="2.2.2" id="h-keyboard-unlock"><span class="secno">2.2.2. </span><span class="content"><dfn data-dfn-for="Keyboard" data-dfn-type="dfn" data-export id="keyboard-unlock">unlock()<a class="self-link" href="#keyboard-unlock"></a></dfn></span><a class="self-link" href="#h-keyboard-unlock"></a></h4>
<p>When <code class="idl"><a data-link-type="idl" href="#dom-keyboard-unlock" id="ref-for-dom-keyboard-unlock①">unlock()</a></code> is called, the user agent must
run the following steps:</p>
<ol>
<li data-md>
<p><a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/infrastructure.html#enqueue-the-following-steps" id="ref-for-enqueue-the-following-steps①">Enqueue the following steps</a> to the <a data-link-type="dfn" href="#keyboard-keyboard-lock-task-queue" id="ref-for-keyboard-keyboard-lock-task-queue②">keyboard lock task queue</a>:</p>
<ol>
<li data-md>
<p>If <a data-link-type="dfn" href="#keyboard-enable-keyboard-lock" id="ref-for-keyboard-enable-keyboard-lock⑤">enable keyboard lock</a> is true, then run the following substeps:</p>
<ol>
<li data-md>
<p><a data-link-type="dfn" href="#unregister-the-system-key-press-handler" id="ref-for-unregister-the-system-key-press-handler">Unregister the system key press handler</a>.</p>
<li data-md>
<p>Set <a data-link-type="dfn" href="#keyboard-enable-keyboard-lock" id="ref-for-keyboard-enable-keyboard-lock⑥">enable keyboard lock</a> to be false.</p>
<li data-md>
<p>Reset <a data-link-type="dfn" href="#keyboard-reserved-key-codes" id="ref-for-keyboard-reserved-key-codes②">reserved key codes</a> to be an empty sequence.</p>
</ol>
</ol>
</ol>
<div></div>
<p class="note" role="note"><span>Note:</span> When a document is closed, the user agent MUST implicitly call <code class="idl"><a data-link-type="idl" href="#dom-keyboard-unlock" id="ref-for-dom-keyboard-unlock②">unlock()</a></code> so that the [system key press handler=] (if any) is
unregistered.</p>
</div>
</div>
<h2 class="heading settled" data-level="3" id="handling-events"><span class="secno">3. </span><span class="content">Handling Keyboard Key Presses</span><a class="self-link" href="#handling-events"></a></h2>
<h3 class="heading settled" data-level="3.1" id="key-press-handler"><span class="secno">3.1. </span><span class="content">System Key Press Handler</span><a class="self-link" href="#key-press-handler"></a></h3>
A <dfn class="dfn-paneled" data-dfn-type="dfn" data-noexport id="system-key-press-handler">system key press handler</dfn> is an platform-specific handler
that can be used to filter keys at the platform level. Since
Keyboard Lock feature is intended to provide access to key
presses that are not normally made available to the browser (for
example, Cmd/Alt-Tab), most platforms will require a special handler
to be set up.
<p>The <a data-link-type="dfn" href="#system-key-press-handler" id="ref-for-system-key-press-handler">system key press handler</a> must have the following properties:</p>
<ul>
<li data-md>
<p>It must process key presses before any user agent keyboard shortcuts
are handled.</p>
<li data-md>
<p>Wherever possible, it should process key presses before any system
keyboard shortcuts are processed.</p>
</ul>
<h4 class="heading settled" data-level="3.1.1" id="registering"><span class="secno">3.1.1. </span><span class="content">Registering</span><a class="self-link" href="#registering"></a></h4>
<p>To <dfn class="dfn-paneled" data-dfn-type="dfn" data-noexport id="register-a-system-key-press-handler">register a system key press handler</dfn>, the user agent
will need to follow the platform-specific steps to add a low-level
hook that will be called whenever the platform begins to process a
new key press.</p>
<p>The exact process for adding a <a data-link-type="dfn" href="#system-key-press-handler" id="ref-for-system-key-press-handler①">system key press handler</a> varies
from platform to platform. For examples of how to register a
low-level hook to process key presses on common platforms, see <a data-link-type="biblio" href="#biblio-lowlevelkeyboardproc">[LowLevelKeyboardProc]</a> for Windows, <a data-link-type="biblio" href="#biblio-quartzeventservices">[QuartzEventServices]</a> for
Mac OS X and <a data-link-type="biblio" href="#biblio-grabkeyboard">[GrabKeyboard]</a> for X Windows.</p>
<p class="note" role="note"><span>Note:</span> If the user agent already has a key press handler registered
for another purpose, then it can optionally extend that handler to
support the Keyboard Lock feature (assuming it meets the
requirements mentioned above).</p>
<h4 class="heading settled" data-level="3.1.2" id="unregistering"><span class="secno">3.1.2. </span><span class="content">Unregistering</span><a class="self-link" href="#unregistering"></a></h4>
<p>To <dfn class="dfn-paneled" data-dfn-type="dfn" data-noexport id="unregister-the-system-key-press-handler">unregister the system key press handler</dfn>, the user
agent will need to follow the platform-specific steps to remove the
(previously added) low-level hook for processing new key press.</p>
<p>As with registering system key press handlers, the process for
unregistering system key press handlers is also platform-specific.
See the references listed in <a href="#registering">§ 3.1.1 Registering</a> for more details and
examples.</p>
<h3 class="heading settled" data-level="3.2" id="handling-keyboard-events"><span class="secno">3.2. </span><span class="content">Handling Keyboard Events</span><a class="self-link" href="#handling-keyboard-events"></a></h3>
<p>In response to the user pressing a key, if a <a data-link-type="dfn" href="#system-key-press-handler" id="ref-for-system-key-press-handler②">system key press handler</a> has been <a data-link-type="dfn" href="#register-a-system-key-press-handler" id="ref-for-register-a-system-key-press-handler①">registered</a>,
it should run the following steps:</p>
<ol>
<li data-md>
<p>Let <var>isFullscreen</var> be set to true if the <a data-link-type="dfn" href="https://fullscreen.spec.whatwg.org/#fullscreen-element" id="ref-for-fullscreen-element">fullscreen element</a> of the <a data-link-type="dfn" href="https://html.spec.whatwg.org/#currently-focused-area-of-a-top-level-browsing-context" id="ref-for-currently-focused-area-of-a-top-level-browsing-context">currently focused area of a top-level browsing context</a> is non-null
(see <a data-link-type="biblio" href="#biblio-fullscreen">[Fullscreen]</a>).</p>
<p class="note" role="note"><span>Note:</span> The <a data-link-type="dfn" href="https://fullscreen.spec.whatwg.org/#fullscreen-element" id="ref-for-fullscreen-element①">fullscreen element</a> would not have focus, for example, if
there was a system dialog being displayed with focus.</p>
<li data-md>
<p>If <var>isFullscreen</var> and <a data-link-type="dfn" href="#keyboard-enable-keyboard-lock" id="ref-for-keyboard-enable-keyboard-lock⑦">enable keyboard lock</a> are all set
to true, then run the following substeps:</p>
<ol>
<li data-md>
<p>Let <var>keyEvent</var> be the key event for the new key press.</p>
<li data-md>
<p>Let <var>code</var> be the value of the <code class="idl"><a data-link-type="idl" href="https://www.w3.org/TR/uievents/#dom-keyboardevent-code" id="ref-for-dom-keyboardevent-code">code</a></code> attribute of <var>keyEvent</var>.</p>
<li data-md>
<p>If <a data-link-type="dfn" href="#keyboard-reserved-key-codes" id="ref-for-keyboard-reserved-key-codes③">reserved key codes</a> is empty or if <var>code</var> is listed in <a data-link-type="dfn" href="#keyboard-reserved-key-codes" id="ref-for-keyboard-reserved-key-codes④">reserved key codes</a>, then run the following substeps:</p>
<ol>
<li data-md>
<p>If <var>code</var> is equal to "Escape", then run the following
substeps:</p>
<ol>
<li data-md>
<p>Optionally overlay a message on the screen telling the
user that they can Hold the Escape key to exit from
fullscreen.</p>
<li data-md>
<p>If the key is held for 2 seconds, then exit from the
keyboard handler and pass the key on to the user agent
for normal processing (which will exit fullscreen
(and pointer lock, if active)).</p>
</ol>
<li data-md>
<p>Dispatch <var>keyEvent</var> directly to the fullsceen document or element,
bypassing any normal user agent processing.</p>
</ol>
<li data-md>
<p>Else, handle the key event as it normally would be handled,
either by dispatching a key event or performing the
usual keyboard shortcut action.</p>
</ol>
</ol>
<p class="note" role="note"><span>Note:</span> This API operates on a "best effort" basis.
It is not required that a conforming implementation be able to
override the OS default behaviour for every possible key combination.
Specifically, most platforms have a “secure attention sequence” (e.g.,
Ctrl-Alt-Del on Windows) that applications cannot override; this
specification does not supersede that.</p>
<p class="note" role="note"><span>Note:</span> When implementing this API, user agents should take care not to change
the order in which keyboard events are dispatched to the page. Keys that are
included in the set of <a data-link-type="dfn" href="#keyboard-reserved-key-codes" id="ref-for-keyboard-reserved-key-codes⑤">reserved key codes</a> must be dispatched in the same
relative order that they would have been sent had they not been included in the
set.</p>
<h2 class="heading settled" data-level="4" id="interactions"><span class="secno">4. </span><span class="content">Integration With Other Web Platform APIs</span><a class="self-link" href="#interactions"></a></h2>
<p><a data-link-type="biblio" href="#biblio-fullscreen">[Fullscreen]</a> and <a data-link-type="biblio" href="#biblio-pointerlock">[PointerLock]</a> are APIs that allow the page to temporarily take
control of part of the user’s experience (screen and mouse cursor, respectively).
Because of the concern for abuse of these features, they provide an "escape" or
"unlock" gesture that the user can rely on to exit those features. By default,
this gesture is pressing the Escape key, which is one of the keys that can be
captured by this API.</p>
<h3 class="heading settled" data-level="4.1" id="escape-key"><span class="secno">4.1. </span><span class="content">Special Considerations with the Escape Key</span><a class="self-link" href="#escape-key"></a></h3>
<p>Because of the special actions associated with the Escape key, when the <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock" id="ref-for-dom-keyboard-lock⑥">lock()</a></code> request includes the Escape key, the user agent may need to make additional
changes to the UX to account for the changed behavior.</p>
<p>For example, if the user agent shows a user message "Press ESC to exit fullscreen"
when Javascript-initiated fullscreen is activated, then that message will need to
be updated when keyboard lock is in effect to read "Press and hold ESC to exit
fullscreen".</p>
<p>If keyboard lock is activated after fullscreen is already in effect, then the user
my see multiple messages about how to exit fullscreen.
For this reason, we recommend that developers call <code class="idl"><a data-link-type="idl" href="#dom-keyboard-lock" id="ref-for-dom-keyboard-lock⑦">lock()</a></code> before they enter
fullscreen:</p>
<pre>navigator.keyboard.lock();
document.documentElement.requestFullscreen();
</pre>
<p>A similar concern with multiple user messages exists when exiting keyboard lock and
fullscreen, so it is recommended to call them in the reverse order:</p>
<pre>document.exitFullscreen();
navigator.keyboard.unlock();
</pre>
<p>In general, developers should only include the Escape key in the set of locked
keys if they actually have need for that key. And it is recommended that, if the
Escape key is locked, the developer should maintain its primary meaning of
allowing the user to exit their current state.</p>
<h3 class="heading settled" data-level="4.2" id="fullscreen-considerations"><span class="secno">4.2. </span><span class="content">Fullscreen Considerations</span><a class="self-link" href="#fullscreen-considerations"></a></h3>
<p>There are two different types of fullscreen available in modern user agents:
JavaScript-initiated fullscreen (via the <a data-link-type="biblio" href="#biblio-fullscreen">[Fullscreen]</a> API) and
user-initiated fullscreen (when the user enters fullscreen using a keyboard
shortcut). The user-initiated fullscreen is often referred to as "F11"
fullscreen since that is a common key shortcut used to enter and exit
fullscreen mode.</p>
<p>F11 fullscreen and JavaScript (JS) fullscreen do not behave the same way.
When a user enters F11 fullscreen, they can only exit it via the same
keyboard shortcut that they used to enter it -- the exitFullscreen()
function will not work in this case. In addition, fullscreen events that are
normally fired for JS fullscreen are not sent for F11 fullscreen.</p>
<p>Because of these differences (and because there is no standard shortcut
for F11 fullscreen), the Keyboard Lock API is only valid when the
a JavaScript-initiated fullscreen is active. During F11 fullscreen, no
Keyboard Lock processing of keyboard events will take place.</p>
<h2 class="heading settled" data-level="5" id="pointerlock-considerations"><span class="secno">5. </span><span class="content">Pointer Lock Considerations</span><a class="self-link" href="#pointerlock-considerations"></a></h2>
<p>Other than the UX changes noted earlier, there are no changes to the operation
of Pointer Lock.</p>
<p>When Pointer Lock is enabled outside of fullscreen, then Keyboard Lock cannot
be enabled.</p>
<p>When Pointer Lock, Keyboard Lock and Fullscreen are all enabled, then the behavior
is unchanged unless Keyboard Lock includes the Escape key. In that case, the
only chages are to the UX (as noted above).</p>
<h2 class="heading settled" data-level="6" id="mobile"><span class="secno">6. </span><span class="content">Mobile Device Considerations</span><a class="self-link" href="#mobile"></a></h2>
<p>Since this is a keyboard-focused API and mobile devices do not commonly
have physical keyboards, this API will not typically be present or
supported on mobile devices.</p>
<p>However, mobile devices may choose to support this API if it makes sense to
do so when a physical keyboard is connected.</p>
<h2 class="heading settled" data-level="7" id="security"><span class="secno">7. </span><span class="content">Security Considerations</span><a class="self-link" href="#security"></a></h2>
<p>One concern with this API is that it could be used to grab all of the keys
and (in conjunction with the <a data-link-type="biblio" href="#biblio-fullscreen">[Fullscreen]</a> and <a data-link-type="biblio" href="#biblio-pointerlock">[PointerLock]</a> API) prevent
the user from exiting the web page.</p>
<p>To prevent this, the user agent MUST provide a way for the user to exit from
keyboard lock even if all of the keys are requested by the API.</p>
<p>This specification requires support for allowing a long (more than 2 second) Escape
key press to trigger an exit from Keyboard Lock. In addition, user agents may choose
to also provide alternate ways to exit Keyboard Lock.</p>
<h2 class="heading settled" data-level="8" id="privacy"><span class="secno">8. </span><span class="content">Privacy Considerations</span><a class="self-link" href="#privacy"></a></h2>
<p>Not applicable. This API does not use or reveal any personal information
about the current user.</p>
<h2 class="heading settled" data-level="9" id="acknowledgements-contributors"><span class="secno">9. </span><span class="content">Acknowledgements</span><a class="self-link" href="#acknowledgements-contributors"></a></h2>