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Overview.bs
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<!--
Coding style convention in this file:
* Use semantic line breaks (http://rhodesmill.org/brandon/2012/one-sentence-per-line/)
* Tabs for indentation, spaces for allignment (http://lea.verou.me/2012/01/why-tabs-are-clearly-superior/)
* Use markdown paragraphs (empty lines between paragraphs) over <p> when practical
* two empty lines above <h*>, one below <h*>, one between <hn> and <hn+1>
* empty line between <ol>, <ul>, <table>, <div> and ajacent text
* Don't close <p>, <li>, <dd>, <dt>, <tr>, <th>, or <td>
* Indent the content and break line after the opening <li>, <dd>, <dt>, <td>, or <th> if it's more than 2 lines long
or for lists where at least some elements are more than 2 lines long
* Empty line between adjacent <li>, <th>, <td>, <tr>, and between <dd> and the next <dt>;
Can be skipped if all items are very short
* Indent the content of <ol>, <ul>, <dl>, <table>, <tr>
* Indent the content of <div class=note> and <div class=example>
-->
<pre class="anchors">
spec: css2; urlPrefix: https://drafts.csswg.org/css2/
urlPrefix: box.html
type: dfn;
text: content edge;
text: padding edge;
</pre>
<pre class='metadata'>
Title: CSS Basic User Interface Module Level 4
ED: https://drafts.csswg.org/css-ui-4/
Status Text: This specification will include and extend <cite>CSS Basic User Interface Module Level 3.</cite> [[CSS-UI-3]]
TR: https://www.w3.org/TR/css-ui-4/
Previous Version: https://www.w3.org/TR/2017/WD-css-ui-4-20171222/
Previous Version: https://www.w3.org/TR/2015/WD-css-ui-4-20150922/
Shortname: css-ui
Level: 4
Group: csswg
Status: ED
Work Status: Revising
Editor: Florian Rivoal, On behalf of Bloomberg, https://florian.rivoal.net/, w3cid 43241
Abstract: This specification describes user interface related
properties and values to style HTML and XML (including XHTML).
It includes and extends user interface related features
from the properties and values of previous CSS levels.
It uses various properties and values
to style basic user interface elements in a document.
At risk: Applicability of 'user-select' to ''::before'' and ''::after''
Can I Use URL: https://drafts.csswg.org/css-ui-3/
Can I Use URL: http://drafts.csswg.org/css-ui-3/
Can I Use URL: https://drafts.csswg.org/css-ui/
Can I Use URL: http://drafts.csswg.org/css-ui/
Can I Use URL: https://www.w3.org/TR/css-ui-3/
Can I Use URL: http://www.w3.org/TR/css-ui-3/
Can I Use URL: https://www.w3.org/TR/css3-ui/
Can I Use URL: http://www.w3.org/TR/css3-ui/
Can I Use URL: https://drafts.csswg.org/css-ui-4/
Can I Use URL: http://drafts.csswg.org/css-ui-4/
Can I Use URL: https://www.w3.org/TR/css-ui-4/
Can I Use URL: http://www.w3.org/TR/css-ui-4/
Ignore Can I Use URL Failure: https://drafts.csswg.org/css-ui-3/
Ignore Can I Use URL Failure: http://drafts.csswg.org/css-ui-3/
Ignore Can I Use URL Failure: https://drafts.csswg.org/css-ui/
Ignore Can I Use URL Failure: http://drafts.csswg.org/css-ui/
Ignore Can I Use URL Failure: https://www.w3.org/TR/css-ui-3/
Ignore Can I Use URL Failure: http://www.w3.org/TR/css-ui-3/
Ignore Can I Use URL Failure: https://www.w3.org/TR/css3-ui/
Ignore Can I Use URL Failure: http://www.w3.org/TR/css3-ui/
Ignore Can I Use URL Failure: https://drafts.csswg.org/css-ui-4/
Ignore Can I Use URL Failure: http://drafts.csswg.org/css-ui-4/
Ignore Can I Use URL Failure: https://www.w3.org/TR/css-ui-4/
Ignore Can I Use URL Failure: http://www.w3.org/TR/css-ui-4/
</pre>
<pre class=link-defaults>
spec:css-writing-modes-4; type:dfn; text:start
spec:css-writing-modes-4; type:dfn; text:end
spec:css2; type:property; text:min-width
spec:css2; type:property; text:max-width
spec:css2; type:property; text:min-height
spec:css2; type:property; text:max-height
spec:css2; type:property; text:bottom
spec:css2; type:property; text:top
spec:css2; type:property; text:right
spec:css2; type:property; text:visibility
spec:css2; type:property; text:z-index
spec:css-pseudo-4; type:selector; text:::before
spec:css-pseudo-4; type:selector; text:::after
spec:css-pseudo-4; type:selector; text:::first-line
spec:css-pseudo-4; type:selector; text:::first-letter
spec:selectors-4; type:selector; text::checked
spec:css-display-3; type:property; text:display
spec:css-color-4; type:value; text:currentcolor
spec:css-overflow-3; type:property; text:overflow
spec:css-sizing-3; type:property; text:box-sizing
spec:css-backgrounds-3; type:property; text:background-image
spec:css-backgrounds-3; type:property; text:border-width
</pre>
<pre class="anchors">
url: https://www.w3.org/TR/CSS21/box.html#border-edge; type: dfn; spec: CSS21; text: border edge
</pre>
<style>
.awesome-table td {padding:5px}
.awesome-table {color:#000;background:#fff;margin: auto;}
</style>
<h2 id="intro">Introduction</h2>
This module describes CSS properties which enable authors
to style user interface related properties and values.
<a href="https://www.w3.org/TR/REC-CSS1#anchor-pseudo-classes">Section 2.1 of CSS1</a> [[CSS1]]
and <a href="https://www.w3.org/TR/CSS2/ui.html">Chapter 18 of CSS2</a> [[CSS21]]
introduced several user interface related properties and values.
<a href="https://www.w3.org/TR/2000/WD-css3-userint-20000216">User Interface for CSS3 (16 February 2000)</a> introduced several new user interface related features.
[[CSS-UI-3]] was later introduced to incorporates, extends, and supersedes these.
This specification continues this work, and in turn replaces [[CSS-UI-3]].
<h3 id="purpose">Purpose</h3>
The purpose of this specification is to achieve the following objectives:
<ul>
<li>Extend the user interface features in [[CSS21]] and [[CSS-UI-3]]
<li>Provide additional CSS mechanisms to augment or replace other
dynamic presentation related features in HTML.
<li>Introduce directional navigation properties to assist in the construction of
user interfaces which make use of a directional navigation model.
</ul>
<h2 id="interaction">Module Interactions</h2>
This document defines new features not present in earlier specifications.
In addition, it replaces and supersedes [[!CSS-UI-3]],
which itself replaced and superseded the following:
<ul>
<li>
<a href="https://www.w3.org/TR/CSS21/ui.html#cursor-props">Section 18.1</a>,
<a href="https://www.w3.org/TR/CSS21/ui.html#dynamic-outlines">section 18.4</a>,
and Information on the stacking of outlines defined in
<a href="https://www.w3.org/TR/CSS21/zindex.html">Appendix E</a>
of Cascading Style Sheets, level 2, revision 1 [[CSS21]]
<li>
<a href="https://www.w3.org/TR/2000/WD-css3-userint-20000216">User Interface for CSS3 (16 February 2000)</a> [[CSS-UI-3]]
</ul>
Note:
<span id="box-model"></span>
<span id="box-sizing"></span>
<span id="propdef-box-sizing"></span>
<span id="valdef-box-sizing-content-box"></span>
<span id="valdef-box-sizing-border-box"></span>
<span id="min-inner-width"></span>
<span id="max-inner-width"></span>
<span id="min-inner-height"></span>
<span id="max-inner-height"></span>
<span id="example-d824f1dc"></span>
<span id="box-sizing-example"></span>
The 'box-sizing' property was previously defined in this section of the specification,
but has been moved to [[CSS-SIZING-3#box-sizing]].
Note:
<span id="text-overflow"></span>
<span id="propdef-text-overflow"></span>
<span id="overflow-clip"></span>
<span id="overflow-ellipsis"></span>
<span id="overflow-string"></span>
<span id="funcdef-text-overflow-fade"></span>
<span id="issue-ebe65138"></span>
<span id="issue-2e22b1d9"></span>
<span id="issue-948cb1ee"></span>
<span id="valdef-text-overflow-fade"></span>
<span id="example-160d0058"></span>
<span id="bidi-ellipsis"></span>
<span id="ellipsing-details"></span>
<span id="ellipsis-interaction"></span>
<span id="example-44082941"></span>
<span id="text-overflow-examples"></span>
<span id="issue-4b5212a2"></span>
<span id="ellipsis-scrolling"></span>
<span id="example-45d2531f"></span>
<span id="example-347bbb66"></span>
The 'text-overflow' property was previously defined in this section of the specification,
but has been moved to [[CSS-OVERFLOW-4#text-overflow]].
<h2 id="outline-props" caniuse="outline">Outline properties</h2>
At times, style sheet authors may want to create outlines around
visual objects such as buttons, active form fields, image maps, etc.,
to make them stand out. Outlines differ from borders in the following
ways:
<ol>
<li>Outlines do not take up space.
<li>Outlines may be non-rectangular.
<li>UAs often render outlines on elements in the :focus state.
</ol>
The outline properties control the style of these dynamic outlines.
The stacking of the rendering of these outlines is explicitly left up to implementations
to provide a better user experience per platform.
This supersedes the stacking of outlines as defined in <a href="https://www.w3.org/TR/CSS21/zindex.html">Appendix E of CSS 2.1</a> [[CSS21]].
<strong class="advisement">
Keyboard users,
in particular people with disabilities
who may not be able to interact with the page in any other fashion,
depend on the outline being visible
on elements in the :focus state,
thus authors must not make the outline invisible on such elements
without making sure an alternative highlighting mechanism is provided.
</strong>
The rendering of applying transforms to outlines is left explicitly undefined in CSS3-UI.
<h3 id="outline">Outlines Shorthand: the 'outline' property</h3>
<pre class="propdef">
Name: outline
Value: [ <<'outline-color'>> || <<'outline-style'>> || <<'outline-width'>> ]
Initial: see individual properties
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: see individual properties
Animation type: see individual properties
</pre>
<h3 id="outline-width">Outline Thickness: the 'outline-width' property</h3>
<pre class="propdef">
Name: outline-width
Value: <<line-width>>
Initial: medium
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: absolute length; ''0'' if the outline style is ''border-style/none''.
Animation type: <a href="https://drafts.csswg.org/css3-transitions/#animtype-length">length</a>
</pre>
<h3 id="outline-style">Outline Patterns: the 'outline-style' property</h3>
<pre class="propdef">
Name: outline-style
Value: auto | <<outline-line-style>>
Initial: none
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: as specified
</pre>
<h3 id="outline-color">Outline Colors: the 'outline-color' property</h3>
<pre class="propdef">
Name: outline-color
Value: <<color>> | invert
Initial: invert
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: The computed value for ''outline-color/invert'' is ''outline-color/invert''.
For <<color>> values, see <a>resolving color values</a> in [[!CSS-COLOR-4]].
Animation Type: <a href="https://drafts.csswg.org/css3-transitions/#animtype-color">color</a>
</pre>
The outline created with the outline properties is drawn "over" a box,
i.e., the outline is always on top,
and doesn't influence the position or size of the box,
or of any other boxes.
Therefore, displaying or suppressing outlines does not cause reflow.
Outlines may be non-rectangular.
For example, if the element is broken across several lines,
the outline should be an outline or minimum set of outlines
that encloses all the element's boxes.
Each part of the outline should be fully connected
rather than open on some sides
(as borders on inline elements are when lines are broken).
The parts of the outline are not required to be rectangular.
To the extent that the outline follows the <a>border edge</a>,
it should follow the 'border-radius' curve.
The position of the outline may be affected by descendant boxes.
User agents should use an algorithm for determining
the outline that encloses a region appropriate
for conveying the concept of focus to the user.
Note: This specification does not define the exact position or shape of the outline, but it is typically drawn immediately outside the border box.
The 'outline-width' property accepts
the same values as 'border-width'
([[css-backgrounds-3#the-border-width]]).
<dfn><<outline-line-style>></dfn> accepts
the same values as <<line-style>>
([[css-backgrounds-3#the-border-style]])
with the same meaning,
except that
<span class=css>hidden</span> is not a legal outline style.
In addition,
the 'outline-style' property
accepts the value ''outline-style/auto''.
The ''outline-style/auto'' value permits the user agent
to render a custom outline style,
typically a style which is either a user interface default for the platform,
or perhaps a style that is richer
than can be described in detail in CSS,
e.g. a rounded edge outline with semi-translucent outer pixels
that appears to glow.
As such, this specification does not define how the
'outline-color'
is incorporated or used (if at all) when rendering
''outline-style/auto'' style outlines.
User agents may treat ''outline-style/auto'' as
''outline-style/solid''.
The 'outline-color' property
accepts all colors, as well as the keyword <dfn dfn-type=value dfn-for=outline-color>invert</dfn>.
''outline-color/invert'' is expected to perform a color inversion on the pixels on the screen.
This is a common trick to ensure the focus border is visible,
regardless of color background.
Conformant UAs may ignore the ''outline-color/invert'' value
on platforms that do not support color inversion of the pixels on the screen.
If the UA does not support the ''outline-color/invert'' value
then it must reject that value at parse-time, and
the initial value of the 'outline-color' property
is the ''color/currentColor'' keyword.
The 'outline' property is a shorthand property,
and sets all three of 'outline-style',
'outline-width',
and 'outline-color'.
Note: The outline is the same on all sides.
In contrast to borders,
there are no ''outline-top'' or ''outline-left'' etc. properties.
This specification does not define how multiple overlapping outlines are drawn,
or how outlines are drawn for boxes that are partially obscured behind other elements.
<div class="example">
Here's an example of drawing a thick outline around a BUTTON element:
<pre><code class="lang-css">
button { outline: thick solid }
</code></pre>
</div>
Graphical user interfaces may use outlines around elements
to tell the user which element on the page has the focus.
These outlines are in addition to any borders,
and switching outlines on and off should not cause the document to reflow.
The focus is the subject of user interaction in a document
(e.g. for entering text or selecting a button).
<div class="example">
For example, to draw a thick black line around an element when it has the focus,
and a thick red line when it is active,
the following rules can be used:
<pre><code class="lang-css">
:focus { outline: thick solid black }
:active { outline: thick solid red }
</code></pre>
</div>
Note: Since the outline does not affect formatting
(i.e., no space is left for it in the box model),
it may well overlap other elements on the page.
<h3 id="outline-offset">Offsetting the Outline: the 'outline-offset' property</h3>
By default, the outline is drawn starting just outside the <a>border edge</a>.
However, it is possible to offset the outline and draw it beyond the <a>border edge</a>.
<pre class="propdef">
Name: outline-offset
Value: <<length>>
Initial: 0
Applies to: all elements
Inherited: no
Percentages: N/A
Computed value: <<length>> value in absolute units (px or physical).
Animation Type: <a href="https://drafts.csswg.org/css3-transitions/#animtype-length">length</a>
</pre>
If the computed value of 'outline-offset'
is anything other than 0,
then the outline is outset from the <a>border edge</a> by that amount.
<div class="example">
For example,
to leave 2 pixels of space between a focus outline
and the element that has the focus or is active,
the following rule can be used:
<pre><code class="lang-css">
:focus,:active { outline-offset: 2px }
</code></pre>
</div>
<p id=negative-offset>Negative values must cause the outline
to shrink into the border box.
Both the height and the width of outside of the shape
drawn by the outline should not become smaller
than twice the computed value of the 'outline-width' property,
to make sure that an outline can be rendered
even with large negative values.
User Agents should apply this constraint
independently in each dimension.
If the outline is drawn as multiple disconnected shapes,
this constraint applies to each shape separately.
<h2 id="resizing">
<!--maintaining old anchors back from when text-overflow was defined here--><span id="resizing-and-overflow"></span>
Resizing</h2>
CSS2.1 provides a mechanism for controlling the appearance of a scrolling mechanism
(e.g. scrollbars)
on block container elements.
This specification adds to that a mechanism for controlling
user resizability of elements as well as the ability to specify text overflow behavior.
<h3 id="resize" caniuse="css-resize">Resizing Boxes: the 'resize' property</h3>
The 'resize' property allows the author
to specify whether or not an element is resizable by the user,
and if so, along which axis/axes.
<pre class="propdef">
Name: resize
Value: none | both | horizontal | vertical
Initial: none
Applies to: elements with 'overflow' other than visible,
and optionally replaced elements such as images, videos, and iframes
Inherited: no
Percentages: N/A
Computed value: as specified
</pre>
<dl>
<dt>none
<dd>The UA does not present a resizing mechanism on the element,
and the user is given no direct manipulation mechanism to resize the element.
<dt>both
<dd>The UA presents a bidirectional resizing mechanism
to allow the user to adjust both the height and the width of the element.
<dt>horizontal
<dd>The UA presents a unidirectional horizontal resizing mechanism
to allow the user to adjust only the width of the element.
<dt>vertical
<dd>The UA presents a unidirectional vertical resizing mechanism
to allow the user to adjust only the height of the element.
</dl>
Currently it is possible to control the appearance of the scrolling mechanism (if any)
on an element using the 'overflow' property
(e.g. <code class="lang-css">overflow: scroll</code> vs. <code class="lang-css">overflow: hidden</code> etc.).
The purpose of the 'resize' property
is to allow control over the appearance and function of the resizing mechanism
(e.g. a resize box or widget) on the element.
Note: The resizing mechanism is NOT the same as the scrolling mechanism,
nor is it related to any UA mechanism for zooming.
The scrolling mechanism allows the user
to determine which portion of the contents of an element is shown.
The resizing mechanism allows the user
to determine the size of the element.
The 'resize' property applies to elements
whose computed 'overflow' value
is something other than ''visible''.
UAs may also apply it,
regardless of the value of the 'overflow' property,
to:
<ul>
<li>Replaced elements representing images or videos, such as <{img}>, <{video}>, <{picture}>, <{svg}>, <{object}>, or <{canvas}>.
<li>The <{iframe}> element.
</ul>
The effect of the 'resize' property on generated content is undefined.
Implementations should not apply the 'resize' property to generated content.
Note: the 'resize' property may apply to generated content in the future
if there is implementation of <a href="https://drafts.csswg.org/css-pseudo/#CSSPseudoElement-interface">Interface CSSPseudoElement</a>.
When an element is resized by the user,
the user agent sets
the 'width' and 'height' properties
to px unit length values of the size indicated by the user,
in the element’s <a href="https://www.w3.org/TR/css-style-attr/#style-attribute">style attribute</a> DOM,
replacing existing property declaration(s), if any,
without ''!important'', if any.
If an element is resized in only one dimension,
only the corresponding property is set, not both.
The precise direction of resizing
(i.e. altering the top left of the element or altering the bottom right)
may depend on a number of CSS layout factors
including whether the element is absolutely positioned,
whether it is positioned using the 'right'
and 'bottom' properties,
whether the language of the element is right-to-left etc.
The UA should consider the direction of resizing
(as determined by CSS layout),
as well as platform conventions and constraints when deciding
how to convey the resizing mechanism to the user.
The user agent must allow the user to resize the element
with no other constraints than what is imposed by
'min-width', 'max-width', 'min-height', and 'max-height'.
Note: There may be situations where user attempts to resize an element
appear to be overriden or ignored, e.g. because of ''!important'' cascading declarations that supersede
that element’s <a href="https://www.w3.org/TR/css-style-attr/#style-attribute">style attribute</a>
'width' and 'height' properties in the DOM.
Changes to the computed value of an element's 'resize' property
do not reset changes to the <a href="https://www.w3.org/TR/css-style-attr/#style-attribute">style attribute</a> made due to
user resizing of that element.
<div class="example">
For example,
to make iframes scrollable <em>and</em> resizable,
the following rule can be used:
<pre><code class="lang-css">
iframe,object[type^="text/"],
object[type$="+xml"],object[type="application/xml"]
{
overflow:auto;
resize:both;
}
</code></pre>
</div>
<h2 id="pointing-keyboard">Pointing Devices and Keyboards</h2>
<h3 id="pointer-interaction">Pointer interaction</h3>
<h4 id="cursor" caniuse="css3-cursors">Styling the Cursor: the 'cursor' property</h4>
<pre class="propdef">
Name: cursor
Value: [ [<<url>> [<x> <y>]?,]* <br>
[ auto | default | none |<br>
context-menu | help | pointer | progress | wait | <br>
cell | crosshair | text | vertical-text | <br>
alias | copy | move | no-drop | not-allowed | grab | grabbing | <br>
e-resize | n-resize | ne-resize | nw-resize | s-resize | se-resize | sw-resize | w-resize |
ew-resize | ns-resize | nesw-resize | nwse-resize |
col-resize | row-resize |
all-scroll |<br>
zoom-in | zoom-out <br>
] ]
Initial: auto
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: as specified, except with any relative URLs converted to absolute
</pre>
This property specifies the type of cursor to be displayed for the pointing device
when the cursor's hotspot is within the element's <a>border edge</a>.
Note: As per [[css-backgrounds-3#the-border-radius]], the <a>border edge</a> is affected by 'border-radius'.
In the case of overlapping elements,
which element determines the type of cursor
is based on hit testing:
the element determining the cursor
is the one that would receive a click
initiated from this position.
Note: The specifics of hit testing
are out of scope of this specification.
Hit testing will hopefully be defined
in a future revision of CSS or HTML.
User agents may ignore the cursor property over native user-agent controls such as scrollbars, resizers, or other native UI widgets e.g. those that may be used inside some user agent specific implementations of form elements.
User agents may also ignore the cursor property
and display a cursor of their choice
to indicate various states of the UA's user interface,
such as a busy cursor when the page is not responding,
or a text cursor when the user is performing text selection.
Note: [[HTML]] defines <a href="https://html.spec.whatwg.org/multipage/rendering.html#image-maps-2">special handling of image maps</a>
for the 'cursor' property.
Values have the following meanings:
<dl dfn-type=value dfn-for=cursor>
<dt>image cursors
<dd>
<dl>
<dt><<url>>
<dd>
The user agent retrieves the cursor from the resource designated by the URI.
If the user agent cannot handle the first cursor of a list of cursors,
it must attempt to handle the second, etc.
If the user agent cannot handle any user-defined cursor,
it must use the cursor keyword at the end of the list.
Conforming User Agents may, instead of <<url>>, support <<image>> which is a superset.
The UA must support the following image file formats:
<ul>
<li>
PNG, as defined in [[!PNG]]
<li>
SVG, as defined in [[!SVG11]],
in <a href="https://www.w3.org/TR/SVG2/conform.html#secure-static-mode">secure static mode</a> [[!SVG2]],
if it has an intrinsic size.
<li>
any other non-animated image file format that they support
for <<image>> in other properties,
such as the the 'background-image' property
</ul>
In addition, the UA should support the following image file formats:
<ul>
<li>
SVG, as defined in [[!SVG11]],
in <a href="https://www.w3.org/TR/SVG2/conform.html#secure-animated-mode">secure animated mode</a> [[!SVG2]],
if it has an intrinsic size.
<li>
any other animated image file format that they support
for <<image>> in other properties,
such as the the 'background-image' property
</ul>
The UA may also support additional file formats,
including SVG, as defined in [[!SVG11]],
in secure static mode or secure animated mode [[!SVG2]],
even if it does not have an intrinsic size.
Note: The CSS Working group initially intended support for all SVG,
intrinsically sized or not.
Support for non intrinsically sized SVG was downgraded from mandatory to optional due
to lack of implementations.
Note: At the time of writing this specification (spring 2015),
the only file formats supported for cursors in common desktop browsers are
the .ico and .cur file formats, as designed by Microsoft.
For compatibility with legacy content,
UAs are encouraged to support these,
even though the lack of an open specification
makes it impossible to have a normative requirement
about these formats.
Some information on these formats can be found
<a href="https://en.wikipedia.org/wiki/ICO_%28file_format%29">on Wikipedia</a>.
The <a>default object size</a> for cursor images is
a UA-defined size that should be based on
the size of a typical cursor on the UA's operating system.
The <a>concrete object size</a> is determined using
the <a>default sizing algorithm</a>.
If an operating system is
<strong>incapable</strong> of rendering a cursor above a given size,
cursors larger than that size must be shrunk to within
the OS-supported size bounds,
while maintaining the cursor image's intrinsic ratio, if any.
The optional <x> and <y> coordinates
identify the exact position within the image which is the pointer position (i.e., the hotspot).
<dt><x>
<dt><y>
<dd>
Each is a <<number>>.
The x-coordinate and y-coordinate of the position
in the cursor's coordinate system (left/top relative)
which represents the precise position that is being pointed to.
Note: This specification does not define
how the coordinate systems of the various types of <<image>> are established,
and defers these definitions to [[CSS4-IMAGES]].
If the values are unspecified,
then the intrinsic hotspot defined inside the image resource itself is used.
If both the values are unspecific and the referenced cursor has no defined hotspot,
the effect is as if a value of "0 0" were specified.
If the coordinates of the hotspot,
as specified either inside the image resource or
by <x> and <y> values,
fall outside of the cursor image,
they must be clamped (independently) to fit.
</dl>
<dt>general purpose cursors
<dd>
<dl>
<dt style="cursor:auto"><dfn>auto</dfn>
<dd>
The UA determines the cursor to display based on the current context.
Specifically, ''cursor/auto'' behaves as ''cursor/text'' over selectable text or editable elements,
and ''cursor/default'' otherwise.
<dt style="cursor:default"><dfn>default</dfn>
<dd>The platform-dependent default cursor.
Often rendered as an arrow.
<dt style="cursor:none"><dfn>none</dfn>
<dd>No cursor is rendered for the element.
</dl>
<dt>links and status cursors
<dd>
<dl>
<dt style="cursor:context-menu"><dfn>context-menu</dfn>
<dd>A context menu is available for the object under the cursor.
Often rendered as an arrow with a small menu-like graphic next to it.
<dt style="cursor:help"><dfn>help</dfn>
<dd>Help is available for the object under the cursor.
Often rendered as a question mark or a balloon.
<dt style="cursor:pointer"><dfn>pointer</dfn>
<dd>The cursor is a pointer that indicates a link.
Often rendered as the backside of a hand with the index finger extended.
Unless otherwise specified,
UAs must apply ''cursor: pointer'' to hyperlinks
for all supported document formats
via the <a lt="User Agent Origin">UA stylesheet</a>,
using a normal (i.e. not <a>!important</a>) declaration.
<dt style="cursor:progress"><dfn>progress</dfn>
<dd>
A progress indicator. The program is performing some processing,
but is different from ''wait'' in that the user may still interact
with the program. Often rendered as a spinning beach ball,
or an arrow with a watch or hourglass.
<dt style="cursor:wait"><dfn>wait</dfn>
<dd>Indicates that the program is busy and the user should wait.
Often rendered as a watch or hourglass.
</dl>
<dt>selection cursors
<dd>
<dl>
<dt style="cursor:cell"><dfn>cell</dfn>
<dd>Indicates that a cell or set of cells may be selected.
Often rendered as a thick plus-sign with a dot in the middle.
<dt style="cursor:crosshair"><dfn>crosshair</dfn>
<dd>A simple crosshair (e.g., short line segments resembling a "+" sign).
Often used to indicate a two dimensional bitmap selection mode.
<dt style="cursor:text"><dfn>text</dfn>
<dd>
Indicates text that may be selected. Often rendered as a vertical I-beam.
User agents may automatically display a horizontal I-beam/cursor
(e.g. same as the ''vertical-text'' keyword)
for vertical text, or for that matter,
any angle of I-beam/cursor for text that is rendered at any particular angle.
<dt style="cursor:vertical-text"><dfn>vertical-text</dfn>
<dd>Indicates vertical-text that may be selected.
Often rendered as a horizontal I-beam.
</dl>
<dt>drag and drop cursors
<dd>
<dl>
<dt style="cursor:alias"><dfn>alias</dfn>
<dd>Indicates an alias of/shortcut to something is to be created.
Often rendered as an arrow with a small curved arrow next to it.
<dt style="cursor:copy"><dfn>copy</dfn>
<dd>Indicates something is to be copied.
Often rendered as an arrow with a small plus sign next to it.
<dt style="cursor:move"><dfn>move</dfn>
<dd>Indicates something is to be moved.
<dt style="cursor:no-drop"><dfn>no-drop</dfn>
<dd>Indicates that the dragged item cannot be dropped at the current cursor location.
Often rendered as a hand or pointer with a small circle with a line through it.
<dt style="cursor:not-allowed"><dfn>not-allowed</dfn>
<dd>Indicates that the requested action will not be carried out.
Often rendered as a circle with a line through it.
<dt style="cursor:grab"><dfn>grab</dfn>
<dd>Indicates that something can be grabbed (dragged to be moved).
Often rendered as the backside of an open hand.
<dt style="cursor:grabbing"><dfn>grabbing</dfn>
<dd>Indicates that something is being grabbed (dragged to be moved).
Often rendered as the backside of a hand with fingers closed mostly out of view.
</dl>
<dt>resizing and scrolling cursors
<dd>
<dl>
<dt>
<span style="cursor:e-resize"><dfn>e-resize</dfn></span>,
<span style="cursor:n-resize"><dfn>n-resize</dfn></span>,
<span style="cursor:ne-resize"><dfn>ne-resize</dfn></span>,
<span style="cursor:nw-resize"><dfn>nw-resize</dfn></span>,
<span style="cursor:s-resize"><dfn>s-resize</dfn></span>,
<span style="cursor:se-resize"><dfn>se-resize</dfn></span>,
<span style="cursor:sw-resize"><dfn>sw-resize</dfn></span>,
<span style="cursor:w-resize"><dfn>w-resize</dfn></span>
<dd>
Indicates that some edge is to be moved.
For example, the ''se-resize'' cursor is used
when the movement starts from the south-east corner of the box.
<dt>
<span style="cursor:ew-resize"><dfn>ew-resize</dfn></span>,
<span style="cursor:ns-resize"><dfn>ns-resize</dfn></span>,
<span style="cursor:nesw-resize"><dfn>nesw-resize</dfn></span>,
<span style="cursor:nwse-resize"><dfn>nwse-resize</dfn></span>
<dd>Indicates a bidirectional resize cursor.
<dt style="cursor:col-resize"><dfn>col-resize</dfn>
<dd>Indicates that the item/column can be resized horizontally.
Often rendered as arrows pointing left and right with a vertical bar separating them.
<dt style="cursor:row-resize"><dfn>row-resize</dfn>
<dd>Indicates that the item/row can be resized vertically.
Often rendered as arrows pointing up and down with a horizontal bar separating them.
<dt style="cursor:all-scroll"><dfn>all-scroll</dfn>
<dd>Indicates that the something can be scrolled in any direction.
Often rendered as arrows pointing up, down, left, and right with a dot in the middle.
</dl>
<dt caniuse="css3-cursors-newer" id="zooming-cursors">zooming cursors
<dd>
<dl>
<dt>
<span style="cursor:zoom-in"> <dfn>zoom-in</dfn></span>,
<span style="cursor:zoom-out"> <dfn>zoom-out</dfn></span>
<dd>
Indicates that something can be zoomed (magnified) in or out,
and often rendered as a magnifying glass with a "+" or "-" in the center of the glass,
for ''zoom-in'' and ''zoom-out'' respectively.
</dl>
</dl>
<div class="example">
Here is an example of using several cursor values.
<pre><code class="lang-css">
:link,:visited {
cursor: url(example.svg#linkcursor),
url(hyper.cur),
url(hyper.png) 2 3,
pointer
}
</code></pre>
This example sets the cursor on all hyperlinks (whether visited or not)
to an external <a href="https://www.w3.org/TR/SVG/interact.html#CursorElement">SVG cursor</a> ([[SVG11]], section 16.8.3).
User agents that don't support SVG cursors would simply skip
to the next value and attempt to use the "hyper.cur" cursor.
If that cursor format was also not supported,
the UA could attempt to use the "hyper.png" cursor with the explicit hotspot.
Finally if the UA does not support any of those image cursor formats, the UA would skip to the last value
and render the ''pointer'' cursor.
</div>
<h5 id="canvas_cursor">Cursor of the canvas</h5>
The document <a href="https://www.w3.org/TR/CSS21/intro.html#the-canvas">canvas</a>
is the infinite surface over which the document is rendered [[!CSS21]].
Since no element corresponds to the canvas,
in order to allow styling of the cursor when not over any element,
the canvas cursor re-uses the root element's cursor.
However, if no boxes are generated for the root element
(for example, if the root element has ''display: none''),
then the canvas cursor is the platform-dependent default cursor.
Note: An element might be invisible,
but still generate boxes. For example,
if the element has ''visibility: hidden'' but not ''display: none'',
boxes are generated for it and its cursor is used for the canvas.
<h3 id="insertion-caret">Insertion caret</h3>
<h4 id="caret-color" caniuse="css-caret-color">Coloring the Insertion Caret: the 'caret-color' property</h4>
<pre class="propdef">
Name: caret-color
Value: auto | <<color>>
Initial: auto
Applies to: all elements
Inherited: yes
Percentages: N/A
Computed value: The computed value for ''caret-color/auto'' is ''caret-color/auto''.
For <<color>> values, see <a>resolving color values</a> in [[!CSS-COLOR-4]].
Animation Type: <a href="https://drafts.csswg.org/css3-transitions/#animtype-color">color</a>
</pre>
<dl>
<dt>auto
<dd>
User agents should use ''currentColor''.
User agents may automatically adjust the color of caret
to ensure good visibility and contrast with the surrounding content,
possibly based on the currentColor, background, shadows, etc.
Note: When 'caret-shape' is ''caret-shape/block'',
ensuring good visibility and contrast
is best achieved with a UA determined color other than ''currentColor''.
<dt><<color>>
<dd>The insertion caret is colored with the specified color.
</dl>
The caret is a visible indicator of the insertion point in an element where text (and potentially other content) is inserted by the user. This property controls the color of that visible indicator.
Note: UAs might have additional things that count as “carets”.
For example, some UAs can show a “navigation caret”,
which acts similarly to an insertion caret
but can be moved around in non-editable text,
and is functionally a caret.
On the other hand, the cursor image shown
when hovering over text when the 'cursor' property is ''cursor/auto'',
or when hovering over an element where the 'cursor' property is ''cursor/text'' or ''cursor/vertical-text'',
though it sometimes resembles a caret, is not a caret (it's a cursor).
<div class="example">
Example: a textarea with
<code class="lang-css">caret-color:#00aacc;</code>
<textarea style="caret-color:#00aacc;">
caret-color:#00aacc
</textarea>
</div>
<!--
<h4 id="caret-animation">Animation of the insertion caret: 'caret-animation'</h4>
<pre class='propdef'>
Name: caret-animation
Value: auto | blink | none | fade
Initial: auto
Applies to: elements that accept input
Inherited: yes
Percentages: N/A
Computed value: Same as specified value.
Animatable: no
</pre>
On most platforms and in most UAs,
the text insertion caret blinks.
This property allows the author
to control the speed at which it blinks,
or to turn off blinking entirely.
<dl dfn-type=value dfn-for=caret-animation>
<dt><dfn>auto</dfn>
<dd>
The UA determines how the caret should be animated, if at all.
It should match platform conventions,
and may be adjusted based on context.
Note: This is typically rendered as a blinking caret.