Scrollable element is keyboard accessible

  • Rule Type:atomic
  • Rule Id: 0ssw9k
  • Last modified: May 18, 2020
  • Accessibility Requirements Mapping:
    • 2.1.1 Keyboard (Level: A)
      • Learn More about 2.1.1 (Keyboard)
      • Required for conformance to WCAG 2.0 and above on level A and above.
      • Outcome mapping:
        • Any failed outcomes: success criterion is not satisfied.
        • All passed outcomes: success criterion needs further testing.
        • An inapplicable outcome: success criterion needs further testing.
    • G202: Ensuring keyboard control for all functionality
  • Input Aspects:

Description

This rule checks that scrollable elements can be scrolled by keyboard

Applicability

Any HTML element that has visible children in the flat tree for which one of the following is true:

Expectation

Each test target is either included in sequential focus navigation or has a descendant in the flat tree that is included in sequential focus navigation.

Note: Focus must be on or in a scrollable region, to ensure there is some element from which arrow keys can be used to control the scroll position. This can still create an issue if scripts are used to prevent the keyboard events from reaching the scrollable region. This must be tested separately.

Assumptions

This rule assumes that all scrollable elements with visible content need to be keyboard accessible. Scrollable elements that do not need to be keyboard accessible, perhaps because their content is purely decorative or because scroll can be controlled some other way, may fail this rule but still satisfy success criterion 2.1.1 Keyboard.

Accessibility Support

No accessibility support issues known.

Background

Test Cases

Passed

Passed Example 1

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This scrollable section element is included in sequential focus navigation because it has a tabindex attribute set to 0.

<section style="height: 100px; width: 500px; overflow: scroll;" tabindex="0">
	<h1>WCAG 2.1 Abstract</h1>
	<p>
		Web Content Accessibility Guidelines (WCAG) 2.1 covers a wide range of recommendations for making Web content more
		accessible. Following these guidelines will make content more accessible to a wider range of people with
		disabilities, including accommodations for blindness and low vision, deafness and hearing loss, limited movement,
		speech disabilities, photosensitivity, and combinations of these, and some accommodation for learning disabilities
		and cognitive limitations; but will not address every user need for people with these disabilities. These guidelines
		address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines
		will also often make Web content more usable to users in general.
	</p>
</section>

Passed Example 2

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This scrollable section element contains a link that is included in sequential focus navigation.

<section style="height: 100px; width: 500px; overflow: scroll;">
	<h1>
		<a href="//www.w3.org/TR/WCAG21/#abstract">
			WCAG 2.1 Abstract
		</a>
	</h1>
	<p>
		Web Content Accessibility Guidelines (WCAG) 2.1 covers a wide range of recommendations for making Web content more
		accessible. Following these guidelines will make content more accessible to a wider range of people with
		disabilities, including accommodations for blindness and low vision, deafness and hearing loss, limited movement,
		speech disabilities, photosensitivity, and combinations of these, and some accommodation for learning disabilities
		and cognitive limitations; but will not address every user need for people with these disabilities. These guidelines
		address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines
		will also often make Web content more usable to users in general.
	</p>
</section>

Failed

Failed Example 1

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This vertically scrollable section element is not included in sequential focus navigation, nor does it have any descendants that are.

<section style="height: 100px; width: 500px; overflow-y: scroll">
	<h1>WCAG 2.1 Abstract</h1>
	<p>
		Web Content Accessibility Guidelines (WCAG) 2.1 covers a wide range of recommendations for making Web content more
		accessible. Following these guidelines will make content more accessible to a wider range of people with
		disabilities, including accommodations for blindness and low vision, deafness and hearing loss, limited movement,
		speech disabilities, photosensitivity, and combinations of these, and some accommodation for learning disabilities
		and cognitive limitations; but will not address every user need for people with these disabilities. These guidelines
		address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines
		will also often make Web content more usable to users in general.
	</p>
</section>

Failed Example 2

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This horizontally scrollable section element is not included in sequential focus navigation, nor does it have any descendants that are.

<style>
	section {
		height: 100px;
		width: 400px;
		overflow-y: auto;
		white-space: nowrap;
	}
	section > img {
		display: inline-block;
		width: 80px;
	}
</style>
<h1>Our sponsors:</h1>
<section>
	<img src="/test-asset/shared/w3c-logo.png" alt="W3C" />
	<img src="/test-asset/shared/eu-logo.svg" alt="EU" />
	<img src="/test-asset/shared/w3c-logo.png" alt="W3C" />
	<img src="/test-asset/shared/eu-logo.svg" alt="EU" />
	<img src="/test-asset/shared/w3c-logo.png" alt="W3C" />
	<img src="/test-asset/shared/eu-logo.svg" alt="EU" />
	<img src="/test-asset/shared/w3c-logo.png" alt="W3C" />
</section>

Inapplicable

Inapplicable Example 1

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This section element has a computed overflow of visible.

<section style="height: 95px; width: 500px;">
	<h1>WCAG 2.1 Abstract</h1>
	<p>
		Web Content Accessibility Guidelines (WCAG) 2.1 covers a wide range of recommendations for making Web content more
		accessible. Following these guidelines will make content more accessible to a wider range of people with
		disabilities, including accommodations for blindness and low vision, deafness and hearing loss, limited movement,
		speech disabilities, photosensitivity, and combinations of these, and some accommodation for learning disabilities
		and cognitive limitations; but will not address every user need for people with these disabilities. These guidelines
		address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines
		will also often make Web content more usable to users in general.
	</p>
</section>

Inapplicable Example 2

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This section element has a scroll distance of 0 in both directions.

<section style="height: 95px; width: 500px; overflow: auto;">
	<p>
		<a href="//www.w3.org/TR/WCAG21/#abstract">
			WCAG 2.1 Abstract
		</a>
	</p>
</section>

Inapplicable Example 3

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This section element is not scrollable because it has a computed overflow of hidden.

<h1>
	<a href="//www.w3.org/TR/WCAG21/#abstract">
		WCAG 2.1 Abstract
	</a>
</h1>
<section style="height: 95px; width: 500px; overflow: hidden;">
	<p>
		Web Content Accessibility Guidelines (WCAG) 2.1 covers a wide range of recommendations for making Web content more
		accessible. Following these guidelines will make content more accessible to a wider range of people with
		disabilities, including accommodations for blindness and low vision, deafness and hearing loss, limited movement,
		speech disabilities, photosensitivity, and combinations of these, and some accommodation for learning disabilities
		and cognitive limitations; but will not address every user need for people with these disabilities. These guidelines
		address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines
		will also often make Web content more usable to users in general.
	</p>
</section>

Inapplicable Example 4

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This scrollable section element has no visible content.

<p>This is what a scrollbar looks like:</p>
<section style="height: 20px; width: 500px; overflow-x:scroll;">
	<div style="width: 1000px; height: 1px;"></div>
</section>

Inapplicable Example 5

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This section element has a horizontal scroll distance that is less than its horizontal padding, and vertical scroll distance that is less than its vertical padding.

<section style="height: 210px; width: 500px; overflow: scroll; padding: 30px;">
	<div role="heading" aria-level="1">WCAG 2.1 Abstract</div>
	<div style="width: 520px">
		Web Content Accessibility Guidelines (WCAG) 2.1 covers a wide range of recommendations for making Web content more
		accessible. Following these guidelines will make content more accessible to a wider range of people with
		disabilities, including accommodations for blindness and low vision, deafness and hearing loss, limited movement,
		speech disabilities, photosensitivity, and combinations of these, and some accommodation for learning disabilities
		and cognitive limitations; but will not address every user need for people with these disabilities. These guidelines
		address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines
		will also often make Web content more usable to users in general.
	</div>
</section>

Inapplicable Example 6

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This iframe element is not a scrollable element.

<iframe src="//www.w3.org/TR/WCAG21/#abstract" width="500" height="200"></iframe>

Glossary

Outcome

An outcome is a conclusion that comes from evaluating an ACT Rule on a test subject or one of its constituent test target. An outcome can be one of the three following types:

  • Inapplicable: No part of the test subject matches the applicability
  • Passed: A test target meets all expectations
  • Failed: A test target does not meet all expectations

Note: A rule has one passed or failed outcome for every test target. When there are no test targets the rule has one inapplicable outcome. This means that each test subject will have one or more outcomes.

Note: Implementations using the EARL10-Schema can express the outcome with the outcome property. In addition to passed, failed and inapplicable, EARL 1.0 also defined an incomplete outcome. While this cannot be the outcome of an ACT Rule when applied in its entirety, it often happens that rules are only partially evaluated. For example, when applicability was automated, but the expectations have to be evaluated manually. Such "interim" results can be expressed with the incomplete outcome.

Scrollable Elements

A scrollable element is an element with a horizontal scroll distance or a vertical scroll distance greater than 0.

note: Elements such as iframe which can render a nested browsing context are not scrollable elements. The scrollbars on some iframe elements come from the content inside the nested browsing context.

Visible

Content perceivable through sight.

Content is considered visible if making it fully transparent would result in a difference in the pixels rendered for any part of the document that is currently within the viewport or can be brought into the viewport via scrolling.

Content is defined in WCAG.

Examples for Visible

Note: The examples presented here are non-normative and not testable. They serve to illustrate some common pitfalls about the definition and to help the implementers of ACT rules understand it.

This span element is visible (by default, elements are visible).

<span>Now you can see me!</span>

This span element is not visible because of the CSS visibility property.

<span style="visibility: hidden">I'm the invisible man</span>

This span element is not visible because of the CSS display property.

<span style="display: none">I'm the invisible man</span>

This span element is not visible because it is positioned off-screen

<span style="position: absolute; top: -9999px; left: -9999px;">Incredible how you can</span>

This span element is not visible because it contains only whitespace and line breaks.

<span>
	<br />
	&nbsp;
</span>

This span element is not visible because it has the exact same color as its background.

<span style="color: #00F; background: #00F;">See right through me</span>

Useful Links


Implementations

This section is not part of the official rule. It is populated dynamically and not accounted for in the change history or the last modified date. This section will not be included in the rule when it is published on the W3C website.

ToolConsitencyCompleteReport
axe-coreconsistentYesView Report
QualWebpartially-consistentYesView Report

Acknowledgments

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