Accessibility Through Responsive Design

Report
Accessibility Through
Responsive Design
Justin Stockton
Email: [email protected]
Twitter: @poorgeek
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Topics
• Accessibility as availability
• Approaches to mobile development
• What is responsive design?
– Fluid Grids
– Flexible Media
– Media Queries
• Approaches to testing
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Disability Employment App Challenge
• Presented through
Challenge.gov in summer
of 2012
• Sponsored by Department
of Labor’s Office of
Disability Employment
Policy (ODEP)
• Build accessible websites
and apps to help
employers and people with
disabilities
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https://accessjobs.devis.com/
Proof of Concept!
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Our Goals
• Very focused and simple to use
• Accessible (508 and WCAG 2.0 compliant)
• Easy for employers to manage
– Adding markup to existing job postings includes
them in our search
• Challenge ourselves to achieve a more
universal design
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Smartphone Ownership
• Survey conducted by Pew Internet and
American Life Project, July-August 2012
– http://www.pewinternet.org/Reports/2012/Smart
phone-Update-Sept-2012/Findings.aspx
• 45% of Americans (16+) now own
smartphones (~107 million people)
• Increased from 35% in May 2011 (increase of
~24 million people)
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Tablet Ownership
• Survey conducted by Pew Internet and
American Life Project, July-Sept 2013
– http://pewinternet.org/Reports/2013/Tabletsand-ereaders/Findings.aspx
• 35% of Americans (16+) now own tablet
computers, up from 4% in September 2010
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Why is this Meaningful?
• 21% of cell phone owners primarily use their
phone to access the internet
– http://www.pewinternet.org/Reports/2013/CellInternet/Summary-of-Findings.aspx
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Refining Our Definition of Accessibility
• We have a responsibility to ensure that the
web is usable for everyone
• Accessibility as “availability”
• Taking a device–agnostic approach to
accessible web design and making it available
to as many people as possible on as many
devices as possible
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APPROACHES TO MOBILE
DEVELOPMENT
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“No Mobile” Approach
• Website that does not offer
a tailored mobile experience
(either app or website)
• Can still be viewable on
most devices, but not
particularly usable
• Not common, but still a
problem
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What’s Wrong With Traditional Mobile
Approaches?
• Features left out for mobile users
– Might make sense, but too often due to
assumptions instead of user studies
• Content parity
– Same content should be available everywhere
– If redirects are not properly set up, sharing links
can be problematic
• Maintaining several code bases
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Native Mobile Applications
• Barrier to entry
– Device and even OS version
• Accessibility
– Different considerations and techniques compared
to web design
– varies based on platform
• Less of an issue for web applications
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Mobile Websites
• “Browser sniffing”
– Method that identifies which browser and
operating system you are using
– Requires maintaining a list of browsers and
operating systems
– Some websites only serving mobile to Webkitbased browsers, regardless of whether other
browsers could render them
• Accessibility
– Disabling zoom
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Mobile Websites and Native Apps
Are Not Evil
• Both offer experience tailored to mobile
devices
• Native applications can take advantage of
advanced device capabilities
– Web browsers are catching up
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RESPONSIVE DESIGN
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New Approach - Responsive Design
• Proposed by Ethan Marcotte on A List Apart in
May 2010
– http://www.alistapart.com/articles/responsive-webdesign/
• One website for all devices
• Optimized for different contexts (not devices)
using:
– Fluid grids
– Flexible media
– CSS Media Queries
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Grid Systems
• A way of organizing
different pieces of
information along
vertical and
horizontal axes
• Have existed in
some form since
medieval times
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Fluid Grids
• Fluid grid = width of boxes is defined in
percentage rather than fixed units (pixels, em)
– Can grow or shrink as the screen width changes
– Allows for utilizing all available space
– Avoids issue of horizontal scrolling
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Fluid Grids on Access Jobs
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Semantic Grid Code Example
.span4 {
width: 33%
}
Traditional grid markup in HTML:
<article class=“span4”>
</article>
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Flexible Media
• Similar concept to fluid grids, but applied to
images and movies
• Dimensions of media can change depending
on screen size
• Not used much on Access Jobs
– Logo
– Screenshots
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Flexible Media Code Example
img, object {
max-width: 100%;
}
• Can result in problems in older browsers that don’t
support max-width (Internet Explorer 7)
– Set width to 100%
• Flickr documented how to deal with poor image scaling
using proprietary Microsoft CSS filters
– http://code.flickr.net/2008/11/12/on-ui-quality-the-littlethings-client-side-image-resizing/
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Responsive Images
• Desire has arisen to serve different images
based on media queries
– Existing images look blurry on displays with high
pixel density
– If images are going to be viewed at small sizes, no
point in serving large resolution images
– Tricky because bandwidth != screen size
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Several Approaches
• New attribute for HTML image element –
“srcset”
• New HTML picture element
• Both allow specifying additional image
sources depending on different criteria
• Still in “proposed” status, not part of
specification
• W3C Responsive Images Community Group
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Media Queries
• Part of CSS3 specification
• Extends existing media type functionality that
allowed style sheets for print, screen, etc.
• Gives more granular control as to when
different CSS rules are applied
– Based on media features such as screen
width/height, screen orientation, pixel density,
etc…
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Media Query Code Example
.job {
display: block;
}
@media screen and (min-width: 650px) and (maxwidth: 960px) {
.job {
margin: 0.52%;
display: inline-block;
width: 48.6111%;
}
}
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Breakpoints
• Breakpoints are defined resolution points
(typically width) specified in media queries at
which different CSS styles are applied
• Breakpoints used on Access Jobs:
– Below 650 (small screen)
– 650-960 (tablet)
– Above 960 (desktop)
• Should be chosen based on your content rather
than known resolutions of popular devices
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Media Queries In Action
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Media Query Support
• Mobile browsers
– iOS Safari (3.2+)
– Android Browser (2.1+)
• Desktop browsers
–
–
–
–
Internet Explorer (9+)
Firefox (3.5+)
Chrome (4+)
Safari (4+)
• Full list at http://caniuse.com/css-mediaqueries
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How To Handle Lack of
Media Query Support
• Respond.js
– Adds support for min/max-width to IE 6-8
• Mobile-first approach for other browsers
– Default CSS = single column layout
– Introduce additional complexity inside media
queries (unsupported browsers will just ignore
this)
• Can still target with browser-specific style
sheets if this approach is undesirable
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Responsive Design and Accessibility
• Responsive design does not make a site
accessible, so care must be taken to comply with
existing accessibility guidelines
• Besides improving availability:
– Flexible layouts handle zooming/scaling very well
• No horizontal scroll bars
– Lowers barrier to entry for assistive technology
• Inexpensive mobile devices now come with built-in assistive
technology
– Freedom of choice for assistive technology
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APPROACHES TO TESTING
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Testing
• Need to take a pragmatic approach – testing on every
device is unrealistic
– Examine web analytics to find appropriate devices to
target
– Take advantage of devices owned by yourself and
coworkers
– Consider starting a local device lab
– Simulators/Emulators are available for iOS (Mac Only),
Android
• Desktop browsers are typically multi-platform
– If not, virtualization can be used
• Browserstack.com
• http://www.modern.ie/
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Mobile Testing and Debugging
• Don’t need to manually retest on each device
– Adobe Edge Inspect
– Mixture
• Remote inspection
– Web Inspector Remote
– Adobe Edge Inspect
– Remote Web Inspector (iOS/Mac)
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Testing Access Jobs
• Physical Device Testing
– iPhone, iPad, Android Phones
• Desktop Testing
– Testing multiple versions of IE using VMs
• http://www.modern.ie/en-us/virtualization-tools
• Testing breakpoints
– Manually (resizing browser)
– http://responsivepx.com/
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Any Questions?
Email: [email protected]
Twitter: @poorgeek
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