Making Airbnb’s Android app extra accessible | by Julia Fu | The Airbnb Tech Weblog | Jan, 2023

By: Julia Fu, Peter Elliott

At Airbnb, we’ve been consciously designing and constructing merchandise to be equally usable by all customers. Making our cell apps and web sites extra accessible not solely aligns with our firm’s mission of making a world the place individuals can belong anyplace, but additionally helps the civil rights of individuals with disabilities and complies with the regulation.

On this article, we spotlight a number of the efforts we’ve made to make the app extra accessible, for instance, labeling UI components, grouping associated content material, supporting massive font scale, offering heading and web page names. The Airbnb app is without doubt one of the hottest journey apps with tens of millions of customers and helps many options. Making such a posh app extra accessible is a large endeavor that we’re constantly engaged on.

At Airbnb, we observe trade greatest practices to make the Android app accessible. If you’re , you’ll find all greatest practices we observe from the official Android documentation for platform particular tips and the Web Content Accessibility Guidelines as an trade commonplace. Right here we need to spotlight a number of examples the place we apply the perfect practices:

Finest Apply: content material descriptions

All the pieces shall have correct content material descriptions until they need to be ignored by assistive know-how. In these examples, the share button has a content material description that TalkBack reads aloud. TalkBack skips the home icon.

Finest apply: grouping

Components of a pure group might be introduced along with focusable containers for higher usability and accuracy. As an example, Talkback reads all itemizing content material on the cardboard collectively.

Finest apply: font scale

UI shall be usable when the person will increase the system font scale.

Default vs enlarged font scale:

Scaling greatest practices

The Airbnb Android app is a big app with many screens. It could be exhausting and never scalable if we wanted so as to add accessibility code in all places. Happily, our Design Language System allows us to broadly apply these greatest practices throughout product surfaces in a extremely environment friendly means. Each display is constructed with a set of reusable UI elements. Once we enhance the accessibility for one part, the change applies to all of the pages with this part as a part of the view. This has a long-lasting optimistic impact on our app’s accessibility enhancements. Right here’s an instance:

Take SectionHeader for example. This UI part is used to speak the construction on the web page and group content material collectively. We mark this part to be an accessibility heading within the part code so it’s accessible in all screens that include this part.

We invested in automated accessibility testing and linting to run with each code commit, which creates a fast suggestions loop for engineers and empowers them to make the app accessible at code writing time. The checks are quick, dependable, and scale effectively with our fast-growing options within the Android app.

Automated testing

We arrange Espresso-based automated testing to examine for accessibility points. Espresso is a well-liked testing library for Android UI with built-in accessibility checks. It helps a complete set of accessibility guidelines and is simple to arrange:

If accessibility checks fail, the take a look at outputs an error stack hint that engineers can use to debug the problem. For instance:

On this instance, engineers can present a content material description to the picture view to fulfill accessibility necessities.

We additionally screenshot take a look at our elements with a bigger font dimension to make sure the habits is right utilizing Happo.

Linting

Along with automated testing, we additionally enabled linting, together with Android Lint guidelines for accessibility and customized lint guidelines constructed with Ktlint.

Right here is an instance of an Android accessibility lint rule:

Apart from the built-in Android Lint, we additionally use Ktlint to construct customized lint guidelines. As an example, when a person navigates to a brand new display, we offer a web page identify for a display reader to announce. We use the next rule to make it possible for the web page identify is localized.

Lint guidelines are easy to arrange and supply well timed suggestions, however linting has limitations — it will probably solely carry out static code evaluation.

Immediately, these automated checks run as a part of CI (Steady Integration) checks for each code commit. If a pull request doesn’t go the checks, it is going to be blocked from being merged into the first code department. We nonetheless use guide testing to cowl the areas that automated checks don’t cowl, such because the traversal order of UI components on a web page. Automated and guide checks complement one another effectively.

Over the previous yr, we’ve been integrating Jetpack Compose into our app. Google’s Accessibility in Compose documentation has been a terrific useful resource to make sure our Compose elements and screens stay accessible. Whereas there are some notable issues lacking that existed with Views (e.g. focus order modification), Compose continues to be a younger library and we look ahead to future enhancements. Listed below are a few issues value mentioning about our Compose-specific accessibility tooling:

Proactively encourage content material descriptions within the API

Considered one of our tips for UI elements is that content material descriptions uncovered by way of a perform parameter shouldn’t use a default worth. This brings accessibility to the highest of thoughts when an engineer makes use of the part as they should take into account what worth to go. A null worth continues to be acceptable in circumstances the place that UI ingredient isn’t essential for accessibility.

Web page identify bulletins

When utilizing Fragments and Views, we use the View.setAccessibilityPaneTitle() and View.announceForAccessibility() APIs when navigating to a brand new display to announce a descriptive web page identify to the person. These APIs don’t exist in Compose however we wished to maintain the performance because it helps to supply extra context as to what the brand new display shows. Our present workaround units sure semantics on the display’s outer composable:

We use the liveRegion property so modifications might be introduced when the content material description modifications. That is helpful for pages whose total content material is set by a response from the server. On this case, TalkBack would announce “Content material Loading” whereas the community request is pending, adopted by “Content material Loaded” when it completes, and eventually the web page description outlined within the server response. One draw back of this method is that it requires the outer container to be focusable, which requires an extra navigation motion to get to the content material.

Making our Android app extra accessible has been an impactful journey. Enhancing app accessibility entails following greatest practices, including rigorous enforcements, frequently studying from errors, and placing within the work. All of those are worthy efforts to ensure an app works for all customers.

If you’re enthusiastic about constructing extremely accessible merchandise and the framework to assist them, try a few of our associated open positions:

Staff Android Software Engineer, Guest

Senior iOS Software Engineer, Infrastructure

It’s a big endeavor to make a posh app just like the Airbnb Android app extra accessible. This work wouldn’t be potential with out the large efforts from the digital accessibility crew and the close-knit Android group at Airbnb. Each engineer has contributed to creating the options they personal accessible. Making the Android app extra accessible is an ongoing effort and it couldn’t succeed with out all of them.

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