Android Nomad #58 - Semantics vs. clearAndSetSemantics in Compose

When implementing accessibility in a Compose UI, semantics and clearAndSetSemantics plays a critical role to order or group content for accessibility services.

Core Concepts

• Semantics: In Jetpack Compose, semantics are used to provide non-visual information about UI elements to accessibility services like TalkBack. This information helps users who are visually impaired or have other disabilities understand and interact with the app.
• semantics Modifier: This modifier allows developers to customize the semantic information associated with a composable element.
• clearAndSetSemantics Modifier: This modifier provides a way to completely replace the default semantics of a composable element with a custom description.

Choosing Between semantics and clearAndSetSemantics

The choice between these modifiers depends on the structure and desired accessibility behavior of the composable:

• semantics for Single Elements or Merging Children: Use the semantics modifier when:
• The composable element has no children, and you want to modify its default accessibility behavior.
• The composable element has children, but you want them to be treated as a single logical element by accessibility services. In this case, set the mergeDescendants parameter to true.
• You want some children to retain their individual semantics even when merging; set mergeDescendants to true on those specific children.
• clearAndSetSemantics for Custom Parent Descriptions: Use the clearAndSetSemantics modifier when you want to:
• Provide a completely custom description for a parent element, overriding any descriptions from its children. This ensures only the custom description is read by accessibility services.

Important Considerations

• Combined Descriptions: Even when using mergeDescendants with a custom contentDescription in the semantics modifier, the system will read both the custom description and the merged descendant description. This could lead to redundant or confusing information for the user.

Conclusion

By understanding the nuances of semantics and clearAndSetSemantics, we can create more inclusive and accessible apps for all users. Proper implementation of these modifiers ensures that users with disabilities can effectively navigate and interact with the UI through assistive technologies like TalkBack.

You can read my previous post on how to implement accessibility for android apps.

Android Nomad #49 - Apps for Accessibility

Before implementing accessibility in Android apps, it's essential to consider a range of factors to ensure your app is inclusive and usable by people with disabilities. Here's a breakdown:

Android NomadSido