Motion Actuation
Summary:
WCAG 2.5.4, "Motion Actuation," focuses on ensuring that web functionalities triggered by motion or device orientation can also be operated through conventional interfaces. This is key for users who can't or prefer not to use motion controls, like those with motor impairments.
What:
This guideline mandates alternatives to motion-based controls. If an action can be triggered by tilting or shaking a device, there should also be a way to perform the same action using a button, link, or other traditional control.
Why:
Reliance on motion control excludes users unable to perform such gestures. Providing alternatives ensures everyone, regardless of their physical abilities, can access and use all functionalities.
Examples and Scenarios:
- Shake to Undo: In an app where shaking the device undoes an action, offer a visible 'Undo' button.
- Tilt to Scroll: For a game where tilting the device scrolls the view, include on-screen arrows for scrolling.
- Gesture-Based Commands: If a photo app uses a swirling motion to open filters, also provide a button to access these filters.
How to Comply:
- Websites: Implement button-based alternatives for any motion-induced actions.
- Mobile Apps: Provide on-screen controls for actions usually operated by device movement.
- Software Applications: Include settings to disable motion controls and use standard input methods.
Exceptions:
- Essential Motions: If the motion is integral to the function (like a fitness app tracking movement).
- Ambient Actions: Actions that rely on environmental factors, such as a light sensor adjusting screen brightness, may not need alternatives.