Pointer Cancellation
Summary:
WCAG 2.5.2, "Pointer Cancellation," is about making interactions with web content less error-prone for users who rely on touch or pointer devices. This criterion benefits users with motor impairments or anyone who might accidentally activate a control.
What:
It requires that functions activated by a single pointer can be canceled or undone, particularly ensuring that the "down-event" (like a mouse-down or a touch-start) does not trigger the action. Activate functions on press release.
Why:
This guideline helps prevent accidental activations, allowing users to abort or undo actions if they change their mind or touch something inadvertently.
Examples and Scenarios:
- Buttons on Websites: A button should not activate until the user releases the mouse button or lifts their finger.
- Drag-and-Drop Features: Allow users to cancel a drag-and-drop action mid-operation.
- Interactive Sliders: Ensure that releasing the click or touch finalizes the slider's position, not the initial contact.
How to Comply:
- Websites: Design interactive elements so that actions are completed on the "up-event" rather than the "down-event."
- Mobile Apps: Implement touch controls that are forgiving and allow users to cancel actions mid-way.
- Software Applications: Ensure that pointer interactions are designed to minimize accidental activations.
Exceptions:
- Essential Immediate Actions: If completing an action on the down-event is essential, such as for piano key simulations in music software.
- Complex Interactions: In specific complex interactions where immediate response is necessary and integral to the functionality.