Pointer Cancellation requires that functions don’t complete on the down-click of a pointer.
Some users may need extra help using a mouse or prefer to use assistive technology in place of a mouse. It’s important to reduce the chances of an accidental click for these users by ensuring that the down-click of a mouse pointer alone doesn’t complete a function.
How to Pass ‘Pointer Cancellation’
- Ensure that actions are only taken when a pointer is clicked and released within the boundary of the target.
- Abort actions where the pointer is released outside the boundary of the target.
Exceptions to ‘Pointer Cancellation’
Where it’s essential the action occurs on the down-click.
This might seem rare but is relevant to keyboard emulators, where a letter appears typed on the down-press of a key (and therefore the down-press of a mouse in an emulator. A music keyboard or shooting game may also need the action to complete on the down-click. In these instances there are often other ways for users to change an action that don’t need pointer cancellation.