FastClick is instantiated on the body element, so all visible elements on this page will receive fast clicks - except one.

The layers marked A and B both have onClick handlers that will attempt to trigger focus on the text input programatically. However, on iOS, event handlers that are triggered by programmatic events are not allowed to trigger focus on other elements.

Only B will succeed at triggering focus on the input element, because it has a clickevent class which will instruct FastClick not to trigger a programmatic click and let the system click event go through instread.