Action sheet

An action sheet is a menu that has been re-cut for a thumb. The choices arrive at the bottom of the screen, where the hand already is, stacked as full width rows rather than a floating list of small targets. Because it is modal, everything behind it is inert until an answer is given, and because the answer is always available, the last row is Cancel.

It is defined by what raised it. An action sheet is a response to something you just did, usually a Share or a More button, and it lists the ways that one action could go. That is the difference between it and a drawer, which is a place you navigate to, and it is why the sheet carries no title in the common case: the button you just pressed is the title. When the choices need explaining, or one of them destroys something, the sheet grows a short message at the top and the destructive row takes on ink of its own, at the top of the list on Apple’s platforms and never next to Cancel.

The vocabulary splits by platform, which is where reviews go wrong. Apple’s human interface guidelines say action sheet; Material calls the same surface a bottom sheet and treats it as a container that can hold anything, a list of actions being only one filling. Android also has no Cancel row, since the system back gesture is the way out, so a sheet ported straight across gains a button that duplicates the hardware. Say “a bottom sheet of actions” when the audience is mixed.

On a wide screen the pattern stops making sense: a modal strip across the bottom of a desktop window is far from the pointer and covers content for no reason. The same choices become an anchored menu next to the control, which is why an interface that runs on both usually keeps one list of commands and two presentations of it.