Module acknowledgement 

A passing acknowledgement: “Link copied”, said once in a small pill near the bottom of the surface, then gone.

Some actions leave nothing to see. A copy changes the clipboard, which is out of sight, so the person cannot tell whether anything happened. That needs an answer, but not a notification: a notification waits to be read, stacks with its peers and is kept in the centre. This answer is only about the moment it confirms, the way a phone shows “Copied” for a moment.

• It never takes focus and has no controls.
• A new one replaces the one showing, so a burst of copies shows one pill.
• It is a polite live region, so a screen reader says it once, after what it is already saying.
• It holds for ACKNOWLEDGEMENT_HOLD, the last ACKNOWLEDGEMENT_FADE of that fading out. With reduced motion it disappears without the fade.

Structs

Acknowledgement

One acknowledgement and when it was raised.

AcknowledgementLayer

The layer that shows an Acknowledger’s words over a surface: lay it out over the whole surface, draw it above everything else.

Acknowledger

Where acknowledgements are raised from: cheap to clone, handed to whatever confirms an action (a host’s page, a search action).

Constants

ACKNOWLEDGEMENT_FADE

The fade at the end of ACKNOWLEDGEMENT_HOLD.

ACKNOWLEDGEMENT_HOLD

How long an acknowledgement stays: enough to read two or three words after the action, short enough to be gone before the next one.