Gesture recognizer specification

A gesture recognizer generates continuous or discrete events from a stream of device input events. This specification describes the MVP expectations for a gesture recognition system.

MVP expectations

Able to be attached to an element

When attached to an element, any interactions with that element will be interpreted by the gesture recognizer and turned into gesture events.

Support continuous and discrete types

Gestures may be recognized continuously (many related events over time) or discretely (once).

The output might be a location, translation, rotation, or scale. It should not generate all types of output simultaneously.

Support active and at rest states

Gestures may be active or at rest. A continuous gesture is active for a period of time until it comes to rest. A discrete gesture is instantaneously active and then at rest.

Velocity

Continuous gesture recognizers include a velocity with each event.