Purely functional recognition of Drag and Click gestures over a W3C Pointer Event -compatible API, for Scala/Scala.js

Built on top of State provided by the Cats library.

See also slidedeck about the library design.

Contains the library code:

• GestureProcessor converts a series of PointerEvents into a series of GestureEvents, while updating a Finite State Machine represented by PointerState.

• Optionally, GestureAndRegionProcessor[R] can extend the functionality to tracking the region R where the gesture began and completed, if any. The region itself is provided by the user of the library an can be any type, so long a there is a search function (Double, Double) => Option[R] to find the region R at a coordinate, if any.

• Coordinates are modeled as (Double, Double)

Published for both Scala.jvm and Scala.js.

SBT: "com.github.benhutchison" %%% "gesture" % "0.5"

Shows a working demo of the recognition system, implemented over an HTML canvas. Colored rectangles can be created and dragged around the screen.

To try it out, clone the project, run sbt demo/fullOptJS, and then load file demo/demo-opt.html in a browser.