Purely functional recognition of Drag and Click gestures over a W3C Pointer Event -compatible API, for Scala/Scala.js
Built on top of the
State monad provided by the Cats library.
Contains the library code:
GestureProcessorconverts a series of
PointerEvents into a series of
GestureEvents, while updating a Finite State Machine represented by
GestureAndRegionProcessor[R]can extend the functionality to tracking the region
Rwhere 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
Rat a coordinate, if any.
Coordinates are modeled as
Published for both Scala.jvm and Scala.js.
"com.github.benhutchison" %%% "gesture" % "0.3"
|0.1||Jan 16||Initial release|
|0.2||Oct 16||Upgrade libs, cats to 0.7.2, scalajs-dom to 0.9|
|0.3||Nov 16||Scala 2.12, cats to 0.8.1|
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.
The demo uses the reliable Points polyfill developed by Rich Harris to provide Pointer Events across browsers/devices.