what if we describe UI transitions in React's way? Previously written in ClojureScript.

Demo https://r.Quamolit.org/quamolit.calcit/

Features:

• declarative component markups for Canvas
• React-like components, element DSLs, event handlers, global Store
• animation abstractions

Quamolit is trying to combine two things:

• declarative programming experience like React
• canvas API drawing and animations

Seeing from MVC, animations has Models too. Said by FRP(Functional Reactive Programming), the Model for animations is values changing over time, like a stream. It does have a Model, a Model for animations. But we want to program in a declarative way, which means we need that Model to be generated from our code. Meanwhile CSS animations is not we want because of the private animation states, we need global app state. So question, how to expression a time varying Model with declarative code?

Define components:

defcomp comp-demo ()
  group ({})

defcomp comp-demo-tick (states)
  let
      cursor $ :cursor states
      state $ or (:data states) {} (:demo :demo)
    []
      fn (elapsed d!)
        ; "this is there you handle animation states"
        d! cursor (merge state state-changes)
      group ({})
        group ({})

It requires some boilerplate code to start a Quamolit project. I would suggest starting by forking my workflow.

Shape records:

• name keyword
• props a hashmap of:
• • ... styles used in Canvas API
• • event a hashmap of events, mainly :click events
• children sorted hashmap with values of child nodes

Component record:

• name keyword
• on-tick function to update animation state at every tick
• tree cached from render tree

line $ {}
  :x0 0
  :y0 0
  :x1 40
  :y1 40
  :line-width 4
  :stroke-style (hsl 200 870 50)
  :line-cap :round
  :line-join :round
  :milter-limit 8

arc $ {}
  :x 0 :y 0:r 40
  :s-angle 0
  :e-angle 60
  :line-width 4
  :counterclockwise true
  :line-cap :round
  :line-join :round
  :miter-limit 8
  :fill-style nil
  :stroke-style nil

rect $ {}
  :w 100
  :h 40
  :x $ - (/ w 2)
  :y $ - (/ h 2)
  :line-width 2

text $ {}
  :x 0
  :y 0
  :fill-style (hsl 0 0 0)
  :text-align :center
  :base-linee :middle
  :size 20
  :font-family |Optima
  :max-width 400
  :text |todo

image $ {}
  :src "|lotus.jpg"
  :sx 0
  :sy 0
  :sw 40
  :sh 40
  :dx 0
  :dy 0
  :dw 40
  :dh 40

translate $ {}
  :x 0
  :y 0

scale $ {}
  :ratio 1.2

alpha $ {}
  :opacity 0.5

rotate $ {}
  :angle 30

button $ {}
  :x 0
  :y 0
  :w 100
  :h 40
  :text "|button"
  :surface-color (hsl 0 80 80)
  :text-color (hsl 0 0 10)
  :font-family "|Optima"
  :font-size 20

input $ {}
  :w 0
  :h 0
  :text "|TODO"

comp-debug data $ {}


comp-slider (>> states :v)
  {}
    :value $ :v state
    :unit 0.2
    :on-change $ fn (v d!)
      d! cursor $ assoc state :v v
    :position $ [] 100 40
    :min -4
    :max 40
    :title "\"long long title"

:require
  quamolit.hud-logs :refer $ hud-log

hug-log :data "|more data"

To run this project, with calcit_runner and Vite:

yarn
cr --emit-js --once
yarn vite

By rethinking MVC and GUI during using React, I developed the need of writing animations with declarative code. It was late 2014. I created the first prototype with CoffeeScript but it's not viable. In early 2016, I rewrote it with ClojureScript, which is last version of Quamolit. Now it's being rewritten in calcit-js.

MIT