Rx-flavor reactive WinForm

Rx-WinForm.fsx

#I "packages/Rx-Linq/lib/net45"
#I "packages/Rx-Interfaces/lib/net45"
#I "packages/Rx-Core/lib/net45"
#I "packages/FSharp.Control.Reactive/lib/net40"

#r "FSharp.Control.Reactive.dll"
#r "System.Reactive.Core.dll"
#r "System.Reactive.Interfaces.dll"
#r "System.Reactive.Linq.dll"

open System
open System.Windows.Forms
open System.Drawing
open FSharp.Control.Reactive

type Action =
  | Increment
  | Decrement


let form = new Form(Width= 400, Height = 300, Visible = true, Text = "Hello World")
form.TopMost <- true

let panel = new FlowLayoutPanel()
panel.Dock <- DockStyle.Fill
panel.WrapContents <- false

let incBtn = new Button()
let decBtn = new Button()
let label = new Label()


incBtn.Text <- "+"
decBtn.Text <- "-"

incBtn.AutoSize <- true
decBtn.AutoSize <- true

panel.Controls.Add(decBtn)
panel.Controls.Add(label)
panel.Controls.Add(incBtn)

let model = 0

let view model =
  label.Text <- sprintf "%d" model


let update (model : int32) (action : Action) =
  match action with
    | Increment -> model + 1
    | Decrement -> model - 1


let increment = Observable.map (fun _ -> Increment) incBtn.Click
let decrement = Observable.map (fun _ -> Decrement) decBtn.Click

let stateObservable =
  Observable.merge increment decrement
  |> Observable.scanInit model update

Observable.subscribe view stateObservable

form.Controls.Add(panel)

form.Show()