//GUI: Creates a simple form with two buttons
namespace Demo
module GUI =
    open System.Windows.Forms

    let form = new Form(Text="Demo", TopMost=true)

    let btnAdd0 = new Button(Text="0", Top=123, Left=75)
    let btnAdd1 = new Button(Text="1", Top=100)
    let btnAdd2 = new Button(Text="2", Top=100, Left=75)
    let btnAdd3 = new Button(Text="3", Top=100, Left=150)
    let btnAdd4 = new Button(Text="4", Top=80)
    let btnAdd5 = new Button(Text="5", Top=80, Left=75)
    let btnAdd6 = new Button(Text="6", Top=80, Left=150)
    let btnAdd7 = new Button(Text="7", Top=60 )
    let btnAdd8 = new Button(Text="8", Top=60, Left=75)
    let btnAdd9 = new Button(Text="9", Top=60, Left=150)

    let btnAddition = new Button(Text="+", Top=123, Left=225)
    let btnSubtraction = new Button(Text="-", Top=100, Left=225)
    let btnMultiplication = new Button(Text="*", Top=80, Left=225)
    let btnDivison = new Button(Text="/", Top=60, Left=225)
    let btnEquals =  new Button(Text="=", Top=123, Left=150)
    let btnDot = new Button(Text=",", Top=123)

    let inputDisplay = new Label(Text="", BorderStyle = BorderStyle.Fixed3D)
    let outputDisplay = new Label(Text="", Top=40, BorderStyle = BorderStyle.Fixed3D)
    let outputExpressionDisplay = new Label(Text="", Top=20, BorderStyle = BorderStyle.Fixed3D)

    let buttonList = [btnAdd0; btnAdd1; btnAdd2; btnAdd3; btnAdd4; btnAdd5; btnAdd6; btnAdd7; btnAdd8;
                        btnAdd9; btnAddition; btnSubtraction; btnMultiplication; btnDivison; btnEquals; btnDot]

    form.Controls.AddRange [| btnAdd0 ; btnAdd1; btnAdd2 ; btnAdd3; btnAdd4 ; btnAdd5; btnAdd6 ; btnAdd7; btnAdd8 ; btnAdd9;
                             btnAddition; btnSubtraction; btnMultiplication; btnDivison; btnEquals;
                             btnDot; outputDisplay; inputDisplay; outputExpressionDisplay|]