button.tu

unit
class sButton
    export initialize, pointInButton, draw
    var x1, x2, y1, y2 : int
    procedure initialize (vx1, vy1, vx2, vy2 : int)
        x1 := vx1
        x2 := vx2
        y1 := vy1
        y2 := vy2
    end initialize
    
    function pointInButton (x, y : int) : boolean
        if x1 < x and y1 < y and x2 > x and y2 > y then
            result true
        end if
        result false
    end pointInButton
    
    procedure draw (prevornext : int)
        Draw.FillBox (x1, y1, x2, y2, red)
        var height := abs(y2 - y1)
        var x := x1 %+ abs(x2 - x1) div 2
        var y := y1 + abs(y2 - y1) div 2
        const TRIANGLE_COLOUR := yellow
        if prevornext = 0 then %point backwords
            for i : 0 .. height div 2
                drawline (x + height div 3 + i,
                    y + i,
                    x + height div 3 + i,
                    y - i, TRIANGLE_COLOUR)
            end for
            elsif prevornext = 1 then %point forwards
            for i : 0 .. height div 2
                drawline (x + height div 3 + i,
                    y + height div 2 - i,
                    x + height div 3 + i,
                    y - height div 2 + i, TRIANGLE_COLOUR)
            end for
        end if
    end draw
    
end sButton