Monkey-X - Getting started - Class in List - updating and drawing - code example

Import mojo

' what is the size of the screen.
Global screenwidth:Int=640
Global screenheight:Int=480

Class alien
    ' initialisation of variables for this class.
    Field ax:Int
    Field ay:Int
    Field deleteme:Bool=False
    Method New(x:Int,y:Int)
        ' assign the location of the alien
        ax = x
        ay = y        
    End Method
    Method update()'update method
        ' copy the mouse x and y into local variables
        Local x:Int=MouseX()
        Local y:Int=MouseY()
        If MouseDown(MOUSE_LEFT) 'if mouse pressed
        If rectsoverlap(x,y,1,1,ax,ay,16,16) 'if ontop of alien
            deleteme = True 'flag for deletion
        End If
        End If
    End Method
    Method draw() 'draw method
        SetColor 255,255,255
        DrawRect ax,ay,16,16
    End Method
    ' little helper function
    Function rectsoverlap:Bool(x1:Int, y1:Int, w1:Int, h1:Int, x2:Int, y2:Int, w2:Int, h2:Int)
        If x1 >= (x2 + w2) Or (x1 + w1) <= x2 Then Return False
        If y1 >= (y2 + h2) Or (y1 + h1) <= y2 Then Return False
        Return True
    End Function    
End Class

' Start a list to store classes into
Global myalien:List<alien> = New List<alien>

Class MyGame Extends App

    Method OnCreate()
        ' frames per second (refresh rate)
        SetUpdateRate(60)
        For Local i=0 Until 50
            myalien.AddLast(New alien(Rnd(screenwidth),Rnd(screenheight)))
        Next
    End Method
    Method OnUpdate()
        'update the alien
        For Local i:=Eachin myalien
            i.update
        Next
        'delete from list if set for deletion
        For Local i:=Eachin myalien
            If i.deleteme = True Then myalien.Remove(i)
        Next
    End Method
    Method OnRender()
        Cls 0,0,0 
        'draw the aliens
        For Local i:=Eachin myalien
            i.draw
        Next
        SetColor 255,255,255
        DrawText "Press on a alien to make him disappear.",0,0
    End Method
End Class


Function Main()
    New MyGame()
End Function