+class Column(pygame.sprite.Sprite, EventHandlerMixin) :
+
+ def __init__(self, hue, rect) :
+ pygame.sprite.Sprite.__init__(self)
+ sur = pygame.surface.Surface(rect.size)
+ rgba = hls_to_rgba_8bits(hue, OFF_LUMINANCE, OFF_SATURATION)
+ sur.fill(rgba)
+ self.stateOff = sur
+ self.rectOff = rect
+
+ topRgba = hls_to_rgba_8bits(hue, ON_TOP_LUMINANCE, ON_SATURATION)
+ bottomRgba = hls_to_rgba_8bits(hue, ON_BOTTOM_LUMINANCE, ON_SATURATION)
+ onWidth = rect.width * ON_COLUMN_OVERSIZING
+ onLeft = rect.centerx - onWidth / 2
+ rectOn = pygame.Rect((onLeft, 0),
+ (onWidth, rect.height))
+ self.stateOn = gradients.vertical(rectOn.size, topRgba, bottomRgba)
+ self.rectOn = rectOn
+
+ self.image = self.stateOff
+ self.rect = rect
+
+ def update(self, state) :
+ group = self.groups()[0]
+ if state :
+ group.change_layer(self, 1)
+ self.image = self.stateOn
+ self.rect = self.rectOn
+ else :
+ group.change_layer(self, 0)
+ self.image = self.stateOff
+ self.rect = self.rectOff