hangeZoomWindowSize :: (Double -> Double) -> AppController -> AppController
changeZoomWindowSize f app = let zf = appZoomFactor app in app { appZoomFactor = f zf }

changeZoomWindowSize :: (Double -> Double) -> AppController -> AppController
changeZoomWindowSize f app = let zf = appZoomFactor app in app { appZoomFactor = f zf }
changeZoomWindowSize f app = let zf = appZoomFactor app in app { appZoomFactor = f zf }