Function newScrollDim

javascript/atoms/window.js:364–372

(positionDim, scrollDim, viewportDim)

  }

  function newScrollDim(positionDim, scrollDim, viewportDim) {
    if (positionDim < scrollDim) {
      return positionDim;
    } else if (positionDim >= scrollDim + viewportDim) {
      return positionDim - viewportDim + 1;
    } else {
      return scrollDim;
    }
  }
};