Suggestion: Zoom in/out the window when using the mouse wheel to zoom in/out the previewd image

[YandLiu]

如题
一个细节：当窗口已经被放大至最大（宽度/高度之一达到屏幕宽度/高度）时，继续放大图像就没必要再放大窗口了，就像IrfanView一样。
As the title writes
Also, a trivial point, please don't zoom in the window further when it's already the maximized (I mean it reaches the max width or length of the screen). Just like how IrfanView behaves.