NSButton setImage with transparent PNG causes flashing
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I have a NSButton with a transparent image (round button, PNG 24) on a dark background. When it is clicked it I swap the image with `[_button setImage:[NSImage imageNamed:@"secondImage"]]`. Works fine except that when I press the image for a short moment the image appears square with a white "background" (the area of the image which is actually transparent). As soon as the image gets swapped the white "background" disappears. It is like there is a lag and while the new image is loading the transparency is ignored.

Can I preload the image, or tell it to fist display once it is loaded?

Thanks