restoreCachedImage()
Splices the window’s cached image rectangles, if any, back into its raster image (and buffer if it has one), undoing the effect of any drawing performed within those areas since they were established using Cacheimage(in:).
Declaration
func restoreCachedImage()Discussion
You must invoke flush() after this method to guarantee proper redisplay. An NSWindow object automatically discards its cached image rectangles when it displays.