#import "GBBorderView.h" @implementation GBBorderView - (void)awakeFromNib { self.wantsLayer = true; } - (BOOL)wantsUpdateLayer { return true; } - (void)updateLayer { /* Wonderful, wonderful windowserver(?) bug. Using 0,0,0 here would cause it to render garbage on fullscreen windows on some High Sierra machines. Any other value, including the one used here (which is rendered exactly the same due to rounding) works around this bug. */ self.layer.backgroundColor = [NSColor colorWithCalibratedRed:0 green:0 blue:1.0 / 1024.0 alpha:1.0].CGColor; } @end