New MaskedCorners Property In CALayer

CALayer MaskedCorners

Looks like there’s a new property of CALayer that, according to documentation, allows you to specify which corners of a CALayer receive the masking treatment when setting the cornerRadius property. New value is called maskedCorners and it takes a new CACornerMask struct instance.

This should be really useful. Came upon it because I’m adding a padding view to the bottom of the DrinkSelector (The bottom bar of the main screen with the 5 drink type icons) to Drink Keeper for iPhone X support, and only wanted the rounded corners on the bottom to follow the screen. Looks like Apple knew exactly what I needed!

Apple’s online docs don’t have any information, but here is the doc block from Xcode.

/* Defines which of the four corners receives the masking when using *cornerRadius' property. Defaults to all four corners. */`

@property CACornerMask maskedCorners CA_AVAILABLE_STARTING (10.13, 11.0, 11.0, 4.0); /* Bit definitions formaskedCorners' property. */`

typedef NS_OPTIONS (NSUInteger, CACornerMask) { kCALayerMinXMinYCorner = 1U << 0, kCALayerMaxXMinYCorner = 1U << 1, kCALayerMinXMaxYCorner = 1U << 2, kCALayerMaxXMaxYCorner = 1U << 3, };