needsDisplay(forKey:)
Returns a Boolean indicating whether changes to the specified key require the layer to be redisplayed.
Declaration
class func needsDisplay(forKey key: String) -> BoolParameters
- key:
A string that specifies an attribute of the layer.
Return Value
true if the layer requires a redisplay.
Discussion
Subclasses can override this method and return true if the layer should be redisplayed when the value of the specified attribute changes. Animations changing the value of the attribute also trigger redisplay.
The default implementation of this method returns false.