# canDraw(_:zoomScale:) Returns a Boolean value that indicates whether the overlay view is ready to draw its content. ``` func canDraw(_ mapRect: MKMapRect, zoomScale: MKZoomScale) -> Bool ``` ## Parameters `mapRect` The map rectangle that the renderer needs to update. `zoomScale` The current scale factor applied to the map. ## Return Value if this overlay renderer is ready to draw its contents on the map or if it is not. ## Discussion Overlay renderers can override this method in situations where they may depend on the availability of other information to draw their contents. For example, a renderer showing traffic information might want to delay drawing until it has all of the traffic data it needs. In such a case, it can return from this method to indicate that it’s not ready. An overlay renderer might also return if it doesn’t draw content in the specified rectangle. If you return from this method, your application is responsible for calling the [`setNeedsDisplay(_:zoomScale:)`](/documentation/MapKit/MKOverlayRenderer/setNeedsDisplay(_:zoomScale:)) method when the overlay renderer subsequently becomes ready to draw its contents. The default implementation of this method returns . --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)