# Drawing Draw the content of custom views and update that content when the view’s size or appearance changes. ## Topics ### Drawing the View’s Content [`func updateLayer()`](/documentation/AppKit/NSView/updateLayer()) Updates the view’s content by modifying its underlying layer. [`func draw(NSRect)`](/documentation/AppKit/NSView/draw(_:)) Overridden by subclasses to draw the view’s image within the specified rectangle. [`var clipsToBounds: Bool`](/documentation/AppKit/NSView/clipsToBounds) A Boolean value that indicates whether the view, and its subviews, confine their drawing areas to the bounds of the view. [`var canDrawConcurrently: Bool`](/documentation/AppKit/NSView/canDrawConcurrently) A Boolean value indicating whether the view can draw its contents on a background thread. [`var visibleRect: NSRect`](/documentation/AppKit/NSView/visibleRect) The portion of the view that isn’t clipped by its superviews. [`func getRectsBeingDrawn(UnsafeMutablePointer?>?, count: UnsafeMutablePointer?)`](/documentation/AppKit/NSView/getRectsBeingDrawn(_:count:)) Returns by indirection a list of nonoverlapping rectangles that define the area the view is being asked to draw in [`draw(_:)`](/documentation/AppKit/NSView/draw(_:)). [`func needsToDraw(NSRect) -> Bool`](/documentation/AppKit/NSView/needsToDraw(_:)) Returns a Boolean value indicating whether the specified rectangle intersects any part of the area that the view is being asked to draw. [`var wantsDefaultClipping: Bool`](/documentation/AppKit/NSView/wantsDefaultClipping) A Boolean value indicating whether AppKit’s default clipping behavior is in effect. [`func bitmapImageRepForCachingDisplay(in: NSRect) -> NSBitmapImageRep?`](/documentation/AppKit/NSView/bitmapImageRepForCachingDisplay(in:)) Returns a bitmap-representation object suitable for caching the specified portion of the view. [`func cacheDisplay(in: NSRect, to: NSBitmapImageRep)`](/documentation/AppKit/NSView/cacheDisplay(in:to:)) Draws the specified area of the view, and its descendants, into a provided bitmap-representation object. [`enum NSBorderType`](/documentation/AppKit/NSBorderType) These constants specify the type of a view’s border. ### Drawing the View in Fullscreen Mode [`func enterFullScreenMode(NSScreen, withOptions: [NSView.FullScreenModeOptionKey : Any]?) -> Bool`](/documentation/AppKit/NSView/enterFullScreenMode(_:withOptions:)) Sets the view to full screen mode. [`func exitFullScreenMode(options: [NSView.FullScreenModeOptionKey : Any]?)`](/documentation/AppKit/NSView/exitFullScreenMode(options:)) Instructs the view to exit full screen mode. [`var isInFullScreenMode: Bool`](/documentation/AppKit/NSView/isInFullScreenMode) A Boolean value indicating whether the view is in full screen mode. [`struct FullScreenModeOptionKey`](/documentation/AppKit/NSView/FullScreenModeOptionKey) These constants are keys that you can use in the options dictionary in [`enterFullScreenMode(_:withOptions:)`](/documentation/AppKit/NSView/enterFullScreenMode(_:withOptions:)) and [`exitFullScreenMode(options:)`](/documentation/AppKit/NSView/exitFullScreenMode(options:)). ### Invalidating the View’s Content [`func setNeedsDisplay(NSRect)`](/documentation/AppKit/NSView/setNeedsDisplay(_:)) Marks the region of the view within the specified rectangle as needing display, increasing the view’s existing invalid region to include it. [`var needsDisplay: Bool`](/documentation/AppKit/NSView/needsDisplay) A Boolean value that determines whether the view needs to be redrawn before being displayed. [`func display()`](/documentation/AppKit/NSView/display()) Displays the view and all its subviews if possible, invoking each of the `NSView` methods [`lockFocus()`](/documentation/AppKit/NSView/lockFocus()), [`draw(_:)`](/documentation/AppKit/NSView/draw(_:)), and [`unlockFocus()`](/documentation/AppKit/NSView/unlockFocus()) as necessary. [`func display(NSRect)`](/documentation/AppKit/NSView/display(_:)) Acts as [`display()`](/documentation/AppKit/NSView/display()), but confining drawing to a rectangular region of the view. [`func displayIgnoringOpacity(NSRect)`](/documentation/AppKit/NSView/displayIgnoringOpacity(_:)) Displays the view but confines drawing to a specified region and does not back up to the first opaque ancestor—it simply causes the view and its descendants to execute their drawing code. [`func displayIgnoringOpacity(NSRect, in: NSGraphicsContext)`](/documentation/AppKit/NSView/displayIgnoringOpacity(_:in:)) Causes the view and its descendants to be redrawn to the specified graphics context. [`func displayIfNeeded()`](/documentation/AppKit/NSView/displayIfNeeded()) Displays the view and all its subviews if any part of the view has been marked as needing display. [`func displayIfNeeded(NSRect)`](/documentation/AppKit/NSView/displayIfNeeded(_:)) Acts as [`displayIfNeeded()`](/documentation/AppKit/NSView/displayIfNeeded()), confining drawing to a specified region of the view. [`func displayIfNeededIgnoringOpacity()`](/documentation/AppKit/NSView/displayIfNeededIgnoringOpacity()) Acts as [`displayIfNeeded()`](/documentation/AppKit/NSView/displayIfNeeded()), except that this method doesn’t back up to the first opaque ancestor—it simply causes the view and its descendants to execute their drawing code. [`func displayIfNeededIgnoringOpacity(NSRect)`](/documentation/AppKit/NSView/displayIfNeededIgnoringOpacity(_:)) Acts as [`displayIfNeeded()`](/documentation/AppKit/NSView/displayIfNeeded()), but confining drawing to `aRect` and not backing up to the first opaque ancestor—it simply causes the view and its descendants to execute their drawing code. [`func translateRectsNeedingDisplay(in: NSRect, by: NSSize)`](/documentation/AppKit/NSView/translateRectsNeedingDisplay(in:by:)) Translates the display rectangles by the specified delta. [`var isOpaque: Bool`](/documentation/AppKit/NSView/isOpaque) A Boolean value indicating whether the view fills its frame rectangle with opaque content. [`func viewWillDraw()`](/documentation/AppKit/NSView/viewWillDraw()) Informs the view that it’s required to draw content. ### Updating the View When Property Values Change [`struct Invalidating`](/documentation/AppKit/NSView/Invalidating) A property wrapper that notifies the system that a property value change has invalidated an aspect of the containing view. [`protocol NSViewInvalidating`](/documentation/AppKit/NSViewInvalidating) Implements a type of invalidation that can occur on a view that requires an update. ### Managing Live Resize [`var inLiveResize: Bool`](/documentation/AppKit/NSView/inLiveResize) A Boolean value indicating whether the view is being rendered as part of a live resizing operation. [`var preservesContentDuringLiveResize: Bool`](/documentation/AppKit/NSView/preservesContentDuringLiveResize) A Boolean value indicating whether the view optimizes live-resize operations by preserving content that has not moved. [`func getRectsExposedDuringLiveResize(UnsafeMutablePointer, count: UnsafeMutablePointer)`](/documentation/AppKit/NSView/getRectsExposedDuringLiveResize(_:count:)) Returns a list of rectangles indicating the newly exposed areas of the view. [`var rectPreservedDuringLiveResize: NSRect`](/documentation/AppKit/NSView/rectPreservedDuringLiveResize) The rectangle identifying the portion of your view that did not change during a live resize operation. [`func viewWillStartLiveResize()`](/documentation/AppKit/NSView/viewWillStartLiveResize()) Informs the view of the start of a live resize—the user has started resizing the view. [`func viewDidEndLiveResize()`](/documentation/AppKit/NSView/viewDidEndLiveResize()) Informs the view of the end of a live resize—the user has finished resizing the view. --- 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)