# QLPreviewPanelDelegate A protocol for the delegate of the Quick Look preview panel. ``` protocol QLPreviewPanelDelegate : NSWindowDelegate ``` ## Overview You can implement these methods to perform custom tasks in response to events in the preview panel. ## Topics ### Optional Methods [`func previewPanel(QLPreviewPanel!, handle: NSEvent!) -> Bool`](/documentation/QuickLookUI/QLPreviewPanelDelegate/previewPanel(_:handle:)) Handles an event that the preview panel receives, but doesn’t handle. [`func previewPanel(QLPreviewPanel!, sourceFrameOnScreenFor: (any QLPreviewItem)!) -> NSRect`](/documentation/QuickLookUI/QLPreviewPanelDelegate/previewPanel(_:sourceFrameOnScreenFor:)) Returns the screen rectangle for a given preview item. [`func previewPanel(QLPreviewPanel!, transitionImageFor: (any QLPreviewItem)!, contentRect: UnsafeMutablePointer!) -> Any!`](/documentation/QuickLookUI/QLPreviewPanelDelegate/previewPanel(_:transitionImageFor:contentRect:)) Returns the image to use for the transition zoom effect for a given item. ## Relationships ### Inherits From [`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol) [`NSWindowDelegate`](/documentation/AppKit/NSWindowDelegate) --- 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)