previewPanel(_:transitionImageFor:contentRect:)
Returns the image to use for the transition zoom effect for a given item.
Declaration
optional func previewPanel(_ panel: QLPreviewPanel!, transitionImageFor item: (any QLPreviewItem)!, contentRect: UnsafeMutablePointer<NSRect>!) -> Any!Parameters
- panel:
The preview panel.
- item:
The item the system is previewing.
- contentRect:
The rectangle within a preview image that actually represents the content of the document. For icons, the actual rectangle is typically smaller than the icon itself.
Return Value
The image to use for the transition zoom effect for the item.
Discussion
The system invokes this optional method when the preview panel opens or closes to provide a smooth transition when zooming. The return type of the function should be an instance of NSImage.