draggingImageForItems(at:with:offset:)
This method computes and returns an image to use for dragging.
Declaration
func draggingImageForItems(at indexes: IndexSet, with event: NSEvent, offset dragImageOffset: NSPointPointer) -> NSImageParameters
- indexes:
The index set of the items to be dragged.
- event:
Mouse drag event.
- dragImageOffset:
An in/out parameter that will initially be set to Nszeropoint. it can be modified to reposition the returned image. A
dragImageOffsetof Nszeropoint will cause the image to be centered under the mouse.
Return Value
An image containing a rendering of the visible portions of the views for each item.
Discussion
You can override the default image by subclassing NSCollectionView and overriding this method, or by implementing the collectionView(_:draggingImageForItemsAt:with:offset:) delegate method, it will be preferred over this method.