collectionView(_:canDragItemsAt:with:)

Declaration

@MainActor optional func collectionView(_ collectionView: NSCollectionView, canDragItemsAt indexPaths: Set<IndexPath>, with event: NSEvent) -> Bool

Parameters

• collectionView:

  The collection view making the request.

• indexPaths:

  The index paths of the items about to be dragged.

• event:

  The mouse-down event that began the drag operation.

Return Value

true if the drag operation can begin or false if it cannot.

Discussion

If you do not implement this method and your collection view has only one section, the collection view calls the legacy collectionView(_:canDragItemsAt:with:) method. If you do not implement either method, the collection view assumes a return value of true.

See Also

Drag and Drop Support

• Supporting Collection View Drag and Drop Through File Promises
• collectionView(_:pasteboardWriterForItemAt:)
• collectionView(_:writeItemsAt:to:)
• collectionView(_:namesOfPromisedFilesDroppedAtDestination:forDraggedItemsAt:)
• collectionView(_:draggingImageForItemsAt:with:offset:)
• collectionView(_:draggingSession:willBeginAt:forItemsAt:)
• collectionView(_:draggingSession:endedAt:dragOperation:)
• collectionView(_:updateDraggingItemsForDrag:)
• collectionView(_:validateDrop:proposedIndexPath:dropOperation:)
• collectionView(_:acceptDrop:indexPath:dropOperation:)