Instance Method

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) -> NSImage

Parameters

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 dragImageOffset of 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.

See Also

Legacy Collection View Support

var itemPrototype: NSCollectionViewItem?

The receiver’s collection view item prototype.

Deprecated
func newItem(forRepresentedObject: Any) -> NSCollectionViewItem

Returns the collection view item that is used for the specified object.

Deprecated
var selectionIndexes: IndexSet

The indexes of the currently selected items.

var maxNumberOfRows: Int

The maximum number of rows that the collection view displays.

Deprecated
var maxNumberOfColumns: Int

The maximum number of columns that the collection view displays.

Deprecated
var minItemSize: NSSize

The minimum size (in points) of items in the collection view grid.

Deprecated
var maxItemSize: NSSize

The maximum size (in points) of items in the collection view grid.

Deprecated
func item(at: Int) -> NSCollectionViewItem?

Returns the collection view item for the represented object at the specified index.

func frameForItem(at: Int) -> NSRect

Returns the frame of the collection view item at the specified index.

func frameForItem(at: Int, withNumberOfItems: Int) -> NSRect

Returns the frame of an item based on the number of items in the collection view.