targetContentOffset(forProposedContentOffset:withScrollingVelocity:)
Returns the offset value to use for the collection view’s content at the end of scrolling.
Declaration
func targetContentOffset(forProposedContentOffset proposedContentOffset: NSPoint, withScrollingVelocity velocity: NSPoint) -> NSPointParameters
- proposedContentOffset:
The proposed point (in the collection view’s coordinate space) for the lower-left corner of the visible content. The collection view calculates this value as the most likely value to use at the end of animations.
- velocity:
The current horizontal and vertical scrolling velocities. The value is specified in points per second.
Return Value
The offset value that you want to use for the content.
Discussion
Use this method to position the collection view’s content appropriately after scrolling. This method tells the scroll view where to stop scrolling so that the collection view’s content is displayed optimally. For example, you might use this method to adjust the proposed content offset so that it falls on a boundary between rows of items, as opposed to stopping in the middle of a row.
See Also
Providing Layout Information
layoutAttributesClassprepare()collectionViewContentSizelayoutAttributesForElements(in:)layoutAttributesForItem(at:)layoutAttributesForSupplementaryView(ofKind:at:)layoutAttributesForDecorationView(ofKind:at:)layoutAttributesForDropTarget(at:)layoutAttributesForInterItemGap(before:)targetContentOffset(forProposedContentOffset:)