Instance Method

layoutAttributesForDecorationViewOfKind:atIndexPath:

Returns the layout attributes of the decoration view at the specified location in your layout.

Declaration

- (NSCollectionViewLayoutAttributes *)layoutAttributesForDecorationViewOfKind:(NSCollectionViewDecorationElementKind)elementKind atIndexPath:(NSIndexPath *)indexPath;

Parameters

elementKind

A string that identifies the type of the decoration view. Use this string to differentiate the decoration views in a given section.

indexPath

The index path of the decoration view. Use this parameter to determine which section contains the decoration view.

Return Value

A layout attributes object containing the layout information to apply to the decoration view.

Discussion

If your layout includes decoration views, you must override this method. In your implementation, create an instance of the appropriate layout attributes class and fill the resulting object with the layout information for the corresponding decoration view. You define the supported decoration views by assigning each one a string that identifies its kind. Use the elementKind and indexPath properties to identify the specific decoration view whose attributes were requested.

You can call this method from other layout-related methods when you want to retrieve layout information for decoration views. Call this method only for decoration views. Do not call it to retrieve layout attributes for items or supplementary views.

See Also

Providing Layout Information

layoutAttributesClass

Returns the class to use for layout attribute objects

- prepareLayout

Prepares the layout object to begin laying out content.

collectionViewContentSize

The width and height of the collection view’s contents.

- layoutAttributesForElementsInRect:

Returns the layout attribute objects for all items and views in the specified rectangle.

- layoutAttributesForItemAtIndexPath:

Returns the layout attributes for the item at the specified index path.

- layoutAttributesForSupplementaryViewOfKind:atIndexPath:

Returns the layout attributes of the supplementary view at the specified location in your layout.

- layoutAttributesForDropTargetAtPoint:

Returns layout attributes for the drop target at the specified point.

- layoutAttributesForInterItemGapBeforeIndexPath:

Returns layout attributes for the inter-item gap at the specified location in your layout.

- targetContentOffsetForProposedContentOffset:

Returns the offset value to use after an animated layout update or change.

- targetContentOffsetForProposedContentOffset:withScrollingVelocity:

Returns the offset value to use for the collection view’s content at the end of scrolling.