Building An Interactive Grid View

This demo shows a few techniques on how to build a re-ordable grid view based on stock UICollectionView API.

Here are the main UIKit APIs used by this demo:

• UICollectionViews compositional layout API.
• UICollectionViewDiffableDataSource and its reordering support.
• UIContextMenuConfiguration for presenting optional menus from each displayed cell.

The view is driven by a two-column layout that supports two cell sizes:

• Compact (half width)
• Regular (full width)

Other goals

• The layout must dynamically adjust while the user drags cells arounds.
• The user must be able to long-press on cell to present a standard iOS context menu.

Additional details can be found in this blog post.