Monday, December 31, 2018

How To Reorder cells in UICollectionView using Swift

While building out a feature, in one of our Apps, I was faced with a need to reorder the cells in UICollectionView using Swift.

I looked around and found many ways of doing it, some of them work and some of them didn't. Heres an implementation that we ended up using and which is working for sure.

The Solution

Here are the steps to get the reorder feature working using drag and drop

  • We need to implement the method collectionView(_ collectionView: UICollectionView, canMoveItemAt indexPath: IndexPath) -> Bool from the UICollectionViewDelegate protocol, to indicate that the cells in UICollectionView can be moved around.
  • Next, we need to implement the UILongPressGestureRecognizer for the UICollectionView so that we can better handle the long press gesture
  • We are adding the gesture recognizer to the UICollectionView and setting up the callback method to handleLongGesture(gesture: UILongPressGestureRecognizer)
  • In the callback method we are letting the UICollectionView know about the interactions. 
  • Most of the work is already done, only thing left is to handle what should happen when the items are moved around. This can be achieved by implementing the method collectionView(_ collectionView: UICollectionView, moveItemAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath) from the UICollectionViewDelegate.
Thats about all the code thats needed to achieve reordering of cells in UICollectionView using Swift!

1 comment:

Have some Fun!