I have a collection view (using a compositional layout and a diffable data source) that has a segmented control in its header. When the control value changes, the cells update to a different UICollectionViewCell class with all new data. It mostly works as expected. The issue is that my collection view scrolls back to the top when the I apply my snapshot. How can I keep it from scrolling?
Called when my view loads:
func initialDataSourceSetUp() {
var snapshot = NSDiffableDataSourceSnapshot<Section, SampleDataObject>()
snapshot.appendSections([.main])
snapshot.appendItems(sampleData)
sampleDataSource.apply(snapshot, animatingDifferences: true, completion: nil)
}
Called when the segmented control changes:
func updateDataSource() {
var snapshotSectionMain = sampleDataSource.snapshot(for: .main)
snapshotSectionMain.deleteAll()
if currentSegment == 0 {
snapshotSectionMain.append(sampleData)
} else {
snapshotSectionMain.append(sampleData2)
}
sampleDataSource.apply(snapshotSectionMain, to: .main)
}
Setting up my Cells and Supplementary view:
sampleDataSource = UICollectionViewDiffableDataSource(collectionView: collectionView, cellProvider: { (collectionView, indexPath, item) -> UICollectionViewCell? in
if self.currentSegment == 0 {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: BasicRentalItemCollectionViewCell.identifier, for: indexPath) as! BasicRentalItemCollectionViewCell
cell.imageMain.image = item.image
cell.labelTitle.text = item.title
return cell
} else {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CustomerReviewCollectionViewCell.identifier, for: indexPath) as! CustomerReviewCollectionViewCell
cell.labelTitle.text = item.title
cell.imageViewAvatar.image = item.image
return cell
}
})
sampleDataSource.supplementaryViewProvider = { collectionView, kind, indexPath in
guard kind == UICollectionView.elementKindSectionHeader else {
return nil
}
let header = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: ProfileHeaderView.identifier, for: indexPath) as! ProfileHeaderView
header.delegate = self
header.user = self.user
header.isPersonalProfile = self.isPersonalProfile
return header
}