why are my collectionViewCell's displaying unusual behavior? - ios

Question

For some reason, my collectionViewCell's are unrecognized when they are selected. It's not until another cell is touched afterwards that the previous cell is recognized. To explain how I realized this, I added the following code to my collectionView's didDeselectItemAtIndexPath method: println("user tapped on cell # \(indexPath.row)"). When I run the app and select a cell, my console doesn't respond until I tap another cell, then it reads the println I added. For instance, if I select the first cell, the debugger doesn't print anything until i select another cell, then the console reads "user tapped on thumbnail # 0".
Now I've added an animation to my collectionView that enlarges each cell on selection, so this is how I know it isn't an indexPath issue because the cell indexPath # that is printed in the console is the correct cell that is enlarged in the view, but like i said, the cell isn't animated on its selection, not until i select another cell afterwards.
Here is my collectionView delegate and dataSource logic:
// MARK: UICollectionViewDataSource
override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return self.books.count
}
override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as! MyCollectionViewCell
// Configure the cell
let book = self.books[indexPath.row]
let coverImage = book.coverImage
if coverImage == nil {
book.fetchCoverImage({ (image, error) -> Void in
if self.collectionView != nil {
collectionView.reloadItemsAtIndexPaths([indexPath])
}
})
} else {
let imageView = cell.imageView
imageView.image = book.coverImage
}
return cell
}
override func collectionView(collectionView: UICollectionView, didDeselectItemAtIndexPath indexPath: NSIndexPath) {
let cell = collectionView.cellForItemAtIndexPath(indexPath) as! MyCollectionViewCell
let book = self.books[indexPath.row]
self.selectedImageView = cell.imageView
if !isModeModal {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller = storyboard.instantiateViewControllerWithIdentifier("DetailViewController") as! DetailViewController
controller.imageSelected = book.coverImage
self.navigationController?.pushViewController(controller, animated: true)
}
println("user tapped on thumbnail # \(indexPath.row)")
}
}
Why is this behavior occurring?

Answer 1

I didn't run your code, but I think, that the problem could be caused by didDeselectItemAtIndexPath. Try to use didSelectItemAtIndexPath instead.
If necessary you can add deselectItemAtIndexPath :
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
collectionView.deselectItemAtIndexPath(indexPath: NSIndexPath, animated: Bool)
}