How to Set a specific Image to a specific array position? - ios

Question

I am using a UICollectionView for Horizontal scrolling having six images in the array. What I want is when an item at index path x(1) is clicked an array with images to be set on remaining items(0,2,3,4,5) except position 1. Can we set a specific image at a specific position of an array if yes then how?
In the case of Android, it is like
if (selectedPosition < 0) {
viewHolder.imageView.setImageResource(coloredSmiley[position]);
} else {
viewHolder.imageView.setImageResource(selectedPosition == position ? coloredSmiley[position] : greySmiley[position]);
}
import UIKit
class ViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource {
var selectedImageButton = -1
var imagearray = ["AngrysmIcon1", "UpsetsmIcon2", "ConfusedsmIcon3", "MehsmIcon4", "CurioussmIcon5" , "HappysmIcon6"]
var bwimagearray = ["AngrysmIcon1Inactive", "UpsetsmIcon2Inactive", "ConfusedsmIcon3Inactive", "MehsmIcon4Inactive", "CurioussmIcon5Inactive", "HappysmIcon6Inactive"]
var positiontag = ["0", "1", "2", "3", "4", "5"]
override func viewDidLoad() {
super.viewDidLoad()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return self.positiontag.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! UIcollectionViewCellCollectionViewCell
cell.imagev.image = UIImage(named: imagearray[indexPath.row])
return cell
}
func numberOfSections(in collectionView: UICollectionView) -> Int {
return 1
}
internal func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedImageButton = indexPath.row
let cell = collectionView.cellForItem(at: indexPath) as! UIcollectionViewCellCollectionViewCell
if selectedImageButton < 0 {
//cell.imagev.image = bwimagearray[indexPath.row]
} else {
cell.imagev.image = UIImage(named: imagearray[indexPath.row])
}
}
}
Where selectedposition is global with value -1

Answer 1

From the Android snippet, i believe you need to change cellForRowAt as below,
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! UIcollectionViewCellCollectionViewCell
let imageName: String
if selectedImageButton < 0 {
imageName = imagearray[indexPath.row]
} else {
imageName = selectedImageButton == indexPath.row ? imagearray[indexPath.row] : bwimagearray[indexPath.row]
}
cell.imagev.image = UIImage(named: imageName)
return cell
}
And then set the selectedImageButton in didSelectItemAt and reload the collectionView,
internal func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedImageButton = indexPath.row
collectionView.reloadData()
}
Note: ReloadData may not be recommended and you should look for some more reactive way to notify the cells to update image.

Answer 2

Add this to cellForItemAt
if cell.isSelected {
cell.imagev.image = UIImage(named: imagearray[indexPath.row])
} else {
cell.imagev.image = UIImage(named: bwimagearray[indexPath.row])
}
and following to didSelectItemAt
collectionView.reloadData()
But would recommend to move the logic that set all this to cell something like below mentioned
class UIcollectionViewCellCollectionViewCell: UICollectionViewCell {
override var isSelected: Bool {
get {
return super.isSelected
}
set {
super.isSelected = newValue
updateImage()
}
}
private func updateImage() {
if isSelected {
imagev.image = UIImage(named: imagearray[indexPath.row])
} else {
imagev.image = UIImage(named: bwimagearray[indexPath.row])
}
}
}