Swift CollectionView Custom Layout Cell spacing - ios

Question

I am following the GitHub source to implement CustomCollectionViewLayout, the problem is occurring when i add space between cells but the functions like minimumLineSpacingForSectionAtIndex and setting edge insets functions are not calling even the delegate has been set. Please let me know how can i set space between each column, since i need space of 15 after first column and space of 10 after other columns.
This is what i have achieved so far:
class DemoGraphicCollectionViewLayout: UICollectionViewLayout {
var numberOfColumns : Int = 0
var itemAttributes : NSMutableArray!
var itemsSize : NSMutableArray!
var contentSize : CGSize!
override func prepare() {
if self.collectionView?.numberOfSections == 0 {
return
}
if (self.itemAttributes != nil && self.itemAttributes.count > 0) {
for section in 0..<self.collectionView!.numberOfSections {
let numberOfItems : Int = self.collectionView!.numberOfItems(inSection: section)
for index in 0..<numberOfItems {
if section != 0 && index != 0 {
continue
}
let attributes : UICollectionViewLayoutAttributes = self.layoutAttributesForItem(at: IndexPath(item: index, section: section))
if section == 0 {
var frame = attributes.frame
frame.origin.y = self.collectionView!.contentOffset.y
attributes.frame = frame
}
if index == 0 {
var frame = attributes.frame
frame.origin.x = self.collectionView!.contentOffset.x
attributes.frame = frame
}
}
}
return
}
if (self.itemsSize == nil || self.itemsSize.count != numberOfColumns) {
self.calculateItemsSize()
}
var column = 0
var xOffset : CGFloat = 0
var yOffset : CGFloat = 0
var contentWidth : CGFloat = 0
var contentHeight : CGFloat = 0
numberOfColumns = (collectionView?.numberOfSections)!
for section in 0..<self.collectionView!.numberOfSections {
let sectionAttributes = NSMutableArray()
for index in 0..<numberOfColumns {
var itemSize = (self.itemsSize[index] as AnyObject).cgSizeValue
let indexPath = IndexPath(item: index, section: section)
let attributes = UICollectionViewLayoutAttributes(forCellWith: indexPath)
attributes.frame = CGRect(x: xOffset, y: yOffset, width: (itemSize?.width)!, height: (itemSize?.height)!).integral
if section == 0 {
itemSize = CGSize(width: 150, height: 30)
}
if section == 0 && index == 0 {
attributes.zIndex = 1024;
} else if section == 0 || index == 0 {
attributes.zIndex = 1023
}
if section == 0 {
var frame = attributes.frame
frame.origin.y = self.collectionView!.contentOffset.y
frame.size.height = 30
attributes.frame = frame
}
if index == 0 {
var frame = attributes.frame
frame.origin.x = self.collectionView!.contentOffset.x
attributes.frame = frame
}
sectionAttributes.add(attributes)
xOffset += (itemSize?.width)!
column += 1
if column == numberOfColumns {
if xOffset > contentWidth {
contentWidth = xOffset
}
column = 0
xOffset = 0
yOffset += (itemSize?.height)!
}
}
if (self.itemAttributes == nil) {
self.itemAttributes = NSMutableArray(capacity: self.collectionView!.numberOfSections)
}
self.itemAttributes .add(sectionAttributes)
}
let attributes : UICollectionViewLayoutAttributes = (self.itemAttributes.lastObject as AnyObject).lastObject as! UICollectionViewLayoutAttributes
contentHeight = attributes.frame.origin.y + attributes.frame.size.height
self.contentSize = CGSize(width: contentWidth, height: CGFloat(0))
}
override var collectionViewContentSize : CGSize {
return self.contentSize
}
override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes {
let aa = self.itemAttributes[indexPath.section] as! NSMutableArray
return aa[indexPath.row] as! UICollectionViewLayoutAttributes
}
override func layoutAttributesForElements(in rect: CGRect) ->[UICollectionViewLayoutAttributes]? {
var attributes = [UICollectionViewLayoutAttributes]()
if let itemAttributes = self.itemAttributes as NSArray as? [[UICollectionViewLayoutAttributes]] {
for section in itemAttributes {
let filteredArray = section.filter {evaluatedObject in
return rect.intersects(evaluatedObject.frame)
}
attributes.append(contentsOf: filteredArray)
}
}
return attributes
}
override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
return true
}
func sizeForItemWithColumnIndex(_ columnIndex: Int) -> CGSize {
return CGSize(width: 150, height: 130)
}
func calculateItemsSize() {
self.itemsSize = NSMutableArray(capacity: (collectionView?.numberOfSections)!)
for index in 0..<(collectionView?.numberOfSections)! {
self.itemsSize.add(NSValue(cgSize: self.sizeForItemWithColumnIndex(index)))
}
}
}

Answer 1

Try this code. you will only need to replace UIImageView Object with your custom View.
https://github.com/krishnads/KConfigurableCollectionViewDemo

Answer 2

Well, I have tested the code for third party library and i also face the similar issue i.e my delegate methods were not calling. While investigating the issue I found that:
Method minimumInteritemSpacingForSectionAt is a part of UICollectionViewDelegateFlowLayout which is used by the UICollectionViewFlowLayout. The CustomCollectionLayout is a subclass of UICollectionViewLayout and not UICollectionViewFlowLayout. Thats why the delegate methods are not called.
You have an opportunity to adjust the layout in prepare method as mentioned in the source link. Unfortunately i didn't get enough time to implement it but I hope you will find some solution.
Here I found this info