Swift3

[farazhaider88]

Can you please update this code for swift3

[farazhaider88]

any update on this please??

[pboudoin]

Any update please?

[iad24]

to those who want it now:

//
// CustomCollectionViewLayout.swift
// CustomCollectionLayout
//
// Created by JOSE MARTINEZ on 15/12/2014.
// Copyright (c) 2014 brightec. All rights reserved.
//

import UIKit

class CustomCollectionViewLayout: UICollectionViewLayout {

let numberOfColumns = 8
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
    
    for section in 0..<self.collectionView!.numberOfSections {
        let sectionAttributes = NSMutableArray()
        
        for index in 0..<numberOfColumns {
            let 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 && 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
                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: contentHeight)
}

override var collectionViewContentSize : CGSize {
    return self.contentSize
}

override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes! {
    //return self.itemAttributes[indexPath.section][indexPath.row] as! UICollectionViewLayoutAttributes
    let arr = self.itemAttributes[indexPath.section] as! NSMutableArray
    return arr[indexPath.row] as! UICollectionViewLayoutAttributes
}

override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
    var attributes = [UICollectionViewLayoutAttributes]()
    if self.itemAttributes != nil {
        for section in self.itemAttributes {
            
            let filteredArray  =  (section as! NSMutableArray).filtered(
                
                using: NSPredicate(block: { (evaluatedObject , bindings) -> Bool in
                    let a = evaluatedObject as! UICollectionViewLayoutAttributes
                    return rect.intersects(a.frame)
                })
                ) as! [UICollectionViewLayoutAttributes]
            
            
            attributes.append(contentsOf: filteredArray)
            
        }
    }
    
    return attributes
}

override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
    return true
}

func sizeForItemWithColumnIndex(_ columnIndex: Int) -> CGSize {
    var text : String = ""
    switch (columnIndex) {
    case 0:
        text = "Col 0"
    case 1:
        text = "Col 1"
    case 2:
        text = "Col 2"
    case 3:
        text = "Col 3"
    case 4:
        text = "Col 4"
    case 5:
        text = "Col 5"
    case 6:
        text = "Col 6"
    default:
        text = "Col 7"
    }
    
    let size : CGSize = (text as NSString).size(attributes: [NSFontAttributeName: UIFont.systemFont(ofSize: 17.0)])
    let width : CGFloat = size.width + 25
    return CGSize(width: width, height: 30)
}

func calculateItemsSize() {
    self.itemsSize = NSMutableArray(capacity: numberOfColumns)
    for index in 0..<numberOfColumns {
        self.itemsSize.add(NSValue(cgSize: self.sizeForItemWithColumnIndex(index)))
    }
}

}

[L-Jovi]

@iad24 thanks for your example :)

[starkindustries]

Hey everyone, I made a version using Storyboards instead of nibs. I also incorporated agoettler's changes to use native Swift arrays instead of NSMutableArray. The link is below. Let me know if you have questions or suggestions.
https://github.com/starkindustries/CustomCollectionViewLayout