- added supporting section headers

MagicLab-team · Jul 4, 2017 · 32152bd · 32152bd
1 parent bb2ee95
commit 32152bd
Show file tree

Hide file tree

Showing 2 changed files with 47 additions and 7 deletions.
diff --git a/PinterestLayout/PinterestLayout.swift b/PinterestLayout/PinterestLayout.swift
@@ -13,9 +13,16 @@ import UIKit
 
 public protocol CollectionViewLayoutDelegate {
 
-    func collectionView(collectionView: UICollectionView, heightForImageAtIndexPath indexPath: IndexPath, withWidth: CGFloat) -> CGFloat
+    func collectionView(collectionView: UICollectionView,
+                        sizeForSectionHeaderViewForSection section: Int) -> CGSize
 
-    func collectionView(collectionView: UICollectionView, heightForAnnotationAtIndexPath indexPath: IndexPath, withWidth: CGFloat) -> CGFloat
+    func collectionView(collectionView: UICollectionView,
+                        heightForImageAtIndexPath indexPath: IndexPath,
+                        withWidth: CGFloat) -> CGFloat
+
+    func collectionView(collectionView: UICollectionView,
+                        heightForAnnotationAtIndexPath indexPath: IndexPath,
+                        withWidth: CGFloat) -> CGFloat
 }
 
 
@@ -98,11 +105,32 @@ public class PinterestLayout: UICollectionViewLayout {
                 xOffsets.append(CGFloat(collumn) * collumnWidth)
             }
 
-            var yOffsets = [CGFloat](repeating: 0, count: numberOfColumns)
-
             for section in 0..<numberOfSections {
                 let numberOfItems = self.numberOfItems(inSection: section)
 
+                let headerY = contentHeight
+                let headerSize = delegate.collectionView(
+                    collectionView: collectionView,
+                    sizeForSectionHeaderViewForSection: section
+                )
+                let headerX = (contentWidth - headerSize.width) / 2
+                let headerFrame = CGRect(
+                    origin: CGPoint(x: headerX, y: headerY),
+                    size: headerSize
+                )
+                let attributes = PinterestLayoutAttributes(
+                    forSupplementaryViewOfKind: UICollectionElementKindSectionHeader,
+                    with: IndexPath(item: 0, section: section)
+                )
+                attributes.frame = headerFrame
+                cache.append(attributes)
+
+                contentHeight = headerFrame.maxY
+                var yOffsets = [CGFloat](
+                    repeating: contentHeight,
+                    count: numberOfColumns
+                )
+
                 for item in 0..<numberOfItems {
                     let indexPath = IndexPath(item: item, section: section)
 

diff --git a/PinterestLayoutExample/PinterestVC.swift b/PinterestLayoutExample/PinterestVC.swift
@@ -13,8 +13,12 @@ import AVFoundation
 
 class PinterestVC: UICollectionViewController {
 
-    var images: [[UIImage]] = [[#imageLiteral(resourceName: "new_york"), #imageLiteral(resourceName: "bigben_river"), #imageLiteral(resourceName: "dubai"), #imageLiteral(resourceName: "4"), #imageLiteral(resourceName: "tiger"), #imageLiteral(resourceName: "5")], [#imageLiteral(resourceName: "adelaide_castle"), #imageLiteral(resourceName: "rys"), #imageLiteral(resourceName: "12"), #imageLiteral(resourceName: "cat"), #imageLiteral(resourceName: "6"), #imageLiteral(resourceName: "city"), #imageLiteral(resourceName: "9"), #imageLiteral(resourceName: "ph"), #imageLiteral(resourceName: "paris"), #imageLiteral(resourceName: "2"), #imageLiteral(resourceName: "bridge"), #imageLiteral(resourceName: "elephants")], [#imageLiteral(resourceName: "venice"), #imageLiteral(resourceName: "bw_new_york"), #imageLiteral(resourceName: "10"), #imageLiteral(resourceName: "kittens"), #imageLiteral(resourceName: "deer"), #imageLiteral(resourceName: "11"), #imageLiteral(resourceName: "8"), #imageLiteral(resourceName: "13"), #imageLiteral(resourceName: "squirell"), #imageLiteral(resourceName: "lion"), #imageLiteral(resourceName: "nature"), #imageLiteral(resourceName: "4")]]
-
+    var images: [[UIImage]] = [
+        [#imageLiteral(resourceName: "new_york"), #imageLiteral(resourceName: "bigben_river"), #imageLiteral(resourceName: "dubai"), #imageLiteral(resourceName: "4"), #imageLiteral(resourceName: "tiger"), #imageLiteral(resourceName: "5")],
+        [#imageLiteral(resourceName: "adelaide_castle"), #imageLiteral(resourceName: "rys"), #imageLiteral(resourceName: "12"), #imageLiteral(resourceName: "cat"), #imageLiteral(resourceName: "6"), #imageLiteral(resourceName: "city"), #imageLiteral(resourceName: "9"), #imageLiteral(resourceName: "ph"), #imageLiteral(resourceName: "paris"), #imageLiteral(resourceName: "2"), #imageLiteral(resourceName: "bridge"), #imageLiteral(resourceName: "elephants")],
+        [#imageLiteral(resourceName: "venice"), #imageLiteral(resourceName: "bw_new_york"), #imageLiteral(resourceName: "10"), #imageLiteral(resourceName: "kittens"), #imageLiteral(resourceName: "deer"), #imageLiteral(resourceName: "11"), #imageLiteral(resourceName: "8"), #imageLiteral(resourceName: "13"), #imageLiteral(resourceName: "squirell"), #imageLiteral(resourceName: "lion"), #imageLiteral(resourceName: "nature"), #imageLiteral(resourceName: "4")]
+    ]
+
     override func viewDidLoad() {
         super.viewDidLoad()
 
@@ -46,7 +50,7 @@ class PinterestVC: UICollectionViewController {
 
 //MARK: UICollectionViewDataSource
 
-extension PinterestVC {
+extension PinterestVC: UICollectionViewDelegateFlowLayout {
 
     override func numberOfSections(in collectionView: UICollectionView) -> Int {
         return images.count
@@ -78,6 +82,14 @@ extension PinterestVC {
 
 extension PinterestVC: CollectionViewLayoutDelegate {
 
+    func collectionView(collectionView: UICollectionView,
+                        sizeForSectionHeaderViewForSection section: Int) -> CGSize {
+        return CGSize(
+            width: collectionView.frame.width,
+            height: 0
+        )
+    }
+
     func collectionView(collectionView: UICollectionView,
                         heightForImageAtIndexPath indexPath: IndexPath,
                         withWidth: CGFloat) -> CGFloat {