source-code

source-code/ALTs/AltStore/Browse/BrowseCollectionViewCell.swift

@@ -0,0 +1,98 @@
+//
+//  BrowseCollectionViewCell.swift
+//  AltStore
+//
+//  Created by Riley Testut on 7/15/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import UIKit
+
+import Roxas
+
+import Nuke
+
+@objc class BrowseCollectionViewCell: UICollectionViewCell
+{
+    var imageURLs: [URL] = [] {
+        didSet {
+            self.dataSource.items = self.imageURLs as [NSURL]
+        }
+    }
+    private lazy var dataSource = self.makeDataSource()
+    
+    @IBOutlet var bannerView: AppBannerView!
+    @IBOutlet var subtitleLabel: UILabel!
+    
+    @IBOutlet private(set) var screenshotsCollectionView: UICollectionView!
+    
+    override func awakeFromNib()
+    {
+        super.awakeFromNib()
+        
+        self.contentView.preservesSuperviewLayoutMargins = true
+        
+        // Must be registered programmatically, not in BrowseCollectionViewCell.xib, or else it'll throw an exception 🤷‍♂️.
+        self.screenshotsCollectionView.register(ScreenshotCollectionViewCell.self, forCellWithReuseIdentifier: RSTCellContentGenericCellIdentifier)
+        
+        self.screenshotsCollectionView.delegate = self
+        self.screenshotsCollectionView.dataSource = self.dataSource
+        self.screenshotsCollectionView.prefetchDataSource = self.dataSource
+    }
+}
+
+private extension BrowseCollectionViewCell
+{
+    func makeDataSource() -> RSTArrayCollectionViewPrefetchingDataSource<NSURL, UIImage>
+    {
+        let dataSource = RSTArrayCollectionViewPrefetchingDataSource<NSURL, UIImage>(items: [])
+        dataSource.cellConfigurationHandler = { (cell, screenshot, indexPath) in
+            let cell = cell as! ScreenshotCollectionViewCell
+            cell.imageView.image = nil
+            cell.imageView.isIndicatingActivity = true
+        }
+        dataSource.prefetchHandler = { (imageURL, indexPath, completionHandler) in
+            return RSTAsyncBlockOperation() { (operation) in
+                ImagePipeline.shared.loadImage(with: imageURL as URL, progress: nil, completion: { (response, error) in
+                    guard !operation.isCancelled else { return operation.finish() }
+                    
+                    if let image = response?.image
+                    {
+                        completionHandler(image, nil)
+                    }
+                    else
+                    {
+                        completionHandler(nil, error)
+                    }
+                })
+            }
+        }
+        dataSource.prefetchCompletionHandler = { (cell, image, indexPath, error) in
+            let cell = cell as! ScreenshotCollectionViewCell
+            cell.imageView.isIndicatingActivity = false
+            cell.imageView.image = image
+            
+            if let error = error
+            {
+                print("Error loading image:", error)
+            }
+        }
+        
+        return dataSource
+    }
+}
+
+extension BrowseCollectionViewCell: UICollectionViewDelegateFlowLayout
+{
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
+    {
+        // Assuming 9.0 / 16.0 ratio for now.
+        let aspectRatio: CGFloat = 9.0 / 16.0
+
+        let itemHeight = collectionView.bounds.height
+        let itemWidth = itemHeight * aspectRatio
+
+        let size = CGSize(width: itemWidth.rounded(.down), height: itemHeight.rounded(.down))
+        return size
+    }
+}