[AltStore] Adds redesigned AppViewController to view/download AltStore apps

AltStore/Browse/BrowseViewController.swift

@@ -36,6 +36,18 @@ class BrowseViewController: UICollectionViewController
         let collectionViewLayout = self.collectionViewLayout as! UICollectionViewFlowLayout
         collectionViewLayout.itemSize.width = self.view.bounds.width
     }
+    
+    override func prepare(for segue: UIStoryboardSegue, sender: Any?)
+    {
+        guard segue.identifier == "showApp" else { return }
+        
+        guard let cell = sender as? UICollectionViewCell, let indexPath = self.collectionView.indexPath(for: cell) else { return }
+        
+        let app = self.dataSource.item(at: indexPath)
+        
+        let appViewController = segue.destination as! AppViewController
+        appViewController.app = app
+    }
 }
 
 private extension BrowseViewController

AltStore/Browse/ScreenshotCollectionViewCell.swift

@@ -18,11 +18,25 @@ class ScreenshotCollectionViewCell: UICollectionViewCell
     required init?(coder aDecoder: NSCoder)
     {
         self.imageView = UIImageView(image: nil)
-        self.imageView.layer.cornerRadius = 8
         self.imageView.layer.masksToBounds = true
         
         super.init(coder: aDecoder)
         
         self.addSubview(self.imageView, pinningEdgesWith: .zero)
     }
+    
+    override func layoutSubviews()
+    {
+        super.layoutSubviews()
+        
+        if let image = self.imageView.image, (image.size.height / image.size.width) > ((16.0 / 9.0) + 0.1)
+        {
+            // Image aspect ratio is taller than 16:9, so assume it's an X-style screenshot and set corner radius.
+            self.imageView.layer.cornerRadius = max(self.imageView.bounds.width / 9.8, 8)
+        }
+        else
+        {
+            self.imageView.layer.cornerRadius = 0
+        }        
+    }
 }