Hide placeholder image from link card when none provided

Closes #358

Tusker/Views/Status/StatusCardView.swift

@@ -23,15 +23,16 @@ class StatusCardView: UIView {
     private let activeBackgroundColor = UIColor.secondarySystemFill
     private let inactiveBackgroundColor = UIColor.secondarySystemBackground
     
-    private var imageRequest: ImageCache.Request?
     private var isGrayscale = false
     
     private var hStack: UIStackView!
     private var titleLabel: UILabel!
     private var descriptionLabel: UILabel!
     private var domainLabel: UILabel!
-    private var imageView: UIImageView!
+    private var imageView: CachedImageView!
     private var placeholderImageView: UIImageView!
+    private var leadingSpacer: UIView!
+    private var trailingSpacer: UIView!
     
     override init(frame: CGRect) {
         super.init(frame: frame)
@@ -76,20 +77,22 @@ class StatusCardView: UIView {
         ])
         vStack.axis = .vertical
         vStack.alignment = .leading
-        vStack.distribution = .fill
         vStack.spacing = 0
         
-        imageView = UIImageView()
+        imageView = CachedImageView(cache: .attachments)
         imageView.contentMode = .scaleAspectFill
         imageView.clipsToBounds = true
         
-        let spacer = UIView()
+        leadingSpacer = UIView()
-        spacer.backgroundColor = .clear
+        leadingSpacer.backgroundColor = .clear
+        trailingSpacer = UIView()
+        trailingSpacer.backgroundColor = .clear
         
         hStack = UIStackView(arrangedSubviews: [
+            leadingSpacer,
             imageView,
             vStack,
-            spacer,
+            trailingSpacer,
         ])
         hStack.translatesAutoresizingMaskIntoConstraints = false
         hStack.axis = .horizontal
@@ -107,6 +110,7 @@ class StatusCardView: UIView {
         placeholderImageView.translatesAutoresizingMaskIntoConstraints = false
         placeholderImageView.contentMode = .scaleAspectFit
         placeholderImageView.tintColor = .gray
+        placeholderImageView.isHidden = true
 
         addSubview(placeholderImageView)
         
@@ -114,9 +118,10 @@ class StatusCardView: UIView {
             imageView.heightAnchor.constraint(equalTo: heightAnchor),
             imageView.widthAnchor.constraint(equalTo: imageView.heightAnchor),
             
-            vStack.heightAnchor.constraint(equalTo: heightAnchor, constant: -8),
+            vStack.heightAnchor.constraint(lessThanOrEqualTo: heightAnchor, constant: -8),
             
-            spacer.widthAnchor.constraint(equalToConstant: 4),
+            leadingSpacer.widthAnchor.constraint(equalToConstant: 4),
+            trailingSpacer.widthAnchor.constraint(equalToConstant: 4),
             
             hStack.leadingAnchor.constraint(equalTo: leadingAnchor),
             hStack.trailingAnchor.constraint(equalTo: trailingAnchor),
@@ -128,8 +133,6 @@ class StatusCardView: UIView {
             placeholderImageView.centerXAnchor.constraint(equalTo: imageView.centerXAnchor),
             placeholderImageView.centerYAnchor.constraint(equalTo: imageView.centerYAnchor),
         ])
-        
-        NotificationCenter.default.addObserver(self, selector: #selector(updateUIForPreferences), name: .preferencesChanged, object: nil)
     }
     
     override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
@@ -161,10 +164,15 @@ class StatusCardView: UIView {
             return
         }
         
-        self.imageView.image = nil
+        if let image = card.image {
-        
+            imageView.update(for: URL(image), blurhash: card.blurhash)
-        updateGrayscaleableUI(card: card)
+            imageView.isHidden = false
-        updateUIForPreferences()
+            leadingSpacer.isHidden = true
+        } else {
+            imageView.update(for: nil)
+            imageView.isHidden = true
+            leadingSpacer.isHidden = false
+        }
         
         let title = card.title.trimmingCharacters(in: .whitespacesAndNewlines)
         titleLabel.text = title
@@ -182,37 +190,6 @@ class StatusCardView: UIView {
         }
     }
     
-    @objc private func updateUIForPreferences() {
-        if isGrayscale != Preferences.shared.grayscaleImages,
-           let card = card {
-            updateGrayscaleableUI(card: card)
-        }
-    }
-    
-    private func updateGrayscaleableUI(card: Card) {
-        isGrayscale = Preferences.shared.grayscaleImages
-        
-        if let imageURL = card.image {
-            placeholderImageView.isHidden = true
-            
-            imageRequest = ImageCache.attachments.get(URL(imageURL)!, completion: { (_, image) in
-                guard let image = image,
-                      self.card?.image == imageURL,
-                      let transformedImage = ImageGrayscalifier.convertIfNecessary(url: URL(imageURL)!, image: image) else {
-                    return
-                }
-                DispatchQueue.main.async {
-                    self.imageView.image = transformedImage
-                }
-            })
-            if imageRequest != nil {
-                loadBlurHash()
-            }
-        } else {
-            placeholderImageView.isHidden = false
-        }
-    }
-    
     private func loadBlurHash() {
         guard let card = card, let hash = card.blurhash else { return }