Image Accessibility (#543)

* Configure Accessibility Parameters on Images.

Sources/Models/Image.swift

@@ -15,13 +15,17 @@ public struct Image: Decodable {
     public var size: Int
     public var width: Int
     public var url: URL
+    public var accessibilityLabel: String?
+    public var isDecorative: Bool
 
-    public init(height: Int, isURLOptimizationEnabled: Bool, name: String, size: Int, width: Int, url: URL) {
+    public init(height: Int, isURLOptimizationEnabled: Bool, name: String, size: Int, width: Int, url: URL, accessibilityLabel: String?, isDecorative: Bool) {
         self.height = height
         self.isURLOptimizationEnabled = isURLOptimizationEnabled
         self.name = name
         self.size = size
         self.width = width
         self.url = url
+        self.accessibilityLabel = accessibilityLabel
+        self.isDecorative = isDecorative
     }
 }

Sources/UI/ScreenViewController.swift

@@ -240,6 +240,9 @@ open class ScreenViewController: UICollectionViewController, UICollectionViewDat
 
         let background = screen.background
 
+        backgroundImageView.isAccessibilityElement = !(background.image?.isDecorative ?? true)
+        backgroundImageView.accessibilityLabel = background.image?.accessibilityLabel
+
         switch background.contentMode {
         case .fill:
             backgroundImageView.contentMode = .scaleAspectFill

Sources/UI/Views/BlockCell.swift

@@ -91,17 +91,20 @@ class BlockCell: UICollectionViewCell {
         let view = content ?? self
 
         guard !(block is TextPollBlock), !(block is ImagePollBlock), !(block is WebViewBlock) else {
-            // Polls and webviews implement their own a11y.
+            // Polls and WebViews implement their own accessibility.
             return
         }
 
-        // Some Rover blocks do not currently have a11y alternative descriptions available.
-        let hasContent = !(block is ImageBlock) && !(block is RectangleBlock)
+        // true if the block is an image and is marked as isDecorative.
+        let isImageWithoutContent = ((block as? ImageBlock)?.image.isDecorative) ?? false
+
+        // Some Rover blocks should not be visible to accessibility:
+        let hasContent = !(block is RectangleBlock) && !isImageWithoutContent
 
         // All Rover blocks that have meaningful content should be a11y, or if they at least have tap behaviour.
         view.isAccessibilityElement = hasContent || block.tapBehavior != .none
 
-        // tapbehaviour be mapped to the `link` a11y trait:
+        // TabBehavior is mapped to the `link` accessibility trait:
         switch block.tapBehavior {
         case .goToScreen(_), .openURL(_, _), .presentWebsite(_):
             view.accessibilityTraits.applyTrait(trait: .link, to: true)

Sources/UI/Views/Extensions/UIImageView.swift

@@ -16,6 +16,9 @@ extension UIImageView {
         self.alpha = 0.0
         self.image = nil
 
+        self.isAccessibilityElement = background?.image.map { !$0.isDecorative } ?? false
+        self.accessibilityLabel = background?.image?.accessibilityLabel
+
         // Background color is used for tiled backgrounds
         self.backgroundColor = UIColor.clear
 

Sources/UI/Views/ImageCell.swift

@@ -30,6 +30,8 @@ class ImageCell: BlockCell {
         imageView.alpha = 0.0
         imageView.image = nil
 
+        imageView.accessibilityLabel = imageBlock.image.accessibilityLabel
+
         if let image = ImageStore.shared.image(for: imageBlock.image, frame: frame) {
             imageView.image = image
             imageView.alpha = 1.0