Unify emoji replacement code

Tusker/Views/BaseEmojiLabel.swift

@@ -19,10 +19,15 @@ protocol BaseEmojiLabel: AnyObject {
 }
 
 extension BaseEmojiLabel {
-    func replaceEmojis(in string: String, emojis: [Emoji], identifier: String, completion: @escaping (NSAttributedString) -> Void) {
-        let matches = emojiRegex.matches(in: string, options: [], range: NSRange(location: 0, length: string.utf16.count))
+    func replaceEmojis(in attributedString: NSAttributedString, emojis: [Emoji], identifier: String?, completion: @escaping (_ attributedString: NSAttributedString, _ didReplaceEmojis: Bool) -> Void) {
+        guard !emojis.isEmpty else {
+            completion(attributedString, false)
+            return
+        }
+        
+        let matches = emojiRegex.matches(in: attributedString.string, options: [], range: NSRange(location: 0, length: attributedString.length))
         guard !matches.isEmpty else {
-            completion(NSAttributedString(string: string))
+            completion(attributedString, false)
             return
         }
         
@@ -33,8 +38,8 @@ extension BaseEmojiLabel {
         
         for emoji in emojis {
             // only make requests for emojis that are present in the text to avoid making unnecessary network requests
-            guard matches.contains(where: { (match) in
-                let matchShortcode = (string as NSString).substring(with: match.range(at: 1))
+            guard matches.contains(where: { (match) -> Bool in
+                let matchShortcode = (attributedString.string as NSString).substring(with: match.range(at: 1))
                 return emoji.shortcode == matchShortcode
             }) else {
                 continue
@@ -57,7 +62,7 @@ extension BaseEmojiLabel {
         }
         
         guard foundEmojis else {
-            completion(NSAttributedString(string: string))
+            completion(attributedString, false)
             return
         }
         
@@ -65,10 +70,10 @@ extension BaseEmojiLabel {
             // if e.g. the account changes before all emojis are loaded, don't bother trying to set them
             guard let self = self, self.emojiIdentifier == identifier else { return }
             
-            let mutAttrString = NSMutableAttributedString(string: string)
+            let mutAttrString = NSMutableAttributedString(attributedString: attributedString)
             // replaces the emojis starting from the end of the string as to not alter the indices of preceeding emojis
             for match in matches.reversed() {
-                let shortcode = (string as NSString).substring(with: match.range(at: 1))
+                let shortcode = (attributedString.string as NSString).substring(with: match.range(at: 1))
                 guard let emojiImage = emojiImages[shortcode] else {
                     continue
                 }
@@ -78,7 +83,11 @@ extension BaseEmojiLabel {
                 mutAttrString.replaceCharacters(in: match.range, with: attachmentStr)
             }
             
-            completion(mutAttrString)
+            completion(mutAttrString, true)
         }
     }
+    
+    func replaceEmojis(in string: String, emojis: [Emoji], identifier: String?, completion: @escaping (_ attributedString: NSAttributedString, _ didReplaceEmojis: Bool) -> Void) {
+        replaceEmojis(in: NSAttributedString(string: string), emojis: emojis, identifier: identifier, completion: completion)
+    }
 }

Tusker/Views/ContentTextView.swift

@@ -13,7 +13,7 @@ import SafariServices
 
 private let emojiRegex = try! NSRegularExpression(pattern: ":(\\w+):", options: [])
 
-class ContentTextView: LinkTextView {
+class ContentTextView: LinkTextView, BaseEmojiLabel {
     
     weak var navigationDelegate: TuskerNavigationDelegate?
     weak var overrideMastodonController: MastodonController?
@@ -24,6 +24,11 @@ class ContentTextView: LinkTextView {
     
     private(set) var hasEmojis = false
     
+    var emojiIdentifier: String?
+    var emojiRequests: [ImageCache.Request] = []
+    var emojiFont: UIFont { defaultFont }
+    var emojiTextColor: UIColor { defaultColor }
+    
     // The link range currently being previewed
     private var currentPreviewedLinkRange: NSRange?
     // The preview created in the previewForHighlighting method, so that we can use the same one in previewForDismissing.
@@ -51,45 +56,11 @@ class ContentTextView: LinkTextView {
     
     // MARK: - Emojis
     func setEmojis(_ emojis: [Emoji]) {
-        guard !emojis.isEmpty else {
-            hasEmojis = false
-            return
-        }
-        hasEmojis = true
-        
-        let emojiImages = MultiThreadDictionary<String, UIImage>(name: "ContentTextView Emoji Images")
-        
-        let group = DispatchGroup()
-        
-        for emoji in emojis {
-            group.enter()
-            _ = ImageCache.emojis.get(emoji.url) { (_, image) in
-                defer { group.leave() }
-                guard let image = image,
-                      let transformedImage = ImageGrayscalifier.convertIfNecessary(url: emoji.url, image: image) else {
-                    return
-                }
-                emojiImages[emoji.shortcode] = transformedImage
+        replaceEmojis(in: attributedText!, emojis: emojis, identifier: emojiIdentifier) { attributedString, didReplaceEmojis in
+            guard didReplaceEmojis else {
+                return
             }
-        }
-        
-        group.notify(queue: .main) {
-            let mutAttrString = NSMutableAttributedString(attributedString: self.attributedText!)
-            let string = mutAttrString.string
-            let matches = emojiRegex.matches(in: string, options: [], range: mutAttrString.fullRange)
-            // replaces the emojis started from the end of the string as to not alter the indexes of the other emojis
-            for match in matches.reversed() {
-                let shortcode = (string as NSString).substring(with: match.range(at: 1))
-                guard let emojiImage = emojiImages[shortcode] else {
-                    continue
-                }
-                
-                let attachment = NSTextAttachment(emojiImage: emojiImage, in: self.font!, with: self.textColor ?? .label)
-                let attachmentStr = NSAttributedString(attachment: attachment)
-                mutAttrString.replaceCharacters(in: match.range, with: attachmentStr)
-            }
-            
-            self.attributedText = mutAttrString
+            self.attributedText = attributedString
             self.setNeedsLayout()
             self.setNeedsDisplay()
         }

Tusker/Views/EmojiLabel.swift

@@ -26,7 +26,7 @@ class EmojiLabel: UILabel, BaseEmojiLabel {
         emojiRequests = []
         hasEmojis = true
         
-        replaceEmojis(in: attributedText.string, emojis: emojis, identifier: identifier) { [weak self] (newAttributedText) in
+        replaceEmojis(in: attributedText.string, emojis: emojis, identifier: identifier) { [weak self] (newAttributedText, _) in
             guard let self = self, self.emojiIdentifier == identifier else { return }
             self.attributedText = newAttributedText
             self.setNeedsLayout()

Tusker/Views/MultiSourceEmojiLabel.swift

@@ -37,7 +37,7 @@ class MultiSourceEmojiLabel: UILabel, BaseEmojiLabel {
         recombine()
         
         for (index, (string, emojis)) in pairs.enumerated() {
-            self.replaceEmojis(in: string, emojis: emojis, identifier: identifier) { (attributedString) in
+            self.replaceEmojis(in: string, emojis: emojis, identifier: identifier) { (attributedString, _) in
                 attributedStrings[index] = attributedString
                 DispatchQueue.main.async { [weak self] in
                     guard let self = self, self.emojiIdentifier == identifier else { return }

Tusker/Views/StatusContentTextView.swift

@@ -15,6 +15,7 @@ class StatusContentTextView: ContentTextView {
     
     func setTextFrom(status: StatusMO) {
         statusID = status.id
+        emojiIdentifier = status.id
         setTextFromHtml(status.content)
         setEmojis(status.emojis)
     }