Add syntax highlight logic in formatter

Components/Sources/ComponentsObjC/WKSourceEditorFormatterStrikethrough.m

@@ -1,5 +1,70 @@
 #import "WKSourceEditorFormatterStrikethrough.h"
+#import "WKSourceEditorColors.h"
+
+@interface WKSourceEditorFormatterStrikethrough ()
+
+@property (nonatomic, strong) NSDictionary *strikethroughAttributes;
+@property (nonatomic, strong) NSRegularExpression *strikethroughRegex;
+
+@end
 
 @implementation WKSourceEditorFormatterStrikethrough
 
+- (instancetype)initWithColors:(WKSourceEditorColors *)colors fonts:(WKSourceEditorFonts *)fonts {
+    self = [super initWithColors:colors fonts:fonts];
+    if (self) {
+        _strikethroughAttributes = @{
+            NSForegroundColorAttributeName: colors.greenForegroundColor,
+            WKSourceEditorCustomKeyColorGreen: [NSNumber numberWithBool:YES]
+        };
+
+        _strikethroughRegex = [[NSRegularExpression alloc] initWithPattern:@"(<s>)(\\s*.*?)(<\\/s>)" options:0 error:nil];
+    }
+
+    return self;
+}
+
+- (void)addSyntaxHighlightingToAttributedString:(nonnull NSMutableAttributedString *)attributedString inRange:(NSRange)range {
+    [self.strikethroughRegex enumerateMatchesInString:attributedString.string
+                                        options:0
+                                          range:range
+                                     usingBlock:^(NSTextCheckingResult *_Nullable result, NSMatchingFlags flags, BOOL *_Nonnull stop) {
+            NSRange fullMatch = [result rangeAtIndex:0];
+            NSRange openingRange = [result rangeAtIndex:1];
+            NSRange contentRange = [result rangeAtIndex:2];
+            NSRange closingRange = [result rangeAtIndex:3];
+
+            if (openingRange.location != NSNotFound) {
+                [attributedString addAttributes:self.strikethroughAttributes range:openingRange];
+            }
+
+            if (closingRange.location != NSNotFound) {
+                [attributedString addAttributes:self.strikethroughAttributes range:closingRange];
+            }
+        }];
+}
+
+- (void)updateColors:(WKSourceEditorColors *)colors inAttributedString:(NSMutableAttributedString *)attributedString inRange:(NSRange)range {
+
+    NSMutableDictionary *mutAttributes = [[NSMutableDictionary alloc] initWithDictionary:self.strikethroughAttributes];
+    [mutAttributes setObject:colors.greenForegroundColor forKey:NSForegroundColorAttributeName];
+    self.strikethroughAttributes = [[NSDictionary alloc] initWithDictionary:mutAttributes];
+
+    [attributedString enumerateAttribute:WKSourceEditorCustomKeyColorGreen
+                                 inRange:range
+                                 options:nil
+                              usingBlock:^(id value, NSRange localRange, BOOL *stop) {
+        if ([value isKindOfClass: [NSNumber class]]) {
+            NSNumber *numValue = (NSNumber *)value;
+            if ([numValue boolValue] == YES) {
+                [attributedString addAttributes:self.strikethroughAttributes range:localRange];
+            }
+        }
+    }];
+}
+
+- (void)updateFonts:(WKSourceEditorFonts *)fonts inAttributedString:(NSMutableAttributedString *)attributedString inRange:(NSRange)range {
+    // No special font handling needed for references
+}
+
 @end