1 files changed, 49 insertions, 0 deletions
diff --git a/platform/ios/src/UIColor+MGLAdditions.mm b/platform/ios/src/UIColor+MGLAdditions.mm
index 41c066c206..9ca39acda4 100644
--- a/platform/ios/src/UIColor+MGLAdditions.mm
+++ b/platform/ios/src/UIColor+MGLAdditions.mm
@@ -21,3 +21,52 @@
 }
 
 @end
+
+@implementation NSExpression (MGLColorAdditions)
+
++ (NSExpression *)mgl_expressionForRGBComponents:(NSArray<NSExpression *> *)components {
+    if (UIColor *color = [self mgl_colorWithRGBComponents:components]) {
+        return [NSExpression expressionForConstantValue:color];
+    }
+    
+    NSExpression *color = [NSExpression expressionForConstantValue:[UIColor class]];
+    NSExpression *alpha = [NSExpression expressionForConstantValue:@1.0];
+    return [NSExpression expressionForFunction:color
+                                  selectorName:@"colorWithRed:green:blue:alpha:"
+                                     arguments:[components arrayByAddingObject:alpha]];
+}
+
++ (NSExpression *)mgl_expressionForRGBAComponents:(NSArray<NSExpression *> *)components {
+    if (UIColor *color = [self mgl_colorWithRGBComponents:components]) {
+        return [NSExpression expressionForConstantValue:color];
+    }
+    
+    NSExpression *color = [NSExpression expressionForConstantValue:[UIColor class]];
+    return [NSExpression expressionForFunction:color
+                                  selectorName:@"colorWithRed:green:blue:alpha:"
+                                     arguments:components];
+}
+
++ (UIColor *)mgl_colorWithRGBComponents:(NSArray<NSExpression *> *)components {
+    if (components.count < 3 || components.count > 4) {
+        return nil;
+    }
+    
+    for (NSExpression *component in components) {
+        if (component.expressionType != NSConstantValueExpressionType) {
+            return nil;
+        }
+        
+        NSNumber *number = (NSNumber *)component.constantValue;
+        if (![number isKindOfClass:[NSNumber class]]) {
+            return nil;
+        }
+    }
+    
+    return [UIColor colorWithRed:[components[0].constantValue doubleValue] / 255.0
+                           green:[components[1].constantValue doubleValue] / 255.0
+                            blue:[components[2].constantValue doubleValue] / 255.0
+                           alpha:components.count == 3 ? [components[3].constantValue doubleValue] : 1.0];
+}
+
+@end