refresh control flickering fix (#8172)

Co-authored-by: Georgy Steshin <gosha212@gmail.com>

Author: markdevocht

ios/RNNRefreshControll.m

@@ -0,0 +1,91 @@
+/**
+ * Fix for UIRefreshControl spinner flicker with large titles.
+ * iOS UIKit internally toggles hidden state during layout changes,
+ * causing the spinner to flicker. This swizzles setHidden to block
+ * visibility changes while the control is actively refreshing.
+ */
+
+#import <UIKit/UIKit.h>
+#import <objc/runtime.h>
+
+static char kRNNIsEndingRefreshKey;
+
+@implementation UIRefreshControl (RNNStable)
+
++ (void)load {
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        Class class = [self class];
+        
+        // Swizzle setHidden
+        SEL originalSelector = @selector(setHidden:);
+        SEL swizzledSelector = @selector(rnn_setHidden:);
+        
+        Method originalMethod = class_getInstanceMethod(class, originalSelector);
+        Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
+        
+        BOOL didAddMethod = class_addMethod(class,
+                                            originalSelector,
+                                            method_getImplementation(swizzledMethod),
+                                            method_getTypeEncoding(swizzledMethod));
+        
+        if (didAddMethod) {
+            class_replaceMethod(class,
+                                swizzledSelector,
+                                method_getImplementation(originalMethod),
+                                method_getTypeEncoding(originalMethod));
+        } else {
+            method_exchangeImplementations(originalMethod, swizzledMethod);
+        }
+        
+        // Swizzle endRefreshing
+        SEL originalEndSelector = @selector(endRefreshing);
+        SEL swizzledEndSelector = @selector(rnn_endRefreshing);
+        
+        Method originalEndMethod = class_getInstanceMethod(class, originalEndSelector);
+        Method swizzledEndMethod = class_getInstanceMethod(class, swizzledEndSelector);
+        
+        didAddMethod = class_addMethod(class,
+                                       originalEndSelector,
+                                       method_getImplementation(originalEndMethod),
+                                       method_getTypeEncoding(originalEndMethod));
+        
+        if (didAddMethod) {
+            class_replaceMethod(class,
+                                swizzledEndSelector,
+                                method_getImplementation(originalEndMethod),
+                                method_getTypeEncoding(originalEndMethod));
+        } else {
+            method_exchangeImplementations(originalEndMethod, swizzledEndMethod);
+        }
+    });
+}
+
+- (BOOL)rnn_isEndingRefresh {
+    return [objc_getAssociatedObject(self, &kRNNIsEndingRefreshKey) boolValue];
+}
+
+- (void)rnn_setIsEndingRefresh:(BOOL)value {
+    objc_setAssociatedObject(self, &kRNNIsEndingRefreshKey, @(value), OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+}
+
+- (void)rnn_endRefreshing {
+    [self rnn_setIsEndingRefresh:YES];
+    [self rnn_endRefreshing];
+    [self rnn_setIsEndingRefresh:NO];
+}
+
+- (void)rnn_setHidden:(BOOL)hidden {
+    if ([self rnn_isEndingRefresh]) {
+        [self rnn_setHidden:hidden];
+        return;
+    }
+    
+    if (self.isRefreshing) {
+        return;
+    }
+    
+    [self rnn_setHidden:hidden];
+}
+
+@end