chore(ios): bring back (currently unused) code related to #712 and #705

Author: igorbej

ios/RNCPagerScrollView.h

@@ -0,0 +1,8 @@
+/*
+NOTE: This file is *not* currently used, for context see:
+- https://github.com/callstack/react-native-pager-view/pull/783#discussion_r1410295171
+- https://github.com/callstack/react-native-pager-view/pull/783#discussion_r1410316201
+*/
+
+@interface RNCPagerScrollView : UIScrollView <UIGestureRecognizerDelegate>
+@end

ios/RNCPagerScrollView.m

@@ -0,0 +1,31 @@
+/*
+NOTE: This file is *not* currently used, for context see:
+- https://github.com/callstack/react-native-pager-view/pull/783#discussion_r1410295171
+- https://github.com/callstack/react-native-pager-view/pull/783#discussion_r1410316201
+*/
+
+#import "RNCPagerScrollView.h"
+
+@implementation RNCPagerScrollView
+- (instancetype)initWithFrame:(CGRect)frame {
+    if (self = [super initWithFrame:frame]) {
+        self.panGestureRecognizer.delegate = self;
+    }
+    return self;
+}
+
+- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
+    if (gestureRecognizer == self.panGestureRecognizer) {
+        CGPoint velocity = [self.panGestureRecognizer velocityInView:self];
+        UIUserInterfaceLayoutDirection layoutDirection = [UIView userInterfaceLayoutDirectionForSemanticContentAttribute:self.semanticContentAttribute];
+        BOOL isLTR = UIUserInterfaceLayoutDirectionLeftToRight == layoutDirection;
+        BOOL isBackGesture = (isLTR && velocity.x > 0) || (!isLTR && velocity.x < 0);
+        // if it's back gesture and scroll view is at the beginning of scroll we allow simultaneous gesture
+        if (isBackGesture && self.contentOffset.x <= 0) {
+            return YES;
+        }
+    }
+    return NO;
+}
+
+@end