IBOutletCollection set ordering in Interface Builder

Question

I am using IBOutletCollections to group several Instances of similar UI Elements. In particular I group a number of UIButtons (which are similar to buzzers in a quiz game) a

Answer 1

I needed this ordering for a collection of UITextField objects for setting where the "Next" button on the keyboard would lead to (field tabbing). This is going to be an international app so I wanted the language direction to be ambiguous.

.h

#import 

@interface NSArray (UIViewSort)

- (NSArray *)sortByUIViewOrigin;

@end

.m

#import "NSArray+UIViewSort.h"

@implementation NSArray (UIViewSort)

- (NSArray *)sortByUIViewOrigin {
    NSLocaleLanguageDirection horizontalDirection = [NSLocale characterDirectionForLanguage:[[NSLocale currentLocale] objectForKey:NSLocaleLanguageCode]];
    NSLocaleLanguageDirection verticalDirection = [NSLocale lineDirectionForLanguage:[[NSLocale currentLocale] objectForKey:NSLocaleLanguageCode]];
    UIView *window = [[UIApplication sharedApplication] delegate].window;
    return [self sortedArrayUsingComparator:^NSComparisonResult(id object1, id object2) {
        CGPoint viewOrigin1 = [(UIView *)object1 convertPoint:((UIView *)object1).frame.origin toView:window];
        CGPoint viewOrigin2 = [(UIView *)object2 convertPoint:((UIView *)object2).frame.origin toView:window];
        if (viewOrigin1.y < viewOrigin2.y) {
            return (verticalDirection == kCFLocaleLanguageDirectionLeftToRight) ? NSOrderedDescending : NSOrderedAscending;
        }
        else if (viewOrigin1.y > viewOrigin2.y) {
            return (verticalDirection == kCFLocaleLanguageDirectionLeftToRight) ? NSOrderedAscending : NSOrderedDescending;
        }
        else if (viewOrigin1.x < viewOrigin2.x) {
            return (horizontalDirection == kCFLocaleLanguageDirectionTopToBottom) ? NSOrderedDescending : NSOrderedAscending;
        }
        else if (viewOrigin1.x > viewOrigin2.x) {
            return (horizontalDirection == kCFLocaleLanguageDirectionTopToBottom) ? NSOrderedAscending : NSOrderedDescending;
        }
        else return NSOrderedSame;
    }];
}

@end

Usage (after layout)

- (void)viewDidAppear:(BOOL)animated {
    _availableTextFields = [_availableTextFields sortByUIViewOrigin];

    UITextField *previousField;
    for (UITextField *field in _availableTextFields) {
        if (previousField) {
            previousField.nextTextField = field;
        }
        previousField = field;
    }
}