gistfile1.txt

- (UIView *) findCommonSuperViewBetween: (UIView *)viewA
                                    and: (UIView *)viewB
{
    if (!viewA && !viewB) {
        return nil;
    }
    
    if (!viewA) {
        return viewB.superview;
    }
    if (!viewB) {
        return viewA.superview;
    }
    
    NSMutableArray *viewASuperViews = [NSMutableArray new];
    NSMutableArray *viewBSuperViews = [NSMutableArray new];
    UIView *superViewA = viewA.superview;
    UIView *superViewB = viewB.superview;
    BOOL getAllASuperViews = NO;
    BOOL getAllBSuperViews = NO;
    
    BOOL found = NO;
    while (!found) {
        
        if (!getAllASuperViews) {
            if (superViewA) {
                [viewASuperViews addObject:superViewA];
                superViewA = superViewA.superview;
            }
            else
            {
                getAllASuperViews = YES;
            }
        }
        
        if (!getAllBSuperViews) {
            if (superViewB) {
                [viewBSuperViews addObject:superViewB];
                superViewB = superViewB.superview;
            }
            else
            {
                getAllBSuperViews = YES;
            }
        }
        
        found = (getAllASuperViews && getAllBSuperViews);
    }
    
    UIView *commonSuperView = nil;
    if (viewASuperViews.count < viewBSuperViews.count) {
        commonSuperView = viewASuperViews.firstObject;
    }
    else
    {
        commonSuperView = viewBSuperViews.firstObject;
    }
    return commonSuperView;
}