A UITableView category for traversing index paths.

UITableView+IndexPathHelpers.m

#import <UIKit/UIKit.h>

@interface UITableView (IndexPathHelpers)

- (NSIndexPath *)minimumIndexPath;
- (NSIndexPath *)maximumIndexPath;
- (NSIndexPath *)incrementIndexPath:(NSIndexPath *)indexPath;
- (NSIndexPath *)decrementIndexPath:(NSIndexPath *)indexPath;

@end

@implementation UITableView (IndexPathHelpers)

- (NSIndexPath *)minimumIndexPath {
    return [NSIndexPath indexPathForRow:0 inSection:0];
}

- (NSIndexPath *)maximumIndexPath {
    NSInteger lastSection = self.numberOfSections - 1;
    NSInteger lastRow = [self numberOfRowsInSection:lastSection] - 1;
    return [NSIndexPath indexPathForRow:lastRow inSection:lastSection];
}

- (NSIndexPath *)incrementIndexPath:(NSIndexPath *)indexPath {
    if ([indexPath compare:self.maximumIndexPath] == NSOrderedSame) return nil;
    
    NSInteger lastRow = [self numberOfRowsInSection:indexPath.section] - 1;
    if (indexPath.row == lastRow) return [NSIndexPath indexPathForRow:0 inSection:(indexPath.section + 1)];
    else return [NSIndexPath indexPathForRow:(indexPath.row + 1) inSection:indexPath.section];
}

- (NSIndexPath *)decrementIndexPath:(NSIndexPath *)indexPath {
    if ([indexPath compare:self.minimumIndexPath] == NSOrderedSame) return nil;
    if (indexPath.row == 0) {
        NSInteger lastRow = [self numberOfRowsInSection:(indexPath.section - 1)];
        return [NSIndexPath indexPathForRow:lastRow inSection:(indexPath.section - 1)];
    } else return [NSIndexPath indexPathForRow:(indexPath.row - 1) inSection:indexPath.section];
}

@end