Mix-in protocol that keeps selected table view cell during interactive pop

RLRTableViewCellSelectionDuringInteractivePopAndPush.h

/*
 RLRTableViewCellSelectionDuringInteractivePopAndPush.h
 
 Copyright ©2014 Kazki Miura. All rights reserved.
*/

#import <UIKit/UIKit.h>


@protocol RLRTableViewCellSelectionDuringInteractivePopAndPush
@required
- (UITableView*)tableView;
@end

RLRTableViewCellSelectionDuringInteractivePopAndPush.m

/*
 RLRTableViewCellSelectionDuringInteractivePopAndPush.m
 
 Copyright ©2014 Kazki Miura. All rights reserved.
*/

#import "RLRTableViewCellSelectionDuringInteractivePopAndPush.h"
#import "REKit.h"


// Constants
static void *kLoadedKey = @"RLRTableViewCellSelectionDuringInteractivePopAndPush_loaded";
static NSString *const kBlockKey = @"RLRTableViewCellSelectionDuringInteractivePopAndPushBlock";


@implementation UIViewController (RLRTableViewCellSelectionDuringInteractivePopAndPush)

+ (void)load
{
	@autoreleasepool {
		for (Class class in RESubclassesOfClass([UIViewController class], YES)) {
			if ([class conformsToProtocol:@protocol(RLRTableViewCellSelectionDuringInteractivePopAndPush)]
			&& ![[class superclass] conformsToProtocol:@protocol(RLRTableViewCellSelectionDuringInteractivePopAndPush)]
			&& ![[class associatedValueForKey:kLoadedKey] boolValue]
			&& [class instancesRespondToSelector:@selector(tableView)]
			){
				// Raise loaded flag
				[class setAssociatedValue:@(YES) forKey:kLoadedKey policy:OBJC_ASSOCIATION_RETAIN];
				
				#pragma mark └ -[class viewWillAppear:]
				RESetBlock(class, @selector(viewWillAppear:), NO, kBlockKey, ^(UIViewController<RLRTableViewCellSelectionDuringInteractivePopAndPush> *vc, BOOL animated) {
					// supermethod
					RESupermethod(nil, vc, animated);
					
					// Deselect
					UITableView *tableView;
					NSIndexPath *indexPath;
					tableView = vc.tableView;
					indexPath = [tableView indexPathForSelectedRow];
					if (!indexPath) {
						return;
					}
					[tableView deselectRowAtIndexPath:indexPath animated:animated];
					
					#pragma mark └ -[class viewWillDisappear:]
					RESetBlock(class, @selector(viewWillDisappear:), NO, kBlockKey, ^(UIViewController<RLRTableViewCellSelectionDuringInteractivePopAndPush> *vc, BOOL animated) {
						// supermethod
						RESupermethod(nil, vc, animated);
						
						// Reselect
						[tableView selectRowAtIndexPath:indexPath animated:animated scrollPosition:UITableViewScrollPositionNone];
					});
					
					#pragma mark └ -[class viewDidAppear:]
					RESetBlock(class, @selector(viewDidAppear:), NO, kBlockKey, ^(UIViewController<RLRTableViewCellSelectionDuringInteractivePopAndPush> *vc, BOOL animated) {
						// supermethod
						RESupermethod(nil, vc, animated);
						
						// Remove blocks
						[class removeBlockForInstanceMethod:@selector(viewWillDisappear:) key:kBlockKey];
						[class removeBlockForInstanceMethod:@selector(viewDidDisappear:) key:kBlockKey];
						RERemoveCurrentBlock();
					});
					
					#pragma mark └ -[class viewDidDisappear:]
					RESetBlock(class, @selector(viewDidDisappear:), NO, kBlockKey, ^(UIViewController<RLRTableViewCellSelectionDuringInteractivePopAndPush> *vc, BOOL animated) {
						// supermethod
						RESupermethod(nil, vc, animated);
						
						// Remove blocks
						[class removeBlockForInstanceMethod:@selector(viewWillDisappear:) key:kBlockKey];
						[class removeBlockForInstanceMethod:@selector(viewDidAppear:) key:kBlockKey];
						RERemoveCurrentBlock();
					});
				});
			}
		}
	}
}

@end