Smoothly deselect table and collection view cells on dismissal, including interactive dismiss and interactively-partially-dismiss-then-cancel-then-dismiss-again

UIViewController+Deselection.swift

extension UIViewController {

    func rz_smoothlyDeselectRows(tableView tableView: UITableView?) {
        let selectedIndexPaths = tableView?.indexPathsForSelectedRows ?? []

        if let coordinator = transitionCoordinator() {
            coordinator.animateAlongsideTransitionInView(parentViewController?.view, animation: { context in
                selectedIndexPaths.forEach {
                    tableView?.deselectRowAtIndexPath($0, animated: context.isAnimated())
                }
            }, completion: { context in
                if context.isCancelled() {
                    selectedIndexPaths.forEach {
                        tableView?.selectRowAtIndexPath($0, animated: false, scrollPosition: .None)
                    }
                }
            })
        }
        else {
            selectedIndexPaths.forEach {
                tableView?.deselectRowAtIndexPath($0, animated: false)
            }
        }
    }

    func rz_smoothlyDeselectItems(collectionView collectionView: UICollectionView?) {
        let selectedIndexPaths = collectionView?.indexPathsForSelectedItems() ?? []

        if let coordinator = transitionCoordinator() {
            coordinator.animateAlongsideTransitionInView(parentViewController?.view, animation: { context in
                selectedIndexPaths.forEach {
                    collectionView?.deselectItemAtIndexPath($0, animated: context.isAnimated())
                }
            }, completion: { context in
                if context.isCancelled() {
                    selectedIndexPaths.forEach {
                        collectionView?.selectItemAtIndexPath($0, animated: false, scrollPosition: .None)
                    }
                }
            })
        }
        else {
            selectedIndexPaths.forEach {
                collectionView?.deselectItemAtIndexPath($0, animated: false)
            }
        }
    }

}

UIViewController+RZDeselection.h

@import UIKit;

@interface UIViewController (RZDeselection)

- (void)rz_smoothlyDeselectRowsInTableView:(UITableView *)tableView;

- (void)rz_smoothlyDeselectItemsInCollectionView:(UICollectionView *)collectionView;

@end

UIViewController+RZDeselection.m

#import "UIViewController+RZDeselection.h"

@implementation UIViewController (RZDeselection)

- (void)rz_smoothlyDeselectRowsInTableView:(UITableView *)tableView
{
    NSArray<NSIndexPath *> *selectedIndexPaths = [tableView indexPathsForSelectedRows];
    if (self.transitionCoordinator) {
        [self.transitionCoordinator animateAlongsideTransitionInView:self.parentViewController.view animation:^(id<UIViewControllerTransitionCoordinatorContext> _Nonnull context) {
            for (NSIndexPath *indexPath in selectedIndexPaths) {
                [tableView deselectRowAtIndexPath:indexPath animated:context.isAnimated];
            }

        } completion:^(id<UIViewControllerTransitionCoordinatorContext> _Nonnull context) {
            if (context.isCancelled) {
                for (NSIndexPath *indexPath in selectedIndexPaths) {
                    [tableView selectRowAtIndexPath:indexPath animated:NO scrollPosition:UITableViewScrollPositionNone];
                }
            }
        }];
    }
    else {
        for (NSIndexPath *indexPath in selectedIndexPaths) {
            [tableView deselectRowAtIndexPath:indexPath animated:NO];
        }
    }
}

- (void)rz_smoothlyDeselectItemsInCollectionView:(UICollectionView *)collectionView
{
    NSArray<NSIndexPath *> *selectedIndexPaths = [collectionView indexPathsForSelectedItems];
    if (self.transitionCoordinator) {
        [self.transitionCoordinator animateAlongsideTransitionInView:self.parentViewController.view animation:^(id<UIViewControllerTransitionCoordinatorContext> _Nonnull context) {
            for (NSIndexPath *indexPath in selectedIndexPaths) {
                [collectionView deselectItemAtIndexPath:indexPath animated:context.isAnimated];
            }

        } completion:^(id<UIViewControllerTransitionCoordinatorContext> _Nonnull context) {
            if (context.isCancelled) {
                for (NSIndexPath *indexPath in selectedIndexPaths) {
                    [collectionView selectItemAtIndexPath:indexPath animated:NO scrollPosition:UICollectionViewScrollPositionNone];
                }
            }
        }];
    }
    else {
        for (NSIndexPath *indexPath in selectedIndexPaths) {
            [collectionView deselectItemAtIndexPath:indexPath animated:NO];
        }
    }
}

@end