An example of animated rearranging of a UITableView

TableViewAnimatedRearranging.swift

import PlaygroundSupport
import UIKit

/**
 This playground is an example of how how to move cells when the data source of a table view
 changes.
 */

class TVDataSource: NSObject, UITableViewDataSource {
  private let tableView: UITableView

  init(tableView: UITableView) {
    self.tableView = tableView
    super.init()

    tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
    tableView.dataSource = self
  }

  // The data to show in the table view
  private var options = [1, 2, 3, 4, 5]

  func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return options.count
  }

  func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
    cell.textLabel?.text = "\(options[indexPath.row])"
    return cell
  }

  @objc func handleRefresh() {
    // New order of the data
    let shuffledOptions = options.shuffled()

    // The difference between the old data and the new data
    let difference = shuffledOptions.difference(from: options)

    // An array to hold the removed index paths
    var removeIndexPaths: [IndexPath] = []

    // An array to hold the inserted index paths
    var insertIndexPaths: [IndexPath] = []

    // Get all the differences and populate the arrays above
    for change in difference {
      switch change {
      // If the change is a `remove`, then we want to remove that row
      case .remove(let offset, _, _):
        removeIndexPaths.append(IndexPath(row: offset, section: 0))
      // If the change is an `insert`, then we want to insert that row
      case .insert(let offset, _, _):
        insertIndexPaths.append(IndexPath(row: offset, section: 0))
      }
    }

    // Assign the new data before inserting / removing because
    // tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
    // will be triggered and we want the new data to be available to the inserted cells
    options = shuffledOptions

    /*
     https://developer.apple.com/documentation/uikit/uitableview/1614987-moverow
     You can combine row-move operations with row-insertion and row-deletion operations within a
     beginUpdates()–endUpdates() block to have all changes occur together as a single animation.
     */
    tableView.beginUpdates()
    // Rows will be inserted from the left
    tableView.insertRows(at: insertIndexPaths, with: .left)
    // Rows will be deleted to the right
    tableView.deleteRows(at: removeIndexPaths, with: .right)
    tableView.endUpdates()
  }
}

// Code to show the table view and refresh button

let view = UIView(frame: CGRect(origin: .zero, size: CGSize(width: 400, height: 400)))
view.backgroundColor = .white

let tableView = UITableView()
let dataSource = TVDataSource(tableView: tableView)

view.addSubview(tableView)
tableView.translatesAutoresizingMaskIntoConstraints = false

tableView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
tableView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
tableView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true

let refreshButton = UIButton()
refreshButton.setTitle("Refresh", for: .normal)
refreshButton.setTitleColor(.red, for: .normal)
view.addSubview(refreshButton)

refreshButton.translatesAutoresizingMaskIntoConstraints = false
refreshButton.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
refreshButton.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
refreshButton.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true

refreshButton.topAnchor.constraint(equalTo: tableView.bottomAnchor, constant: 12).isActive = true

refreshButton.addTarget(
  dataSource,
  action: #selector(TVDataSource.handleRefresh),
  for: .touchUpInside
)

PlaygroundPage.current.liveView = view