After reordering cell is behind another cell - ios

Question

I'm trying to create a reorder indicator. So what I'm trying to do is that when the user is dragging the cell. That on the place the user wants to drop the cell an other cell is added with a background. I already achieved that. But when the user drops the cell, the indicator cell needs to be deleted and the table must stay the same like the user intended to.
Now I have the following problem. When the user drops the cell. The indicator cell is correctly removed but the dropped cell is behind another cell suddenly.
Screenshots to clarify:
My code:
import UIKit
import PureLayout
class ViewController: UIViewController {
lazy var tableView: UITableView = {
let tableView = UITableView(forAutoLayout: ())
tableView.delegate = self
tableView.dataSource = self
tableView.separatorStyle = .SingleLine
tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "Default")
tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "Indicator")
tableView.tableFooterView = UIView()
return tableView
}()
private var data: [Int] = [Int]()
private var isIndicatorRowAddedInSection: Bool = false
private var lastIndicatorRowIndexPath: NSIndexPath?
override func viewDidLoad() {
super.viewDidLoad()
self.view.addSubview(self.tableView)
self.tableView.autoPinEdgesToSuperviewEdgesWithInsets(UIEdgeInsetsZero, excludingEdge: .Top)
self.tableView.autoPinEdgeToSuperviewEdge(.Top, withInset: 40)
for index in 0..<20 {
data.append(index)
}
self.tableView.editing = true
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
extension ViewController: UITableViewDelegate {
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 44
}
func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
}
func tableView(tableView: UITableView, canMoveRowAtIndexPath indexPath: NSIndexPath) -> Bool {
return true
}
func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) {
if let lastIndexPath = self.lastIndicatorRowIndexPath {
print("Need to delete a row on section \(lastIndexPath.section) row \(lastIndexPath.row)")
self.isIndicatorRowAddedInSection = false
self.lastIndicatorRowIndexPath = nil
tableView.beginUpdates()
tableView.deleteRowsAtIndexPaths([lastIndexPath], withRowAnimation: .Fade)
tableView.endUpdates()
}
let itemToMove = self.data[fromIndexPath.row]
self.data.removeAtIndex(fromIndexPath.row)
self.data.insert(itemToMove, atIndex: toIndexPath.row)
}
func tableView(tableView: UITableView, editingStyleForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCellEditingStyle {
return .None
}
func tableView(tableView: UITableView, shouldIndentWhileEditingRowAtIndexPath indexPath: NSIndexPath) -> Bool {
return false
}
func tableView(tableView: UITableView, targetIndexPathForMoveFromRowAtIndexPath sourceIndexPath: NSIndexPath,
toProposedIndexPath proposedDestinationIndexPath: NSIndexPath) -> NSIndexPath {
if let lastIndexPath = self.lastIndicatorRowIndexPath {
print("Target indexpath indexpath to delete row \(lastIndexPath.section) row \(lastIndexPath.row)")
self.isIndicatorRowAddedInSection = false
tableView.beginUpdates()
tableView.deleteRowsAtIndexPaths([lastIndexPath], withRowAnimation: .Fade)
tableView.endUpdates()
self.lastIndicatorRowIndexPath = nil
}
self.isIndicatorRowAddedInSection = true
self.lastIndicatorRowIndexPath = proposedDestinationIndexPath
tableView.beginUpdates()
print("Indicator view inserted at section \(proposedDestinationIndexPath.section) row \(proposedDestinationIndexPath.row)")
tableView.insertRowsAtIndexPaths([NSIndexPath(forRow: proposedDestinationIndexPath.row, inSection: proposedDestinationIndexPath.section)], withRowAnimation: .Automatic)
tableView.endUpdates()
return proposedDestinationIndexPath
}
}
extension ViewController: UITableViewDataSource {
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if self.isIndicatorRowAddedInSection {
return self.data.count + 1
}
return self.data.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if let indicatorIndexPath = self.lastIndicatorRowIndexPath where isIndicatorRowAddedInSection {
if indicatorIndexPath.section == indexPath.section && indicatorIndexPath.row == indexPath.row {
let cell = tableView.dequeueReusableCellWithIdentifier("Indicator", forIndexPath: indexPath)
return cell
}
}
let cell = tableView.dequeueReusableCellWithIdentifier("Default", forIndexPath: indexPath)
cell.textLabel?.text = String(self.data[indexPath.row])
return cell
}
}
I don't see the problem. Can someone help me?

Answer 1

I found the problem. In the moveRow it is executed on Thread 1 (main thread) but it seems like it's not. Because when you wrap it with a dispatch async to the main thread it just works.
Full working code:
import UIKit
import PureLayout
class ViewController: UIViewController {
lazy var tableView: UITableView = {
let tableView = UITableView(forAutoLayout: ())
tableView.delegate = self
tableView.dataSource = self
tableView.separatorStyle = .SingleLine
tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "Default")
tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "Indicator")
tableView.tableFooterView = UIView()
return tableView
}()
private var data: [Int] = [Int]()
private var isIndicatorRowAddedInSection: Bool = false
private var lastIndicatorRowIndexPath: NSIndexPath?
override func viewDidLoad() {
super.viewDidLoad()
self.view.addSubview(self.tableView)
self.tableView.autoPinEdgesToSuperviewEdgesWithInsets(UIEdgeInsetsZero, excludingEdge: .Top)
self.tableView.autoPinEdgeToSuperviewEdge(.Top, withInset: 40)
for index in 0..<5 {
data.append(index)
}
self.tableView.editing = true
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
extension ViewController: UITableViewDelegate {
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 44
}
func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
}
func tableView(tableView: UITableView, canMoveRowAtIndexPath indexPath: NSIndexPath) -> Bool {
return true
}
func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) {
let itemToMove = self.data[fromIndexPath.row]
self.data.removeAtIndex(fromIndexPath.row)
self.data.insert(itemToMove, atIndex: toIndexPath.row - 1)
dispatch_async(dispatch_get_main_queue(), { () -> Void in
if let lastIndexPath = self.lastIndicatorRowIndexPath {
print("Need to delete a row on section \(lastIndexPath.section) row \(lastIndexPath.row)")
self.isIndicatorRowAddedInSection = false
self.lastIndicatorRowIndexPath = nil
tableView.beginUpdates()
// Need to put some logic if you pull to top it has to be + 1
tableView.deleteRowsAtIndexPaths([NSIndexPath(forRow: lastIndexPath.row - 1, inSection: 0)], withRowAnimation: .Fade)
tableView.endUpdates()
}
})
}
func tableView(tableView: UITableView, editingStyleForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCellEditingStyle {
return .None
}
func tableView(tableView: UITableView, shouldIndentWhileEditingRowAtIndexPath indexPath: NSIndexPath) -> Bool {
return false
}
func tableView(tableView: UITableView, targetIndexPathForMoveFromRowAtIndexPath sourceIndexPath: NSIndexPath,
toProposedIndexPath proposedDestinationIndexPath: NSIndexPath) -> NSIndexPath {
if let lastIndexPath = self.lastIndicatorRowIndexPath {
print("Target indexpath indexpath to delete row \(lastIndexPath.section) row \(lastIndexPath.row)")
self.isIndicatorRowAddedInSection = false
tableView.beginUpdates()
tableView.deleteRowsAtIndexPaths([lastIndexPath], withRowAnimation: .None)
tableView.endUpdates()
self.lastIndicatorRowIndexPath = nil
}
self.isIndicatorRowAddedInSection = true
self.lastIndicatorRowIndexPath = proposedDestinationIndexPath
tableView.beginUpdates()
print("Indicator view inserted at section \(proposedDestinationIndexPath.section) row \(proposedDestinationIndexPath.row)")
tableView.insertRowsAtIndexPaths([NSIndexPath(forRow: proposedDestinationIndexPath.row, inSection: proposedDestinationIndexPath.section)], withRowAnimation: .Automatic)
tableView.endUpdates()
return proposedDestinationIndexPath
}
}
extension ViewController: UITableViewDataSource {
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if self.isIndicatorRowAddedInSection {
return self.data.count + 1
}
return self.data.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if let indicatorIndexPath = self.lastIndicatorRowIndexPath where isIndicatorRowAddedInSection {
if indicatorIndexPath.section == indexPath.section && indicatorIndexPath.row == indexPath.row {
let cell = tableView.dequeueReusableCellWithIdentifier("Indicator", forIndexPath: indexPath)
cell.textLabel?.text = "IndicatorView: ROW \(indexPath.row) SECTION = \(indexPath.section)"
print("Indictorview cell for row")
return cell
}
}
let cell = tableView.dequeueReusableCellWithIdentifier("Default", forIndexPath: indexPath)
cell.textLabel?.text = "ROW = \(indexPath.row) SECTION = \(indexPath.section)"
return cell
}
}