Activity indicator view in table cell - swift

Question

I have a table, I want to make it so that when I click on a cell, the activity indicator spins around it, and not somewhere in an incomprehensible place
It looks like this. In the code, I have the MainViewController module and the Presenter module which determines when to start the activity indicator. I have an outlet
#IBOutlet weak var activity: UIActivityIndicatorView! = UIActivityIndicatorView(style: .gray)
I have two functions in the view controller that start the animation and stop
func startActivity() {
activity.startAnimating()
}
func stopActivity() {
activity.stopAnimating()
}
there is a function that handles a click on a cell
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
output.callFromThePresenter(array: array[indexPath.row])
}
This function is implemented in the presenter.
func callFromThePresenter(array: String) {
let userInteractiveQueue = DispatchQueue.global(qos: .userInteractive)
async {
DispatchQueue.main.async {
self.view.startActivity()
}
userInteractiveQueue.async {
self.interactor.functionFromInteractor(data: array)
}
}
}
as I assumed, in the view controller, when you click on a cell, the callFromThePresenter () function will work, and the animation function and the data transfer function in the Interactor will start in it, as soon as the Interactor has completed this function, it will return the data to the Presenter and inside the call back function, I will run the stopActivity () function. And it worked until I decided to set the positioning
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
output.callFromThePresenter(array: array[indexPath.row])
let cell = tableView.cellForRow(at: indexPath)
cell?.accessoryView = self.activity
}
as soon as i added these two lines
let cell = tableView.cellForRow(at: indexPath)
cell?.accessoryView = self.activity
I broke everything, as if I started up, I click on the table cell and the wheel turns where it is needed and everything works, but after receiving the result, I poke at some cell again, the whole program hangs, and I don’t know for what reason . At the same time, the functions work out how much I can understand it, because it comes to the console that the function was launched and got some result, but then the whole UI hangs tight and I can't do anything

Answer 1

Simple example:
In Interface Builder set the Style of the table view cell to custom.
Drag a label and an activity indicator into the cell and set appropriate constraints if needed.
Select the activity indicator, press ⌘⌥4 (Attributes Inspector) and check Hides When Stopped.
Create a custom class, a subclass of UITableViewCell in the project
class TitleCell: UITableViewCell {
#IBOutlet weak var titleLabel: UILabel!
#IBOutlet weak var activity: UIActivityIndicatorView!
var isRunning : Bool = false {
didSet {
isRunning ? activity.startAnimating() : activity.stopAnimating()
}
}
}
Set the class of the prototype cell in Interface Builder to TitleCell and connect the label and the indicator to the IBOutlets
Create a data model with at least a title and a isRunning property.
struct Model {
let title: String
var isRunning : Bool
}
Declare a data source array
var items = [Model]()
In cellForRow update the UI elements (replace the identifier with your real identifier)
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! TitleCell
let item = items[indexPath.row]
cell.titleLabel!.text = item.title
cell.isRunning = item.isRunning
return cell
}
To start and stop the indicator implement didSelectRow
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: false)
items[indexPath.row].isRunning.toggle()
tableView.reloadRows(at: [indexPath], with: .none)
}
To change the state of the indicator use always the pattern to set isRunning in the model and reload the row.