Wrapping NSTableView with Swift UI: How to use Bindings? - ios

Question

I am having a hard time managing the data that I want to pass to a
wrapped NSTableView View with SwiftUI. I tried using an NSViewControllerRepresentable but the problem is that my info is not getting updated as it should be.
I have a huge list (hundreds of thousands of items) of an ObservableObject:
class FileObject: ObservableObject, Identifiable {
var id : String
#Published var line : String
init(id : String, line : String) {
self.id = id
self.line = line
}
}
This is how I am calling my NSViewControllerRepresentable inside SwiftUI:
struct NSLinesList: View {
#Binding var lines: [FileObject]
var body: some View {
LinesListTableRepresentable(objects: self.$lines)
}
}
And this is the implementation of the NSViewController which contains a table view.
I have made the Coordinator to be the dataSource and the delegate of the tableView which is inside the NSViewController.
private let kColumnIDContentId = "number"
private let kColumnIdContent = "content"
struct LinesListTableRepresentable: NSViewControllerRepresentable {
typealias NSViewControllerType = LinesListViewController
#Binding var objects : [FileObject]
func makeCoordinator() -> Coordinator {
return Coordinator(self)
}
func makeNSViewController(context: Context) -> LinesListViewController {
let storyboard = NSStoryboard.init(name: .init("Main"), bundle: nil)
let controller = storyboard.instantiateController(withIdentifier: "LinesListViewController") as! LinesListViewController
return controller
}
func updateNSViewController(_ nsViewController: NSViewControllerType, context: Context) {
nsViewController.tableView.dataSource = context.coordinator
nsViewController.tableView.delegate = context.coordinator
log.info("update the table view with \(self.objects.count) items")
nsViewController.refresh()
}
}
extension LinesListTableRepresentable {
class Coordinator : NSObject, NSTableViewDelegate, NSTableViewDataSource {
private let parent: LinesListTableRepresentable
init(_ representable : LinesListTableRepresentable) {
parent = representable
super.init()
}
#objc public func numberOfRows(in tableView: NSTableView) -> Int {
log.info("current object count inside table view: \(self.parent.objects.count)")
return self.parent.objects.count
}
#objc func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? {
guard let columnId = tableColumn?.identifier else { return nil }
let currentLine = self.parent.objects[row]
switch columnId {
case .init(kColumnIDContentId):
let tableCellView = tableView.makeView(withIdentifier: NSUserInterfaceItemIdentifier(rawValue: "lineNumbercell"), owner: self) as! LogNumberTableCell
tableCellView.contentField.stringValue = "\(row)"
tableCellView.wantsLayer = true
return tableCellView
case .init(kColumnIdContent):
let tableCellView = tableView.makeView(withIdentifier: NSUserInterfaceItemIdentifier(rawValue: "lineContentCell"), owner: self) as! LogContentTableCell
tableCellView.contentField.stringValue = currentLine.line
default:
break
}
return nil
}
}
}
I am putting some objects inside the objects, and although the LinesListTableRepresentable is getting the objects updated, the Coordinator always has 0 items!
My console output is this one:
2020-08-02T15:56:21+0300 info: update the table view with 2275 items
2020-08-02T15:56:21+0300 info: current object count inside table view: 0
So it seems that the self.parent.objects.count is always zero.
Can someone help with this?