mastodon-ios/Mastodon/Scene/Profile/Timeline/UserTimelineViewModel+Diffa...

91 lines
3.0 KiB
Swift

//
// UserTimelineViewModel+Diffable.swift
// Mastodon
//
// Created by MainasuK Cirno on 2021-3-30.
//
import UIKit
import Combine
extension UserTimelineViewModel {
func setupDiffableDataSource(
tableView: UITableView,
statusTableViewCellDelegate: StatusTableViewCellDelegate
) {
diffableDataSource = StatusSection.diffableDataSource(
tableView: tableView,
context: context,
configuration: StatusSection.Configuration(
authContext: authContext,
statusTableViewCellDelegate: statusTableViewCellDelegate,
timelineMiddleLoaderTableViewCellDelegate: nil,
filterContext: .none,
activeFilters: nil
)
)
// set empty section to make update animation top-to-bottom style
var snapshot = NSDiffableDataSourceSnapshot<StatusSection, StatusItem>()
snapshot.appendSections([.main])
diffableDataSource?.apply(snapshot)
// trigger timeline reloading
$userIdentifier
.receive(on: DispatchQueue.main)
.sink { [weak self] _ in
guard let self = self else { return }
self.stateMachine.enter(UserTimelineViewModel.State.Reloading.self)
}
.store(in: &disposeBag)
let needsTimelineHidden = Publishers.CombineLatest3(
$isBlocking,
$isBlockedBy,
$isSuspended
).map { $0 || $1 || $2 }
Publishers.CombineLatest(
statusFetchedResultsController.$records,
needsTimelineHidden.removeDuplicates()
)
.debounce(for: .milliseconds(300), scheduler: DispatchQueue.main)
.sink { [weak self] records, needsTimelineHidden in
guard let self = self else { return }
guard let diffableDataSource = self.diffableDataSource else { return }
var snapshot = NSDiffableDataSourceSnapshot<StatusSection, StatusItem>()
snapshot.appendSections([.main])
guard !needsTimelineHidden else {
diffableDataSource.apply(snapshot)
return
}
let items = records.map { StatusItem.status(record: $0) }
snapshot.appendItems(items, toSection: .main)
if let currentState = self.stateMachine.currentState {
switch currentState {
case is State.Initial,
is State.Reloading,
is State.Loading,
is State.Idle,
is State.Fail:
snapshot.appendItems([.bottomLoader], toSection: .main)
case is State.NoMore:
break
default:
assertionFailure()
break
}
}
diffableDataSource.applySnapshot(snapshot, animated: false)
}
.store(in: &disposeBag)
}
}