Save and restore scroll position when transitioning between three column mode and normal. Issue #1242

This commit is contained in:
Maurice Parker 2019-11-11 16:59:42 -06:00
parent 2617744d49
commit 766cd2f868
2 changed files with 22 additions and 2 deletions

View File

@ -25,6 +25,7 @@ class MasterTimelineViewController: UITableViewController, UndoableCommandRunner
weak var coordinator: SceneCoordinator!
var undoableCommands = [UndoableCommand]()
let scrollPositionQueue = CoalescingQueue(name: "Scroll Position", interval: 0.3, maxInterval: 1.0)
private let keyboardManager = KeyboardManager(type: .timeline)
override var keyCommands: [UIKeyCommand]? {
@ -73,6 +74,13 @@ class MasterTimelineViewController: UITableViewController, UndoableCommandRunner
override func viewWillAppear(_ animated: Bool) {
applyChanges(animate: false)
// Restore the scroll position if we have one stored
if let restoreIndexPath = coordinator.timelineMiddleIndexPath {
tableView.scrollToRow(at: restoreIndexPath, at: .middle, animated: false)
}
// Hide the search controller if we don't have any rows
if dataSource.snapshot().numberOfItems < 1 {
navigationItem.searchController?.isActive = false
}
@ -288,6 +296,10 @@ class MasterTimelineViewController: UITableViewController, UndoableCommandRunner
coordinator.selectArticle(article, animated: true)
}
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
scrollPositionQueue.add(self, #selector(scrollPositionDidChange))
}
// MARK: Notifications
@objc dynamic func unreadCountDidChange(_ notification: Notification) {
@ -366,6 +378,10 @@ class MasterTimelineViewController: UITableViewController, UndoableCommandRunner
titleView?.label.text = coordinator.timelineName
}
@objc func scrollPositionDidChange() {
coordinator.timelineMiddleIndexPath = tableView.middleVisibleRow()
}
// MARK: Reloading
func queueReloadAvailableCells() {

View File

@ -135,6 +135,8 @@ class SceneCoordinator: NSObject, UndoableCommandRunner, UnreadCountProvider {
var timelineFetcher: ArticleFetcher? {
didSet {
timelineMiddleIndexPath = nil
if timelineFetcher is Feed {
showFeedNames = false
} else {
@ -153,6 +155,8 @@ class SceneCoordinator: NSObject, UndoableCommandRunner, UnreadCountProvider {
}
}
var timelineMiddleIndexPath: IndexPath?
private(set) var showFeedNames = false
private(set) var showIcons = false
@ -1589,7 +1593,7 @@ private extension SceneCoordinator {
subSplitViewController!.showDetailViewController(navController, sender: self)
masterFeedViewController.restoreSelectionIfNecessary(adjustScroll: true)
masterTimelineViewController!.restoreSelectionIfNecessary(adjustScroll: true)
masterTimelineViewController!.restoreSelectionIfNecessary(adjustScroll: false)
// We made sure this was there above when we called configureDoubleSplit
return subSplitViewController!