From aac3c865618085c564d1a0080fa259e37ef017a7 Mon Sep 17 00:00:00 2001
From: Maurice Parker <mo@vincode.io>
Date: Tue, 10 Sep 2019 16:38:59 -0500
Subject: [PATCH] Ensure that selected feed is visible when transitioning to
 three panel mode

---
 iOS/MasterFeed/MasterFeedViewController.swift | 27 ++++++++++---------
 iOS/SceneCoordinator.swift                    |  1 +
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/iOS/MasterFeed/MasterFeedViewController.swift b/iOS/MasterFeed/MasterFeedViewController.swift
index fdbb03302..f5e38726e 100644
--- a/iOS/MasterFeed/MasterFeedViewController.swift
+++ b/iOS/MasterFeed/MasterFeedViewController.swift
@@ -441,6 +441,16 @@ class MasterFeedViewController: UITableViewController, UndoableCommandRunner {
 	
 	// MARK: API
 	
+	func restoreSelectionIfNecessary(adjustScroll: Bool) {
+		if let indexPath = coordinator.masterFeedIndexPathForCurrentTimeline() {
+			if adjustScroll {
+				tableView.selectRowAndScrollIfNotVisible(at: indexPath, animated: false, deselect: coordinator.isRootSplitCollapsed)
+			} else {
+				tableView.selectRow(at: indexPath, animated: false, scrollPosition: .none)
+			}
+		}
+	}
+
 	func updateFeedSelection() {
 		if let indexPath = coordinator.currentFeedIndexPath {
 			if tableView.indexPathForSelectedRow != indexPath {
@@ -500,9 +510,8 @@ class MasterFeedViewController: UITableViewController, UndoableCommandRunner {
 		coordinator.expandFolder(indexPath)
 		reloadNode(parent)
 
-		self.applyChanges(animate: true) { [weak self] in
+		self.applyChanges(animate: true, adjustScroll: true) { [weak self] in
 			if let indexPath = self?.coordinator.indexPathFor(node) {
-				self?.tableView.scrollToRow(at: indexPath, at: .middle, animated: true)
 				self?.coordinator.selectFeed(indexPath)
 				completion?()
 			}
@@ -543,11 +552,11 @@ private extension MasterFeedViewController {
 		var snapshot = dataSource.snapshot()
 		snapshot.reloadItems([node])
 		dataSource.apply(snapshot, animatingDifferences: false) { [weak self] in
-			self?.restoreSelectionIfNecessary()
+			self?.restoreSelectionIfNecessary(adjustScroll: false)
 		}
 	}
 	
-	func applyChanges(animate: Bool, completion: (() -> Void)? = nil) {
+	func applyChanges(animate: Bool, adjustScroll: Bool = false, completion: (() -> Void)? = nil) {
         var snapshot = NSDiffableDataSourceSnapshot<Int, Node>()
 		let sections = coordinator.allSections
 		snapshot.appendSections(sections)
@@ -557,7 +566,7 @@ private extension MasterFeedViewController {
 		}
         
 		dataSource.apply(snapshot, animatingDifferences: animate) { [weak self] in
-			self?.restoreSelectionIfNecessary()
+			self?.restoreSelectionIfNecessary(adjustScroll: adjustScroll)
 			completion?()
 		}
 	}
@@ -636,7 +645,7 @@ private extension MasterFeedViewController {
 		var snapshot = dataSource.snapshot()
 		snapshot.reloadItems(nodes)
 		dataSource.apply(snapshot, animatingDifferences: false) { [weak self] in
-			self?.restoreSelectionIfNecessary()
+			self?.restoreSelectionIfNecessary(adjustScroll: false)
 		}
 	}
 	
@@ -669,12 +678,6 @@ private extension MasterFeedViewController {
 		self.applyChanges(animate: true)
 	}
 
-	func restoreSelectionIfNecessary() {
-		if let indexPath = coordinator.masterFeedIndexPathForCurrentTimeline() {
-			tableView.selectRowAndScrollIfNotVisible(at: indexPath, animated: false, deselect: coordinator.isRootSplitCollapsed)
-		}
-	}
-
 	func makeFeedContextMenu(indexPath: IndexPath, includeDeleteRename: Bool) -> UIContextMenuConfiguration {
 		return UIContextMenuConfiguration(identifier: nil, previewProvider: nil, actionProvider: { [ weak self] suggestedActions in
 			
diff --git a/iOS/SceneCoordinator.swift b/iOS/SceneCoordinator.swift
index 7b33a202a..09cfff8d8 100644
--- a/iOS/SceneCoordinator.swift
+++ b/iOS/SceneCoordinator.swift
@@ -1620,6 +1620,7 @@ private extension SceneCoordinator {
 		let navController = addNavControllerIfNecessary(controller, showButton: false)
 		subSplitViewController!.showDetailViewController(navController, sender: self)
 		
+		masterFeedViewController.restoreSelectionIfNecessary(adjustScroll: true)
 		masterTimelineViewController!.restoreSelectionIfNecessary()
 		
 		// Return the shim controller