From 2f0acad86641ad52084781d6acbc4bda2d0b82eb Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Wed, 30 Nov 2022 16:47:06 -0500
Subject: [PATCH] Return to previous item when the selected
 list/hashtag/instance is removed from the sidebar

---
 .../Main/MainSidebarViewController.swift      | 37 ++++++++++++++++---
 1 file changed, 31 insertions(+), 6 deletions(-)

diff --git a/Tusker/Screens/Main/MainSidebarViewController.swift b/Tusker/Screens/Main/MainSidebarViewController.swift
index 98b63dfa..4101d260 100644
--- a/Tusker/Screens/Main/MainSidebarViewController.swift
+++ b/Tusker/Screens/Main/MainSidebarViewController.swift
@@ -209,6 +209,12 @@ class MainSidebarViewController: UIViewController {
     }
     
     private func reloadLists(_ lists: [List]) {
+        if let selectedItem,
+           case .list(let list) = selectedItem,
+           !lists.contains(where: { $0.id == list.id }) {
+            returnToPreviousItem()
+        }
+        
         var exploreSnapshot = NSDiffableDataSourceSectionSnapshot<Item>()
         exploreSnapshot.append([.listsHeader])
         exploreSnapshot.expand([.listsHeader])
@@ -240,24 +246,36 @@ class MainSidebarViewController: UIViewController {
     }
     
     @objc private func reloadSavedHashtags() {
-        var hashtagsSnapshot = NSDiffableDataSourceSectionSnapshot<Item>()
-        hashtagsSnapshot.append([.savedHashtagsHeader])
-        hashtagsSnapshot.expand([.savedHashtagsHeader])
         let hashtags = fetchSavedHashtags().map {
             Item.savedHashtag(Hashtag(name: $0.name, url: $0.url))
         }
+        if let selectedItem,
+           case .savedHashtag(_) = selectedItem,
+           !hashtags.contains(selectedItem) {
+            returnToPreviousItem()
+        }
+        
+        var hashtagsSnapshot = NSDiffableDataSourceSectionSnapshot<Item>()
+        hashtagsSnapshot.append([.savedHashtagsHeader])
+        hashtagsSnapshot.expand([.savedHashtagsHeader])
         hashtagsSnapshot.append(hashtags, to: .savedHashtagsHeader)
         hashtagsSnapshot.append([.addSavedHashtag], to: .savedHashtagsHeader)
         self.dataSource.apply(hashtagsSnapshot, to: .savedHashtags)
     }
     
     @objc private func reloadSavedInstances() {
-        var instancesSnapshot = NSDiffableDataSourceSectionSnapshot<Item>()
-        instancesSnapshot.append([.savedInstancesHeader])
-        instancesSnapshot.expand([.savedInstancesHeader])
         let instances = fetchSavedInstances().map {
             Item.savedInstance($0.url)
         }
+        if let selectedItem,
+           case .savedInstance(_) = selectedItem,
+           !instances.contains(selectedItem) {
+            returnToPreviousItem()
+        }
+
+        var instancesSnapshot = NSDiffableDataSourceSectionSnapshot<Item>()
+        instancesSnapshot.append([.savedInstancesHeader])
+        instancesSnapshot.expand([.savedInstancesHeader])
         instancesSnapshot.append(instances, to: .savedInstancesHeader)
         instancesSnapshot.append([.addSavedInstance], to: .savedInstancesHeader)
         self.dataSource.apply(instancesSnapshot, to: .savedInstances)
@@ -278,6 +296,13 @@ class MainSidebarViewController: UIViewController {
             return
         }
     }
+    
+    private func returnToPreviousItem() {
+        let item = previouslySelectedItem ?? .tab(.timelines)
+        previouslySelectedItem = nil
+        select(item: item, animated: true)
+        sidebarDelegate?.sidebar(self, didSelectItem: item)
+    }
 
     private func showAddList() {
         let service = CreateListService(mastodonController: mastodonController, present: { self.present($0, animated: true