From cb2bb215d3d5041ea1f25fc271814b035f40ea06 Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Sat, 2 Apr 2022 11:50:04 -0400
Subject: [PATCH] Change sidebar Discover section to be collapsible

---
 .../Main/MainSidebarViewController.swift      | 27 ++++++++++++-------
 .../Main/MainSplitViewController.swift        |  4 +--
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/Tusker/Screens/Main/MainSidebarViewController.swift b/Tusker/Screens/Main/MainSidebarViewController.swift
index 251ad9dc..403fc11b 100644
--- a/Tusker/Screens/Main/MainSidebarViewController.swift
+++ b/Tusker/Screens/Main/MainSidebarViewController.swift
@@ -148,21 +148,24 @@ class MainSidebarViewController: UIViewController {
         ], toSection: .compose)
         if mastodonController.instanceFeatures.instanceType.isMastodon,
            !Preferences.shared.hideDiscover {
-            addDiscoverSection(to: &snapshot)
+            snapshot.insertSections([.discover], afterSection: .compose)
         }
         dataSource.apply(snapshot, animatingDifferences: false)
         
+        applyDiscoverSectionSnapshot()
         reloadLists()
         reloadSavedHashtags()
         reloadSavedInstances()
     }
     
-    private func addDiscoverSection(to snapshot: inout NSDiffableDataSourceSnapshot<Section, Item>) {
-        snapshot.insertSections([.discover], afterSection: .compose)
-        snapshot.appendItems([
+    private func applyDiscoverSectionSnapshot() {
+        var discoverSnapshot = NSDiffableDataSourceSectionSnapshot<Item>()
+        discoverSnapshot.append([.discoverHeader])
+        discoverSnapshot.append([
             .trendingTags,
             .profileDirectory,
-        ], toSection: .discover)
+        ], to: .discoverHeader)
+        dataSource.apply(discoverSnapshot, to: .discover)
     }
     
     private func ownInstanceLoaded(_ instance: Instance) {
@@ -244,12 +247,14 @@ class MainSidebarViewController: UIViewController {
         let hide = Preferences.shared.hideDiscover
         if hasSection && hide {
             snapshot.deleteSections([.discover])
+            dataSource.apply(snapshot)
         } else if !hasSection && !hide {
-            addDiscoverSection(to: &snapshot)
+            snapshot.insertSections([.discover], afterSection: .compose)
+            dataSource.apply(snapshot)
+            applyDiscoverSectionSnapshot()
         } else {
             return
         }
-        dataSource.apply(snapshot)
     }
 
     // todo: deduplicate with ExploreViewController
@@ -330,7 +335,7 @@ extension MainSidebarViewController {
     enum Item: Hashable {
         case tab(MainTabBarViewController.Tab)
         case search, bookmarks
-        case trendingTags, profileDirectory
+        case discoverHeader, trendingTags, profileDirectory
         case listsHeader, list(List), addList
         case savedHashtagsHeader, savedHashtag(Hashtag), addSavedHashtag
         case savedInstancesHeader, savedInstance(URL), addSavedInstance
@@ -343,6 +348,8 @@ extension MainSidebarViewController {
                 return "Search"
             case .bookmarks:
                 return "Bookmarks"
+            case .discoverHeader:
+                return "Discover"
             case .trendingTags:
                 return "Trending Hashtags"
             case .profileDirectory:
@@ -386,7 +393,7 @@ extension MainSidebarViewController {
                 return "number"
             case .savedInstance(_):
                 return "globe"
-            case .listsHeader, .savedHashtagsHeader, .savedInstancesHeader:
+            case .discoverHeader, .listsHeader, .savedHashtagsHeader, .savedInstancesHeader:
                 return nil
             case .addList, .addSavedHashtag, .addSavedInstance:
                 return "plus"
@@ -395,7 +402,7 @@ extension MainSidebarViewController {
         
         var hasChildren: Bool {
             switch self {
-            case .listsHeader, .savedHashtagsHeader, .savedInstancesHeader:
+            case .discoverHeader, .listsHeader, .savedHashtagsHeader, .savedInstancesHeader:
                 return true
             default:
                 return false
diff --git a/Tusker/Screens/Main/MainSplitViewController.swift b/Tusker/Screens/Main/MainSplitViewController.swift
index c0261bd6..e80439b7 100644
--- a/Tusker/Screens/Main/MainSplitViewController.swift
+++ b/Tusker/Screens/Main/MainSplitViewController.swift
@@ -215,7 +215,7 @@ extension MainSplitViewController: UISplitViewControllerDelegate {
             let explore = exploreNav.viewControllers.first as! ExploreViewController
             explore.searchControllerStatusOnAppearance = false
             
-        case .listsHeader, .addList, .savedHashtagsHeader, .addSavedHashtag, .savedInstancesHeader, .addSavedInstance:
+        case .discoverHeader, .listsHeader, .addList, .savedHashtagsHeader, .addSavedHashtag, .savedInstancesHeader, .addSavedInstance:
             // These items are not selectable in the sidebar collection view, so this code is unreachable.
             fatalError("unreachable")
         }
@@ -345,7 +345,7 @@ fileprivate extension MainSidebarViewController.Item {
             return HashtagTimelineViewController(for: hashtag, mastodonController: mastodonController)
         case let .savedInstance(url):
             return InstanceTimelineViewController(for: url, parentMastodonController: mastodonController)
-        case .listsHeader, .addList, .savedHashtagsHeader, .addSavedHashtag, .savedInstancesHeader, .addSavedInstance:
+        case .discoverHeader, .listsHeader, .addList, .savedHashtagsHeader, .addSavedHashtag, .savedInstancesHeader, .addSavedInstance:
             return nil
         }
     }