Use search results controller

// FREEBIE

Signal/src/ViewControllers/HomeView/ConversationSearchViewController.swift

@@ -5,7 +5,7 @@
 import Foundation
 
 @objc
-class ConversationSearchViewController: UITableViewController, UISearchBarDelegate {
+class ConversationSearchViewController: UITableViewController {
 
     var searchResultSet: SearchResultSet = SearchResultSet.empty
 
@@ -125,31 +125,19 @@ class ConversationSearchViewController: UITableViewController, UISearchBarDelega
     // MARK: UISearchBarDelegate
 
     @objc
-    public var searchBar: UISearchBar?
-
-    override func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
-        guard let searchBar = self.searchBar else {
-            owsFail("\(logTag) searchBar was unexpectedly nil")
-            return
-        }
-
-        searchBar.resignFirstResponder()
-    }
-
-    public func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
+    public func updateSearchResults(searchText: String) {
         guard searchText.stripped.count > 0 else {
             self.searchResultSet = SearchResultSet.empty
-            self.view.isHidden = true
             return
         }
 
-        self.view.isHidden = false
+        // TODO: async?
+        // TODO: debounce?
 
         self.uiDatabaseConnection.read { transaction in
             self.searchResultSet = self.searcher.results(searchText: searchText, transaction: transaction)
         }
 
-        // TODO: debounce
         // TODO: more perfomant way to do this?
         self.tableView.reloadData()
     }
@@ -242,7 +230,9 @@ class MessageSearchResultCell: UITableViewCell {
         // Bold snippet text
         do {
 
-            // FIXME - apply our font without clobbering bold.
+            // FIXME - The snippet marks up the matched search text with <b> tags.
+            // We can parse this into an attributed string, but it also takes on an undesirable font.
+            // We want to apply our own font without clobbering bold in the process - maybe by enumerating and inspecting the attributes? Or maybe we can pass in a base font?
             let attributedSnippet = try NSMutableAttributedString(data: encodedString,
                                                                   options: [NSAttributedString.DocumentReadingOptionKey.documentType: NSAttributedString.DocumentType.html],
                                                                   documentAttributes: nil)

Signal/src/ViewControllers/HomeView/HomeViewController.m

@@ -38,7 +38,7 @@ typedef NS_ENUM(NSInteger, HomeViewMode) {
 
 NSString *const kArchivedConversationsReuseIdentifier = @"kArchivedConversationsReuseIdentifier";
 
-@interface HomeViewController () <UITableViewDelegate, UITableViewDataSource, UIViewControllerPreviewingDelegate>
+@interface HomeViewController () <UITableViewDelegate, UITableViewDataSource, UIViewControllerPreviewingDelegate, UISearchResultsUpdating>
 
 @property (nonatomic) UITableView *tableView;
 @property (nonatomic) UILabel *emptyBoxLabel;
@@ -56,8 +56,9 @@ NSString *const kArchivedConversationsReuseIdentifier = @"kArchivedConversations
 
 // Mark: Search
 
-@property (nonatomic) UISearchBar *searchBar;
-@property (nonatomic) ConversationSearchViewController *searchController;
+//@property (nonatomic) UISearchBar *searchBar;
+@property (nonatomic) UISearchController *searchController;
+@property (nonatomic) ConversationSearchViewController *searchResultsController;
 
 // Dependencies
 
@@ -297,26 +298,14 @@ NSString *const kArchivedConversationsReuseIdentifier = @"kArchivedConversations
     
     // Search
     
-    UISearchBar *searchBar = [UISearchBar new];
-    _searchBar = searchBar;
-    searchBar.searchBarStyle = UISearchBarStyleMinimal;
-    searchBar.placeholder = NSLocalizedString(@"HOME_VIEW_CONVERSATION_SEARCHBAR_PLACEHOLDER", @"Placeholder text for search bar which filters conversations.");
-    searchBar.backgroundColor = [UIColor whiteColor];
-    [searchBar sizeToFit];
-    
     // Setting tableHeader calls numberOfSections, which must happen after updateMappings has been called at least once.
-    ConversationSearchViewController *searchController = [ConversationSearchViewController new];
+    ConversationSearchViewController *searchResultsController = [ConversationSearchViewController new];
+    self.searchResultsController = searchResultsController;
+    UISearchController *searchController = [[UISearchController alloc] initWithSearchResultsController:searchResultsController];
     self.searchController = searchController;
-    [self addChildViewController:searchController];
-    searchController.view.frame = self.view.frame;
-    [self.view addSubview:searchController.view];
-    // TODO - better/more flexible way to pin below search bar?
-    [searchController.view autoPinEdgesToSuperviewEdgesWithInsets:UIEdgeInsetsMake(60, 0, 0, 0)];
-    searchBar.delegate = searchController;
-    searchController.searchBar = searchBar;
-    
-    OWSAssert(self.tableView.tableHeaderView == nil);
-    self.tableView.tableHeaderView = self.searchBar;
+    searchController.searchResultsUpdater = self;
+    self.tableView.tableHeaderView = self.searchController.searchBar;
+    self.definesPresentationContext = YES;
         
     [self updateBarButtonItems];
 }
@@ -871,6 +860,13 @@ NSString *const kArchivedConversationsReuseIdentifier = @"kArchivedConversations
     return YES;
 }
 
+#pragma mark - SearchResultsUpdating
+
+- (void)updateSearchResultsForSearchController:(UISearchController *)searchController
+{
+    [self.searchResultsController updateSearchResultsWithSearchText:self.searchController.searchBar.text];
+}
+
 #pragma mark - HomeFeedTableViewCellDelegate
 
 - (void)tableViewCellTappedDelete:(NSIndexPath *)indexPath