From f70c2ed6df42da25202e86f2c69f5dc37b2c5a81 Mon Sep 17 00:00:00 2001
From: Marc Palmer <marc@anyware.co.uk>
Date: Wed, 5 Sep 2018 15:11:08 +0100
Subject: [PATCH 1/2] Auto-scroll to the current/next session in Programme

---
 .../ProgrammeTableViewController.swift        | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/iOSDevUK/Controllers/Sessions/ProgrammeTableViewController.swift b/iOSDevUK/Controllers/Sessions/ProgrammeTableViewController.swift
index ac60549..159b056 100644
--- a/iOSDevUK/Controllers/Sessions/ProgrammeTableViewController.swift
+++ b/iOSDevUK/Controllers/Sessions/ProgrammeTableViewController.swift
@@ -21,6 +21,8 @@ class ProgrammeTableViewController: UIViewController, UITableViewDelegate, UITab
     
     var selectedSessionItem: SessionItem?
     
+    var shouldScrollToCurrent: Bool = true
+    
     // MARK: - Lifecycle
     
     override func viewDidLoad() {
@@ -43,6 +45,16 @@ class ProgrammeTableViewController: UIViewController, UITableViewDelegate, UITab
         super.didReceiveMemoryWarning()
     }
 
+    override func viewDidAppear(_ animated: Bool) {
+        super.viewDidAppear(animated)
+        
+        if shouldScrollToCurrent {
+            // We'd rather not animate, but how can we know when the table view knows the correct
+            // size for all the cells in order to scroll to the right place, before the view appears?
+            scrollToCurrentSession(animated: true)
+        }
+    }
+    
     // MARK: - Data Initialisation
     
     func accessDayList(withContext context: NSManagedObjectContext) -> [Day] {
@@ -86,6 +98,41 @@ class ProgrammeTableViewController: UIViewController, UITableViewDelegate, UITab
         }
     }
     
+    /// Find the current or next session for the current set of sessions and scroll to it.
+    func scrollToCurrentSession(animated: Bool) {
+        guard let fetchedResultsController = fetchedResultsController,
+                let sections = fetchedResultsController.sections else {
+            return
+        }
+        
+        /// Find the session in the already-fetched results
+        let now = Date()
+        let nextOrCurrentSession = fetchedResultsController.fetchedObjects?.first { session in
+            guard let startTimeNSDate = session.startTime,
+                    let endTimeNSDate = session.endTime else {
+                return false
+            }
+            let startTime = startTimeNSDate as Date
+            let endTime = endTimeNSDate as Date
+            return (startTime <= now && endTime >= now) || (startTime >= now)
+        }
+        
+        /// If we found one, resolve it to a section index and row
+        if let sessionToScrollTo = nextOrCurrentSession {
+            for (sectionIndex, section) in sections.enumerated() {
+                if let rowIndex = section.objects?.firstIndex(where: {
+                    let session = $0 as! Session
+                    return session == sessionToScrollTo
+                }) {
+                    tableView.scrollToRow(at: IndexPath(row: rowIndex, section: sectionIndex), at: .top, animated: animated)
+                    break
+                }
+            }
+        }
+        
+        shouldScrollToCurrent = false
+    }
+    
     // MARK: - Segmented Control
     
     func setupSegmentedControlWithDays(_ days: [Day]) {

From 2b05d64e893235a657978d6c7343a1f7fb17ded4 Mon Sep 17 00:00:00 2001
From: Marc Palmer <marc@anyware.co.uk>
Date: Thu, 6 Sep 2018 17:15:51 +0100
Subject: [PATCH 2/2] Code review updates

---
 .../ProgrammeTableViewController.swift        | 21 +++++--------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/iOSDevUK/Controllers/Sessions/ProgrammeTableViewController.swift b/iOSDevUK/Controllers/Sessions/ProgrammeTableViewController.swift
index 159b056..8e616cf 100644
--- a/iOSDevUK/Controllers/Sessions/ProgrammeTableViewController.swift
+++ b/iOSDevUK/Controllers/Sessions/ProgrammeTableViewController.swift
@@ -100,33 +100,22 @@ class ProgrammeTableViewController: UIViewController, UITableViewDelegate, UITab
     
     /// Find the current or next session for the current set of sessions and scroll to it.
     func scrollToCurrentSession(animated: Bool) {
-        guard let fetchedResultsController = fetchedResultsController,
-                let sections = fetchedResultsController.sections else {
+        guard let fetchedResultsController = fetchedResultsController else {
             return
         }
         
         /// Find the session in the already-fetched results
-        let now = Date()
         let nextOrCurrentSession = fetchedResultsController.fetchedObjects?.first { session in
-            guard let startTimeNSDate = session.startTime,
-                    let endTimeNSDate = session.endTime else {
+            guard let endTime = session.endTime else {
                 return false
             }
-            let startTime = startTimeNSDate as Date
-            let endTime = endTimeNSDate as Date
-            return (startTime <= now && endTime >= now) || (startTime >= now)
+            return endTime.timeIntervalSinceNow > 0
         }
         
         /// If we found one, resolve it to a section index and row
         if let sessionToScrollTo = nextOrCurrentSession {
-            for (sectionIndex, section) in sections.enumerated() {
-                if let rowIndex = section.objects?.firstIndex(where: {
-                    let session = $0 as! Session
-                    return session == sessionToScrollTo
-                }) {
-                    tableView.scrollToRow(at: IndexPath(row: rowIndex, section: sectionIndex), at: .top, animated: animated)
-                    break
-                }
+            if let indexPathOfSessionToScrollTo = fetchedResultsController.indexPath(forObject: sessionToScrollTo) {
+                tableView.scrollToRow(at: indexPathOfSessionToScrollTo, at: .top, animated: animated)
             }
         }