Use bindables the whole way

osu.Game/Online/API/Requests/Responses/APIChangelogBuild.cs

@@ -7,7 +7,7 @@ using System.Collections.Generic;
 
 namespace osu.Game.Online.API.Requests.Responses
 {
-    public class APIChangelogBuild
+    public class APIChangelogBuild : IEquatable<APIChangelogBuild>
     {
         [JsonProperty("id")]
         public long Id { get; set; }
@@ -42,6 +42,8 @@ namespace osu.Game.Online.API.Requests.Responses
             public APIChangelogBuild Previous { get; set; }
         }
 
+        public bool Equals(APIChangelogBuild other) => this.Id == other?.Id;
+
         public override string ToString() => $"{UpdateStream.DisplayName} {DisplayVersion}";
     }
 }

osu.Game/Online/API/Requests/Responses/APIUpdateStream.cs

@@ -25,13 +25,7 @@ namespace osu.Game.Online.API.Requests.Responses
         [JsonProperty("latest_build")]
         public APIChangelogBuild LatestBuild { get; set; }
 
-        public bool Equals(APIUpdateStream other)
+        public bool Equals(APIUpdateStream other) => this.Id == other?.Id;
-        {
-            if (ReferenceEquals(null, other)) return false;
-            if (ReferenceEquals(this, other)) return true;
-
-            return Id == other.Id;
-        }
 
         public ColourInfo Colour
         {

osu.Game/Overlays/Changelog/ChangelogHeader.cs

@@ -3,6 +3,7 @@
 
 using System;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
@@ -17,6 +18,8 @@ namespace osu.Game.Overlays.Changelog
 {
     public class ChangelogHeader : OverlayHeader
     {
+        public readonly Bindable<APIChangelogBuild> Current = new Bindable<APIChangelogBuild>();
+
         public Action ListingSelected;
 
         private const string listing_string = "Listing";
@@ -29,6 +32,8 @@ namespace osu.Game.Overlays.Changelog
                 if (e.NewValue == listing_string)
                     ListingSelected?.Invoke();
             };
+
+            Current.ValueChanged += showBuild;
         }
 
         [BackgroundDependencyLoader]
@@ -37,35 +42,24 @@ namespace osu.Game.Overlays.Changelog
             TabControl.AccentColour = colours.Violet;
         }
 
-        private APIChangelogBuild displayedBuild;
-
         private ChangelogHeaderTitle title;
 
-        public void ShowBuild(APIChangelogBuild build)
+        private void showBuild(ValueChangedEvent<APIChangelogBuild> e)
         {
-            hideBuildTab();
+            if (e.OldValue != null)
+                TabControl.RemoveItem(e.OldValue.ToString());
 
-            displayedBuild = build;
+            if (e.NewValue != null)
-
-            TabControl.AddItem(build.ToString());
-            TabControl.Current.Value = build.ToString();
-
-            title.Version = build.UpdateStream.DisplayName;
-        }
-
-        public void ShowListing()
-        {
-            hideBuildTab();
-
-            title.Version = null;
-        }
-
-        private void hideBuildTab()
-        {
-            if (displayedBuild != null)
             {
-                TabControl.RemoveItem(displayedBuild.ToString());
+                TabControl.AddItem(e.NewValue.ToString());
-                displayedBuild = null;
+                TabControl.Current.Value = e.NewValue.ToString();
+
+                title.Version = e.NewValue.UpdateStream.DisplayName;
+            }
+            else
+            {
+                TabControl.Current.Value = listing_string;
+                title.Version = null;
             }
         }
 

osu.Game/Overlays/ChangelogOverlay.cs

@@ -1,12 +1,14 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading;
+using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Audio;
 using osu.Framework.Audio.Sample;
+using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Shapes;
@@ -32,6 +34,23 @@ namespace osu.Game.Overlays
 
         private List<APIChangelogBuild> builds;
 
+        public readonly Bindable<APIChangelogBuild> Current = new Bindable<APIChangelogBuild>();
+
+        public void ShowListing() => Current.Value = null;
+
+        /// <summary>
+        /// Fetches and shows a specific build from a specific update stream.
+        /// </summary>
+        /// <param name="build">Must contain at least <see cref="APIUpdateStream.Name"/> and
+        /// <see cref="APIChangelogBuild.Version"/>. If <see cref="APIUpdateStream.DisplayName"/> and
+        /// <see cref="APIChangelogBuild.DisplayVersion"/> are specified, the header will instantly display them.</param>
+        public void ShowBuild([NotNull] APIChangelogBuild build)
+        {
+            if (build == null) throw new ArgumentNullException(nameof(build));
+
+            Current.Value = build;
+        }
+
         [BackgroundDependencyLoader]
         private void load(AudioManager audio, OsuColour colour)
         {
@@ -73,22 +92,30 @@ namespace osu.Game.Overlays
                 },
             };
 
-            // todo: better
             badges.Current.ValueChanged += e =>
             {
-                if (e.NewValue?.LatestBuild != null)
+                if (e.NewValue != null)
                     ShowBuild(e.NewValue.LatestBuild);
             };
 
             sampleBack = audio.Sample.Get(@"UI/generic-select-soft");
-        }
 
-        protected override void PopIn()
+            header.Current.BindTo(Current);
-        {
-            base.PopIn();
 
-            if (!initialFetchPerformed)
+            Current.BindValueChanged(e =>
-                fetchListing();
+            {
+                if (e.NewValue != null)
+                {
+                    badges.Current.Value = e.NewValue.UpdateStream;
+
+                    loadContent(new ChangelogSingleBuild(e.NewValue));
+                }
+                else
+                {
+                    badges.Current.Value = null;
+                    loadContent(new ChangelogListing(builds));
+                }
+            });
         }
 
         public override bool OnPressed(GlobalAction action)
@@ -96,13 +123,13 @@ namespace osu.Game.Overlays
             switch (action)
             {
                 case GlobalAction.Back:
-                    if (content.Child is ChangelogListing)
+                    if (Current.Value == null)
                     {
                         State = Visibility.Hidden;
                     }
                     else
                     {
-                        ShowListing();
+                        Current.Value = null;
                         sampleBack?.Play();
                     }
 
@@ -112,34 +139,12 @@ namespace osu.Game.Overlays
             return false;
         }
 
-        public void ShowListing()
+        protected override void PopIn()
         {
-            if (content.Children.FirstOrDefault() is ChangelogListing)
+            base.PopIn();
-                return;
 
-            header.ShowListing();
+            if (!initialFetchPerformed)
-            badges.Current.Value = null;
+                fetchListing();
-            loadContent(new ChangelogListing(builds));
-        }
-
-        /// <summary>
-        /// Fetches and shows a specific build from a specific update stream.
-        /// </summary>
-        /// <param name="build">Must contain at least <see cref="APIUpdateStream.Name"/> and
-        /// <see cref="APIChangelogBuild.Version"/>. If <see cref="APIUpdateStream.DisplayName"/> and
-        /// <see cref="APIChangelogBuild.DisplayVersion"/> are specified, the header will instantly display them.</param>
-        public void ShowBuild(APIChangelogBuild build)
-        {
-            if (build == null)
-            {
-                ShowListing();
-                return;
-            }
-
-            header.ShowBuild(build);
-            badges.Current.Value = build.UpdateStream;
-
-            loadContent(new ChangelogSingleBuild(build));
         }
 
         private bool initialFetchPerformed;
@@ -158,7 +163,7 @@ namespace osu.Game.Overlays
                 builds = res.Builds;
                 badges.Populate(res.Streams);
 
-                ShowListing();
+                Current.TriggerChange();
             };
             req.Failure += _ => initialFetchPerformed = false;