Add session-wide storage as a safer alternative to statics (#6216)

Add session-wide storage as a safer alternative to statics

Co-authored-by: Dean Herbert <pe@ppy.sh>

osu.Game/Configuration/InMemoryConfigManager.cs

@@ -0,0 +1,22 @@
+// 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 osu.Framework.Configuration;
+
+namespace osu.Game.Configuration
+{
+    public class InMemoryConfigManager<T> : ConfigManager<T>
+        where T : struct
+    {
+        public InMemoryConfigManager()
+        {
+            InitialiseDefaults();
+        }
+
+        protected override void PerformLoad()
+        {
+        }
+
+        protected override bool PerformSave() => true;
+    }
+}

osu.Game/Configuration/SessionStatics.cs

@@ -0,0 +1,21 @@
+// 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.
+
+namespace osu.Game.Configuration
+{
+    /// <summary>
+    /// Stores global per-session statics. These will not be stored after exiting the game.
+    /// </summary>
+    public class SessionStatics : InMemoryConfigManager<Static>
+    {
+        protected override void InitialiseDefaults()
+        {
+            Set(Static.LoginOverlayDisplayed, false);
+        }
+    }
+
+    public enum Static
+    {
+        LoginOverlayDisplayed,
+    }
+}

osu.Game/OsuGameBase.cs

@@ -191,6 +191,7 @@ namespace osu.Game
             dependencies.Cache(KeyBindingStore = new KeyBindingStore(contextFactory, RulesetStore));
             dependencies.Cache(SettingsStore = new SettingsStore(contextFactory));
             dependencies.Cache(RulesetConfigCache = new RulesetConfigCache(SettingsStore));
+            dependencies.Cache(new SessionStatics());
             dependencies.Cache(new OsuColour());
 
             fileImporters.Add(BeatmapManager);

osu.Game/Screens/Menu/MainMenu.cs

@@ -63,13 +63,15 @@ namespace osu.Game.Screens.Menu
         protected override BackgroundScreen CreateBackground() => background;
 
         private Bindable<int> holdDelay;
+        private Bindable<bool> loginDisplayed;
 
         private ExitConfirmOverlay exitConfirmOverlay;
 
         [BackgroundDependencyLoader(true)]
-        private void load(DirectOverlay direct, SettingsOverlay settings, OsuConfigManager config)
+        private void load(DirectOverlay direct, SettingsOverlay settings, OsuConfigManager config, SessionStatics statics)
         {
             holdDelay = config.GetBindable<int>(OsuSetting.UIHoldActivationDelay);
+            loginDisplayed = statics.GetBindable<bool>(Static.LoginOverlayDisplayed);
 
             if (host.CanExit)
             {
@@ -170,7 +172,6 @@ namespace osu.Game.Screens.Menu
             Beatmap.ValueChanged += beatmap_ValueChanged;
         }
 
-        private bool loginDisplayed;
         private bool exitConfirmed;
 
         protected override void LogoArriving(OsuLogo logo, bool resuming)
@@ -198,10 +199,10 @@ namespace osu.Game.Screens.Menu
 
             bool displayLogin()
             {
-                if (!loginDisplayed)
+                if (!loginDisplayed.Value)
                 {
                     Scheduler.AddDelayed(() => login?.Show(), 500);
-                    loginDisplayed = true;
+                    loginDisplayed.Value = true;
                 }
 
                 return true;