Pull up singleton behaviour.

Assets/Cryville/Common/Unity/SingletonBehaviour.cs

@@ -0,0 +1,25 @@
+using UnityEngine;
+
+namespace Cryville.Common.Unity {
+	public abstract class SingletonBehaviour<TSelf> : MonoBehaviour where TSelf : SingletonBehaviour<TSelf> {
+		static TSelf s_instance;
+		public static TSelf Instance {
+			get {
+				return s_instance;
+			}
+		}
+		bool _validInstance;
+		protected virtual void Awake() {
+			if (s_instance != null) {
+				Debug.LogErrorFormat("Duplicate singleton behaviour {0}", typeof(TSelf));
+				Destroy(gameObject);
+				return;
+			}
+			s_instance = (TSelf)this;
+			_validInstance = true;
+		}
+		protected virtual void OnDestroy() {
+			if (_validInstance) s_instance = null;
+		}
+	}
+}

Assets/Cryville/Common/Unity/SingletonBehaviour.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 9dd02eadcf1c6e745939a75a797c9093
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Cryville/Crtr/Browsing/UI/ResourceBrowserMaster.cs

@@ -1,10 +1,11 @@
+using Cryville.Common.Unity;
 using Cryville.Crtr.Browsing.Actions;
 using Cryville.Crtr.Config.UI;
 using System.Collections.Generic;
 using UnityEngine;
 
 namespace Cryville.Crtr.Browsing.UI {
-	public class ResourceBrowserMaster : MonoBehaviour {
+	public class ResourceBrowserMaster : SingletonBehaviour<ResourceBrowserMaster> {
 		[SerializeField]
 		ConfigPanelMaster m_configPanel;
 		[SerializeField]
@@ -21,7 +22,7 @@ namespace Cryville.Crtr.Browsing.UI {
 
 		public ActionManager Actions { get; private set; }
 
-		void Awake() {
+		protected override void Awake() {
 			Actions = new ActionManager();
 			Actions.Register(new PlayChartAction());
 

Assets/Cryville/Crtr/DiscordController.cs

@@ -6,13 +6,11 @@
 using Discord;
 using System;
 #endif
-using UnityEngine;
+using Cryville.Common.Unity;
 
 namespace Cryville.Crtr {
-	internal class DiscordController : MonoBehaviour {
+	internal class DiscordController : SingletonBehaviour<DiscordController> {
 #if COMPILE
-		public static DiscordController Instance;
-
 		const long CLIENT_ID = 1059021675578007622L;
 
 		Discord.Discord dc;
@@ -20,7 +18,6 @@ namespace Cryville.Crtr {
 		long launchTime;
 
 		void Start() {
-			Instance = this;
 			launchTime = (long)(DateTime.UtcNow - DateTime.UnixEpoch).TotalSeconds;
 			try {
 				dc = new Discord.Discord(CLIENT_ID, (UInt64)CreateFlags.NoRequireDiscord);

Assets/Cryville/Crtr/UI/Master.cs

@@ -1,24 +1,13 @@
-using System;
+using Cryville.Common.Unity;
 using UnityEngine;
 
 namespace Cryville.Crtr.UI {
-	internal class Master : MonoBehaviour {
-		static Master s_instance;
-		public static Master Instance { get { return s_instance; } }
-
+	internal class Master : SingletonBehaviour<Master> {
 #pragma warning disable IDE0044
 		[SerializeField]
 		private GameObject m_menu;
 #pragma warning restore IDE0044
 
-		void Awake() {
-			if (s_instance != null) {
-				Destroy(gameObject);
-				throw new InvalidOperationException("Attempted to initialize a singleton twice.");
-			}
-			s_instance = this;
-		}
-
 		internal void ShowMenu() { m_menu.SetActive(true); }
 		internal void HideMenu() { m_menu.SetActive(false); }
 

Assets/Cryville/Crtr/UI/Menu.cs

@@ -1,3 +1,4 @@
+using Cryville.Common.Unity;
 using Cryville.Common.Unity.UI;
 using Cryville.Crtr.Browsing.UI;
 using System.Collections.Generic;
@@ -6,7 +7,7 @@ using UnityEngine;
 using unity = UnityEngine;
 
 namespace Cryville.Crtr.UI {
-	public class Menu : MonoBehaviour {
+	internal class Menu : SingletonBehaviour<Menu> {
 #pragma warning disable IDE0044
 		[SerializeField]
 		ResourceBrowserMaster m_browserMaster;
@@ -24,7 +25,7 @@ namespace Cryville.Crtr.UI {
 		bool initialized = false;
 		int totalTasks = 0;
 #pragma warning disable IDE0051
-		void Awake() {
+		protected override void Awake() {
 			Game.Init();
 			m_contents.SetActive(true);
 			PushTitle("Chart Browser");

Assets/Cryville/Crtr/UI/PopupManager.cs

@@ -1,23 +1,11 @@
-using System;
+using Cryville.Common.Unity;
 using UnityEngine;
-using UnityEngine.UI;
 
 namespace Cryville.Crtr.UI {
-	public class PopupManager : MonoBehaviour {
-		static PopupManager s_instance;
-		public static PopupManager Instance { get { return s_instance; } }
-
+	public class PopupManager : SingletonBehaviour<PopupManager> {
 		[SerializeField]
 		GameObject m_popupPrefab;
 
-		void Awake() {
-			if (s_instance != null) {
-				Destroy(gameObject);
-				throw new InvalidOperationException("Attempted to initialize a singleton twice.");
-			}
-			s_instance = this;
-		}
-
 		public void Create(string msg) {
 			Instantiate(m_popupPrefab, transform, false).GetComponent<Popup>().Message = msg;
 		}