add chat method + event to api

APITestMod/APITestMod.cs

@@ -23,6 +23,7 @@ public class APITestMod : ModBehaviour
 
 			qsbAPI.OnPlayerJoin().AddListener((uint playerId) => ModHelper.Console.WriteLine($"{playerId} joined the game!", MessageType.Success));
 			qsbAPI.OnPlayerLeave().AddListener((uint playerId) => ModHelper.Console.WriteLine($"{playerId} left the game!", MessageType.Success));
+			qsbAPI.OnChatMessage().AddListener((string message, uint from) => ModHelper.Console.WriteLine($"Chat message \"{message}\" from {from} ({(from == uint.MaxValue ? "QSB" : qsbAPI.GetPlayerName(from))})"));
 
 			button.onClick.AddListener(() =>
 			{
@@ -52,6 +53,9 @@ public class APITestMod : ModBehaviour
 				ModHelper.Console.WriteLine("Sending float message test...");
 				qsbAPI.RegisterHandler<float>("apitest-float", MessageHandler);
 				qsbAPI.SendMessage("apitest-float", 3.14f, receiveLocally: true);
+
+				qsbAPI.SendChatMessage("Non-system chat message", false, Color.white);
+				qsbAPI.SendChatMessage("System chat message", true, Color.cyan);
 			});
 		};
 	}

APITestMod/IQSBAPI.cs

@@ -1,5 +1,6 @@
 using System;
 using OWML.Common;
+using UnityEngine;
 using UnityEngine.Events;
 
 public interface IQSBAPI
@@ -96,4 +97,23 @@ public interface IQSBAPI
 	void RegisterHandler<T>(string messageType, Action<uint, T> handler);
 
 	#endregion
+
+	#region Chat
+
+	/// <summary>
+	/// Invoked when a chat message is received.
+	/// The string is the message body.
+	/// The uint is the player who sent the message. If it's a system message, this is uint.MaxValue.
+	/// </summary>
+	UnityEvent<string, uint> OnChatMessage();
+
+	/// <summary>
+	/// Sends a message in chat.
+	/// </summary>
+	/// <param name="message">The text of the message.</param>
+	/// <param name="systemMessage">If false, the message is sent as if the local player wrote it manually. If true, the message has no player attached to it, like the player join messages.</param>
+	/// <param name="color">The color of the message.</param>
+	void SendChatMessage(string message, bool systemMessage, Color color);
+
+	#endregion
 }

QSB/API/IQSBAPI.cs

@@ -1,5 +1,6 @@
 using System;
 using OWML.Common;
+using UnityEngine;
 using UnityEngine.Events;
 
 public interface IQSBAPI
@@ -96,4 +97,23 @@ public interface IQSBAPI
 	void RegisterHandler<T>(string messageType, Action<uint, T> handler);
 
 	#endregion
+
+	#region Chat
+
+	/// <summary>
+	/// Invoked when a chat message is received.
+	/// The string is the message body.
+	/// The uint is the player who sent the message. If it's a system message, this is uint.MaxValue.
+	/// </summary>
+	UnityEvent<string, uint> OnChatMessage();
+
+	/// <summary>
+	/// Sends a message in chat.
+	/// </summary>
+	/// <param name="message">The text of the message.</param>
+	/// <param name="systemMessage">If false, the message is sent as if the local player wrote it manually. If true, the message has no player attached to it, like the player join messages.</param>
+	/// <param name="color">The color of the message.</param>
+	void SendChatMessage(string message, bool systemMessage, Color color);
+
+	#endregion
 }

QSB/API/QSBAPI.cs

@@ -5,7 +5,10 @@ using QSB.Messaging;
 using QSB.Player;
 using System;
 using System.Linq;
+using QSB.HUD;
+using QSB.HUD.Messages;
 using UnityEngine.Events;
+using UnityEngine;
 
 namespace QSB.API;
 
@@ -35,6 +38,17 @@ public class QSBAPI : IQSBAPI
 
 	public void RegisterHandler<T>(string messageType, Action<uint, T> handler)
 		=> AddonDataManager.RegisterHandler(messageType.GetStableHashCode(), handler);
+
+	public UnityEvent<string, uint> OnChatMessage() => MultiplayerHUDManager.OnChatMessageEvent;
+
+	public void SendChatMessage(string message, bool systemMessage, Color color)
+	{
+		var fromName = systemMessage
+			? "QSB"
+			: QSBPlayerManager.LocalPlayer.Name;
+
+		new ChatMessage($"{fromName}: {message}", color).Send();
+	}
 }
 
 internal static class QSBAPIEvents

QSB/HUD/Messages/ChatMessage.cs

@@ -4,6 +4,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using QSB.Player;
 using UnityEngine;
 
 namespace QSB.HUD.Messages;
@@ -17,5 +18,27 @@ public class ChatMessage : QSBMessage<(string message, Color color)>
 	public override void OnReceiveRemote()
 	{
 		MultiplayerHUDManager.Instance.WriteMessage(Data.message, Data.color);
+
+		var fromPlayer = QSBPlayerManager.GetPlayer(From);
+		var qsb = false;
+		string name;
+		if (Data.message.StartsWith("QSB: "))
+		{
+			name = "QSB: ";
+			qsb = true;
+		}
+		else if (Data.message.StartsWith($"{fromPlayer.Name}: "))
+		{
+			name = $"{fromPlayer.Name}: ";
+		}
+		else
+		{
+			// uhhh idk what happened
+			MultiplayerHUDManager.OnChatMessageEvent.Invoke(Data.message, From);
+			return;
+		}
+
+		var messageWithoutName = Data.message.Remove(Data.message.IndexOf(name), name.Length);
+		MultiplayerHUDManager.OnChatMessageEvent.Invoke(messageWithoutName, qsb ? uint.MaxValue : From);
 	}
 }

QSB/HUD/MultiplayerHUDManager.cs

@@ -9,6 +9,7 @@ using QSB.WorldSync;
 using System;
 using System.Linq;
 using UnityEngine;
+using UnityEngine.Events;
 using UnityEngine.InputSystem;
 using UnityEngine.SceneManagement;
 using UnityEngine.UI;
@@ -42,6 +43,9 @@ public class MultiplayerHUDManager : MonoBehaviour, IAddComponentOnStart
 
 	public static readonly ListStack<HUDIcon> HUDIconStack = new(true);
 
+	public class ChatEvent : UnityEvent<string, uint> { }
+	public static readonly ChatEvent OnChatMessageEvent = new();
+
 	private void Start()
 	{
 		Instance = this;
@@ -87,7 +91,8 @@ public class MultiplayerHUDManager : MonoBehaviour, IAddComponentOnStart
 	// perks of being a qsb dev :-)
 	public void WriteSystemMessage(string message, Color color)
 	{
-		WriteMessage(message, color);
+		WriteMessage($"QSB: {message}", color);
+		OnChatMessageEvent.Invoke(message, uint.MaxValue);
 	}
 
 	public void WriteMessage(string message, Color color)