Message Queue

https://github.com/GandhiGames/message_queue Find this articles project on GitHub.

What is it?

A simple event based debug message queue. Easily display messages on-screen for a set amount of time from anywhere in your codebase. I use it to quickly show debug messages on mobile devices.

To show a message, simply raise a message event:

Events.instance.Raise (new MessageEvent ("Show this message for 3 seconds", Time.time + 3f, MessagePriority.High));

The colour of messages changes based on the priority.A message event has associated information such as time raised, how long to display the message, and the message priority.

public interface IMessageEvent
{
	DateTime timeRaised { get; }
	float displayTime { get; }
	MessagePriority priority { get; }
	object message { get; }
}

The complete message queue code:

public class MessageQueue : MonoBehaviour
{
	public bool logToConsole = false;
	public bool prependDateTime = false;
	
	[Header ("Message Colours")]
	public Color
	highPriorityColour = Color.red;
	public Color normalPriorityColour = Color.black;
	public Color lowPriorityColour = Color.white;
	
	[Header ("Message Font Style")]
	public FontStyle
	highPriorityStyle = FontStyle.Bold;
	public FontStyle normalPriorityStyle = FontStyle.Normal;
	public FontStyle lowPriorityStyle = FontStyle.Normal;
	
	[Header ("Message Location")]
	public Vector2
	queueLocation = new Vector2 (25, 25); 
	public Vector2 messageSize = new Vector2 (200, 15); 
	
	private static readonly GUIStyle LOW_PRIORTY = new GUIStyle (), NORMAL_PRIORITY = new GUIStyle (), HIGH_PRIORITY = new GUIStyle ();
	private List<IMessageEvent> _pending = new List<IMessageEvent> ();
	
	void OnEnable ()
	{
		if (_pending.Count > 0) 
		{
			_pending.Clear ();
		}

		LOW_PRIORTY.normal.textColor = lowPriorityColour;
		LOW_PRIORTY.fontStyle = lowPriorityStyle;
		NORMAL_PRIORITY.normal.textColor = normalPriorityColour;
		NORMAL_PRIORITY.fontStyle = normalPriorityStyle;
		HIGH_PRIORITY.normal.textColor = highPriorityColour;
		HIGH_PRIORITY.fontStyle = highPriorityStyle;
		Events.instance.AddListener<MessageEvent> (OnMessage);
	}
	
	void OnDisable ()
	{
		Events.instance.RemoveListener<MessageEvent> (OnMessage);
	}
	
	void Update ()
	{
		for (int i = _pending.Count - 1; i>=0; i--) 
		{
			if (Time.time > _pending [i].displayTime) _pending.RemoveAt (i);
		}
	}
	
	void OnMessage (IMessageEvent e)
	{
		_pending.Add (e);
		
		if (logToConsole) 
		{
			Debug.Log ("Message Recieved [" + System.DateTime.Now + "]: " + e.message.ToString ());
		}
	}
	
	void OnGUI ()
	{
		float yPos = queueLocation.y;
	
		foreach (var m in _pending) 
		{
			GUIStyle style = GetMessageStyle (m);
			string message = (prependDateTime) ? "[" + m.timeRaised + "]: " + m.message.ToString () : m.message.ToString ();
			GUI.Label (new Rect (queueLocation.x, yPos, messageSize.x, messageSize.y), message, style);
			yPos += messageSize.y;
		}
	}
	
	GUIStyle GetMessageStyle (IMessageEvent e)
	{
		switch (e.priority) 
		{
			case MessagePriority.Low: return LOW_PRIORTY;
			case MessagePriority.Medium: return NORMAL_PRIORITY;
			default: return HIGH_PRIORITY;
		}
	}
}

Thank you for reading 🙂