Added a way to load levels on a thread other than the Unity thread.

ExampleProject/HelloWorld/Assets/Plugins/Sphero/NoSpheroConnectedView.cs

@@ -27,6 +27,13 @@ public class NoSpheroConnectedView : MonoBehaviour {
 
 	// UI Padding Variables
 	int m_ViewPadding = 20;
+
+	private ThreadSafeLoadLevel m_threadSafeLoadLevel;
+
+	void Awake()
+	{
+		m_threadSafeLoadLevel = ThreadSafeLoadLevel.Instance;
+	}
 
 	void Start () {	
 		ViewSetup();
@@ -59,7 +66,10 @@ private void ReceiveNotificationMessage(object sender, SpheroDeviceMessenger.Mes
 		SpheroDeviceNotification message = (SpheroDeviceNotification)eventArgs.Message;
 		if( message.NotificationType == SpheroDeviceNotification.SpheroNotificationType.CONNECTED ) {
 			// Go to the desired scene
-			Application.LoadLevel (m_NextLevel); 
+			if (m_threadSafeLoadLevel != null)
+			{
+				m_threadSafeLoadLevel.LoadLevel(m_NextLevel);
+			}
 		}
 	}
 
@@ -125,7 +135,10 @@ void OnGUI() {
 		getASpheroButtonY = backgroundY+(backgroundHeight*0.85f) - (buttonHeight/2);
 		// If the get a Sphero button is clicked
 		if( GUI.Button (new Rect(getASpheroButtonX, getASpheroButtonY,buttonWidth,buttonHeight), "") ) {
-			Application.LoadLevel("SpheroConnectionScene");
+			if (m_threadSafeLoadLevel != null)
+			{
+				m_threadSafeLoadLevel.LoadLevel("SpheroConnectionScene");
+			}
 		}
 #endif		
 	}

ExampleProject/HelloWorld/Assets/Plugins/Sphero/SpheroConnectionView.cs

@@ -60,6 +60,8 @@ public class SpheroConnectionView : MonoBehaviour {
     Vector2 windowMargin = new Vector2(0,0);
     Vector2 listMargin = new Vector2(40,40);
     private Rect windowRect;
+
+	private ThreadSafeLoadLevel m_threadSafeLoadLevel;
 
 	/* Use this to initialize the view */
 	private void ViewSetup() {
@@ -72,6 +74,11 @@ private void ViewSetup() {
 			// Display that it doesn't work with these platforms?
 		#endif
 	}
+
+	void Awake()
+	{
+		m_threadSafeLoadLevel = ThreadSafeLoadLevel.Instance;
+	}
 
 	/* Use these for initialization */
 	void Start () {	
@@ -106,7 +113,10 @@ void SetupIOS() {
 	 */
 	void CheckForSpheroConnection() {
 		if( m_SpheroProvider.GetConnectedSpheros().Length == 0 ) {
-			Application.LoadLevel("NoSpheroConnectedScene");	
+			if (m_threadSafeLoadLevel != null)
+			{
+				m_threadSafeLoadLevel.LoadLevel("NoSpheroConnectedScene");
+			}
 		}
 	}
 
@@ -157,7 +167,10 @@ private void ReceiveNotificationMessage(object sender, SpheroDeviceMessenger.Mes
 			if( !m_MultipleSpheros ) {
 				m_Title = "Connection Success";
 				SpheroDeviceMessenger.SharedInstance.NotificationReceived -= ReceiveNotificationMessage;
-				Application.LoadLevel(m_NextLevel); 
+				if (m_threadSafeLoadLevel != null)
+				{
+					m_threadSafeLoadLevel.LoadLevel(m_NextLevel);
+				}
 			}
 		}
 		else if( message.NotificationType == SpheroDeviceNotification.SpheroNotificationType.CONNECTION_FAILED ) {
@@ -281,7 +294,10 @@ void OnGUI() {
 			// Check if we are done adding robots
 			if( buttonLabel.Equals("Done") ){
 				SpheroDeviceMessenger.SharedInstance.NotificationReceived -= ReceiveNotificationMessage;
-				Application.LoadLevel(m_NextLevel); 	
+				if (m_threadSafeLoadLevel != null)
+				{
+					m_threadSafeLoadLevel.LoadLevel(m_NextLevel);
+				}
 			}
 			// Check if we have a Sphero connected
 			else if( m_SpheroLabelSelected >= 0 ) {

ExampleProject/HelloWorld/Assets/Plugins/Sphero/ThreadSafeLoadLevel.cs

@@ -0,0 +1,82 @@
+using System.Threading;
+using UnityEngine;
+
+/// <summary>
+/// The goal of this class is to let you load levels (from the Sphero callbacks) in a way that 
+/// doesn't try to make Unity calls on a thread other than the Unity thread. Unity takes issue with
+/// this and will throw a crashing-tantrum.
+/// </summary>
+public class ThreadSafeLoadLevel : MonoBehaviour
+{
+	#region Static instance management
+	/// <summary>
+	/// Static instance of this script
+	/// </summary>
+	private static ThreadSafeLoadLevel s_instance;
+
+	/// <summary>
+	/// No creating an instance after OnApplicationQuit is called - can get funky in the editor
+	/// </summary>
+	private static bool m_exiting;
+
+	/// <summary>
+	/// Gets the static instance of his script. This is *NOT* thread safe. Call it from Unity's
+	/// thread (creates a Unity object)
+	/// </summary>
+	public static ThreadSafeLoadLevel Instance
+	{
+		get
+		{
+			if (s_instance == null && !m_exiting)
+			{
+				var go = new GameObject("ThreadSafeLoadLevel");
+				s_instance = go.AddComponent<ThreadSafeLoadLevel>();
+			}
+			return s_instance;
+		}
+	}
+	#endregion
+
+	/// <summary>
+	/// An object to lock on
+	/// </summary>
+	private readonly Object m_lock = new Object();
+
+	/// <summary>
+	/// The level we want to load
+	/// </summary>
+	private string m_levelToLoad;
+
+	#region Unity-style callbacks
+	void Update()
+	{
+		// non-blocking lock acquire
+		if (Monitor.TryEnter(m_lock))
+		{
+			if (!string.IsNullOrEmpty(m_levelToLoad))
+			{
+				Application.LoadLevel(m_levelToLoad);
+			}
+
+			Monitor.Exit(m_lock);
+		}
+	}
+
+	void OnApplicationQuit()
+	{
+		m_exiting = true;
+	}
+	#endregion
+
+	/// <summary>
+	/// Loads the given level by name
+	/// </summary>
+	/// <param name="levelName">a level we wish to load</param>
+	public void LoadLevel(string levelName)
+	{
+		lock (m_lock)
+		{
+			m_levelToLoad = levelName;
+		}
+	}
+}

ExampleProject/SensorStreaming/Assets/Plugins/Sphero/NoSpheroConnectedView.cs

@@ -27,6 +27,13 @@ public class NoSpheroConnectedView : MonoBehaviour {
 
 	// UI Padding Variables
 	int m_ViewPadding = 20;
+
+	private ThreadSafeLoadLevel m_threadSafeLoadLevel;
+
+	void Awake()
+	{
+		m_threadSafeLoadLevel = ThreadSafeLoadLevel.Instance;
+	}
 
 	void Start () {	
 		ViewSetup();
@@ -59,7 +66,10 @@ private void ReceiveNotificationMessage(object sender, SpheroDeviceMessenger.Mes
 		SpheroDeviceNotification message = (SpheroDeviceNotification)eventArgs.Message;
 		if( message.NotificationType == SpheroDeviceNotification.SpheroNotificationType.CONNECTED ) {
 			// Go to the desired scene
-			Application.LoadLevel (m_NextLevel); 
+			if (m_threadSafeLoadLevel != null)
+			{
+				m_threadSafeLoadLevel.LoadLevel(m_NextLevel);
+			}
 		}
 	}
 
@@ -125,7 +135,10 @@ void OnGUI() {
 		getASpheroButtonY = backgroundY+(backgroundHeight*0.85f) - (buttonHeight/2);
 		// If the get a Sphero button is clicked
 		if( GUI.Button (new Rect(getASpheroButtonX, getASpheroButtonY,buttonWidth,buttonHeight), "") ) {
-			Application.LoadLevel("SpheroConnectionScene");
+			if (m_threadSafeLoadLevel != null)
+			{
+				m_threadSafeLoadLevel.LoadLevel("SpheroConnectionScene");
+			}
 		}
 #endif		
 	}

ExampleProject/SensorStreaming/Assets/Plugins/Sphero/SpheroConnectionView.cs

@@ -60,6 +60,8 @@ public class SpheroConnectionView : MonoBehaviour {
     Vector2 windowMargin = new Vector2(0,0);
     Vector2 listMargin = new Vector2(40,40);
     private Rect windowRect;
+
+	private ThreadSafeLoadLevel m_threadSafeLoadLevel;
 
 	/* Use this to initialize the view */
 	private void ViewSetup() {
@@ -72,6 +74,11 @@ private void ViewSetup() {
 			// Display that it doesn't work with these platforms?
 		#endif
 	}
+
+	void Awake()
+	{
+		m_threadSafeLoadLevel = ThreadSafeLoadLevel.Instance;
+	}
 
 	/* Use these for initialization */
 	void Start () {	
@@ -106,7 +113,10 @@ void SetupIOS() {
 	 */
 	void CheckForSpheroConnection() {
 		if( m_SpheroProvider.GetConnectedSpheros().Length == 0 ) {
-			Application.LoadLevel("NoSpheroConnectedScene");	
+			if (m_threadSafeLoadLevel != null)
+			{
+				m_threadSafeLoadLevel.LoadLevel("NoSpheroConnectedScene");
+			}
 		}
 	}
 
@@ -157,7 +167,10 @@ private void ReceiveNotificationMessage(object sender, SpheroDeviceMessenger.Mes
 			if( !m_MultipleSpheros ) {
 				m_Title = "Connection Success";
 				SpheroDeviceMessenger.SharedInstance.NotificationReceived -= ReceiveNotificationMessage;
-				Application.LoadLevel(m_NextLevel); 
+				if (m_threadSafeLoadLevel != null)
+				{
+					m_threadSafeLoadLevel.LoadLevel(m_NextLevel);
+				}
 			}
 		}
 		else if( message.NotificationType == SpheroDeviceNotification.SpheroNotificationType.CONNECTION_FAILED ) {
@@ -281,7 +294,10 @@ void OnGUI() {
 			// Check if we are done adding robots
 			if( buttonLabel.Equals("Done") ){
 				SpheroDeviceMessenger.SharedInstance.NotificationReceived -= ReceiveNotificationMessage;
-				Application.LoadLevel(m_NextLevel); 	
+				if (m_threadSafeLoadLevel != null)
+				{
+					m_threadSafeLoadLevel.LoadLevel(m_NextLevel);
+				}
 			}
 			// Check if we have a Sphero connected
 			else if( m_SpheroLabelSelected >= 0 ) {

ExampleProject/SensorStreaming/Assets/Plugins/Sphero/ThreadSafeLoadLevel.cs

@@ -0,0 +1,82 @@
+using System.Threading;
+using UnityEngine;
+
+/// <summary>
+/// The goal of this class is to let you load levels (from the Sphero callbacks) in a way that 
+/// doesn't try to make Unity calls on a thread other than the Unity thread. Unity takes issue with
+/// this and will throw a crashing-tantrum.
+/// </summary>
+public class ThreadSafeLoadLevel : MonoBehaviour
+{
+	#region Static instance management
+	/// <summary>
+	/// Static instance of this script
+	/// </summary>
+	private static ThreadSafeLoadLevel s_instance;
+
+	/// <summary>
+	/// No creating an instance after OnApplicationQuit is called - can get funky in the editor
+	/// </summary>
+	private static bool m_exiting;
+
+	/// <summary>
+	/// Gets the static instance of his script. This is *NOT* thread safe. Call it from Unity's
+	/// thread (creates a Unity object)
+	/// </summary>
+	public static ThreadSafeLoadLevel Instance
+	{
+		get
+		{
+			if (s_instance == null && !m_exiting)
+			{
+				var go = new GameObject("ThreadSafeLoadLevel");
+				s_instance = go.AddComponent<ThreadSafeLoadLevel>();
+			}
+			return s_instance;
+		}
+	}
+	#endregion
+
+	/// <summary>
+	/// An object to lock on
+	/// </summary>
+	private readonly Object m_lock = new Object();
+
+	/// <summary>
+	/// The level we want to load
+	/// </summary>
+	private string m_levelToLoad;
+
+	#region Unity-style callbacks
+	void Update()
+	{
+		// non-blocking lock acquire
+		if (Monitor.TryEnter(m_lock))
+		{
+			if (!string.IsNullOrEmpty(m_levelToLoad))
+			{
+				Application.LoadLevel(m_levelToLoad);
+			}
+
+			Monitor.Exit(m_lock);
+		}
+	}
+
+	void OnApplicationQuit()
+	{
+		m_exiting = true;
+	}
+	#endregion
+
+	/// <summary>
+	/// Loads the given level by name
+	/// </summary>
+	/// <param name="levelName">a level we wish to load</param>
+	public void LoadLevel(string levelName)
+	{
+		lock (m_lock)
+		{
+			m_levelToLoad = levelName;
+		}
+	}
+}