Merge pull request #76 from unity/collaboration-support-xcode12

Support multipeer connectivity in iOS 14

Assets/Scenes/ARCollaborationData/CollaborativeSession.cs

         /// </summary>
         public string serviceType
         {
-            get { return m_ServiceType; }
-            set { m_ServiceType = value; }
+            get => m_ServiceType;
+            set => m_ServiceType = value;
         }
 
         ARSession m_ARSession;
         }
     #endif
     }
-}
+}

Assets/Scenes/ARCollaborationData/Editor.meta

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Assets/Scenes/ARCollaborationData/Editor/CollaborationBuildPostprocessor.cs.meta

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Assets/Scenes/ARCollaborationData/Editor/CollaborationBuildPostprocessor.cs

+#if UNITY_IOS
+using System.Collections.Generic;
+using UnityEditor.Build;
+using UnityEditor.Build.Reporting;
+using UnityEditor.iOS.Xcode;
+using System.IO;
+using System.Linq;
+using UnityEditor.Callbacks;
+using UnityEngine;
+using UnityEngine.XR.ARFoundation.Samples;
+
+namespace UnityEditor.XR.ARFoundation.Samples
+{
+    /// <summary>
+    /// This build processor finds all <see cref="CollaborativeSession"/> components in the build and adds the
+    /// necessary plist entries according to https://developer.apple.com/documentation/multipeerconnectivity
+    /// </summary>
+    class CollaborationBuildProcessor : IPostprocessBuildWithReport, IPreprocessBuildWithReport
+    {
+        public int callbackOrder => 2;
+
+        void IPreprocessBuildWithReport.OnPreprocessBuild(BuildReport report)
+        {
+            s_CollaborativeSessions = new List<CollaborativeSession>();
+        }
+
+        static PlistElementArray GetOrCreatePlistElementArray(PlistElementDict dict, string key)
+        {
+            var element = dict[key];
+            return element == null ? dict.CreateArray(key) : element.AsArray();
+        }
+
+        /// <summary>
+        /// Adds necessary plist entries required by iOS 14+.
+        /// See https://developer.apple.com/documentation/multipeerconnectivity for details.
+        /// </summary>
+        /// <param name="report">The BuildReport provided by the post build process.</param>
+        void IPostprocessBuildWithReport.OnPostprocessBuild(BuildReport report)
+        {
+            if (report.summary.platform != BuildTarget.iOS)
+                return;
+
+            if (s_CollaborativeSessions.Count == 0)
+                return;
+
+            var plistPath = Path.Combine(report.summary.outputPath, "Info.plist");
+            var plist = new PlistDocument();
+            plist.ReadFromString(File.ReadAllText(plistPath));
+            var root = plist.root;
+
+            // The app requires permission from the user to use the local network
+            if (root["NSLocalNetworkUsageDescription"] == null)
+            {
+                // If no entry exists, then we will add one with the prompt "Collaborative Session"
+                root["NSLocalNetworkUsageDescription"] = new PlistElementString("Collaborative Session");
+            }
+
+            // Collect all the service names we need to add
+            var bonjourServices = GetOrCreatePlistElementArray(root, "NSBonjourServices");
+            var existingValues = new HashSet<string>(bonjourServices.values
+                .Where(value => value is PlistElementString)
+                .Select(value => value.AsString()));
+            var valuesToAdd = new HashSet<string>();
+
+            foreach (var serviceType in s_CollaborativeSessions
+                .Select(collaborativeSession => collaborativeSession.serviceType)
+                .Where(serviceType => !string.IsNullOrEmpty(serviceType)))
+            {
+                // Each "serviceType" must be registered as a Bonjour Service or the app will crash
+                // See https://developer.apple.com/documentation/bundleresources/information_property_list/nsbonjourservices
+                AddIfNecessary(existingValues, valuesToAdd, $"_{serviceType}._tcp");
+                AddIfNecessary(existingValues, valuesToAdd, $"_{serviceType}._udp");
+            }
+
+            foreach (var value in valuesToAdd)
+            {
+                bonjourServices.AddString(value);
+            }
+
+            File.WriteAllText(plistPath, plist.WriteToString());
+        }
+
+        static void AddIfNecessary(HashSet<string> existingValues, HashSet<string> valuesToAdd, string value)
+        {
+            if (!existingValues.Contains(value))
+                valuesToAdd.Add(value);
+        }
+
+        /// <summary>
+        /// Collects all CollaborativeSession components from each scene in the final build
+        /// </summary>
+        [PostProcessScene]
+        static void OnPostProcessScene()
+        {
+            foreach (var collaborativeSession in Object.FindObjectsOfType<CollaborativeSession>())
+            {
+                s_CollaborativeSessions.Add(collaborativeSession);
+            }
+        }
+
+        static List<CollaborativeSession> s_CollaborativeSessions = new List<CollaborativeSession>();
+    }
+}
+#endif