[Core] Project model fixes

Don't automatically mark projects and solutions as shared after loading or
creating. Instead, SetShared() has to be called explicitly. The Ide calls
SetShared() on solutions opened in the workspace, so the result is more
or less the same.

Also added support for programatically attaching/detaching custom
extensions on projects and solutions.

1 files changed, 26 insertions, 20 deletions

diff --git a/main/src/core/MonoDevelop.Core/MonoDevelop.Projects/ExtensionChain.cs b/main/src/core/MonoDevelop.Core/MonoDevelop.Projects/ExtensionChain.cs
index 60eae48ceb..09fe6e5566 100644
--- a/main/src/core/MonoDevelop.Core/MonoDevelop.Projects/ExtensionChain.cs
+++ b/main/src/core/MonoDevelop.Core/MonoDevelop.Projects/ExtensionChain.cs
@@ -25,13 +25,14 @@
 // THE SOFTWARE.
 using System;
 using System.Collections.Generic;
+using System.Linq;
 
 namespace MonoDevelop.Projects
 {
 	public class ExtensionChain
 	{
-		ChainedExtension first;
 		Dictionary<Type,ChainedExtension> chains = new Dictionary<Type, ChainedExtension> ();
+		ChainedExtension[] extensions;
 
 		public static ExtensionChain Create<T> (T[] extensions) where T:ChainedExtension
 		{
@@ -40,7 +41,7 @@ namespace MonoDevelop.Projects
 			for (int n = extensions.Length - 2; n >= 0; n--)
 				extensions [n].InitChain (c, extensions [n + 1]);
 
-			c.first = extensions [0];
+			c.extensions = extensions;
 			return c;
 		}
 
@@ -49,7 +50,7 @@ namespace MonoDevelop.Projects
 			ChainedExtension e;
 			if (!chains.TryGetValue (typeof(T), out e)) {
 				e = new T ();
-				e.InitChain (this, ChainedExtension.FindNextImplementation<T> (first));
+				e.InitChain (this, ChainedExtension.FindNextImplementation<T> (extensions[0]));
 				chains [typeof(T)] = e;
 			}
 			return (T)e;
@@ -57,32 +58,37 @@ namespace MonoDevelop.Projects
 
 		public IEnumerable<ChainedExtension> GetAllExtensions ()
 		{
-			var e = first;
-			while (e != null) {
-				yield return e;
-				e = e.Next;
-			}
+			return extensions;
 		}
 
-		internal void DisposeExtension (ChainedExtension ext)
+		internal void AddExtension (ChainedExtension ext)
 		{
-			var e = first;
-			var extensions = new List<ChainedExtension> ();
-			while (e != null) {
-				if (e != ext)
-					extensions.Add (e);
-				e = e.Next;
-			}
-			for (int n = extensions.Count - 2; n >= 0; n--)
+			Array.Resize (ref extensions, extensions.Length + 1);
+			extensions [extensions.Length - 1] = ext;
+			Rechain ();
+		}
+
+		internal void RemoveExtension (ChainedExtension ext)
+		{
+			extensions = extensions.Where (e => e != ext).ToArray ();
+			Rechain ();
+		}
+
+		void Rechain ()
+		{
+			// Re-chain every extension
+			for (int n = extensions.Length - 2; n >= 0; n--)
 				extensions [n].InitChain (this, extensions [n + 1]);
-			first = extensions [0];
+			
+			// The first extension object in type-specific chains is a placeholder extension used only to hold
+			// a reference to the real first extension.
 			foreach (var fex in chains)
-				fex.Value.InitChain (this, ChainedExtension.FindNextImplementation (fex.Key, first));
+				fex.Value.InitChain (this, ChainedExtension.FindNextImplementation (fex.Key, extensions[0]));
 		}
 
 		public void Dispose ()
 		{
-			first.DisposeChain ();
+			extensions[0].DisposeChain ();
 		}
 	}
 }