Implement Dispose pattern

Author: shana

src/GitHub.UI/Helpers/SharedDictionaryManager.cs

@@ -72,17 +72,6 @@ public CachingFactory()
                 disposables = new HashSet<IDisposable>();
             }
 
-            public void Dispose()
-            {
-                foreach (var disposable in disposables)
-                {
-                    disposable.Dispose();
-                }
-
-                disposables.Clear();
-                sharedDictionaries.Clear();
-            }
-
             public ResourceDictionary GetOrCreateResourceDictionary(ResourceDictionary owner, Uri uri)
             {
                 TryAddDisposable(owner);
@@ -106,6 +95,29 @@ public void TryAddDisposable(object owner)
                     disposables.Add(disposable);
                 }
             }
+
+            bool disposed;
+            void Dispose(bool disposing)
+            {
+                if (disposed) return;
+                if (disposing)
+                {
+                    disposed = true;
+                    foreach (var disposable in disposables)
+                    {
+                        disposable.Dispose();
+                    }
+
+                    disposables.Clear();
+                    sharedDictionaries.Clear();
+                }
+            }
+
+            public void Dispose()
+            {
+                Dispose(true);
+                GC.SuppressFinalize(this);
+            }
         }
 
         public static Uri FixDesignTimeUri(Uri inUri)

src/GitHub.VisualStudio.UI/Helpers/ThemeDictionaryManager.cs

@@ -7,7 +7,7 @@
 
 namespace GitHub.VisualStudio.UI.Helpers
 {
-    public sealed class ThemeDictionaryManager : SharedDictionaryManager, IDisposable
+    public class ThemeDictionaryManager : SharedDictionaryManager, IDisposable
     {
         static bool isInDesignMode;
         Uri baseThemeUri;
@@ -27,18 +27,6 @@ public override Uri Source
             }
         }
 
-        public void Dispose()
-        {
-            if (baseThemeUri != null)
-            {
-                baseThemeUri = null;
-                if (!isInDesignMode)
-                {
-                    VSColorTheme.ThemeChanged -= OnThemeChange;
-                }
-            }
-        }
-
         void InitTheme(Uri themeUri)
         {
             if (baseThemeUri == null)
@@ -66,5 +54,28 @@ Uri GetCurrentThemeUri()
             var currentTheme = Colors.DetectTheme();
             return new Uri(baseThemeUri, "Theme" + currentTheme + ".xaml");
         }
+
+        bool disposed;
+        private void Dispose(bool disposing)
+        {
+            if (disposed) return;
+            if (disposing)
+            {
+                disposed = true;
+                if (baseThemeUri != null)
+                {
+                    baseThemeUri = null;
+                    if (!isInDesignMode)
+                    {
+                        VSColorTheme.ThemeChanged -= OnThemeChange;
+                    }
+                }
+            }
+        }
+        public void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
     }
 }