Cleaned up item filtering and some other small todos.

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/FeatureGAB.cs

@@ -321,24 +321,20 @@ namespace Acacia.Features.GAB
                         {
                             using (IFolder root = store.GetRootFolder())
                             {
-                                foreach (IFolder folder in root.GetSubFolders<IFolder>())
+                                foreach (IFolder folder in root.GetSubFolders<IFolder>().DisposeEnum())
                                 {
-                                    // TODO: let enumerator handle this
+                                    try
-                                    using (folder)
                                     {
-                                        try
+                                        if (IsGABContactsFolder(folder))
                                         {
-                                            if (IsGABContactsFolder(folder))
+                                            Logger.Instance.Debug(this, "FullResync: Deleting contacts folder: {0}", folder.Name);
-                                            {
+                                            folder.Delete();
-                                                Logger.Instance.Debug(this, "FullResync: Deleting contacts folder: {0}", folder.Name);
-                                                folder.Delete();
-                                            }
-                                        }
-                                        catch (System.Exception e)
-                                        {
-                                            Logger.Instance.Error(this, "FullResync: Exception deleting contacts folder: {0}", e);
                                         }
                                     }
+                                    catch (System.Exception e)
+                                    {
+                                        Logger.Instance.Error(this, "FullResync: Exception deleting contacts folder: {0}", e);
+                                    }
                                 }
                             }
                         }

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Features/GAB/GABHandler.cs

@@ -200,24 +200,21 @@ namespace Acacia.Features.GAB
                 return;
 
             // Process the messages
-            foreach (IItem item in Folder.Items)
+            foreach (IZPushItem item in Folder.Items.Typed<IZPushItem>())
             {
-                // TODO: make type-checking iterator?
+                // Store the entry id to fetch again later, the item will be disposed
-                if (item is IZPushItem)
+                string entryId = item.EntryID;
+                Logger.Instance.Trace(this, "Checking chunk: {0}", item.Subject);
+                if (_feature.ProcessItems2)
                 {
-                    string entryId = item.EntryID;
+                    Tasks.Task(_feature, "ProcessChunk", () =>
-                    Logger.Instance.Trace(this, "Checking chunk: {0}", item.Subject);
-                    if (_feature.ProcessItems2)
                     {
-                        Tasks.Task(_feature, "ProcessChunk", () =>
+                        using (IItem item2 = Folder.GetItemById(entryId))
                         {
-                            using (IItem item2 = Folder.GetItemById(entryId))
+                            if (item2 != null)
-                            {
+                                ProcessMessage((IZPushItem)item2);
-                                if (item2 != null)
+                        }
-                                    ProcessMessage((IZPushItem)item2);
+                    });
-                            }
-                        });
-                    }
                 }
             }
         }

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Stubs/IItems.cs

@@ -25,6 +25,12 @@ namespace Acacia.Stubs
         /// <returns>The current collection, which will be sorted</returns>
         IItems Sort(string field, bool descending);
 
+        /// <summary>
+        /// Filters the items for a specific type.
+        /// </summary>
+        /// <returns>An enumerable for items of the specified type.</returns>
+        IEnumerable<T> Typed<T>() where T : IItem;
+
         /// <summary>
         /// Returns an events subscribption object.
         /// </summary>

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Stubs/OutlookWrappers/AddressBookWrapper.cs

@@ -46,7 +46,7 @@ namespace Acacia.Stubs.OutlookWrappers
 
         public void Clear()
         {
-            foreach(dynamic item in _item.Items.RawEnum())
+            foreach(dynamic item in _item.Items.ComEnum())
             {
                 item.Delete();
             }

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Stubs/OutlookWrappers/FolderWrapper.cs

@@ -207,7 +207,7 @@ namespace Acacia.Stubs.OutlookWrappers
         where FolderType : IFolder
         {
             // Don't release the items, the wrapper manages them
-            foreach (NSOutlook.Folder folder in _item.Folders.RawEnum(false))
+            foreach (NSOutlook.Folder folder in _item.Folders.ComEnum(false))
             {
                 yield return folder.Wrap<FolderType>();
             };
@@ -228,7 +228,7 @@ namespace Acacia.Stubs.OutlookWrappers
             // to prevent exceptions in the log.
             // Don't release the items in RawEnum, they are release manually or handed to WrapFolders.
             NSOutlook.Folder sub = null;
-            foreach(NSOutlook.Folder folder in _item.Folders.RawEnum(false))
+            foreach(NSOutlook.Folder folder in _item.Folders.ComEnum(false))
             {
                 if (folder.Name == name)
                 {

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Stubs/OutlookWrappers/FoldersWrapper.cs

@@ -22,7 +22,7 @@ namespace Acacia.Stubs.OutlookWrappers
         public IEnumerator<IFolder> GetEnumerator()
         {
             // Don't release the items, the wrapper manages them
-            foreach (NSOutlook.Folder folder in _folder.RawItem.Folders.RawEnum(false))
+            foreach (NSOutlook.Folder folder in _folder.RawItem.Folders.ComEnum(false))
             {
                 yield return folder.Wrap<IFolder>();
             };
@@ -31,7 +31,7 @@ namespace Acacia.Stubs.OutlookWrappers
         IEnumerator IEnumerable.GetEnumerator()
         {
             // Don't release the items, the wrapper manages them
-            foreach (NSOutlook.Folder folder in _folder.RawItem.Folders.RawEnum(false))
+            foreach (NSOutlook.Folder folder in _folder.RawItem.Folders.ComEnum(false))
             {
                 yield return folder.Wrap<IFolder>();
             };

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Stubs/OutlookWrappers/ItemsWrapper.cs

@@ -13,6 +13,7 @@ namespace Acacia.Stubs.OutlookWrappers
     {
         // Managed by the caller, not released here
         private readonly FolderWrapper _folder;
+
         private string _field;
         private bool _descending;
 
@@ -28,6 +29,21 @@ namespace Acacia.Stubs.OutlookWrappers
             return this;
         }
 
+        public IEnumerable<T> Typed<T>() where T: IItem
+        {
+            foreach(IItem item in this)
+            {
+                if (typeof(T).IsInstanceOfType(item))
+                {
+                    yield return (T)item;
+                }
+                else
+                {
+                    item.Dispose();
+                }
+            }
+        }
+
         private NSOutlook.Items GetItems()
         {
             return _folder.RawItem.Items;
@@ -35,7 +51,7 @@ namespace Acacia.Stubs.OutlookWrappers
 
         public IEnumerator<IItem> GetEnumerator()
         {
-            return new ItemsEnumerator<IItem>(this, _field, _descending);
+            return new ItemsEnumerator<IItem>(this);
         }
 
         IEnumerator IEnumerable.GetEnumerator()
@@ -51,13 +67,15 @@ namespace Acacia.Stubs.OutlookWrappers
             private IEnumerator _enum;
             private ItemType _last;
 
-            public ItemsEnumerator(ItemsWrapper items, string field, bool descending) : base(items.GetItems())
+            public ItemsEnumerator(ItemsWrapper items) : base(items.GetItems())
             {
-                // TODO: can _items be released here already?
+                // Apply any sort options
-                if (field != null)
+                if (items._field != null)
                 {
-                    this._item.Sort("[" + field + "]", descending);
+                    this._item.Sort("[" + items._field + "]", items._descending);
                 }
+
+                // Get the enumerator
                 this._enum = _item.GetEnumerator();
             }
 

src/AcaciaZPushPlugin/AcaciaZPushPlugin/Utils/Util.cs

@@ -45,7 +45,15 @@ namespace Acacia.Utils
             return a.Equals(b);
         }
 
-        public static IEnumerable<T> RawEnum<T>(this IEnumerable<T> source, bool releaseItems = true)
+        #region Enumeration helpers
+
+        /// <summary>
+        /// Extension for a Com enumeration. Disposes the enumerated object and - optionally - the returned elements.
+        /// </summary>
+        /// <param name="source">The object to be enumerated. This will be released.</param>
+        /// <param name="releaseElements">If true (the default), elements will also be released.</param>
+        /// <returns></returns>
+        public static IEnumerable<T> ComEnum<T>(this IEnumerable<T> source, bool releaseElements = true)
         {
             foreach (T item in source)
             {
@@ -55,14 +63,20 @@ namespace Acacia.Utils
                 }
                 finally
                 {
-                    if (releaseItems)
+                    if (releaseElements)
                         ComRelease.Release(item);
                 }
             }
             ComRelease.Release(source);
         }
 
-        public static IEnumerable RawEnum(this IEnumerable source, bool releaseItems = true)
+        /// <summary>
+        /// Extension for a Com enumeration. Disposes the enumerated object and - optionally - the returned elements.
+        /// </summary>
+        /// <param name="source">The object to be enumerated. This will be released.</param>
+        /// <param name="releaseElements">If true (the default), elements will also be released.</param>
+        /// <returns></returns>
+        public static IEnumerable ComEnum(this IEnumerable source, bool releaseElements = true)
         {
             foreach (object item in source)
             {
@@ -72,13 +86,35 @@ namespace Acacia.Utils
                 }
                 finally
                 {
-                    if (releaseItems)
+                    if (releaseElements)
                         ComRelease.Release(item);
                 }
             }
             ComRelease.Release(source);
         }
 
+        /// <summary>
+        /// Helper for enumeration that disposes the returned items. Note that source will not be disposed,
+        /// as that is normally done by foreach.
+        /// </summary>
+        public static IEnumerable<T> DisposeEnum<T>(this IEnumerable<T> source)
+            where T : IDisposable
+        {
+            foreach (T item in source)
+            {
+                try
+                {
+                    yield return item;
+                }
+                finally
+                {
+                    item.Dispose();
+                }
+            }
+        }
+
+        #endregion
+
         public static void GarbageCollect()
         {
             for (int i = 0; i < 4; ++i)