1 files changed, 617 insertions, 0 deletions

diff --git a/src/WixToolset.Data/Serialize/ElementCollection.cs b/src/WixToolset.Data/Serialize/ElementCollection.cs
new file mode 100644
index 00000000..1d64c5eb
--- /dev/null
+++ b/src/WixToolset.Data/Serialize/ElementCollection.cs
@@ -0,0 +1,617 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Data.Serialize
+{
+    using System;
+    using System.Collections;
+    using System.Globalization;
+
+    /// <summary>
+    /// Collection used in the CodeDOM for the children of a given element. Provides type-checking
+    /// on the allowed children to ensure that only allowed types are added.
+    /// </summary>
+    public class ElementCollection : ICollection, IEnumerable
+    {
+        private CollectionType collectionType;
+        private int totalContainedItems;
+        private int containersUsed;
+        private ArrayList items;
+
+        /// <summary>
+        /// Creates a new element collection.
+        /// </summary>
+        /// <param name="collectionType">Type of the collection to create.</param>
+        public ElementCollection(CollectionType collectionType)
+        {
+            this.collectionType = collectionType;
+            this.items = new ArrayList();
+        }
+
+        /// <summary>
+        /// Enum representing types of XML collections.
+        /// </summary>
+        public enum CollectionType
+        {
+            /// <summary>
+            /// A choice type, corresponding to the XSD choice element.
+            /// </summary>
+            Choice,
+
+            /// <summary>
+            /// A sequence type, corresponding to the XSD sequence element.
+            /// </summary>
+            Sequence
+        }
+
+        /// <summary>
+        /// Gets the type of collection.
+        /// </summary>
+        /// <value>The type of collection.</value>
+        public CollectionType Type
+        {
+            get { return this.collectionType; }
+        }
+
+        /// <summary>
+        /// Gets the count of child elements in this collection (counts ISchemaElements, not nested collections).
+        /// </summary>
+        /// <value>The count of child elements in this collection (counts ISchemaElements, not nested collections).</value>
+        public int Count
+        {
+            get { return this.totalContainedItems; }
+        }
+
+        /// <summary>
+        /// Gets the flag specifying whether this collection is synchronized. Always returns false.
+        /// </summary>
+        /// <value>The flag specifying whether this collection is synchronized. Always returns false.</value>
+        public bool IsSynchronized
+        {
+            get { return false; }
+        }
+
+        /// <summary>
+        /// Gets an object external callers can synchronize on.
+        /// </summary>
+        /// <value>An object external callers can synchronize on.</value>
+        public object SyncRoot
+        {
+            get { return this; }
+        }
+
+        /// <summary>
+        /// Adds a child element to this collection.
+        /// </summary>
+        /// <param name="element">The element to add.</param>
+        /// <exception cref="ArgumentException">Thrown if the child is not of an allowed type.</exception>
+        public void AddElement(ISchemaElement element)
+        {
+            foreach (object obj in this.items)
+            {
+                bool containerUsed;
+
+                CollectionItem collectionItem = obj as CollectionItem;
+                if (collectionItem != null)
+                {
+                    containerUsed = collectionItem.Elements.Count != 0;
+                    if (collectionItem.ElementType.IsAssignableFrom(element.GetType()))
+                    {
+                        collectionItem.AddElement(element);
+
+                        if (!containerUsed)
+                        {
+                            this.containersUsed++;
+                        }
+
+                        this.totalContainedItems++;
+                        return;
+                    }
+
+                    continue;
+                }
+
+                ElementCollection collection = obj as ElementCollection;
+                if (collection != null)
+                {
+                    containerUsed = collection.Count != 0;
+
+                    try
+                    {
+                        collection.AddElement(element);
+
+                        if (!containerUsed)
+                        {
+                            this.containersUsed++;
+                        }
+
+                        this.totalContainedItems++;
+                        return;
+                    }
+                    catch (ArgumentException)
+                    {
+                        // Eat the exception and keep looking. We'll throw our own if we can't find its home.
+                    }
+
+                    continue;
+                }
+            }
+
+            throw new ArgumentException(String.Format(
+                CultureInfo.InvariantCulture,
+                WixDataStrings.EXP_ElementOfTypeIsNotValidForThisCollection,
+                element.GetType().Name));
+        }
+
+        /// <summary>
+        /// Removes a child element from this collection.
+        /// </summary>
+        /// <param name="element">The element to remove.</param>
+        /// <exception cref="ArgumentException">Thrown if the element is not of an allowed type.</exception>
+        public void RemoveElement(ISchemaElement element)
+        {
+            foreach (object obj in this.items)
+            {
+                CollectionItem collectionItem = obj as CollectionItem;
+                if (collectionItem != null)
+                {
+                    if (collectionItem.ElementType.IsAssignableFrom(element.GetType()))
+                    {
+                        if (collectionItem.Elements.Count == 0)
+                        {
+                            return;
+                        }
+
+                        collectionItem.RemoveElement(element);
+
+                        if (collectionItem.Elements.Count == 0)
+                        {
+                            this.containersUsed--;
+                        }
+
+                        this.totalContainedItems--;
+                        return;
+                    }
+
+                    continue;
+                }
+
+                ElementCollection collection = obj as ElementCollection;
+                if (collection != null)
+                {
+                    if (collection.Count == 0)
+                    {
+                        continue;
+                    }
+
+                    try
+                    {
+                        collection.RemoveElement(element);
+
+                        if (collection.Count == 0)
+                        {
+                            this.containersUsed--;
+                        }
+
+                        this.totalContainedItems--;
+                        return;
+                    }
+                    catch (ArgumentException)
+                    {
+                        // Eat the exception and keep looking. We'll throw our own if we can't find its home.
+                    }
+
+                    continue;
+                }
+            }
+
+            throw new ArgumentException(String.Format(
+                CultureInfo.InvariantCulture,
+                WixDataStrings.EXP_ElementOfTypeIsNotValidForThisCollection,
+                element.GetType().Name));
+        }
+
+        /// <summary>
+        /// Copies this collection to an array.
+        /// </summary>
+        /// <param name="array">Array to copy to.</param>
+        /// <param name="index">Offset into the array.</param>
+        public void CopyTo(Array array, int index)
+        {
+            int item = 0;
+            foreach (ISchemaElement element in this)
+            {
+                array.SetValue(element, (long)(item + index));
+                item++;
+            }
+        }
+
+        /// <summary>
+        /// Creates an enumerator for walking the elements in this collection.
+        /// </summary>
+        /// <returns>A newly created enumerator.</returns>
+        public IEnumerator GetEnumerator()
+        {
+            return new ElementCollectionEnumerator(this);
+        }
+
+        /// <summary>
+        /// Gets an enumerable collection of children of a given type.
+        /// </summary>
+        /// <param name="childType">Type of children to get.</param>
+        /// <returns>A collection of children.</returns>
+        /// <exception cref="ArgumentException">Thrown if the type isn't a valid child type.</exception>
+        public IEnumerable Filter(Type childType)
+        {
+            foreach (object container in this.items)
+            {
+                CollectionItem collectionItem = container as CollectionItem;
+                if (collectionItem != null)
+                {
+                    if (collectionItem.ElementType.IsAssignableFrom(childType))
+                    {
+                        return collectionItem.Elements;
+                    }
+
+                    continue;
+                }
+
+                ElementCollection elementCollection = container as ElementCollection;
+                if (elementCollection != null)
+                {
+                    IEnumerable nestedFilter = elementCollection.Filter(childType);
+                    if (nestedFilter != null)
+                    {
+                        return nestedFilter;
+                    }
+
+                    continue;
+                }
+            }
+
+            throw new ArgumentException(String.Format(
+                CultureInfo.InvariantCulture,
+                WixDataStrings.EXP_TypeIsNotValidForThisCollection,
+                childType.Name));
+        }
+
+        /// <summary>
+        /// Adds a type to this collection.
+        /// </summary>
+        /// <param name="collectionItem">CollectionItem representing the type to add.</param>
+        public void AddItem(CollectionItem collectionItem)
+        {
+            this.items.Add(collectionItem);
+        }
+
+        /// <summary>
+        /// Adds a nested collection to this collection.
+        /// </summary>
+        /// <param name="collection">ElementCollection to add.</param>
+        public void AddCollection(ElementCollection collection)
+        {
+            this.items.Add(collection);
+        }
+
+        /// <summary>
+        /// Class used to represent a given type in the child collection of an element. Abstract,
+        /// has subclasses for choice and sequence (which can do cardinality checks).
+        /// </summary>
+        public abstract class CollectionItem
+        {
+            private Type elementType;
+            private ArrayList elements;
+
+            /// <summary>
+            /// Creates a new CollectionItem for the given element type.
+            /// </summary>
+            /// <param name="elementType">Type of the element for this collection item.</param>
+            protected CollectionItem(Type elementType)
+            {
+                this.elementType = elementType;
+                this.elements = new ArrayList();
+            }
+
+            /// <summary>
+            /// Gets the type of this collection's items.
+            /// </summary>
+            /// <value>The type of this collection's items.</value>
+            public Type ElementType
+            {
+                get { return this.elementType; }
+            }
+
+            /// <summary>
+            /// Gets the elements of this collection.
+            /// </summary>
+            /// <value>The elements of this collection.</value>
+            public ArrayList Elements
+            {
+                get { return this.elements; }
+            }
+
+            /// <summary>
+            /// Adds an element to this collection. Must be of an assignable type to the collection's
+            /// type.
+            /// </summary>
+            /// <param name="element">The element to add.</param>
+            /// <exception cref="ArgumentException">Thrown if the type isn't assignable to the collection's type.</exception>
+            public void AddElement(ISchemaElement element)
+            {
+                if (!this.elementType.IsAssignableFrom(element.GetType()))
+                {
+                    throw new ArgumentException(
+                        String.Format(
+                            CultureInfo.InvariantCulture,
+                            WixDataStrings.EXP_ElementIsSubclassOfDifferentType,
+                            this.elementType.Name,
+                            element.GetType().Name),
+                        "element");
+                }
+
+                this.elements.Add(element);
+            }
+
+            /// <summary>
+            /// Removes an element from this collection.
+            /// </summary>
+            /// <param name="element">The element to remove.</param>
+            /// <exception cref="ArgumentException">Thrown if the element's type isn't assignable to the collection's type.</exception>
+            public void RemoveElement(ISchemaElement element)
+            {
+                if (!this.elementType.IsAssignableFrom(element.GetType()))
+                {
+                    throw new ArgumentException(
+                        String.Format(
+                            CultureInfo.InvariantCulture,
+                            WixDataStrings.EXP_ElementIsSubclassOfDifferentType,
+                            this.elementType.Name,
+                            element.GetType().Name),
+                        "element");
+                }
+
+                this.elements.Remove(element);
+            }
+        }
+
+        /// <summary>
+        /// Class representing a choice item. Doesn't do cardinality checks.
+        /// </summary>
+        public class ChoiceItem : CollectionItem
+        {
+            /// <summary>
+            /// Creates a new choice item.
+            /// </summary>
+            /// <param name="elementType">Type of the created item.</param>
+            public ChoiceItem(Type elementType)
+                : base(elementType)
+            {
+            }
+        }
+
+        /// <summary>
+        /// Class representing a sequence item. Can do cardinality checks, if required.
+        /// </summary>
+        public class SequenceItem : CollectionItem
+        {
+            /// <summary>
+            /// Creates a new sequence item.
+            /// </summary>
+            /// <param name="elementType">Type of the created item.</param>
+            public SequenceItem(Type elementType)
+                : base(elementType)
+            {
+            }
+        }
+
+        /// <summary>
+        /// Enumerator for the ElementCollection.
+        /// </summary>
+        private class ElementCollectionEnumerator : IEnumerator
+        {
+            private ElementCollection collection;
+            private Stack collectionStack;
+
+            /// <summary>
+            /// Creates a new ElementCollectionEnumerator.
+            /// </summary>
+            /// <param name="collection">The collection to create an enumerator for.</param>
+            public ElementCollectionEnumerator(ElementCollection collection)
+            {
+                this.collection = collection;
+            }
+
+            /// <summary>
+            /// Gets the current object from the enumerator.
+            /// </summary>
+            public object Current
+            {
+                get
+                {
+                    if (this.collectionStack != null && this.collectionStack.Count > 0)
+                    {
+                        CollectionTuple tuple = (CollectionTuple)this.collectionStack.Peek();
+                        object container = tuple.Collection.items[tuple.ContainerIndex];
+
+                        CollectionItem collectionItem = container as CollectionItem;
+                        if (collectionItem != null)
+                        {
+                            return collectionItem.Elements[tuple.ItemIndex];
+                        }
+
+                        throw new InvalidOperationException(String.Format(
+                            CultureInfo.InvariantCulture,
+                            WixDataStrings.EXP_ElementMustBeChoiceItemOrSequenceItem,
+                            container.GetType().Name));
+                    }
+
+                    return null;
+                }
+            }
+
+            /// <summary>
+            /// Resets the enumerator to the beginning.
+            /// </summary>
+            public void Reset()
+            {
+                if (this.collectionStack != null)
+                {
+                    this.collectionStack.Clear();
+                    this.collectionStack = null;
+                }
+            }
+
+            /// <summary>
+            /// Moves the enumerator to the next item.
+            /// </summary>
+            /// <returns>True if there is a next item, false otherwise.</returns>
+            public bool MoveNext()
+            {
+                if (this.collectionStack == null)
+                {
+                    if (this.collection.Count == 0)
+                    {
+                        return false;
+                    }
+
+                    this.collectionStack = new Stack();
+                    this.collectionStack.Push(new CollectionTuple(this.collection));
+                }
+
+                CollectionTuple tuple = (CollectionTuple)this.collectionStack.Peek();
+
+                if (this.FindNext(tuple))
+                {
+                    return true;
+                }
+
+                this.collectionStack.Pop();
+                if (this.collectionStack.Count == 0)
+                {
+                    return false;
+                }
+
+                return this.MoveNext();
+            }
+
+            /// <summary>
+            /// Pushes a collection onto the stack.
+            /// </summary>
+            /// <param name="elementCollection">The collection to push.</param>
+            private void PushCollection(ElementCollection elementCollection)
+            {
+                if (elementCollection.Count <= 0)
+                {
+                    throw new ArgumentException(String.Format(
+                        CultureInfo.InvariantCulture,
+                        WixDataStrings.EXP_CollectionMustHaveAtLeastOneElement,
+                        elementCollection.Count));
+                }
+
+                CollectionTuple tuple = new CollectionTuple(elementCollection);
+                this.collectionStack.Push(tuple);
+                this.FindNext(tuple);
+            }
+
+            /// <summary>
+            /// Finds the next item from a given tuple.
+            /// </summary>
+            /// <param name="tuple">The tuple to start looking from.</param>
+            /// <returns>True if a next element is found, false otherwise.</returns>
+            private bool FindNext(CollectionTuple tuple)
+            {
+                object container = tuple.Collection.items[tuple.ContainerIndex];
+
+                CollectionItem collectionItem = container as CollectionItem;
+                if (collectionItem != null)
+                {
+                    if (tuple.ItemIndex + 1 < collectionItem.Elements.Count)
+                    {
+                        tuple.ItemIndex++;
+                        return true;
+                    }
+                }
+
+                ElementCollection elementCollection = container as ElementCollection;
+                if (elementCollection != null && elementCollection.Count > 0 && tuple.ItemIndex == -1)
+                {
+                    tuple.ItemIndex++;
+                    this.PushCollection(elementCollection);
+                    return true;
+                }
+
+                tuple.ItemIndex = 0;
+
+                for (int i = tuple.ContainerIndex + 1; i < tuple.Collection.items.Count; ++i)
+                {
+                    object nestedContainer = tuple.Collection.items[i];
+
+                    CollectionItem nestedCollectionItem = nestedContainer as CollectionItem;
+                    if (nestedCollectionItem != null)
+                    {
+                        if (nestedCollectionItem.Elements.Count > 0)
+                        {
+                            tuple.ContainerIndex = i;
+                            return true;
+                        }
+                    }
+
+                    ElementCollection nestedElementCollection = nestedContainer as ElementCollection;
+                    if (nestedElementCollection != null && nestedElementCollection.Count > 0)
+                    {
+                        tuple.ContainerIndex = i;
+                        this.PushCollection(nestedElementCollection);
+                        return true;
+                    }
+                }
+
+                return false;
+            }
+
+            /// <summary>
+            /// Class representing a single point in the collection. Consists of an ElementCollection,
+            /// a container index, and an index into the container.
+            /// </summary>
+            private class CollectionTuple
+            {
+                private ElementCollection collection;
+                private int containerIndex;
+                private int itemIndex = -1;
+
+                /// <summary>
+                /// Creates a new CollectionTuple.
+                /// </summary>
+                /// <param name="collection">The collection for the tuple.</param>
+                public CollectionTuple(ElementCollection collection)
+                {
+                    this.collection = collection;
+                }
+
+                /// <summary>
+                /// Gets the collection for the tuple.
+                /// </summary>
+                public ElementCollection Collection
+                {
+                    get { return this.collection; }
+                }
+
+                /// <summary>
+                /// Gets and sets the index of the container in the collection.
+                /// </summary>
+                public int ContainerIndex
+                {
+                    get { return this.containerIndex; }
+                    set { this.containerIndex = value; }
+                }
+
+                /// <summary>
+                /// Gets and sets the index of the item in the container.
+                /// </summary>
+                public int ItemIndex
+                {
+                    get { return this.itemIndex; }
+                    set { this.itemIndex = value; }
+                }
+            }
+        }
+    }
+}