TreeNodeCollection.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / xsp / System / Web / UI / WebControls / TreeNodeCollection.cs / 1 / TreeNodeCollection.cs
                        

                        
                            namespace System.Web.UI.WebControls { 
    using System;
    using System.Collections;
    using System.Collections.Generic;
    using System.ComponentModel; 
    using System.Globalization;
    using System.Text; 
    using System.Web.UI; 
    using System.Security.Permissions;
 

    [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)]
    public sealed class TreeNodeCollection : ICollection, IStateManager {
        private List _list; 
        private TreeNode _owner;
        private bool _updateParent; 
        private int _version; 

        private bool _isTrackingViewState; 

        private List _log;

 
        public TreeNodeCollection() : this(null, true) {
        } 
 

        public TreeNodeCollection(TreeNode owner) : this(owner, true) { 
        }

        internal TreeNodeCollection(TreeNode owner, bool updateParent) {
            _owner = owner; 
            _list = new List();
            _updateParent = updateParent; 
        } 

 
        public int Count {
            get {
                return _list.Count;
            } 
        }
 
 
        public bool IsSynchronized {
            get { 
                return ((ICollection)_list).IsSynchronized;
            }
        }
 
        private List Log {
            get { 
                if (_log == null) { 
                    _log = new List();
                } 
                return _log;
            }
        }
 

        public object SyncRoot { 
            get { 
                return ((ICollection)_list).SyncRoot;
            } 
        }


        public TreeNode this[int index] { 
            get {
                return _list[index]; 
            } 
        }
 

        public void Add(TreeNode child) {
            AddAt(Count, child);
        } 

 
        public void AddAt(int index, TreeNode child) { 
            if (child == null) {
                throw new ArgumentNullException("child"); 
            }

            if (_updateParent) {
                if (child.Owner != null && child.Parent == null) { 
                    child.Owner.Nodes.Remove(child);
                } 
                if (child.Parent != null) { 
                    child.Parent.ChildNodes.Remove(child);
                } 
                if (_owner != null) {
                    child.SetParent(_owner);
                    child.SetOwner(_owner.Owner);
                } 
            }
 
            _list.Insert(index, child); 
            _version++;
 
            if (_isTrackingViewState) {
                ((IStateManager)child).TrackViewState();
                child.SetDirty();
            } 
            Log.Add(new LogItem(LogItemType.Insert, index, _isTrackingViewState));
        } 
 

        public void Clear() { 
            if (this.Count == 0) return;
            if (_owner != null) {
                TreeView owner = _owner.Owner;
                if (owner != null) { 
                    // Clear checked nodes if necessary
                    if (owner.CheckedNodes.Count != 0) { 
                        owner.CheckedNodes.Clear(); 
                    }
                    TreeNode current = owner.SelectedNode; 
                    // Check if the selected item is under this collection
                    while (current != null) {
                        if (this.Contains(current)) {
                            owner.SetSelectedNode(null); 
                            break;
                        } 
                        current = current.Parent; 
                    }
                } 
            }
            foreach (TreeNode node in _list) {
                node.SetParent(null);
            } 

            _list.Clear(); 
            _version++; 
            if (_isTrackingViewState) {
                // Clearing invalidates all previous log entries, so we can just clear them out and save some space 
                Log.Clear();
            }
            Log.Add(new LogItem(LogItemType.Clear, 0, _isTrackingViewState));
        } 

 
        public void CopyTo(TreeNode[] nodeArray, int index) { 
            ((ICollection)this).CopyTo(nodeArray, index);
        } 


        public bool Contains(TreeNode c) {
            return _list.Contains(c); 
        }
 
        internal TreeNode FindNode(string[] path, int pos) { 
            if (pos == path.Length) {
                return _owner; 
            }

            string pathPart = TreeView.UnEscape(path[pos]);
            for (int i = 0; i < Count; i++) { 
                TreeNode node = this[i];
                if (node.Value == pathPart) { 
                    return node.ChildNodes.FindNode(path, pos + 1); 
                }
            } 

            return null;
        }
 

        public IEnumerator GetEnumerator() { 
            return new TreeNodeCollectionEnumerator(this); 
        }
 

        public int IndexOf(TreeNode value) {
            return _list.IndexOf(value);
        } 

 
        public void Remove(TreeNode value) { 
            if (value == null) {
                throw new ArgumentNullException("value"); 
            }

            int index = _list.IndexOf(value);
            if (index != -1) { 
                RemoveAt(index);
            } 
        } 

 
        public void RemoveAt(int index) {
            TreeNode node = _list[index];
            if (_updateParent) {
                TreeView owner = node.Owner; 
                if (owner != null) {
                    if (owner.CheckedNodes.Count != 0) { 
                        // We have to scan the whole tree of subnodes to remove any checked nodes 
                        // (and unselect the selected node if it is a descendant).
                        // That could badly hurt performance, except that removing a node is a pretty 
                        // exceptional event.
                        UnCheckUnSelectRecursive(node);
                    }
                    else { 
                        // otherwise, we can just climb the tree up from the selected node
                        // to see if it is a descendant of the removed node. 
                        TreeNode current = owner.SelectedNode; 
                        // Check if the selected item is under this collection
                        while (current != null) { 
                            if (current == node) {
                                owner.SetSelectedNode(null);
                                break;
                            } 
                            current = current.Parent;
                        } 
                    } 
                }
                node.SetParent(null); 
            }

            _list.RemoveAt(index);
            _version++; 
            Log.Add(new LogItem(LogItemType.Remove, index, _isTrackingViewState));
        } 
 
        internal void SetDirty() {
            foreach (LogItem item in Log) { 
                item.Tracked = true;
            }
            for (int i = 0; i < Count; i++) {
                this[i].SetDirty(); 
            }
        } 
 
        private static void UnCheckUnSelectRecursive(TreeNode node) {
            TreeNodeCollection checkedNodes = node.Owner.CheckedNodes; 
            if (node.Checked) {
                checkedNodes.Remove(node);
            }
            TreeNode selectedNode = node.Owner.SelectedNode; 
            if (node == selectedNode) {
                node.Owner.SetSelectedNode(null); 
                selectedNode = null; 
            }
            // Only recurse if there could be some more work to do 
            if (selectedNode != null || checkedNodes.Count != 0) {
                foreach (TreeNode child in node.ChildNodes) {
                    UnCheckUnSelectRecursive(child);
                } 
            }
        } 
 
        #region ICollection implementation
 
        void ICollection.CopyTo(Array array, int index) {
            if (!(array is TreeNode[])) {
                throw new ArgumentException(SR.GetString(SR.TreeNodeCollection_InvalidArrayType), "array");
            } 
            _list.CopyTo((TreeNode[])array, index);
        } 
        #endregion 

        #region IStateManager implementation 

        /// 
        bool IStateManager.IsTrackingViewState {
            get { 
                return _isTrackingViewState;
            } 
        } 

 
        /// 
        void IStateManager.LoadViewState(object state) {
            object[] nodeState = (object[])state;
            if (nodeState != null) { 
                if (nodeState[0] != null) {
                    string logString = (string)nodeState[0]; 
                    // Process each log entry 
                    string[] items = logString.Split(',');
                    for (int i = 0; i < items.Length; i++) { 
                        string[] parts = items[i].Split(':');
                        LogItemType type = (LogItemType)Int32.Parse(parts[0], CultureInfo.InvariantCulture);
                        int index = Int32.Parse(parts[1], CultureInfo.InvariantCulture);
 
                        if (type == LogItemType.Insert) {
                            if (_owner != null && _owner.Owner != null) { 
                                AddAt(index, _owner.Owner.CreateNode()); 
                            }
                            else { 
                                AddAt(index, new TreeNode());
                            }
                        }
                        else if (type == LogItemType.Remove) { 
                            RemoveAt(index);
                        } 
                        else if (type == LogItemType.Clear) { 
                            Clear();
                        } 
                    }
                }

                for (int i = 0; i < nodeState.Length - 1; i++) { 
                    if ((nodeState[i + 1] != null) && (this[i] != null)) {
                        ((IStateManager)this[i]).LoadViewState(nodeState[i + 1]); 
                    } 
                }
            } 
        }


        ///  
        object IStateManager.SaveViewState() {
            object[] nodes = new object[Count + 1]; 
 
            bool hasViewState = false;
 
            if ((_log != null) && (_log.Count > 0)) {
                // Construct a string representation of the log, delimiting entries with commas
                // and seperator command and index with a colon
                StringBuilder builder = new StringBuilder(); 
                int realLogCount = 0;
                for (int i = 0; i < _log.Count; i++) { 
                    LogItem item = _log[i]; 
                    if (item.Tracked) {
                        builder.Append((int)item.Type); 
                        builder.Append(":");
                        builder.Append(item.Index);
                        if (i < (_log.Count - 1)) {
                            builder.Append(","); 
                        }
 
                        realLogCount++; 
                    }
                } 

                if (realLogCount > 0) {
                    nodes[0] = builder.ToString();
                    hasViewState = true; 
                }
            } 
 
            for (int i = 0; i < Count; i++) {
                nodes[i + 1] = ((IStateManager)this[i]).SaveViewState(); 
                if (nodes[i + 1] != null) {
                    hasViewState = true;
                }
            } 

            return (hasViewState ? nodes : null); 
        } 

 
        /// 
        void IStateManager.TrackViewState() {
            _isTrackingViewState = true;
            for (int i = 0; i < Count; i++) { 
                ((IStateManager)this[i]).TrackViewState();
            } 
        } 
        #endregion
 
        /// 
        ///     Convenience class for storing and using log entries.
        /// 
        private class LogItem { 
            private LogItemType _type;
            private int _index; 
            private bool _tracked; 

            public LogItem(LogItemType type, int index, bool tracked) { 
                _type = type;
                _index = index;
                _tracked = tracked;
            } 

            public int Index { 
                get { 
                    return _index;
                } 
            }

            public bool Tracked {
                get { 
                    return _tracked;
                } 
                set { 
                    _tracked = value;
                } 
            }

            public LogItemType Type {
                get { 
                    return _type;
                } 
            } 

        } 

        /// 
        ///     Convenience enumeration for identifying log commands
        ///  
        private enum LogItemType {
            Insert = 0, 
            Remove = 1, 
            Clear = 2
        } 

        // This is a copy of the ArrayListEnumeratorSimple in ArrayList.cs
        private class TreeNodeCollectionEnumerator : IEnumerator {
            private TreeNodeCollection list; 
            private int index;
            private int version; 
            private TreeNode currentElement; 

            internal TreeNodeCollectionEnumerator(TreeNodeCollection list) { 
                this.list = list;
                this.index = -1;
                version = list._version;
            } 

            public bool MoveNext() { 
                if (version != list._version) 
                    throw new InvalidOperationException(SR.GetString(SR.ListEnumVersionMismatch));
 
                if (index < (list.Count - 1)) {
                    index++;
                    currentElement = list[index];
                    return true; 
                }
                else 
                    index = list.Count; 
                return false;
            } 

            object IEnumerator.Current {
                get {
                    return Current; 
                }
            } 
 
            public TreeNode Current {
                get { 
                    if (index == -1)
                        throw new InvalidOperationException(SR.GetString(SR.ListEnumCurrentOutOfRange));
                    if (index >= list.Count)
                        throw new InvalidOperationException(SR.GetString(SR.ListEnumCurrentOutOfRange)); 
                    return currentElement;
                } 
            } 

            public void Reset() { 
                if (version != list._version)
                    throw new InvalidOperationException(SR.GetString(SR.ListEnumVersionMismatch));
                currentElement = null;
                index = -1; 
            }
        } 
    } 
}

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