TextTreeExtractElementUndoUnit.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Framework / System / Windows / Documents / TextTreeExtractElementUndoUnit.cs / 1 / TextTreeExtractElementUndoUnit.cs
                        

                        
                            //---------------------------------------------------------------------------- 
//
// File: TextTreeExtractElementUndoUnit.cs
//
// Description: Undo unit for TextContainer.ExtractElement calls. 
//
// History: 
//  03/03/2004 : [....] - Created 
//
//--------------------------------------------------------------------------- 

using System;
using MS.Internal;
 
namespace System.Windows.Documents
{ 
    // Undo unit for TextContainer.ExtractElement calls. 
    internal class TextTreeExtractElementUndoUnit : TextTreeUndoUnit
    { 
        //-----------------------------------------------------
        //
        //  Constructors
        // 
        //-----------------------------------------------------
 
        #region Constructors 

        // Creates a new undo unit instance. 
        internal TextTreeExtractElementUndoUnit(TextContainer tree, TextTreeTextElementNode elementNode)
            : base(tree, elementNode.GetSymbolOffset(tree.Generation))
        {
            _symbolCount = elementNode.SymbolCount; 
            _type = elementNode.TextElement.GetType();
            _localValues = LocalValueEnumeratorToArray(elementNode.TextElement.GetLocalValueEnumerator()); 
            _resources = elementNode.TextElement.Resources; 

            // Table requires additional work for storing its Columns collection 
            if (elementNode.TextElement is Table)
            {
                _columns = TextTreeDeleteContentUndoUnit.SaveColumns((Table)elementNode.TextElement);
            } 
        }
 
        #endregion Constructors 

        //------------------------------------------------------ 
        //
        //  Public Methods
        //
        //----------------------------------------------------- 

        #region Public Methods 
 
        // Called by the undo manager.  Restores tree state to its condition
        // when the unit was created.  Assumes the tree state matches conditions 
        // just after the unit was created.
        public override void DoCore()
        {
            TextPointer start; 
            TextPointer end;
            TextElement element; 
 
            VerifyTreeContentHashCode();
 
            start = new TextPointer(this.TextContainer, this.SymbolOffset, LogicalDirection.Forward);
            end = new TextPointer(this.TextContainer, this.SymbolOffset + _symbolCount - 2, LogicalDirection.Forward);

            // Insert a new element. 
            element = (TextElement)Activator.CreateInstance(_type);
            element.Reposition(start, end); 
 
            // Restore local resources
            element.Resources = _resources; 

            // Move end into the scope of the new element.
            end.MoveToNextContextPosition(LogicalDirection.Backward);
            // Then restore local property values. 
            //
            this.TextContainer.SetValues(end, ArrayToLocalValueEnumerator(_localValues)); 
 
            if (element is Table)
            { 
                TextTreeDeleteContentUndoUnit.RestoreColumns((Table)element, _columns);
            }
        }
 
        #endregion Public Methods
 
        //------------------------------------------------------ 
        //
        //  Private Fields 
        //
        //------------------------------------------------------

        #region Private Fields 

        // Count of symbols covered by the extracted TextElement, including its 2 edges. 
        private readonly int _symbolCount; 

        // Type of the extracted TextElement. 
        private readonly Type _type;

        // Collection of all local property values set on the extracted TextElement.
        private readonly PropertyRecord []_localValues; 

        // Resources defined locally on the TextElement 
        private readonly ResourceDictionary _resources; 

        // TableColumns collection 
        private readonly TableColumn[] _columns;

        #endregion Private Fields
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK