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//---------------------------------------------------------------------------
//
// File: TextTreeExtractElementUndoUnit.cs
//
// Description: Undo unit for TextContainer.ExtractElement calls.
//
// History:
// 03/03/2004 : Microsoft - 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 = GetPropertyRecordArray(elementNode.TextElement);
_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
}
}
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