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//---------------------------------------------------------------------------
//
// <copyright file=”TextChangedEventArgs.cs” company=”Microsoft”>
// Copyright (C) Microsoft Corporation. All rights reserved.
// </copyright>
//
//
// Description: TextChanged event argument.
//
// History:
// 09/27/2004 : psarrett - Created
//
//---------------------------------------------------------------------------
using System.ComponentModel;
using System.Windows.Documents;
using System.Collections.Generic;
using System.Collections.ObjectModel;
namespace System.Windows.Controls
{
#region TextChangedEvent
/// <summary>
/// How the undo stack caused or is affected by a text change.
/// </summary>
public enum UndoAction
{
/// <summary>
/// This change will not affect the undo stack at all
/// </summary>
None = 0,
/// <summary>
/// This change will merge into the previous undo unit
/// </summary>
Merge = 1,
/// <summary>
/// This change is the result of a call to Undo()
/// </summary>
Undo = 2,
/// <summary>
/// This change is the result of a call to Redo()
/// </summary>
Redo = 3,
/// <summary>
/// This change will clear the undo stack
/// </summary>
Clear = 4,
/// <summary>
/// This change will create a new undo unit
/// </summary>
Create = 5
}
/// <summary>
/// The delegate to use for handlers that receive TextChangedEventArgs
/// </summary>
public delegate void TextChangedEventHandler(object sender, TextChangedEventArgs e);
/// <summary>
/// The TextChangedEventArgs class represents a type of RoutedEventArgs that
/// are relevant to events raised by changing editable text.
/// </summary>
public class TextChangedEventArgs : RoutedEventArgs
{
/// <summary>
/// constructor
/// </summary>
/// <param name="id">event id</param>
/// <param name="action">UndoAction</param>
/// <param name="changes">ReadOnlyCollection</param>
public TextChangedEventArgs(RoutedEvent id, UndoAction action, ICollection<TextChange> changes) : base()
{
if (id == null)
{
throw new ArgumentNullException("id");
}
if (action < UndoAction.None || action > UndoAction.Create)
{
throw new InvalidEnumArgumentException("action", (int)action, typeof(UndoAction));
}
RoutedEvent=id;
_undoAction = action;
_changes = changes;
}
/// <summary>
/// constructor
/// </summary>
/// <param name="id">event id</param>
/// <param name="action">UndoAction</param>
public TextChangedEventArgs(RoutedEvent id, UndoAction action)
: this(id, action, new ReadOnlyCollection<TextChange>(new List<TextChange>()))
{
}
/// <summary>
/// How the undo stack caused or is affected by this text change
/// </summary>
/// <value>UndoAction enum</value>
public UndoAction UndoAction
{
get
{
return _undoAction;
}
}
/// <summary>
/// A readonly list of TextChanges, sorted by offset in order from the beginning to the end of
/// the document, describing the dirty areas of the document and in what way(s) those
/// areas differ from the pre-change document. For example, if content at offset 0 was:
///
/// The quick brown fox jumps over the lazy dog.
///
/// and changed to:
///
/// The brown fox jumps over a dog.
///
/// Changes would contain two TextChanges with the following information:
///
/// Change 1
/// --------
/// Offset: 5
/// RemovedCount: 6
/// AddedCount: 0
/// PropertyCount: 0
///
/// Change 2
/// --------
/// Offset: 26
/// RemovedCount: 8
/// AddedCount: 1
/// PropertyCount: 0
///
/// If no changes were made, the collection will be empty.
/// </summary>
public ICollection<TextChange> Changes
{
get
{
return _changes;
}
}
/// <summary>
/// The mechanism used to call the type-specific handler on the
/// target.
/// </summary>
/// <param name="genericHandler">
/// The generic handler to call in a type-specific way.
/// </param>
/// <param name="genericTarget">
/// The target to call the handler on.
/// </param>
protected override void InvokeEventHandler(Delegate genericHandler, object genericTarget)
{
TextChangedEventHandler handler;
handler = (TextChangedEventHandler)genericHandler;
handler(genericTarget, this);
}
private UndoAction _undoAction;
private readonly ICollection<TextChange> _changes;
}
#endregion TextChangedEvent
}
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