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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System.Collections.Specialized; // NotifyCollectionChangedEventArgs
using System.Collections.ObjectModel; // Collection, ReadOnlyCollection
namespace System.Windows.Controls
{
/// <summary>
/// Argument for GridViewColumnCollectionChanged event
/// </summary>
internal class GridViewColumnCollectionChangedEventArgs : NotifyCollectionChangedEventArgs
{
/// <summary>
/// constructor (for a property of one column changed)
/// </summary>
/// <param name="column">column whose property changed</param>
/// <param name="propertyName">Name of the changed property</param>
internal GridViewColumnCollectionChangedEventArgs(GridViewColumn column, string propertyName)
: base(NotifyCollectionChangedAction.Reset) // NotifyCollectionChangedEventArgs doesn't have 0 parameter constructor, so pass in an arbitrary parameter.
{
_column = column;
_propertyName = propertyName;
}
/// <summary>
/// constructor (for clear)
/// </summary>
/// <param name="action">must be NotifyCollectionChangedAction.Reset</param>
/// <param name="clearedColumns">Columns removed in reset action</param>
internal GridViewColumnCollectionChangedEventArgs(NotifyCollectionChangedAction action, GridViewColumn[] clearedColumns)
: base(action)
{
_clearedColumns = System.Array.AsReadOnly<GridViewColumn>(clearedColumns);
}
/// <summary>
/// Construct for one-column Add/Remove event.
/// </summary>
internal GridViewColumnCollectionChangedEventArgs(NotifyCollectionChangedAction action, GridViewColumn changedItem, int index, int actualIndex)
: base (action, changedItem, index)
{
Debug.Assert(action == NotifyCollectionChangedAction.Add || action == NotifyCollectionChangedAction.Remove,
"This constructor only supports Add/Remove action.");
Debug.Assert(changedItem != null, "changedItem can't be null");
Debug.Assert(index >= 0, "index must >= 0");
Debug.Assert(actualIndex >= 0, "actualIndex must >= 0");
_actualIndex = actualIndex;
}
/// <summary>
/// Construct for a one-column Replace event.
/// </summary>
internal GridViewColumnCollectionChangedEventArgs(NotifyCollectionChangedAction action, GridViewColumn newItem, GridViewColumn oldItem, int index, int actualIndex)
: base(action, newItem, oldItem, index)
{
Debug.Assert(newItem != null, "newItem can't be null");
Debug.Assert(oldItem != null, "oldItem can't be null");
Debug.Assert(index >= 0, "index must >= 0");
Debug.Assert(actualIndex >= 0, "actualIndex must >= 0");
_actualIndex = actualIndex;
}
/// <summary>
/// Construct for a one-column Move event.
/// </summary>
internal GridViewColumnCollectionChangedEventArgs(NotifyCollectionChangedAction action, GridViewColumn changedItem, int index, int oldIndex, int actualIndex)
: base(action, changedItem, index, oldIndex)
{
Debug.Assert(changedItem != null, "changedItem can't be null");
Debug.Assert(index >= 0, "index must >= 0");
Debug.Assert(oldIndex >= 0, "oldIndex must >= 0");
Debug.Assert(actualIndex >= 0, "actualIndex must >= 0");
_actualIndex = actualIndex;
}
/// <summary>
/// index of the changed column in the internal column list.
/// </summary>
internal int ActualIndex
{
get { return _actualIndex; }
}
private int _actualIndex = -1;
/// <summary>
/// Columns removed in reset action.
/// </summary>
internal ReadOnlyCollection<GridViewColumn> ClearedColumns
{
get { return _clearedColumns; }
}
private ReadOnlyCollection<GridViewColumn> _clearedColumns;
// The following two properties are used to store information of GridViewColumns.PropertyChanged event.
//
// GridViewColumnCollection hookup GridViewColumns.PropertyChanged event. When GridViewColumns.PropertyChanged
// event is raised, GridViewColumnCollection will raised CollectionChanged event with GridViewColumnCollectionChangedEventArgs.
// In the event arg the following two properties will be set, so GridViewRowPresenter will be informed.
//
// GridViewRowPresenter needn't hookup PropertyChanged event of each column, which cost a lot of time in scroll operation.
/// <summary>
/// Column whose property changed
/// </summary>
internal GridViewColumn Column
{
get { return _column; }
}
private GridViewColumn _column;
/// <summary>
/// Name of the changed property
/// </summary>
internal string PropertyName
{
get { return _propertyName; }
}
private string _propertyName;
}
} |