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//---------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
//---------------------------------------------------------------------------
using System;
using System.Windows;
namespace System.Windows.Controls
{
/// <summary>
/// This delegate is used by handlers of the ScrollChangedEvent event.
/// </summary>
/// <param name="sender">The current element along the event's route.</param>
/// <param name="e">The event arguments containing additional information about the event.</param>
/// <returns>Nothing.</returns>
public delegate void ScrollChangedEventHandler(object sender, ScrollChangedEventArgs e);
/// <summary>
/// The ScrollChangedEventsArgs describe a change in scrolling state.
/// </summary>
public class ScrollChangedEventArgs: RoutedEventArgs
{
//-------------------------------------------------------------------
//
// Constructors
//
//-------------------------------------------------------------------
#region Constructors
/// <summary>
/// Constructor
/// </summary>
internal ScrollChangedEventArgs(Vector offset, Vector offsetChange, Size extent, Vector extentChange, Size viewport, Vector viewportChange)
{
_offset = offset;
_offsetChange = offsetChange;
_extent = extent;
_extentChange = extentChange;
_viewport = viewport;
_viewportChange = viewportChange;
}
#endregion Constructors
//-------------------------------------------------------------------
//
// Public Properties (CLR + Avalon)
//
//-------------------------------------------------------------------
#region Public Properties
/// <summary>
/// Updated HorizontalPosition of the scrolled content
/// <seealso cref="System.Windows.Controls.ScrollViewer.HorizontalOffset"/>
/// </summary>
public double HorizontalOffset
{
get { return _offset.X; }
}
/// <summary>
/// Updated VerticalPosition of the scrolled content
/// <seealso cref="System.Windows.Controls.ScrollViewer.VerticalOffset"/>
/// </summary>
public double VerticalOffset
{
get { return _offset.Y; }
}
/// <summary>
/// Change in horizontal offset of the scrolled content
/// <seealso cref="System.Windows.Controls.ScrollViewer.HorizontalOffset"/>
/// </summary>
public double HorizontalChange
{
get { return _offsetChange.X; }
}
/// <summary>
/// Change in vertical offset of the scrolled content
/// <seealso cref="System.Windows.Controls.ScrollViewer.VerticalOffset"/>
/// </summary>
public double VerticalChange
{
get { return _offsetChange.Y; }
}
/// <summary>
/// Updated horizontal size of the viewing window of the ScrollViewer
/// <seealso cref="System.Windows.Controls.ScrollViewer.ViewportWidth"/>
/// </summary>
public double ViewportWidth
{
get { return _viewport.Width; }
}
/// <summary>
/// Updated vertical size of the viewing window of the ScrollViewer.
/// <seealso cref="System.Windows.Controls.ScrollViewer.ViewportHeight"/>
/// </summary>
public double ViewportHeight
{
get { return _viewport.Height; }
}
/// <summary>
/// Change in the horizontal size of the viewing window of the ScrollViewer
/// <seealso cref="System.Windows.Controls.ScrollViewer.ViewportWidth"/>
/// </summary>
public double ViewportWidthChange
{
get { return _viewportChange.X; }
}
/// <summary>
/// Change in the vertical size of the viewing window of the ScrollViewer.
/// <seealso cref="System.Windows.Controls.ScrollViewer.ViewportHeight"/>
/// </summary>
public double ViewportHeightChange
{
get { return _viewportChange.Y; }
}
/// <summary>
/// Updated horizontal size of the scrollable content.
/// <seealso cref="System.Windows.Controls.ScrollViewer.ExtentWidth"/>
/// </summary>
public double ExtentWidth
{
get { return _extent.Width; }
}
/// <summary>
/// Updated vertical size of the scrollable content.
/// <seealso cref="System.Windows.Controls.ScrollViewer.ExtentHeight"/>
/// </summary>
public double ExtentHeight
{
get { return _extent.Height; }
}
/// <summary>
/// Change in the horizontal size of the scrollable content.
/// <seealso cref="System.Windows.Controls.ScrollViewer.ExtentWidth"/>
/// </summary>
public double ExtentWidthChange
{
get { return _extentChange.X; }
}
/// <summary>
/// Change in the vertical size of the scrollable content.
/// <seealso cref="System.Windows.Controls.ScrollViewer.ExtentHeight"/>
/// </summary>
public double ExtentHeightChange
{
get { return _extentChange.Y; }
}
#endregion
//-------------------------------------------------------------------
//
// Protected Methods
//
//-------------------------------------------------------------------
#region Protected Methods
/// <summary>
/// This method is used to perform the proper type casting in order to
/// call the type-safe ScrollChangedEventHandler delegate for the ScrollChangedEvent event.
/// </summary>
/// <param name="genericHandler">The handler to invoke.</param>
/// <param name="genericTarget">The current object along the event's route.</param>
protected override void InvokeEventHandler(Delegate genericHandler, object genericTarget)
{
ScrollChangedEventHandler handler = (ScrollChangedEventHandler)genericHandler;
handler(genericTarget, this);
}
#endregion
//-------------------------------------------------------------------
//
// Private Fields
//
//-------------------------------------------------------------------
#region Private Fields
// Current scroll data
private Vector _offset;
private Vector _offsetChange;
private Size _extent;
private Vector _extentChange;
private Size _viewport;
private Vector _viewportChange;
#endregion
}
}
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