/// <summary>
/// Occurs when the control handles a <see cref="ScrollViewer.ScrollChangedEvent"/> routed event.
/// </summary>
private static void HandleScrollChanged(DependencyObject dobj, ref ScrollChangedInfo scrollInfo, ref RoutedEventData data)
{
if (!MathUtil.IsApproximatelyZero(scrollInfo.ViewportHeightChange))
{
((TextBox)dobj).UpdateScrollViewerSize();
}
data.Handled = true;
}
/// <summary>
/// Retrieves an instance of the <see cref="ScrollChangedRoutedEventData"/> class from the global
/// pool and initializes it for use with a routed event handler.
/// </summary>
/// <param name="source">The object that raised the event.</param>
/// <param name="info">A <see cref="ScrollChangedInfo"/> which describes the change.</param>
/// <param name="handled">A value indicating whether the event has been handled.</param>
/// <param name="autorelease">A value indicating whether the data is automatically released
/// back to the global pool after it has been used by an event handler delegate.</param>
/// <returns>The <see cref="ScrollChangedRoutedEventData"/> instance that was retrieved.</returns>
public static ScrollChangedRoutedEventData Retrieve(Object source, ScrollChangedInfo info, Boolean handled = false, Boolean autorelease = true)
{
var data = default(ScrollChangedRoutedEventData);
lock (pool)
data = pool.Retrieve();
data.OnRetrieved(pool, source, handled, autorelease);
data.HorizontalOffset = info.HorizontalOffset;
data.HorizontalChange = info.HorizontalChange;
data.VerticalOffset = info.VerticalOffset;
data.VerticalChange = info.VerticalChange;
data.ExtentWidth = info.ExtentWidth;
data.ExtentWidthChange = info.ExtentWidthChange;
data.ExtentHeight = info.ExtentHeight;
data.ExtentHeightChange = info.ExtentHeightChange;
data.ViewportWidth = info.ViewportWidth;
data.ViewportWidthChange = info.ViewportWidthChange;
data.ViewportHeight = info.ViewportHeight;
data.ViewportHeightChange = info.ViewportHeightChange;
return(data);
}
/// <summary>
/// Retrieves an instance of the <see cref="ScrollChangedRoutedEventData"/> class from the global
/// pool and initializes it for use with a routed event handler.
/// </summary>
/// <param name="source">The object that raised the event.</param>
/// <param name="info">A <see cref="ScrollChangedInfo"/> which describes the change.</param>
/// <param name="handled">A value indicating whether the event has been handled.</param>
/// <param name="autorelease">A value indicating whether the data is automatically released
/// back to the global pool after it has been used by an event handler delegate.</param>
/// <returns>The <see cref="ScrollChangedRoutedEventData"/> instance that was retrieved.</returns>
public static ScrollChangedRoutedEventData Retrieve(DependencyObject source, ScrollChangedInfo info, Boolean handled = false, Boolean autorelease = true)
{
var data = default(ScrollChangedRoutedEventData);
lock (pool)
data = pool.Retrieve();
data.OnRetrieved(pool, source, handled, autorelease);
data.HorizontalOffset = info.HorizontalOffset;
data.HorizontalChange = info.HorizontalChange;
data.VerticalOffset = info.VerticalOffset;
data.VerticalChange = info.VerticalChange;
data.ExtentWidth = info.ExtentWidth;
data.ExtentWidthChange = info.ExtentWidthChange;
data.ExtentHeight = info.ExtentHeight;
data.ExtentHeightChange = info.ExtentHeightChange;
data.ViewportWidth = info.ViewportWidth;
data.ViewportWidthChange = info.ViewportWidthChange;
data.ViewportHeight = info.ViewportHeight;
data.ViewportHeightChange = info.ViewportHeightChange;
return data;
}
/// <inheritdoc/>
protected override void PositionOverride()
{
if (PART_ContentPresenter != null)
PART_ContentPresenter.PositionChildren();
var newHorizontalOffset = HorizontalOffset;
var newVerticalOffset = VerticalOffset;
var newExtentWidth = ExtentWidth;
var newExtentHeight = ExtentHeight;
var newViewportWidth = ViewportWidth;
var newViewportHeight = ViewportHeight;
var scrollChanged =
!MathUtil.AreApproximatelyEqual(oldHorizontalOffset, newHorizontalOffset) ||
!MathUtil.AreApproximatelyEqual(oldVerticalOffset, newVerticalOffset) ||
!MathUtil.AreApproximatelyEqual(oldExtentWidth, newExtentWidth) ||
!MathUtil.AreApproximatelyEqual(oldExtentHeight, newExtentHeight) ||
!MathUtil.AreApproximatelyEqual(oldViewportWidth, newViewportWidth) ||
!MathUtil.AreApproximatelyEqual(oldViewportHeight, newViewportHeight);
if (scrollChanged)
{
var evtDelegate = EventManager.GetInvocationDelegate<UpfScrollChangedEventHandler>(ScrollChangedEvent);
var evtData = new RoutedEventData(this);
var scrollInfo = new ScrollChangedInfo(
newHorizontalOffset, newHorizontalOffset - oldHorizontalOffset,
newVerticalOffset, newVerticalOffset - oldVerticalOffset,
newExtentWidth, newExtentWidth - oldExtentWidth,
newExtentHeight, newExtentHeight - oldExtentHeight,
newViewportWidth, newViewportWidth - oldViewportWidth,
newViewportHeight, newViewportHeight - oldViewportHeight);
oldHorizontalOffset = newHorizontalOffset;
oldVerticalOffset = newVerticalOffset;
oldExtentWidth = newExtentWidth;
oldExtentHeight = newExtentHeight;
oldViewportWidth = newViewportWidth;
oldViewportHeight = newViewportHeight;
evtDelegate(this, ref scrollInfo, ref evtData);
}
base.PositionOverride();
}
