/// <summary>
/// Scroll a ScrollViewer vertically by a given offset.
///
/// </summary>
/// <param name="viewer">The ScrollViewer.</param><param name="offset">The vertical offset to scroll.</param>
private static void ScrollByVerticalOffset(ScrollViewer viewer, double offset)
{
Debug.Assert(viewer != null, "viewer should not be null!");
offset += viewer.VerticalOffset;
offset = ScrollViewerExtensions.CoerceVerticalOffset(viewer, offset);
viewer.ScrollToVerticalOffset(offset);
}
/// <summary>
/// Handles the mouse wheel event.
///
/// </summary>
/// <param name="sender">The ScrollViewer.</param><param name="e">Event arguments.</param>
private static void OnMouseWheel(object sender, MouseWheelEventArgs e)
{
ScrollViewer viewer = sender as ScrollViewer;
Debug.Assert(viewer != null, "sender should be a non-null ScrollViewer!");
Debug.Assert(e != null, "e should not be null!");
if (e.Handled)
{
return;
}
double offset = ScrollViewerExtensions.CoerceVerticalOffset(viewer, viewer.VerticalOffset - (double)e.Delta);
viewer.ScrollToVerticalOffset(offset);
e.Handled = true;
}
