private void ElementOnLostMouseCapture(object sender, MouseEventArgs mouseEventArgs)
{
_element.MouseMove -= ElementOnMouseMove;
_element.MouseUp -= ElementOnMouseUp;
_element.LostMouseCapture -= ElementOnLostMouseCapture;
if (_previewAdorner != null)
{
var relativePoint = _element.TranslatePoint(new Point(), _itemsControl);
var topAnimation = new DoubleAnimation {
To = relativePoint.Y, Duration = GetAnimationDuration(_itemsControl), EasingFunction = new PowerEase()
};
topAnimation.Completed +=
(o, args) =>
{
AdornerLayer.GetAdornerLayer(_itemsControl).Remove(_previewAdorner);
_previewAdorner = null;
_element.InvalidateProperty(UIElement.OpacityProperty);
_element = null;
};
_previewAdorner.BeginAnimation(PreviewAdorner.TopProperty, topAnimation);
}
if (_startIndex != _lastIndex)
{
_itemsControl.RaiseEvent(new RoutedPropertyChangedEventArgs <int>(_startIndex, _lastIndex, ReorderCompletedEvent));
}
}
private void ElementOnPreviewMouseDown(object sender, MouseEventArgs e)
{
if (!IsEnabled)
{
return;
}
_element = null;
var element = e.OriginalSource as UIElement;
if (element != null)
{
if (!GetIsElementDraggable(element))
{
return;
}
_element = _itemsControl.ContainerFromElement(element) as FrameworkElement;
}
if (_element == null)
{
return;
}
var isCaptured = _element.CaptureMouse();
if (isCaptured)
{
e.Handled = true;
_element.MouseMove += ElementOnMouseMove;
_element.MouseUp += ElementOnMouseUp;
_element.LostMouseCapture += ElementOnLostMouseCapture;
var sourceItem = _element.DataContext;
_startIndex = _collection.IndexOf(sourceItem);
_lastIndex = _startIndex;
var adornerLayer = AdornerLayer.GetAdornerLayer(_itemsControl);
if (adornerLayer != null)
{
_element.SetCurrentValue(UIElement.OpacityProperty, 0.0);
var firstChild = (FrameworkElement)VisualTreeHelper.GetChild(_element, 0);
var top = e.GetPosition(_itemsControl).Y;
_positionDelta = e.GetPosition(_element);
_previewAdorner = new PreviewAdorner(_itemsControl, firstChild)
{
Top = top - _positionDelta.Y
};
adornerLayer.Add(_previewAdorner);
}
}
}
private void ElementOnPreviewMouseDown(object sender, MouseEventArgs e)
{
if (!IsEnabled) return;
_element = null;
var element = e.OriginalSource as UIElement;
if (element != null)
{
if (!GetIsElementDraggable(element)) return;
_element = _itemsControl.ContainerFromElement(element) as FrameworkElement;
}
if (_element == null) return;
var isCaptured = _element.CaptureMouse();
if (isCaptured)
{
e.Handled = true;
_element.MouseMove += ElementOnMouseMove;
_element.MouseUp += ElementOnMouseUp;
_element.LostMouseCapture += ElementOnLostMouseCapture;
var sourceItem = _element.DataContext;
_startIndex = _collection.IndexOf(sourceItem);
_lastIndex = _startIndex;
var adornerLayer = AdornerLayer.GetAdornerLayer(_itemsControl);
if (adornerLayer != null)
{
_element.SetCurrentValue(UIElement.OpacityProperty, 0.0);
var firstChild = (FrameworkElement)VisualTreeHelper.GetChild(_element, 0);
var top = e.GetPosition(_itemsControl).Y;
_positionDelta = e.GetPosition(_element);
_previewAdorner = new PreviewAdorner(_itemsControl, firstChild)
{
Top = top - _positionDelta.Y
};
adornerLayer.Add(_previewAdorner);
}
}
}
private void ElementOnLostMouseCapture(object sender, MouseEventArgs mouseEventArgs)
{
_element.MouseMove -= ElementOnMouseMove;
_element.MouseUp -= ElementOnMouseUp;
_element.LostMouseCapture -= ElementOnLostMouseCapture;
if (_previewAdorner != null)
{
var relativePoint = _element.TranslatePoint(new Point(), _itemsControl);
var topAnimation = new DoubleAnimation { To = relativePoint.Y, Duration = GetAnimationDuration(_itemsControl), EasingFunction = new PowerEase() };
topAnimation.Completed +=
(o, args) =>
{
AdornerLayer.GetAdornerLayer(_itemsControl).Remove(_previewAdorner);
_previewAdorner = null;
_element.InvalidateProperty(UIElement.OpacityProperty);
_element = null;
};
_previewAdorner.BeginAnimation(PreviewAdorner.TopProperty, topAnimation);
}
if (_startIndex != _lastIndex)
{
_itemsControl.RaiseEvent(new RoutedPropertyChangedEventArgs<int>(_startIndex, _lastIndex, ReorderCompletedEvent));
}
}
