internal DragStartingContext InitializeReorder()
{
var dragVisual = this.ListView.DragBehavior.GetReorderVisual(this);
if (dragVisual == null)
{
this.dragVisual = this.ListView.GetContainerForItem();
this.dragVisual.Orientation = this.Orientation;
this.dragVisual.Width = this.ActualWidth;
this.dragVisual.Height = this.ActualHeight;
this.dragVisual.ListView = this.ListView;
this.dragVisual.isDragContent = true;
this.dragVisual.IsSelected = this.IsSelected;
this.ListView.PrepareContainerForItem(this.dragVisual, this.DataContext);
}
(dragVisual as IDragDropElement).SkipHitTest = true;
DragDrop.SetDragPositionMode(this, this.ListView.Orientation == Orientation.Vertical ? DragPositionMode.RailY : DragPositionMode.RailX);
this.Opacity = 0.0;
var surface = new CanvasDragSurface(this.ListView.childrenPanel as FrameworkElement, this.ListView.childrenPanel as Canvas, true);
var payload = new ReorderItemsDragOperation(this, this.DataContext);
this.ListView.DragBehavior.OnReorderStarted(this.DataContext);
return(new DragStartingContext {
DragVisual = dragVisual, Payload = payload, DragSurface = surface, HitTestStrategy = new ReorderListViewItemHitTestStrategy(this, surface.RootElement)
});
}
private object GetDestinationDataItem(ReorderItemsDragOperation data)
{
IEnumerable enumerableSource = this.ListView.ItemsSource as IEnumerable;
IEnumerator enumerator = enumerableSource.GetEnumerator();
int i = 0;
while (i++ <= data.CurrentSourceReorderIndex)
{
enumerator.MoveNext();
}
object destinationDataItem = enumerator.Current;
return(destinationDataItem);
}
private bool ShouldReorder(Point position, ReorderItemsDragOperation data)
{
if (this.reorderCoordinator == null)
{
return(false);
}
var sourceElement = this.reorderCoordinator.Host.ElementAt(data.CurrentSourceReorderIndex);
var startPosition = this.ListView.Orientation == Orientation.Horizontal ? position.X : position.Y;
var itemLength = this.ListView.Orientation == Orientation.Horizontal ? this.ActualWidth : this.ActualHeight;
bool draggingFromStart = startPosition >= itemLength / 2 + DragInitializer.DefaultStartTreshold && startPosition <= itemLength && this.logicalIndex > data.CurrentSourceReorderIndex;
bool draggingFromEnd = startPosition <= itemLength / 2 - DragInitializer.DefaultStartTreshold && startPosition >= 0 && this.logicalIndex < data.CurrentSourceReorderIndex;
bool canReorderColumn = sourceElement != null;
return(canReorderColumn && (draggingFromStart || draggingFromEnd));
}
private bool ShouldReorder(Point position, ReorderItemsDragOperation data)
{
if (this.reorderCoordinator == null || data.CurrentSourceReorderIndex == 0)
{
return(false);
}
var sourceElement = this.reorderCoordinator.Host.ElementAt(data.CurrentSourceReorderIndex);
if (sourceElement == null)
{
return(false);
}
var startPosition = this.Owner.Orientation == Orientation.Horizontal ? position.X : position.Y;
var itemLength = this.Owner.Orientation == Orientation.Horizontal ? this.ActualWidth : this.ActualHeight;
return((startPosition >= itemLength / 2 + DragInitializer.DefaultStartTreshold &&
startPosition <= itemLength && this.logicalIndex > data.CurrentSourceReorderIndex) ||
(startPosition <= itemLength / 2 - DragInitializer.DefaultStartTreshold &&
startPosition >= 0 && this.logicalIndex < data.CurrentSourceReorderIndex));
}
