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)
});
}
DragStartingContext IDragDropElement.DragStarting(DragDropTrigger trigger, object initializeContext)
{
this.ListView.CleanupSwipedItem();
DragStartingContext context = null;
var dataItem = this.DataContext;
if (dataItem != null)
{
bool isExecuted = false;
DragAction?dragAction = null;
if (trigger == DragDropTrigger.Drag && (!this.isHandleEnabled || initializeContext != this.reorderHandle))
{
if (this.ListView.LayoutDefinition is StackLayoutDefinition)
{
if (this.Owner.Orientation == Orientation.Horizontal)
{
if (this.SwipeDirection == ListViewItemSwipeDirection.Forward)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailYForward);
}
else if (this.SwipeDirection == ListViewItemSwipeDirection.Backwards)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailYBackwards);
}
else if (this.SwipeDirection == ListViewItemSwipeDirection.All)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailY);
}
}
else
{
if (this.SwipeDirection == ListViewItemSwipeDirection.Forward)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailXForward);
}
else if (this.SwipeDirection == ListViewItemSwipeDirection.Backwards)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailXBackwards);
}
else if (this.SwipeDirection == ListViewItemSwipeDirection.All)
{
DragDrop.SetDragPositionMode(this, DragPositionMode.RailX);
}
}
isExecuted = this.ListView.commandService.ExecuteCommand(CommandId.ItemDragStarting, new ItemDragStartingContext(dataItem, DragAction.ItemAction, this));
dragAction = DragAction.ItemAction;
}
}
else
{
isExecuted = this.ListView.commandService.ExecuteCommand(CommandId.ItemDragStarting, new ItemDragStartingContext(dataItem, DragAction.Reorder, this));
dragAction = DragAction.Reorder;
}
if (isExecuted && dragAction.HasValue)
{
this.PrepareDragVisual(dragAction.Value);
this.CancelDirectManipulations();
if (dragAction.Value == DragAction.Reorder)
{
context = this.InitializeReorder();
}
else if (dragAction.Value == DragAction.ItemAction)
{
// We might need to cancel manipulations on the dragvisual
//// this.dragVisual.CancelDirectManipulations();
this.UpdateActionContentClipping(0);
CanvasDragSurface dragSurface = new CanvasDragSurface(this.ListView.childrenPanel, this.ListView.childrenPanel as Canvas, false);
dragSurface.MaxPositionOffset = this.listView.ItemSwipeOffset;
context = new DragStartingContext
{
DragSurface = dragSurface,
DragVisual = this.dragVisual,
HitTestStrategy = new ListViewItemHittestStrategy(this, this),
Payload = DragAction.ItemAction
};
}
}
}
return(context);
}
