DragStartingContext IDragDropElement.DragStarting(DragDropTrigger trigger, object initializeContext)
{
this.Opacity = 0;
DragStartingContext context = this.CreateDragContext();
this.Owner.DragBehavior.OnDragStarted(this);
this.Owner.CancelEdit();
this.Owner.ContentFlyout.Hide(DataGridFlyoutId.All);
this.IsSelected = false;
return(context);
}
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 && 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;
this.PrepareDragVisual(dragAction.Value);
}
}
else
{
isExecuted = this.ListView.commandService.ExecuteCommand(CommandId.ItemDragStarting, new ItemDragStartingContext(dataItem, DragAction.Reorder, this));
dragAction = DragAction.Reorder;
this.PrepareDragVisual(dragAction.Value);
}
if (isExecuted && dragAction.HasValue)
{
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);
context = new DragStartingContext
{
DragSurface = new CanvasDragSurface(this.ListView.childrenPanel, this.ListView.childrenPanel as Canvas, false),
DragVisual = this.dragVisual,
HitTestStrategy = new ListViewItemHittestStrategy(this, this),
Payload = DragAction.ItemAction
};
}
}
}
return(context);
}