internal void UpdateSource(IDragEventSource src)
{
if (src.Id != SourceId)
{
throw new InvalidOperationException("Cannot change the source id of pending drag operation");
}
_source = src;
(Position, Modifiers) = src.GetState();
}
internal DataPackageOperation Dropped(IDragEventSource src)
{
// For safety, we don't validate the FrameId for the finalizing actions, we rely only on the _state
if (_state >= State.Completing)
{
return(_acceptedOperation);
}
Update(src);
Enqueue(RaiseDrop);
return(_acceptedOperation);
}
private void Update(IDragEventSource src)
{
// As ugly as it is, it's the behavior of UWP, the CoreDragInfo is a mutable object!
Info.UpdateSource(src);
// Updates the view location to follow the pointer
// Note: This must be set AFTER the Info has been updated
_view.SetLocation(Info.Position);
// As we have multiple sources for the pointer events (capture of the dragged element and DragRoot),
// we make sure to not process the same event twice.
_lastFrameId = src.FrameId;
}
internal CoreDragInfo(
IDragEventSource source,
DataPackageView data,
DataPackageOperation allowedOperations,
object?dragUI = null)
{
_source = source;
(Position, Modifiers) = source.GetState();
Data = data;
AllowedOperations = allowedOperations;
DragUI = dragUI;
}
internal DataPackageOperation Moved(IDragEventSource src)
{
if (_state >= State.Completing || src.FrameId <= _lastFrameId)
{
return(_acceptedOperation);
}
var wasOverWindow = _isOverWindow;
_isOverWindow = Window.Current.Bounds.Contains(src.GetPosition(null));
Update(src); // It's required to do that as soon as possible in order to update the view's location
if (wasOverWindow && !_isOverWindow)
{
Enqueue(RaiseRecoverableLeave);
}
else
{
Enqueue(RaiseEnterOrOver, isIgnorable: _state == State.Over); // This is ignorable only if we already over
}
return(_acceptedOperation);
}
private DragOperation?FindOperation(IDragEventSource src) => _dragOperations.FirstOrDefault(drag => drag.Info.SourceId == src.Id);
public DataPackageOperation ProcessAborted(IDragEventSource src) => FindOperation(src)?.Aborted(src) ?? DataPackageOperation.None;
