ICSharpCode.WpfDesign.Designer.Controls.DragListener.Target_MouseMove C# (CSharp) Method

        void Target_MouseMove(object sender, MouseEventArgs e)
        {
            if (IsDown) {
                DeltaDelta = e.GetPosition(null) - CurrentPoint;
                CurrentPoint += DeltaDelta;

                if (!IsActive) {
                    if (Math.Abs(Delta.X) >= SystemParameters.MinimumHorizontalDragDistance ||
                        Math.Abs(Delta.Y) >= SystemParameters.MinimumVerticalDragDistance) {
                        IsActive = true;
                        CurrentListener = this;

                        if (Started != null) {
                            Started(this);
                        }
                    }
                }

                if (IsActive && Changed != null) {
                    Changed(this);
                }
            }
        }