UnityEditor.SceneView.HandleDragging C# (CSharp) Method

        private void HandleDragging()
        {
            Event current = Event.current;
            switch (current.type)
            {
                case EventType.DragPerform:
                case EventType.DragUpdated:
                    this.CallEditorDragFunctions();
                    if (current.type != EventType.Used)
                    {
                        bool perform = current.type == EventType.DragPerform;
                        if (DragAndDrop.visualMode != DragAndDropVisualMode.Copy)
                        {
                            DragAndDrop.visualMode = InternalEditorUtility.SceneViewDrag(HandleUtility.PickGameObject(Event.current.mousePosition, true), this.pivot, Event.current.mousePosition, perform);
                        }
                        if (perform && (DragAndDrop.visualMode != DragAndDropVisualMode.None))
                        {
                            DragAndDrop.AcceptDrag();
                            current.Use();
                            GUIUtility.ExitGUI();
                        }
                        current.Use();
                    }
                    break;

                case EventType.DragExited:
                    this.CallEditorDragFunctions();
                    this.CleanupEditorDragFunctions();
                    break;
            }
        }