PurplePen.RectangleSelectMode.LeftButtonDown C# (CSharp) Method

        public override MapViewer.DragAction LeftButtonDown(Pane pane, PointF location, float pixelSize, ref bool displayUpdateNeeded)
        {
            if (pane != Pane.Map)
                return MapViewer.DragAction.None;

            PointF handleLocation;

            // Area we initiating a drag of a corner/side?
            if (HitTestHandle(location, pixelSize, out handleLocation, out cursorDrag)) {
                // being dragging the corner
                draggingHandle = true;
                startDrag = location;
                handleDrag = handleLocation;
                dragStartCourseObj = (SelectingRectangleCourseObj) selectingCourseObj.Clone();
                displayUpdateNeeded = true;
                return MapViewer.DragAction.ImmediateDrag;
            }

            // Are we initiating a drag of the whole object?
            if (HitTestDraggable(location, pixelSize)) {
                // Begin dragging the clicked object.
                draggingWhole = true;
                startDrag = location;
                dragStartCourseObj = (SelectingRectangleCourseObj) selectingCourseObj.Clone();
                displayUpdateNeeded = true;
                return MapViewer.DragAction.ImmediateDrag;
            }

            return MapViewer.DragAction.None;
        }