MissionPlanner.GridUI.map_MouseDown C# (CSharp) Method

        private void map_MouseDown(object sender, MouseEventArgs e)
        {
            MouseDownStart = map.FromLocalToLatLng(e.X, e.Y);

            if (e.Button == MouseButtons.Left && Control.ModifierKeys != Keys.Alt)
            {
                isMouseDown = true;
                isMouseDraging = false;

                if (CurrentGMapMarkerStartPos != null)
                    CurrentGMapMarkerIndex = list.FindIndex(c => c.ToString() == CurrentGMapMarkerStartPos.ToString());
            }
        }