System.Windows.Forms.HexBox.KeyInterpreter.PreProcessWmKeyDown_ShiftLeft C# (CSharp) Method

            protected virtual bool PreProcessWmKeyDown_ShiftLeft(ref Message m)
            {
                long pos = _hexBox._bytePos;
                long sel = _hexBox._selectionLength;

                if(pos + sel < 1)
                    return true;

                if(pos+sel <= _bpiStart.Index)
                {
                    if(pos == 0)
                        return true;

                    pos--;
                    sel++;
                }
                else
                {
                    sel = Math.Max(0, sel-1);
                }

                _hexBox.ScrollByteIntoView();
                _hexBox.InternalSelect(pos, sel);

                return true;
            }