Реорганизация интерфейса

Shift.Contains(ssCtrl)

keybd_event(VK_LCONTROL, // так зажимаем левый Ctrl
            0x1D,
            KEYEVENTF_EXTENDEDKEY | 0,
            0);
 
keybd_event(VK_LCONTROL, // так отжимаем левый Ctrl
            0x1D,
            KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,
            0);

//---------------------------------------------------------------------------
void __fastcall TForm1::DBGridMouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift,
          int X, int Y)
{
//if (Shift.Contains(ssRight))
// keybd_event( VK_LCONTROL,0x1D,KEYEVENTF_EXTENDEDKEY | 0,0 );
}
//---------------------------------------------------------------------------
void __fastcall TForm1::DBGridCellClick(TColumn *Column)
{
keybd_event( VK_LCONTROL,0x1D,KEYEVENTF_EXTENDEDKEY | 0,0 );
//keybd_event( VK_LCONTROL,0x1D,KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,0);
}
//---------------------------------------------------------------------------

void __fastcall TForm1::DBGridMouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift,
          int X, int Y)
{
  if (Button==mbLeft) {
    ShowMessage("Левая");
  }
  if (Button==mbRight) {
    ShowMessage("Правая");
  }
}

StringGrid->MouseToCell(X, Y, Col, Row);

DBGrid->MouseCoord(X,Y);

const WM_MOUSEMOVE = 0x200;
const WM_LBUTTONDOWN = 0x201; // Button down
const WM_LBUTTONUP = 0x202; // Button up
const WM_LBUTTONDBLCLK = 0x203; // Double-click
const WM_RBUTTONDOWN = 0x204; // Button down
const WM_RBUTTONUP = 0x205; // Button up
const WM_RBUTTONDBLCLK = 0x206; // Double-click
const WM_MBUTTONDOWN = 0x207; // Button down
const WM_MBUTTONUP = 0x208; // Button up
const WM_MBUTTONDBLCLK = 0x209; // Double-click

void TForm::MouseClick(TMessage &msg)
{
  switch (msg.Msg) {
    case WM_LBUTTONDOWN:
      //...
    break;
    case WM_RBUTTONDOWN:
      //...
    break;
    default:
    ;
  }
}