Re: passing this object

From:

olekk <sashakster@gmail.com>

Newsgroups:

comp.lang.c++.moderated

Date:

Fri, 28 Nov 2008 14:52:13 CST

Message-ID:

<a3620f64-bbd1-483a-871f-92a0da4b4153@k12g2000yqk.googlegroups.com>

Jung, William wrote:

I would like to pass "this" object to a constructor of socket class -
Sock which extends CSocketComm.

Once the socket class processed the data, the socket class use the
reference of CVirtualScreen (this object) - screen.setMessage function
to pass back the message to CVirtualScreen.

Is the following a correct syntax of implementing it?

should I involve reference / pointer in this case?

Please advice the incorrect area of the following code.

===================
class CVirtualScreen
{
public:
    CVirtualScreen();
    ~CVirtualScreen();
    Sock *sock;
}
===================
CVirtualScreen::CVirtualScreen()
{
    // QUESTION ///////////////////////////
    // IS IT CORRECT WAY OF PASSING
    // THIS OBJECT TO SOCKET CLASS??
    // SHOULD I USE & REFERENCE??
    // SHOULD I USE POINTER??
    sock = new Sock(this);
}

Good, but better use kind of smart_pointer for Sock. If only
VirtualScreen uses sock, then auto_ptr is good enough.

===================
class Sock : public CSocketComm
{
public:
Sock(CVirtualScreen screen);
~Sock();

// QUESTION ///////////////////////////
// DO I DECLARE REFERENCE TO CVirtuaqlScreen LIKE THIS WAY??
CVirtuaqlScreen screen;

private:
CVirtualScreen& screen_;

Also can be pointer, especially when you expect a state when Sock
object have no VirtualScreen assigned.

===================
Sock::Sock(CVirtualScreen screen)
{
    // QUESTION ///////////////////////////
    // CAN I SET REFERENCE TO CVirtualScreen LIKE THIS??
    // SHOULD I USE POINTER??
    screenObject = screen
    StartServer();
}

Use initialization list to initialize member object.
Sock::Sock(CVirtualScreen screen) : screen_ ( screen )
{
StartServer();
}

void Sock::OnDataReceived(const LPBYTE lpBuffer, DWORD dwCount)
{
    // do some stuff and output the std::string object
    std::string message = ... etc
    // QUESTION ///////////////////////////
    // ONCE SOCKET PROCESSED THE MESSAGE AND EXTRACT THE DATA
    // SOCKET WILL PASS THE MESSAGE BACK TO CVirtualScreen TO
    // INSERT MESSAGE INTO A MESSAGE QUEUE
    // IS THE FOLLOWING COORECT SYNTAX TO PASS MESSAGE BACK TO
    // CVirtualScreen CLASS??
    screen.setMessage ( message );
}

Looks ok to me

Regards

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