A question about a code

[Qiieha]

Hi,
I found this code at a linux program. It is a client - server application and this is a part of the client.
The communication is ssl encrypted.

Client::Client(QString host,long port,bool fs) 
{
   /*if(!serverConnection)*/ serverConnection = new QSslSocket(this);
 
   serverConnection -> setPeerVerifyMode(QSslSocket::QueryPeer);
   serverConnection -> setLocalCertificate("mycert.pem");
   serverConnection -> setPrivateKey("mycert.pem");
   serverConnection -> connectToHostEncrypted( host, port);
   peerPort = port;
   connected=0;
   fileSend=fs;
   connect(serverConnection, SIGNAL(encrypted()), SLOT(connectionAccepted()));  
   connect(serverConnection,SIGNAL(stateChanged(QAbstractSocket::SocketState)),this, SLOT(socketStateChanged(QAbstractSocket::SocketState)));
   connect(serverConnection, SIGNAL(readyRead()), this, SLOT(readDataFromServer()));    
   connect(serverConnection, SIGNAL(disconnected()), serverConnection, SLOT(deleteLater()));
   connect(serverConnection, SIGNAL(sslErrors(QList<QSslError>)),SLOT(sslErrors(QList<QSslError>)) );
}

Client::Client(QString host,long port,bool fs) 
{
   /*if(!serverConnection)*/ serverConnection = new QSslSocket(this);
     
   serverConnection -> setPeerVerifyMode(QSslSocket::QueryPeer);
   serverConnection -> setLocalCertificate("mycert.pem");
   serverConnection -> setPrivateKey("mycert.pem");
   serverConnection -> connectToHostEncrypted( host, port);
   peerPort = port;
   connected=0;
   fileSend=fs;
   connect(serverConnection, SIGNAL(encrypted()), SLOT(connectionAccepted()));  
   connect(serverConnection,SIGNAL(stateChanged(QAbstractSocket::SocketState)),this, SLOT(socketStateChanged(QAbstractSocket::SocketState)));
   connect(serverConnection, SIGNAL(readyRead()), this, SLOT(readDataFromServer()));    
   connect(serverConnection, SIGNAL(disconnected()), serverConnection, SLOT(deleteLater()));
   connect(serverConnection, SIGNAL(sslErrors(QList<QSslError>)),SLOT(sslErrors(QList<QSslError>)) );
}

To copy to clipboard, switch view to plain text mode 

The programmer calls serverConnection -> connectToHostEncrypted( host, port); and after that he connects the signal encrypted() to the slot connectionAccepted();
But it should be connected first, shouldn't it?

[wysota]

No, the signal won't be emitted before the control returns back to the event loop.

[Qiieha]

thank u for the reply!

[amleto]

but this is not the general case. If you call a method and something inside it emits synchronously before you have connected, oops, you missed the signal.

I believe it is better practice to connect before calling methods that can emit.

[wysota]

The thing is connectToHostEncrypted() doesn't emit. It schedules a connection attempt, just like QWidget::show() doesn't show anything but rather schedules showing the widget.