From bd0f3345a938b35ce6a12f6150373b0955b8dd12 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Sun, 10 Jul 2011 15:24:15 -0500 Subject: Add Qt3 development HEAD version --- doc/html/clientserver-example.html | 352 +++++++++++++++++++++++++++++++++++++ 1 file changed, 352 insertions(+) create mode 100644 doc/html/clientserver-example.html (limited to 'doc/html/clientserver-example.html') diff --git a/doc/html/clientserver-example.html b/doc/html/clientserver-example.html new file mode 100644 index 0000000..b955a1e --- /dev/null +++ b/doc/html/clientserver-example.html @@ -0,0 +1,352 @@ + + + + + +A small client-server example + + + + + + + +

A small client-server example

+ + +

This example shows how two programs can communicate using sockets. +

Two simple example programs are provided, a client program and a +server program. Both use the QSocket class, and the server also uses +QServerSocket class. +

The server listens on port number 4242 and accepts incoming connections. +It sends back every line it receives from the client, prepended with +the line number. +

The client tries to connect to the server on the host specified on the +command line or to localhost if no command line arguments are +specified. You can send single lines to the server. +

Implementation server (server.cpp): +

/****************************************************************************
+** $Id: qt/server.cpp   3.3.8   edited Jan 11 14:37 $
+**
+** Copyright (C) 1992-2007 Trolltech ASA.  All rights reserved.
+**
+** This file is part of an example program for Qt.  This example
+** program may be used, distributed and modified without limitation.
+**
+*****************************************************************************/
+
+#include <qsocket.h>
+#include <qserversocket.h>
+#include <qapplication.h>
+#include <qvbox.h>
+#include <qtextview.h>
+#include <qlabel.h>
+#include <qpushbutton.h>
+#include <qtextstream.h>
+
+#include <stdlib.h>
+
+
+/*
+  The ClientSocket class provides a socket that is connected with a client.
+  For every client that connects to the server, the server creates a new
+  instance of this class.
+*/
+class ClientSocket : public QSocket
+{
+    Q_OBJECT
+public:
+    ClientSocket( int sock, QObject *parent=0, const char *name=0 ) :
+        QSocket( parent, name )
+    {
+        line = 0;
+        connect( this, SIGNAL(readyRead()),
+                SLOT(readClient()) );
+        connect( this, SIGNAL(connectionClosed()),
+                SLOT(deleteLater()) );
+        setSocket( sock );
+    }
+
+    ~ClientSocket()
+    {
+    }
+
+signals:
+    void logText( const QString& );
+
+private slots:
+    void readClient()
+    {
+        QTextStream ts( this );
+        while ( canReadLine() ) {
+            QString str = ts.readLine();
+            emit logText( tr("Read: '%1'\n").arg(str) );
+
+            ts << line << ": " << str << endl;
+            emit logText( tr("Wrote: '%1: %2'\n").arg(line).arg(str) );
+
+            line++;
+        }
+    }
+
+private:
+    int line;
+};
+
+
+/*
+  The SimpleServer class handles new connections to the server. For every
+  client that connects, it creates a new ClientSocket -- that instance is now
+  responsible for the communication with that client.
+*/
+class SimpleServer : public QServerSocket
+{
+    Q_OBJECT
+public:
+    SimpleServer( QObject* parent=0 ) :
+        QServerSocket( 4242, 1, parent )
+    {
+        if ( !ok() ) {
+            qWarning("Failed to bind to port 4242");
+            exit(1);
+        }
+    }
+
+    ~SimpleServer()
+    {
+    }
+
+    void newConnection( int socket )
+    {
+        ClientSocket *s = new ClientSocket( socket, this );
+        emit newConnect( s );
+    }
+
+signals:
+    void newConnect( ClientSocket* );
+};
+
+
+/*
+  The ServerInfo class provides a small GUI for the server. It also creates the
+  SimpleServer and as a result the server.
+*/
+class ServerInfo : public QVBox
+{
+    Q_OBJECT
+public:
+    ServerInfo()
+    {
+        SimpleServer *server = new SimpleServer( this );
+
+        QString itext = tr(
+                "This is a small server example.\n"
+                "Connect with the client now."
+                );
+        QLabel *lb = new QLabel( itext, this );
+        lb->setAlignment( AlignHCenter );
+        infoText = new QTextView( this );
+        QPushButton *quit = new QPushButton( tr("Quit") , this );
+
+        connect( server, SIGNAL(newConnect(ClientSocket*)),
+                SLOT(newConnect(ClientSocket*)) );
+        connect( quit, SIGNAL(clicked()), qApp,
+                SLOT(quit()) );
+    }
+
+    ~ServerInfo()
+    {
+    }
+
+private slots:
+    void newConnect( ClientSocket *s )
+    {
+        infoText->append( tr("New connection\n") );
+        connect( s, SIGNAL(logText(const QString&)),
+                infoText, SLOT(append(const QString&)) );
+        connect( s, SIGNAL(connectionClosed()),
+                SLOT(connectionClosed()) );
+    }
+
+    void connectionClosed()
+    {
+        infoText->append( tr("Client closed connection\n") );
+    }
+
+private:
+    QTextView *infoText;
+};
+
+
+int main( int argc, char** argv )
+{
+    QApplication app( argc, argv );
+    ServerInfo info;
+    app.setMainWidget( &info );
+    info.show();
+    return app.exec();
+}
+
+#include "server.moc"
+

+ +

Implementation client (client.cpp): +

/****************************************************************************
+** $Id: qt/client.cpp   3.3.8   edited Jan 11 14:37 $
+**
+** Copyright (C) 1992-2007 Trolltech ASA.  All rights reserved.
+**
+** This file is part of an example program for Qt.  This example
+** program may be used, distributed and modified without limitation.
+**
+*****************************************************************************/
+
+#include <qsocket.h>
+#include <qapplication.h>
+#include <qvbox.h>
+#include <qhbox.h>
+#include <qtextview.h>
+#include <qlineedit.h>
+#include <qlabel.h>
+#include <qpushbutton.h>
+#include <qtextstream.h>
+
+
+class Client : public QVBox
+{
+    Q_OBJECT
+public:
+    Client( const QString &host, Q_UINT16 port )
+    {
+        // GUI layout
+        infoText = new QTextView( this );
+        QHBox *hb = new QHBox( this );
+        inputText = new QLineEdit( hb );
+        QPushButton *send = new QPushButton( tr("Send") , hb );
+        QPushButton *close = new QPushButton( tr("Close connection") , this );
+        QPushButton *quit = new QPushButton( tr("Quit") , this );
+
+        connect( send, SIGNAL(clicked()), SLOT(sendToServer()) );
+        connect( close, SIGNAL(clicked()), SLOT(closeConnection()) );
+        connect( quit, SIGNAL(clicked()), qApp, SLOT(quit()) );
+
+        // create the socket and connect various of its signals
+        socket = new QSocket( this );
+        connect( socket, SIGNAL(connected()),
+                SLOT(socketConnected()) );
+        connect( socket, SIGNAL(connectionClosed()),
+                SLOT(socketConnectionClosed()) );
+        connect( socket, SIGNAL(readyRead()),
+                SLOT(socketReadyRead()) );
+        connect( socket, SIGNAL(error(int)),
+                SLOT(socketError(int)) );
+
+        // connect to the server
+        infoText->append( tr("Trying to connect to the server\n") );
+        socket->connectToHost( host, port );
+    }
+
+    ~Client()
+    {
+    }
+
+private slots:
+    void closeConnection()
+    {
+        socket->close();
+        if ( socket->state() == QSocket::Closing ) {
+            // We have a delayed close.
+            connect( socket, SIGNAL(delayedCloseFinished()),
+                    SLOT(socketClosed()) );
+        } else {
+            // The socket is closed.
+            socketClosed();
+        }
+    }
+
+    void sendToServer()
+    {
+        // write to the server
+        QTextStream os(socket);
+        os << inputText->text() << "\n";
+        inputText->setText( "" );
+    }
+
+    void socketReadyRead()
+    {
+        // read from the server
+        while ( socket->canReadLine() ) {
+            infoText->append( socket->readLine() );
+        }
+    }
+
+    void socketConnected()
+    {
+        infoText->append( tr("Connected to server\n") );
+    }
+
+    void socketConnectionClosed()
+    {
+        infoText->append( tr("Connection closed by the server\n") );
+    }
+
+    void socketClosed()
+    {
+        infoText->append( tr("Connection closed\n") );
+    }
+
+    void socketError( int e )
+    {
+        infoText->append( tr("Error number %1 occurred\n").arg(e) );
+    }
+
+private:
+    QSocket *socket;
+    QTextView *infoText;
+    QLineEdit *inputText;
+};
+
+
+int main( int argc, char** argv )
+{
+    QApplication app( argc, argv );
+    Client client( argc<2 ? "localhost" : argv[1], 4242 );
+    app.setMainWidget( &client );
+    client.show();
+    return app.exec();
+}
+
+#include "client.moc"
+

+ +