Emit not fire when client connected to server.

MhM93

So silly Question , but I have a server program . when I telnet to my app in command Ubuntu terminal I can see Hello message from my app(server) . I write emit in my code but it does not fire. WHY?!!
this is my codes:
main.cpp:

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include "socketserver.h"

int main(int argc, char *argv[])
{

    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    qmlRegisterType<SocketServer>("SocketServer",1,0,"SocketServer");

    const QUrl url(QStringLiteral("qrc:/main.qml"));
    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                     &app, [url](QObject *obj, const QUrl &objUrl) {
        if (!obj && url == objUrl)
            QCoreApplication::exit(-1);
    }, Qt::QueuedConnection);
    engine.load(url);


    SocketServer svr;
    svr.connections();

    return app.exec();
}

SocketServer.h :

#ifndef SOCKETSERVER_H
#define SOCKETSERVER_H

#include <QObject>
#include <QDebug>
#include <QTcpServer>
#include <QTcpSocket>

class SocketServer : public QObject
{
    Q_OBJECT
    QString m_readst;

    bool m_cnn;

public:
    explicit SocketServer(QObject *parent = nullptr);

    QTcpServer *server;
    QTcpSocket *socket;
    Q_PROPERTY(bool cnn READ cnn WRITE setCnn NOTIFY cnnChanged)
    Q_PROPERTY(QString readst READ readst WRITE setReadst NOTIFY readstChanged)

    QString readst() const;

    bool cnn() const;

signals:
    void isConnected();
    void Connected();

    void readstChanged(QString readst);

    void cnnChanged(bool cnn);

public slots:
    void connections();
    void connectionNew();
    void readServer();
    void setReadst(QString readst);
    void setCnn(bool cnn);
    void test();
};

#endif // SOCKETSERVER_H

SocketServer.cpp :

#include "socketserver.h"

SocketServer::SocketServer(QObject *parent) : QObject(parent)
{

}

QString SocketServer::readst() const
{
    return m_readst;
}

bool SocketServer::cnn() const
{
    return m_cnn;
}

void SocketServer::connections()
{
    server=new QTcpServer(this);
    connect(server,&QTcpServer::newConnection,
            this,&SocketServer::connectionNew,Qt::UniqueConnection);
//    connect(this,&SocketServer::Connected,
//            this,&SocketServer::test);
    if(!server->listen(QHostAddress::Any,1234))
    {

    }
    else {
        qDebug()<<"connected";
        

    }
}

void SocketServer::connectionNew()
{
    //setCnn(true);
    socket=server->nextPendingConnection();
    connect(socket,SIGNAL(readyRead()),
            this,SLOT(readServer()));
    socket->write("Hello\r\n");
    //socket->waitForBytesWritten(2000);

    emit isConnected();
}

void SocketServer::readServer()
{
    setReadst(socket->readAll());
}

void SocketServer::setReadst(QString readst)
{
    if (m_readst == readst)
        return;

    m_readst = readst;
    emit readstChanged(m_readst);
}

void SocketServer::setCnn(bool cnn)
{
    if (m_cnn == cnn)
        return;

    m_cnn = cnn;
    emit cnnChanged(m_cnn);
}

void SocketServer::test()
{
    emit isConnected();
}

and the last one is main.qml :

import QtQuick 2.12
import QtQuick.Controls 2.5
import QtQuick.Window 2.12
import SocketServer 1.0

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
    SocketServer{
        id:myserver
        onIsConnected:{
            lbl.text="Connected"
        }
    }
//    Component.onCompleted:
//    {
//        myserver.connections();
//    }
    Item {
        id: name
        Connections{
            target: myserver
            onCnnChanged:
            {
                if(cnn)
                    lbl.text="Connected"
                else
                    lbl.text="Disconnected"
            }
        }
    }

    Rectangle{
        anchors.fill: parent
        Column{
            width: parent.width
            height: parent.height
            Rectangle
            {
//                color: "pink"
                width: parent.width
                height: 30
                Label
                {
                    id:lbl
                    text:"here"
                }

            }
            Rectangle
            {
//                color: "green"
                border.width: 1
                border.color: "gray"
                width: parent.width
                height: 200
                Text{
                    id:txtrec
                    width: parent.width
                    height: parent.height
                }
            }
            Rectangle
            {
//                color: "red"
                border.width: 1
                border.color: "gray"
                width: parent.width
                height: 50
                TextEdit{
                    id:txtsnd
                    width: parent.width
                    height: parent.height
                }
            }
            Button
            {
                width: parent.width
                height: 50
                text: "SEND"
                onClicked: {myserver.test();}

            }
        }
    }
}

when I click the send button , emit is worked corect, but when I connet to my app ,emit not fire.![this image:]( image url)

Christian Ehrlicher

@MhM93 said in Emit not fire when client connected to server.:

I connet to my app ,emit not fire.!

How do you know that it is not fired? Where do you show it? At least not in the code you posted.

MhM93

@MhM93 said in Emit not fire when client connected to server.:

SocketServer{
id:myserver
onIsConnected:{
lbl.text="Connected"
}
}

its in main.qml:

SocketServer{
        id:myserver
        onIsConnected:{//<------------here 
            lbl.text="Connected"
        }
    }

Christian Ehrlicher

@MhM93 said in Emit not fire when client connected to server.:

onIsConnected

And where do you emit this signal?

MhM93

@MhM93 said in Emit not fire when client connected to server.:

void SocketServer::connectionNew()
{
//setCnn(true);
socket=server->nextPendingConnection();
connect(socket,SIGNAL(readyRead()),
this,SLOT(readServer()));
socket->write("Hello\r\n");
//socket->waitForBytesWritten(2000);
emit isConnected();
}

in SocketServer.cpp:

void SocketServer::connectionNew()
{
    //setCnn(true);
    socket=server->nextPendingConnection();
    connect(socket,SIGNAL(readyRead()),
            this,SLOT(readServer()));
    socket->write("Hello\r\n");
    //socket->waitForBytesWritten(2000);

    emit isConnected();
}

Christian Ehrlicher

Sorry can't help any further - the qml stuff is simply crap - wonder how someone really can build something useful with this. Esp. with that few documentation. Even such a simple usecase as yours isn't properly documented... :(

difix

you have created two SocketServer object, one in C side (in main.cpp) and one in Qml side (in main Qml)

// create a new object
SocketServer{
        id:myserver
        onIsConnected:{
            lbl.text="Connected"
        }
    }

You need to share your C side server.
in main.cpp

 SocketServer svr;
engine.rootContext()->setContextProperty("cServer", &svr);

and use it in Qml

main.qml

    Connections {
        target: cServer
        onConnected: {
            lbl.text="Connected"
        }
        //  more one signal can be used
        onDisconnected: {
            lbl.text="disConnected"
        }
    }

to avoid this error you can use 'qmlRegisterUncreatableType' instead 'qmlRegisterType'

MhM93

@difix said in Emit not fire when client connected to server.:

qmlRegisterUncreatableType

really thanks. yes this is my problem. I create socket in main.cpp and also I create it again in qml