QSignalMapper always giving last set value

gatz

Hello,

I try to connect a couple of delete buttons with QSignalMapper and is opening QMessageBox on each button click.
The problem is, QObject *value always have the same value (the last set value).
I looked on examples and looks like I do it right, but still not working properly. I am doing something wrong? Using Qt 4.8.7.

void MainWindow::setDeviceModel()
{
      // getting models here

    QSignalMapper *signalMapper = new QSignalMapper(this);
    connect(signalMapper, SIGNAL(mapped(QObject*)), this, SLOT(on_sensorDevice_delete_clicked(QObject*)));

    QVBoxLayout *vboxLayout = new QVBoxLayout();
    QObject *deviceObj = new QObject();

    for (int i = 0; i < edificeModel->rowCount(); i++) {
        QGroupBox *groupBox = new QGroupBox(edificeModel->record(i).value(2).toString() + " - " +
                                            edificeModel->record(i).value(1).toString());

        FlowLayout *flowLayout = new FlowLayout();
        flowLayout->setObjectName("edifice"+i);

        QString device = NULL;
        QGroupBox *deviceGroupBox = NULL;
        QVBoxLayout *deviceLayout = NULL;

        deviceObj->setProperty("edificeId", edificeModel->record(i).value(0).toString());

        for (int j = 0; j < dModel->rowCount(); j++) {
            QString deviceVal = dModel->record(j).value(2).toString();
            QString sensorVal = dModel->record(j).value(3).toString();

            // when node change reinitialize layouts
            if (device != deviceVal) {
                if (device != NULL) {
                    deviceGroupBox->setLayout(deviceLayout);
                    flowLayout->addWidget(deviceGroupBox);
                }

                deviceGroupBox = new QGroupBox(deviceVal);
                deviceLayout = new QVBoxLayout();
                deviceLayout->setObjectName(edificeModel->record(i).value(0).toString() + "" +
                                            dModel->record(j).value(0).toString() + "" +
                                            dModel->record(j).value(1).toString());

                device = deviceVal;

                deviceObj->setProperty("deviceId", dModel->record(j).value(0));
                deviceObj->setProperty("deviceName", dModel->record(j).value(2));
            }

            deviceObj->setProperty("sensorId", dModel->record(j).value(1));
            deviceObj->setProperty("sensorName", dModel->record(j).value(3));

            QHBoxLayout *sensorLayout = new QHBoxLayout();

            QPushButton *deleteButton = new QPushButton(this);
            deleteButton->setObjectName("deleteButton"+edificeModel->record(i).value(0).toString() + "" +
                                        dModel->record(j).value(0).toString() + "" +
                                        dModel->record(j).value(1).toString());
            deleteButton->setIcon(awesome->icon(fa::close));
            signalMapper->setMapping(deleteButton, deviceObj);
            connect(deleteButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
            sensorLayout->addWidget(deleteButton);

            QLabel *label = new QLabel(sensorVal, this);
            label->setFixedWidth(150);
            sensorLayout->addWidget(label);
            deviceLayout->addItem(sensorLayout);
        }
        // last device will be left out. We have to add it
        deviceGroupBox->setLayout(deviceLayout);
        flowLayout->addWidget(deviceGroupBox);

        groupBox->setLayout(flowLayout);
        vboxLayout->addWidget(groupBox);
    }

    ui->devices_scrollArea->setLayout(vboxLayout);
}

void MainWindow::on_sensorDevice_delete_clicked(QObject *value) {
    QMessageBox::StandardButton reply;

    QString message = "Are you sure you want to delete '" + value->property("sensorName").toString()
            + "' from device '" + value->property("deviceName").toString() + "'?";
    }
}

hskoglund

Hi, I think it's because you're reusing one QSignalMapper instance for all the QPushButtons (deleteButton).
Try newing up and connecting one signalMapper for every deleteButton you create.

gatz

for this no button works anymore

QSignalMapper *signalMapper = new QSignalMapper(this);
signalMapper->setMapping(deleteButton, deviceObj);
connect(deleteButton, SIGNAL(clicked()), signalMapper, SLOT(map()));

all button works, but getting the same, only last set value

QSignalMapper *signalMapper = new QSignalMapper(this);
signalMapper->setMapping(deleteButton, deviceObj);
connect(deleteButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
connect(signalMapper, SIGNAL(mapped(QObject*)), this, SLOT(on_sensorDevice_delete_clicked(QObject*)));

hskoglund

Oh I see now, you have the same syndrome (too few object instances) with deviceObj.
Try moving the creation of it inside the loop, for example just before doing deviceObj->setProperty("edif...

gatz

Thanks. This solved it. It was indeed because I was using just one deviceObj instance.