QChecbkBox events into QGraphicsScene

Question

I have a problem on the behavior of QCheckBox. I am under Qt5.3.2/MinGW

I create a QGraphicsScene where i add severals QCheckBox via QGraphicsProxyWidget.

To be able to do drag and drop, zoom in / out, I reimplemented the virtual method eventFilter(QObject, QEvent) into QMainWindows and I apply it to my scene: scene->installEventFilter(this);

But I can’t catch QCheckBox signal with QObject::connect :

connect(checkBox, &QCheckBox::clicked, [=](bool value){
qDebug() << "checkBox->objectName() : " << checkBox->objectName();
qDebug() << "value : " << value; });

If I don’t apply event filter on my scene, my QCheckBox work perfectly.

If now I apply event filter on my QCheckbox :

checkBox->installEventFilter(this);

I receive the event of the first one QCheckBox selected. But if I click on another QCheckBox it is the event of the first QCheckBox selected who is received. QCheckBox status are not modified too and I need to change status into QMainWindows::eventfilter :

if(checkbox->isChecked()) checkbox->setChecked(false);
else if(!checkbox->isChecked()) checkbox->setChecked(true);

MainWindow.cpp :

void MainWindow::Display()
{
scene = new QGraphicsScene();
scene->setObjectName("scene");
scene->installEventFilter(this);

for(int i=;i<10;++i){
            QCheckBox *checkBox = new QCheckBox("ID"+QString::number(i));
            checkBox->setObjectName("checkBox"+QString::number(i));
            checkBox->installEventFilter(this);
            checkBox->setChecked(true);
            QString style =  "QCheckBox {background : white;}";
            checkBox->setStyleSheet(style);

//            connect(checkBox, &QCheckBox::clicked, [=](bool value){
//                qDebug() << "checkBox->objectName() : " << checkBox->objectName();
//                qDebug() << "value : " << value; });

            QGraphicsProxyWidget* proxyWidget = scene->addWidget(checkBox);
            proxyWidget->setObjectName("proxyWidget"+QString::number(i));
            proxyWidget->setScale(2);
            proxyWidget->setPos(QPointF(i*50, 24));
            proxyWidget->setFlag(QGraphicsItem::ItemIsSelectable);
            proxyWidget->setZValue(2.0);
        }

        scene->setSceneRect(QRect(0, 0, 500, 200));
        ui->graphicsView->setScene(scene);
        ui->graphicsView->setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
}

bool MainWindow::eventFilter(QObject *object, QEvent *event)
{
    qDebug() << "object->objectName() : " << object->objectName();
    qDebug() << "event->type() : " << event->type();

    if (event->type() == QEvent::MouseButtonDblClick)
    {
        if(object->objectName().contains("checkBox",Qt::CaseInsensitive))
        {
            QCheckBox *checkbox = dynamic_cast<QCheckBox *>(object);
            if(checkbox != nullptr)
            {
                event->setAccepted(true);

                if(checkbox->isChecked()) checkbox->setChecked(false);
                else if(!checkbox->isChecked()) checkbox->setChecked(true);

                checkbox->update();

                return true;
            }
            else return false;
        }
        else return false;
    }
    else
    {
        qDebug() << "default return";
        // standard event processing
        return QObject::eventFilter(object, event);
    }
}

What is it that I'm doing wrong? Thank you.

Are you returning false when you aren't filtering? http://doc.qt.io/qt-5/eventsandfilters.html#event-filters — phyatt, Mar 14 '15 at 14:36
when i am not filtering i return this : else{ return QObject::eventFilter(object, event); } — Gamso, Mar 14 '15 at 14:56
OK, I put some time to understand xD. Actually was needed "return false". thank you @phyatt — Gamso, Mar 14 '15 at 16:50

QChecbkBox events into QGraphicsScene

0 Answers0