Qt: slots are not being called from the second thread - c++

Question

I want to update UI from the second thread, I have created slots which are going to be called from other thread by signaling, but somehow it is not being called from the other thread. Below is the code:
WorkerThread.h
class WorkerThread: public QObject
{
Q_OBJECT
public:
WorkerThread();
~WorkerThread();
public slots:
void onStart();
signals:
void sendMessage(const QString& msg, const int& code);
};
WorkerThread.cpp
#include "workerwhread.h"
WorkerThread::WorkerThread(){}
void WorkerThread::onStart(){
emit sendMessage("start", 100);
}
Usage:
MyWidget.h
namespace Ui {
class MyWidget;
}
class MyWidget: public QWidget
{
Q_OBJECT
public:
explicit MyWidget(QWidget *parent = 0);
~MyWidget();
private slots:
void onGetMessage(const QString &msg, const int& code);
private:
Ui::MyWidget *ui;
QThread *thread = nullptr;
WorkerThread *wt = nullptr;
};
MyWidget.cpp
MyWidget::MyWidget(QWidget *parent) : QWidget(parent), ui(new Ui::MyWidget)
{
ui->setupUi(this);
wt = new WorkerThread;
thread = new QThread;
connect(thread, &QThread::finished, wt, &QObject::deleteLater);
connect(ui->btStart, &QPushButton::clicked, wt, &WorkerThread::onStart);
connect(wt, &WorkerThread::sendMessage, this, &MyWidget::onGetMessage);
wt->moveToThread(thread);
thread->start();
}
void MyWidget::onGetMessage(const QString &msg, const int& code)
{
qDebug() << "message" << msg; // this never being called ????
}
Note: When I pass the connection type Qt::DirectConnectoin, then it is working, but the problem is it is not the GUI thread.
connect(wt, &WorkerThread::sendMessage, this, &MyWidget::onGetMessage, Qt::DirectConnection);
Main
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
w.setWindowIcon(QIcon(":/icons/system.png"));
return a.exec();
}

Answer 1

After a lot of trying and checking the code line by line, I finally found the problem. The reason was with overriding the event() function of QWidget, the return value of event() function is bool, so if you return a true it is OK and working well without throwing any runtime or compile-time error. But it will prevent signal-slot events to happen.
So NOT return true, but return QWidget::event(event); then it will slove the problem.