Q_EMIT not working from connected slot, only with QTimer slot

mfessler

I am trying to use signals and slots to update a widget of another class. I am trying to emit a signal, which works if the slot is hooked up to a QTimer. However if the slot is hooked up to a QPushButton for example, it doesn't work. For example, I have a run() function that it connected to a 1 second QTimer. The run() function contains "Q_EMIT textChanged("Test");" This signal works as expected, emitting a signal. However, if I have a QPushButton connected to a slot, which also contains "Q_EMIT textChanged("Test");" nothing happens when I press the QPushButton...why is this/how can I fix this???

counter.h

class Counter : public QWidget
{
    Q_OBJECT
public:
    explicit Counter(QWidget *parent = 0);

signals:
    void textChanged(const QString &text);

public slots:
    void run();
    void OKalarmLimits();

mainwindow.h
class MainWindow : public QDialog
{
Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    QGridLayout *layout;
    ~MainWindow();
    QPlainTextEdit *box;

public slots:
    void updateWidgets(const QString &text);
    void run();

mainwindow.cpp

MainWindow::MainWindow(QWidget *parent) : QDialog(parent)
{
     QWidget::setFixedHeight(600);
     QWidget::setFixedWidth(600);
     layout = new QGridLayout;

     box = new QPlainTextEdit();
     box->setMaximumHeight(400);
     box->setMinimumWidth(400);
     layout->addWidget(box,0,0);


     QTabWidget *tabWidget = new QTabWidget;
     tabWidget->addTab(new Counter(), tr("Counter"));
     layout->addWidget(tabWidget,1,0);


     QTimer *timer = new QTimer(this);
     connect(timer, SIGNAL(timeout()), this, SLOT(run()));
     timer->start(1000);

     setLayout(layout);
}

MainWindow::~MainWindow() 
{
}

void MainWindow::updateWidgets(const QString &text)
{
   qDebug() << "Here";
   box->appendPlainText(text);
}

void MainWindow::run()
{
    box->appendPlainText("Test");
}

main.cpp

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow s;
    Counter m;
    s.show();
    QObject::connect(&m, SIGNAL(textChanged(QString)), &s,SLOT(updateWidgets(QString)));
    return a.exec&#40;&#41;;
}

counter.cpp

Counter::Counter(QWidget *parent) : QWidget(parent)
{
    QTimer *timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(run()));
    timer->start(1000);

    QGridLayout *layout = new QGridLayout;


    QPushButton *OK = new QPushButton("OK");
    OK->setFixedWidth(50);
    connect(OK,SIGNAL(clicked()),this,SLOT(OKalarmLimits()));


    layout->addWidget(OK);

    setLayout(layout);
}

void Counter::run()
{
    Q_EMIT textChanged("ZOMG");
}

void Counter::OKalarmLimits()
{
    Q_EMIT textChanged("Hello World");
}

ChrisW67

Please edit your post and put the code between a pair of @ symbols