push Button seems disabled

[pencky]

Hey Guys,

I try to create a simple pushButton, but it does not work.
I have a MainWindow, that calls customPlot, which plots real time data.
Now I wanna create a pushButton, that starts plotting these data.

MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui (new Ui::MainWindow)
{
     ui->setupUi(this);
}

void MainWindow:: on_pushButton_clicked()
{
     open_serial();
     setupDemo();  //starts the plot
}

The push Button is above the graph, but if I run the programm the Button looks disabled, so that I cannot click on it.
What does it mean, if the pushButton text is grey so that is looks disabled.
I also checked the checkbox "enable" in the GUI, which is also enabled.
No error is displayed.

Thanks for your help.

[SGaist]

Hi and welcome to devnet,

Is your QPushButton in a layout in another widget that is disabled ?

[alex_malyu]

Does you MainWindow.h have Q_Object macro defined?
Is on_pushButton_clicked a slot? is it connected?

[pencky]

The MainWindow object above the central widget wasn't enabled. I thought I checked it, but didn't.
So thanks for the answers.