How to stop a loop in a QPushButton pressed? - qt

Question

I have a connection with Arduino. I need to send continuously a character to serial port to handle a motor series when I press a button. So I created a QPushButton and I want when it is pressed it send this character.
But when I need to create a loop I don't know how to break it. I tried this solution
...
Class .... {
private:
bool buttonPressed = false;
}
void MainWindow::on_pulsante1_pressed()
{
buttonPressed = true;
while (buttonPressed == true)
{
connect(ui->pulsante1,SIGNAL(released()),this,SLOT(on_pulsante1_released()));
qDebug() << "pressed";
}
}
void MainWindow::on_pulsante1_released()
{
buttonPressed = false;
qDebug() << "released";
}
Where did I do wrong?

Answer 1

You probably want to use a QTimer for that. Also you can define the frequency that the timer fires. For example:
#include <QTimer>
..
Class .... {
private:
QTimer timer;
}
void MainWindow::MainWindow(){
// in your constructor
connect(&timer, [this]{
//
// write to serial here
//
});
}
void MainWindow::on_pulsante1_pressed()
{
qDebug() << "pressed";
timer.start(1); // run this every 1 milisecond
}
void MainWindow::on_pulsante1_released()
{
timer.stop();
qDebug() << "released";
}
}
Take a look to QTimer documentation