updating qlabel image in switch statement

[jvalerio]

I have a small switch function running that I want to update the image of a label depending on the result. The issue I have is that all images are only updated at the end of the run. How can I update each image as each case is evaluated?


int MainWindow::readADC(int range)
{
QPixmap stat_GO (":/res/images/stat_GO.png");
QByteArray data;
bool ok = false;
float r = 0.0;

switch (range)
{
case 24:
serial->waitForReadyRead(1000);
data = serial->readAll();
qDebug() << data;
r = data.toFloat(&ok);
if (!ok) qDebug() << "24VDC Conversion Failed";
qDebug() << r;

if ((r > 23.2) && (r < 24.8)) //Check tolerance (3.3%)
ui->_tstr24Vok->setPixmap(stat_GO);
return 1;
break;

case 3:
serial->waitForReadyRead(1000);
data = serial->readAll();
qDebug() << data;
r = data.toFloat(&ok);
if (!ok) qDebug() << "3.3VDC Conversion Failed";
qDebug() << r;

if ((r > 3.2) && (r < 3.4)) //Check tolerance (3%)
ui->_but3v3Vok->setPixmap(stat_GO);
return 1;
break;

case 12:
serial->waitForReadyRead(1000);
data = serial->readAll();
qDebug() << data;
r = data.toFloat(&ok);
if (!ok) qDebug() << "12VDC Conversion Failed";
qDebug() << r;

if ((r > 11.6) && (r < 12.4)) //Check tolerance (3.3%)
ui->_but12Vok->setPixmap(stat_GO);
return 1;
break;
}
return 0;
}

[Lesiok]

This method is OK. The problem is how this method is invoke. Refreshing the screen needs working event loop. So if You do this calling readADC 3 times You have such a symptom.

[anda_skoa]

Also blocking the main thread and thus the GUI for up to a second (through waitForReadyRead) is usually also a very bad idea.

There really doesn't seem to be a need for this, all branches do that, so the switch could easily be done in a slot connected to readyRead().

The code suprisingly also doesn't even care how much data is reads.

Cheers,
_