Qprocess, qtimer and qprogressbar

jocala

In the code below my progressbar is set to visible and 0, but it's never updated until the routine finishes. Under Windows I get program not responding, although the routine goes on to finishes, give the proper qmessage, and re-hide the progressbar.
@
/////////////////////////////////////////////////////////////////////
void MainWindow::TimerEvent()
{
int value = ui->progressBar->value();
ui->progressBar->setValue(value+1);
}

////////////////////////////////////////////////////////////////////////////
void MainWindow::on_sideload_Button_clicked()
{

if (!isConnected)
   { QMessageBox::critical(
         this,
         tr("adbFire"),
         tr("Device not connected"));
      return;
}

command = "";

QString fileName = QFileDialog::getOpenFileName(this,
      tr("Select app to install"), "/", tr("APK Files (*.apk)"));



if (!fileName.isEmpty() )
{

QMessageBox::StandardButton reply;
  reply = QMessageBox::question(this, "Install", "Install "+fileName+"?",
                                QMessageBox::Yes|QMessageBox::No);
  if (reply == QMessageBox::Yes)
  {




      QProcess *install_apk=new QProcess;


      install_apk->start(adbfile + " install -r " + fileName);

        ui->progressBar->setHidden(false);
        ui->progressBar->setValue(0);
        QTimer *timer = new QTimer(this);
        connect(timer, SIGNAL(timeout()), this, SLOT(TimerEvent()));
        timer->start(100);

      install_apk->waitForFinished(-1);
      command=install_apk->readAll();
      delete install_apk;

      if (command.contains("Success"))
       QMessageBox::information(
                      this,
                     "",
                      "Installed");
          else
           QMessageBox::critical(
                      this,
                      "",
                      "Install failed");


      }

}

ui->progressBar->setHidden(true);

@

andreyc

According to the "doc":http://qt-project.org/doc/qt-5/qprocess.html#waitForFinished
@
install_apk->waitForFinished(-1);
@
"Blocks until the process has finished and the finished() signal has been emitted, or until msecs milliseconds have passed."
You don't give Qt a chance to run an Event loop until the process is finished.

jocala

Thanks for your reply, I had no idea waitForFinished was such a bad citizen!

Unfortunately, removing the waitForFinished(-1); breaks the code, the process quits before the external program finishes. Is there a way around my problem?

qxoz

Simple solution for your case could be like that:
@while(install_apk->state() != QProcess::NotRunning)
qApp->processEvents();
command=install_apk->readAll();
delete install_apk;@

But i recommend you use threads for such things.

jocala

Thanks so much!