How do I make my QProgressDialog show the process of my task in the progress bar?

[lincoln]

Hello guys, I have the following question, how do I so that in QProgressDialog, the progress bar is shown as my task progresses, I have tried and I have not succeeded yet.

Only the full bar is shown, as if it had already finished, but the task still continues to execute.

Here I leave my code, I hope you can help me, thanks in advance.

This is where I do my task, it is a static method, which does the decryption process, this at the same time calls a function called encryptPassword()

void MainWindow::encryptAllData(QStringList data, int rowCount){


  QStringList dataEncrypt{};
  
  for (int row = 0; row < rowCount; ++row) {
      auto rowData = data.value(row);
      dataEncrypt << encryptPassword(rowData);
      
    }

  for(int i = 0; i<dataEncrypt.count(); ++i){
      qInfo() << dataEncrypt.value(i) << '\n';

    }
}

Here is the code for the button that shows the QProgressDialog

QObject::connect(ui->pushButton, &QPushButton::clicked, this, [&](){
    
      QStringList data;
      auto numRows {ui->tableWidget->rowCount()};
     
      for (int row = 0; row < numRows; ++row) {
          data << ui->tableWidget->item(row, 1)->data(Qt::DisplayRole).toString();


        }


      QProgressDialog progressDialog;
      progressDialog.setLabelText("Encriptando datos...");

      QFutureWatcher<void> watcher{};

      QObject::connect(&progressDialog, &QProgressDialog::canceled, &watcher, &QFutureWatcher<void>::cancel);
      QObject::connect(&watcher, &QFutureWatcher<void>::finished, &progressDialog, &QProgressDialog::reset);
      QObject::connect(&watcher, &QFutureWatcher<void>::progressRangeChanged, &progressDialog, &QProgressDialog::setRange);
      QObject::connect(&watcher, &QFutureWatcher<void>::progressValueChanged, &progressDialog, &QProgressDialog::setValue);


      QFuture<void> future = QtConcurrent::run(encryptAllData, data, numRows);
      watcher.setFuture(future);

      progressDialog.exec();
      watcher.waitForFinished();

      if(watcher.isCanceled()){
          QMessageBox::warning(this, qApp->applicationName(), "El proceso fue cancelado!");
        }else{
          QMessageBox::information(this, qApp->applicationName(), "El proceso ha finalizado!");
        }


    });

The encryptPassword method code

QString MainWindow::encryptPassword(const QString& password) {
  QProcess process;
  QStringList arguments;
  arguments << "enc" << "-aes-256-cbc" << "-a" << "-pbkdf2" << "-pass" << "pass:password" << "-in" << "-" << "-out" << "-";
  process.setProgram("openssl");
  process.setArguments(arguments);
  process.start();

  if (!process.waitForStarted()) {
      qDebug() << "Failed to start OpenSSL process.";
      return QString();
    }

  process.write(password.toUtf8());
  process.closeWriteChannel();

  if (!process.waitForFinished()) {
      qDebug() << "Failed to encrypt password with OpenSSL.";
      return QString();
    }

  QString encryptedPassword = process.readAllStandardOutput();
  //  encryptedPassword.remove('\n');
  return encryptedPassword;
}

[JonB]

@lincoln
Regardless of whether your code is right or not, I don't get what you expecting? Running an external program to encrypt a password is (a) presumably going to take milliseconds and (b) won't report any kind of progress anyway. What is the use of a progress bar?

[lincoln]

@JonB

Well, it was a mistake, I am not calling an external process, but I have an encryption function which is this.

The call to openssl was just an alternative that I put in, and that I copied by mistake.

QString MainWindow::encryptText(const QString& text, const QString& key){


  QByteArray encryptedData;
  QByteArray textData = text.toUtf8();
  QByteArray keyData = key.toUtf8();

  QCryptographicHash hash(QCryptographicHash::Sha512);
  hash.addData(keyData);
  QByteArray hashedKey = hash.result();

  // Encriptar el texto utilizando AES
  for (int i = 0; i < textData.size(); ++i) {
      char encryptedChar = textData.at(i) ^ hashedKey.at(i % hashedKey.size());
      encryptedData.append(encryptedChar);
    }

  return QString::fromUtf8(encryptedData.toBase64());



}

[JonB]

@lincoln
Seems to me my comment still stand. You want to show a progress bar while running code to encrypt a password which takes a fraction of a second? And even if it took longer it's not emitting a signal as it progresses that I can see. Where and when is progressValueChanged() being emitted? You need something which takes a while and emits signals as it goes.

I think you might want to look at https://stackoverflow.com/questions/23438044/how-to-communicate-a-progresstext-from-a-qtconcurrentrun-function-or-similar. The last post there shows how someone would need to use it. I would follow a comment to the solutuon:

I think using signals to report progress is the most convenient way when using QtConcurrent::run().