Progress bar Vs loop...

[Rakma74]

Dear Sirs,

I'm filling large Qtable with large data files, and I decided to add a progress bar.
This works properly, however, I decided to add a 'Cancel' button, and things became more complicated.

Indeed, during the data filling (for loops), the program is completely frozen, and no way to move windows, click on the Cancel button ....

Would there be any solution which would help me ?

Thanks a lot in advance,

Best Regards,

Stéphane

// PROGRESS BAR -----------------------------------
 
    // Main window
    QWidget *window_progress_bar = new QWidget;
 
    // Progress bar + button
    QProgressBar *progressbar = new QProgressBar;
    QPushButton *button = new QPushButton ("Cancel");
 
    // Layout
    QHBoxLayout *layout = new QHBoxLayout;
 
    // Layout assignment
    layout->addWidget(progressbar);
    layout->addWidget(button);
 
    // Set Layout
    window_progress_bar->setLayout(layout);
 
    // Show the window
    window_progress_bar->show();
 
    // ------------------------------------------------
 
 
    // Telemetry data importation and filling
    for (unsigned int i=0; i<data->get_row_nb(); i++)
        {
        for (unsigned int j=0; j<data->get_col_nb(); j++)
            {
            data->set_value(i, j, file_reader->get_data(i,j));
            QTableWidgetItem *newItem = new QTableWidgetItem( tr("%1").arg(data->get_value(i,j)) );
            // newItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsUserCheckable);
            table_data->setItem(i, j, newItem);
            }
 
        // Progress bar updating
        progressbar->setValue(100*(i+1)/(data->get_row_nb()));
        }

// PROGRESS BAR -----------------------------------

    // Main window
    QWidget *window_progress_bar = new QWidget;

    // Progress bar + button
    QProgressBar *progressbar = new QProgressBar;
    QPushButton *button = new QPushButton ("Cancel");

    // Layout
    QHBoxLayout *layout = new QHBoxLayout;

    // Layout assignment
    layout->addWidget(progressbar);
    layout->addWidget(button);

    // Set Layout
    window_progress_bar->setLayout(layout);

    // Show the window
    window_progress_bar->show();

    // ------------------------------------------------


    // Telemetry data importation and filling
    for (unsigned int i=0; i<data->get_row_nb(); i++)
        {
        for (unsigned int j=0; j<data->get_col_nb(); j++)
            {
            data->set_value(i, j, file_reader->get_data(i,j));
            QTableWidgetItem *newItem = new QTableWidgetItem( tr("%1").arg(data->get_value(i,j)) );
            // newItem->setFlags(Qt::ItemIsEnabled | Qt::ItemIsUserCheckable);
            table_data->setItem(i, j, newItem);
            }

        // Progress bar updating
        progressbar->setValue(100*(i+1)/(data->get_row_nb()));
        }

To copy to clipboard, switch view to plain text mode 

[code_err]

Maybe multitasking and QThreads?

[wysota]

Try QProgressDialog.

[Rakma74]

Thanks code_err, this is exactely what I needed...


In fact, even if I don't use the QProgressBar, the code is frozen during the 'for' loops...
No particular problem with this in the past, but now, since I want to use a 'Cancel' button, things are different...

Best Regards,

Stéphane


PS : Also, thanks to Wysota

[boudie]

If you want to keep your program resposive, then call qApp->processEvents(); inside the loop.

[Rakma74]

This is absolutely PERFECT !!

Exactely what I needed... I tested it, it works perfectly and is so simple to implement...

Thank you very much Boudie !!