MVC Logic

void MainWindow::openFile(const QString &path)
{
    QString fileName = path;
 
    if (fileName.isNull())
        fileName = QFileDialog::getOpenFileName(this,
            tr("Open File"), "", "C++ Files (*.cpp *.h)");
 
    if (!fileName.isEmpty()) {
        QFile file(fileName);
        if (file.open(QFile::ReadOnly | QFile::Text))
            editor->setPlainText(file.readAll());
 
    }
}