class MainWindow
{
...
private:
    QStringList fonts;
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow),
    progress("Setting up the theme, please wait...", "Abort", 0, 0, this),
    colors()
{
    ui->setupUi(this);
    ui->scrollArea->setWidget(ui->widget);
    readdirs();
    QString oldfont1 = ui->font1->text();
    QString oldfont2 = ui->font2->text();
    QString oldfont3 = ui->font3->text();
    QString oldfont4 = ui->font4->text();
    fonts.append(oldfont1);
    fonts.append(oldfont2);
    fonts.append(oldfont3);
    fonts.append(oldfont4);
//    readSettings();
}

void MainWindow::on_pushButton_clicked()
{
     fonts.at(0); //do something to oldfont1 string
}

The following packages have unmet dependencies:
  libqt4-experimental-dev: Depends: libgles2-sgx-img-dev but it is not installable
                           Depends: opengles-sgx-img-common-dev but it is not installable
                           Depends: libsqlite3-dev but it is not installable

    QFile file("/etc/hildon/theme/colors.config");
    if (!file.open (IO_ReadOnly))
       // didn't work
    QTextStream stream ( &file );
    QString line;
    QHash<QString, QString> variables;
    while( !stream.eof() ) {
         line = stream.readLine();
         //Split
         QStringList splittedLine = line.split("=");
         //Maybe add some checks here (splittedLine.count == 2 etc.)
         variables.insert(splittedLine.at(0), splittedLine.at(1));
    }
    file.close();
    QString oldfont1 = variables.value(key.DefaultTextColor());