#include <QApplication>
#include <QDockWidget>
#include <QListWidget>
#include <QMainWindow>

int main(int argc, char *argv[])
{
  QApplication a(argc, argv);
  QMainWindow w;
  w.show();

  QDockWidget *dock1 = new QDockWidget("&Customers");
  dock1->setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea);
  QListWidget* customerList = new QListWidget(dock1);
  dock1->setWidget(customerList);
  w.addDockWidget(Qt::RightDockWidgetArea, dock1);

  QDockWidget* dock2 = new QDockWidget("Paragraphs");
  QListWidget* paragraphsList = new QListWidget(dock2);
  dock2->setWidget(paragraphsList);
  w.tabifyDockWidget(dock1, dock2);
  dock1->raise();

  return a.exec();
}