Hi. That was a good tip man:

Qt Code: 
  1. splitter = new QSplitter();
  2. 	Q_CHECK_PTR(splitter);
  3.  
  4. 	//tabs
  5. 	m_pToolbox->addItem(m_pTabSifrant,trUtf8("Šifranti"));
  6. 	m_pToolbox->addItem(m_pTabVnos,trUtf8("Vnos"));
  7. 	m_pToolbox->addItem(m_pTabIsci,trUtf8("Iskanje"));	
  8. 	m_pToolbox->addItem(m_pTabNatisni,trUtf8("Tiskanje"));
  9.  
  10. 	//add QToolBox to the splitter widget
  11. 	splitter->insertWidget(0,m_pToolbox);
  12.  
  13. 	//add blank widget to splitter widget --> we'll have to change that to insert a widget we'll use. This is just for testing purposes
  14. 	QWidget *test = new QWidget();
  15. 	splitter->insertWidget(1,test);
  16.  
  17. 	//sets whether the child at index is collapsible to collapse
  18. 	splitter->setCollapsible(0,true);
  19. 	splitter->setCollapsible(1,false);
  20. 	//set's the stretch factor to specific widget
  21. 	splitter->setStretchFactor(0,1);
  22. 	splitter->setStretchFactor(1,3);
  23.  
  24. 	//sets the size of the 2 widgets in QSplitter
  25. 	QList<int> m_SizeList;
  26. 	m_SizeList << 100 << 500;
  27. 	splitter->setSizes(m_SizeList);
  28.  
  29.  
  30. 	//add QSplitter to the main widget
  31. 	m_pMainLayout->addWidget(splitter);
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Now the only thing I want to do is to let the QToolBox resize only 1/3 of the screen (that would be the maximum width for that widget). I've looked everywhere to find function for that, but I couldn't find it. Any tips?