Once you have created the project, open up mainwindow.ui and drag the three different item widgets to your main window. After that, select the main window and click the Layout Vertically button located at the top:
Then, double-click on the List Widget and a new window will pop out. Here, you can add a few dummy items to the List Widget by clicking the + icon, or remove them by selecting an item from the list and clicking the - icon. Click the OK button to apply the final result to the widget:
You can do the ...