Layouts - what are they good for

Video: Playing with Designer (5 MB)

Let's show this one example.

Launch Designer and create a new widget. Make it look like this one:

Now press Ctrl+R to preview it. Try to resize it and see how it behaves.

Sizes of the widgets stay the same no matter what the size of window is.

Now select File label, lineEdit and Browse button and apply horizontal layout.

OK, now click the form so no particular widget is selected. That will select form itself (make sure topmost item in the Object Inspector is highlighted).

Click vertial layout button.

This gives layout to form itself.

Press Ctrl+R and try to resize window.

Widgets now adapt to size of whole window. Have a look at sizePolicy property in Property Editor and experiment with it.

Read QSizePolicy class reference.

To break layout use button.