minWidth

0.0

maxWidth

size

width

minHeight

0.0

maxHeight

size

height

Example 3, it tells us that the

Learning the layout rules for specific widgets

Knowing the general layout rule is necessary, but it’s not enough.

Each widget has a lot of freedom when applying the general rule,
so there is no way of knowing what it will do by just reading
the widget’s name.

If you try to guess, you’ll probably guess wrong.
You can’t know exactly how a widget behaves unless
you’ve read its documentation, or studied its source-code.