Size used for layouting windows.
It specifies a range of valid values and a preferred value.
The values must not violate the relation 0 <= Minimum <= Preferred <= Maximum.
Parameter Minimum
Zero or positive. The value itself is included in the valid
range.
Parameter Maximum
A value larger than or equal to Minimum.
The special value -1 means that there is no upper bound. Every value larger than or
equal to Minimum is valid.