This patch removes size policies and preferred sizes, and replaces them
with min-size and max-size for each widget.
Box layout now works in 3 passes:
1) Set all items (widgets/spacers) to their min-size
2) Distribute remaining space evenly, respecting max-size
3) Place widgets one after the other, adding spacing in between
I've also added convenience helpers for setting a fixed size (which is
the same as setting min-size and max-size to the same value.)
This significantly reduces the verbosity of widget layout and makes GML
a bit more pleasant to write, too. :^)
Problem:
- `(void)` simply casts the expression to void. This is understood to
indicate that it is ignored, but this is really a compiler trick to
get the compiler to not generate a warning.
Solution:
- Use the `[[maybe_unused]]` attribute to indicate the value is unused.
Note:
- Functions taking a `(void)` argument list have also been changed to
`()` because this is not needed and shows up in the same grep
command.