These warnings were always enabled, but we didn't see them due to https://gitlab.com/OpenMW/openmw/-/issues/7882.
I do not fully understand the cause of 7822 as I can't repro it in a minimal CMake project.
Some of these fixes are thought through.
Some are sensible best guesses.
Some are kind of a stab in the dark as I don't know whether there was a
possible bug the warning was telling me about that I've done nothing to
help by introducing a static_cast.
Nearly all of these warnings were about some kind of narrowing
conversion, so I'm not sure why they weren't firing with GCC and Clang,
which have -Wall -Wextra -pedantic set, which should imply -Wnarrowing,
and they can't have been affected by 7882.
There were also some warnings being triggered from Boost code.
The vast majority of library headers that do questionable things weren't
firing warnings off, but for some reason, /external:I wasn't putting
these Boost headers into external mode.
We need these warnings dealt with one way or another so we can switch
the default Windows CI from MSBuild (which doesn't do ccache) to Ninja
(which does).
I have the necessary magic for that on a branch, but the branch won't
build because of these warnings.
It's no longer possible to cycle to widgets that aren't part of the current modal window.
The window manager will remember the focused widget of a modal window on a limited basis (it'll be discarded when a different modal window opens).
(Shift)Tab cycles, arrow keys move to the next button in that direction, Enter/Space accepts.
Note: Unless MyGUI is hacked to bits, clicking on an empty space will annoyingly reset the key focus. Not sure how to deal with that yet.
The visual highlight for selected buttons requires MyGUI commit 632d007429d0bf0c7d7f6c5db4a08353a63dd839 or later to appear (to be released in 3.2.3).