This shows one possible way of adapting the application to support dark
mode, using the default for/background colours and SelectLightDark() for
the custom ones.
Note that this replaces "background" field of the styles in this sample
as it was never used (more precisely, was always specified as "WHITE")
with the new "foregroundDark" field which is set pretty arbitrarily but
differently enough from the foreground used in light mode for the sample
to look better in dark mode.
Also remove some duplicated code for setting styles and remove the code
for setting the defaults completely, as this is unnecessary, and even
harmful, after the changes of the previous commit.
This is a combination of running clang-tidy with modernize-use-nullptr
check for some ports (GTK, X11, OSX) and manual changes to the ports for
which it couldn't be used easily (MSW, DFB) and also manually updating
the docs.
Also replace NULL with null or nullptr in the comments as this is more
consistent with the use of nullptr in the code and makes it simpler to
grep for the remaining occurrences of NULL itself.
And also use null in the assert messages.
Only a few occurrences of "NULL" are still left in non-C files, mostly
corresponding to unclear comments or string output which it might not be
safe to change.
This keyword is not expanded by Git which means it's not replaced with the
correct revision value in the releases made using git-based scripts and it's
confusing to have lines with unexpanded "$Id$" in the released files. As
expanding them with Git is not that simple (it could be done with git archive
and export-subst attribute) and there are not many benefits in having them in
the first place, just remove all these lines.
If nothing else, this will make an eventual transition to Git simpler.
Closes#14487.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74602 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
