bug#47291: bug#51404: Support system dark mode on Windows 10

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> I'm not sure unification is possible here, because the functionality
> is quite different, AFAICT.  At least for the functionality in this
> bug report, we cannot apply the system theme to an existing frame, we
> can only apply it at frame creation time.  So having a handler for
> such changes will be able to affect only the frames created after the
> change.  Or at least that is my understanding; the code definitely
> applies the dark/light theme as part of creating a frame.

Gtk Emacs doesn't respond to dark mode either -- so we have the
opportunity to decide how to handle these things across the board.
Perhaps in Gtk Emacs, dynamic-setting-handle-config-changed-event should
also just set something that will make the next frame creation use
different colours?

> Also, having a dynamic thing that tracks changes in these settings
> would on Windows mean listening and processing a special window-system
> message, which seems to be WM_THEMECHANGED or maybe WM_SETTINGCHANGE.
> But that's not what the code installed in this bug report does.
>
> So the functionality seems similar, but the details differ.

But perhaps Windows should be listening to those events, too?

-- 
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   bloggy blog: http://lars.ingebrigtsen.no