Also implement in QGenericUnixTheme/QKdeTheme/QGnomeTheme/QGtk3Theme.
On Wayland, there is wl_cursor_theme_load() and etc in wayland-cursor.h.
On X11/xcb, cursor theme and size are common, either in XCURSOR_THEME
and XCURSOR_SIZE envs, or in gsettings for gtk/gnome world.
On Windows, cursor theme is part of theme file, see SetWindowTheme in
https://learn.microsoft.com/en-gb/windows/win32/api/uxtheme/nf-uxtheme-setwindowtheme .
For system settings, for example on Windows 10, Mouse Settings,
Additional mouse options, Pointers Tab, Scheme.
On macOS, it looks like cursor theme is deprecated.
Change-Id: I5821377d966c281fb8330da1f5baa7f0ddf86a9f
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
a823366f77