Style preferences in Ren'Py

-- The style preferences set up in options.rpy:

    renpy.register_style_preference("size", "14", style.say_dialogue, "size", 14)
    renpy.register_style_preference("size", "18", style.say_dialogue, "size", 18)
    renpy.register_style_preference("size", "22", style.say_dialogue, "size", 22)
    renpy.register_style_preference("font", "abeezee", style.default, "font", "fonts/abeezee.otf")
    renpy.register_style_preference("font", "opendyslexia", style.default, "font", "fonts/opendyslexia.otf")
    renpy.register_style_preference("labeltextpos", "abeezee", style.say_label, "ypos", -9)
    renpy.register_style_preference("labeltextpos", "opendyslexia", style.say_label, "ypos", -15)
    renpy.register_style_preference("labelpos", "abeezee", style.say_who_window, "ypos", 132)
    renpy.register_style_preference("labelpos", "opendyslexia", style.say_who_window, "ypos", 152)
    renpy.register_style_preference("antialiasing", "off", style.default, "antialias", False)
    renpy.register_style_preference("antialiasing", "on", style.default, "antialias", True)

-- This is in screens.rpy:

##############################################################################
# Preferences
#
# Screen that allows the user to change the preferences.
# http://www.renpy.org/doc/html/screen_special.html#prefereces

screen preferences():

    tag menu
    add "ui/settingsbase.png"
    use navigation
    # Window/fullscreen
    imagebutton auto "ui/window_%s.png" xpos 78 ypos 133 focus_mask None action Preference("display", "window")
    imagebutton auto "ui/fullscreen_%s.png" xpos 188 ypos 133 focus_mask None action Preference("display", "fullscreen")
    # Font style and anti-alias toggle
    imagebutton auto "ui/abeezee_%s.png" xpos 320 ypos 135 focus_mask None action [StylePreference("font", "abeezee"), StylePreference("labeltextpos", "abeezee"), StylePreference("labelpos", "abeezee")]
    imagebutton auto "ui/other_%s.png" xpos 392 ypos 135 focus_mask None action [StylePreference("font", "opendyslexia"), StylePreference("labeltextpos", "opendyslexia"), StylePreference("labelpos", "opendyslexia")]
    imagebutton auto "ui/on_%s.png" xpos 406 ypos 161 focus_mask None action StylePreference("antialiasing", "on")
    imagebutton auto "ui/off_%s.png" xpos 425 ypos 160 focus_mask None action StylePreference("antialiasing", "off")
    # Transitions on/off
    imagebutton auto "ui/showall_%s.png" xpos 521 ypos 133 focus_mask None action Preference("transitions", "all")
    imagebutton auto "ui/shownone_%s.png" xpos 631 ypos 133 focus_mask None action Preference("transitions", "none")

    # Skip all/seen
    imagebutton auto "ui/allmessages_%s.png" xpos 52 ypos 221 focus_mask None action Preference("skip", "all")
    imagebutton auto "ui/seenmessages_%s.png" xpos 188 ypos 221 focus_mask None action Preference("skip", "seen")

    # Font size
    imagebutton auto "ui/14_%s.png" xpos 344 ypos 221 focus_mask None action StylePreference ("size", "14")
    imagebutton auto "ui/18_%s.png" xpos 380 ypos 221 focus_mask None action StylePreference ("size", "18")
    imagebutton auto "ui/22_%s.png" xpos 416 ypos 221 focus_mask None action StylePreference ("size", "22")

    # After choices
    imagebutton auto "ui/stopskipping_%s.png" xpos 500 ypos 221 focus_mask None action Preference("after choices", "stop")
    imagebutton auto "ui/keepskipping_%s.png" xpos 643 ypos 221 focus_mask None action Preference("after choices", "skip")

    # Sliders
    frame xpos 96 ypos 298:
        style_group "pref"
        has vbox
        bar value Preference("auto-forward time")

    frame xpos 456 ypos 298:
        style_group "pref"
        has vbox
        bar value Preference("music volume")

    frame xpos 96 ypos 355:
        style_group "pref"
        has vbox
        bar value Preference("text speed")

    frame xpos 456 ypos 355:
        style_group "pref"
        has vbox
        bar value Preference("sound volume")