Xi's Multiversion UI Lib docs

Build mod menus once with plain Java widgets and run them on Minecraft 1.7.10 to 26.3 across every major loader.

Xi's Multiversion UI Lib (mod id xis_mvui) lets a mod describe its menus with plain Java widgets and run them on every Minecraft version from 1.7.10 to 26.3, on Fabric, Quilt, Legacy Fabric, Forge and NeoForge. Your mod compiles against one small API jar that has no Minecraft classes in it. At runtime the library picks the backend for the running game and draws your widgets with that version's own GUI classes, so menus look like vanilla everywhere.

public Screen create(UiHost host) {
    return MenuScreen.builder("main")
            .title(Text.translatable("mymod.title", "My Mod"))
            .add(Toggle.builder("sounds")
                    .label(Text.translatable("mymod.sounds", "Sounds"))
                    .value(() -> config.sounds)
                    .onChange(v -> config.sounds = v)
                    .build())
            .footer(Button.builder("done").label(UiTexts.DONE).onPress(host::back).build())
            .build();
}

Key facts#

Start here#

1. Installation: add the Maven repository and the API dependency, declare the dependency in your mod metadata, and run a dev client.
2. Your first menu: build and register a working menu in five steps.
3. Build one mod for every loader: structure a mod so one codebase ships to Fabric, Quilt, Forge and NeoForge, from 1.7.10 to 26.3.

All pages#

Guides (how to do one task):

• Build one mod for every loader: shared code, one jar per loader family.
• Register your menu: where to call register on each loader.
• Open your menu: the Options button, the mod list's Config button, your own key or button.
• Several screens and dialogs: host.open, back, close and ConfirmDialog.
• Slow work: files and network: runAsync and StatusLine.
• Validate what players type: validators, error lines and disabling Save.
• Translate your menu: Text, lang files and UiTexts.
• Save and load settings: where the values live and when to write them.
• Read and write options.txt: GameBridge for options-profile mods.
• Key bindings: Keybind, Key, storing keys, checking them in game.
• Test menus without Minecraft: FakeHost in JUnit.

Concepts (how it works):

• State and refresh: the mod owns the values; when suppliers are re-read.
• Ids: the rules for screen and entry ids, and the ids widgets reserve.
• Threads: what runs on the main thread and what may not.
• Failure isolation: what happens when your code throws.
• Backends and versions: how the library picks the code for the running game.

Widgets: which widget to use, then one page each: Button, Label, StatusLine, Toggle, Checkbox, Cycle, Dropdown, SelectList, Slider, NumberField, TextInput, MultiLineInput, StringListEditor, Keybind, ColorPicker, Section.

Examples (complete, copyable):

• A settings menu: a config class, a properties file, toggles, sliders and sections.
• A list manager: a SelectList with Add, Rename and Delete screens.
• A multi-loader mod: every file of a mod that ships for all loaders.

Players and server admins#

The wiki explains how to install the library and use its menus.