Java Addon API

FoundryEngine exposes events and builders for Java developers through NeoForge's event bus.

Setup

Subscribe to FoundryEngine events using @SubscribeEvent on the appropriate bus. All API events are in de.luckymcdev.foundryengine.common.event.

TitleScreenModificationEvent

Modify or cancel title screen buttons:

@SubscribeEvent
public void onTitleScreen(TitleScreenModificationEvent event) {
    if (event.getButtonType() == TitleScreenModificationEvent.ButtonType.REALMS) {
        event.setCanceled(true);
    }
}

GameStageEvent

Listen to stage changes:

@SubscribeEvent
public void onStageAdd(GameStageEvent.Add event) {
    if (event.getStage().getPath().equals("too_early")) {
        event.setCanceled(true);
    }
}

Subclasses: Add (cancellable), Remove (cancellable), Added, Removed. All expose getStage() (returns Identifier) and getPlayer().

BlockModificationEvent

Modify block properties at runtime:

@SubscribeEvent
public void onBlockMod(BlockModificationEvent event) {
    event.hasCollision(false)
        .explosionResistance(1000.0f)
        .lightEmission(15)
        .soundType(SoundType.AMETHYST)
        .friction(0.1f)
        .speedFactor(0.5f)
        .jumpFactor(2.0f)
        .randomlyTicking(true)
        .setDestroySpeed(0.5f)
        .setRequiresTool(true);
}

ItemModificationEvent

Modify item properties at runtime:

@SubscribeEvent
public void onItemMod(ItemModificationEvent event) {
    event.setMaxStackSize(16)
        .setMaxDamage(250)
        .setUnbreakable()
        .setFood(new FoodProperties.Builder()
            .nutrition(4).saturationModifier(0.3f).build())
        .setTool(new Tool(...))
        .setAttributeModifiers(ItemAttributeModifiers.EMPTY);
}

BundleDataGenEvent

Add custom data providers during bundle data generation:

@SubscribeEvent
public void onDataGen(BundleDataGenEvent event) {
    event.addProvider(new MyCustomProvider(
            event.getGenerator().getPackOutput(),
            event.getLookup()));
}

Next

• Events Reference — full event list
• Data Generation — how data generation works
• Editor Themes — custom panel and theme registration