Node Categories Beginner

What Are Categories?

In the LOGO editor, the left-side palette shows all available nodes grouped by category. Each category has a header (like "Basic Logic", "Timers", "I/O") and contains the nodes that belong to it.

When you register a node, you pass a category. All nodes registered with the same SpcNodeCategory instance (or the same categoryId) appear under the same header.

Creating a Category

A category is just a record with an ID and a display name:

// Simplest form — default sort order (5000), no custom icon
public static final SpcNodeCategory MY_SENSORS =
    new SpcNodeCategory("mymod:sensors", "My Sensors");

Then pass it when registering nodes:

SpcNodeRegistry.register(TEMP_SENSOR_SCHEMA, new TempSensorFactory(), MY_SENSORS);
SpcNodeRegistry.register(HUMIDITY_SCHEMA,    new HumidityFactory(),    MY_SENSORS);
SpcNodeRegistry.register(LIGHT_SCHEMA,       new LightFactory(),       MY_SENSORS);
// All three appear under the "My Sensors" header in the palette

Controlling Sort Order

Categories are displayed in the palette sorted by their sortOrder value. Lower numbers appear first.

// Appears early in the palette (before most built-in categories)
new SpcNodeCategory("mymod:sensors", "My Sensors", 500)

// Appears late in the palette (after built-in categories)
new SpcNodeCategory("mymod:advanced", "Advanced", 8000)

Sort order ranges

Custom Icons

You can give your category a custom icon that appears next to the header in the palette. Pass a resource location string pointing to a texture file:

// Category with a custom icon texture
new SpcNodeCategory(
    "create:rotational",                     // category ID
    "Create: Rotational",                    // display name
    2000,                                    // sort order
    "create:textures/gui/cogwheel_icon.png"  // icon texture path
)

Icon details

• The texture path follows standard Minecraft resource location format: "namespace:path"
• Textures are loaded from your mod's resource pack
• Recommended size: 16×16 pixels (same as Minecraft item icons)
• If you don't want an icon, pass null or use a shorter constructor
• Check if a category has an icon: category.hasIcon()

Built-in Categories

SPC ships with these built-in categories (you cannot modify them, but you can add nodes to them if appropriate):

Multiple Categories per Addon

If your addon adds many nodes, split them into multiple categories. This keeps the palette organized and helps players find what they need.

// A Create mod addon might define several categories:
public static final SpcNodeCategory CREATE_ROTATIONAL =
    new SpcNodeCategory("create:rotational", "Create: Rotational", 2000,
        "create:textures/gui/cogwheel.png");

public static final SpcNodeCategory CREATE_FLUID =
    new SpcNodeCategory("create:fluid", "Create: Fluid", 2100,
        "create:textures/gui/fluid_pipe.png");

public static final SpcNodeCategory CREATE_LOGISTICS =
    new SpcNodeCategory("create:logistics", "Create: Logistics", 2200);

// Register nodes into the appropriate category:
SpcNodeRegistry.register(ROTATION_SENSOR, new RotSensorFactory(), CREATE_ROTATIONAL);
SpcNodeRegistry.register(STRESS_GAUGE,    new StressFactory(),    CREATE_ROTATIONAL);
SpcNodeRegistry.register(FLUID_LEVEL,     new FluidFactory(),    CREATE_FLUID);
SpcNodeRegistry.register(BELT_COUNTER,    new BeltFactory(),     CREATE_LOGISTICS);

Full Example: Create Addon Categories

Here's a complete @Mod constructor showing how a Create addon would organize its nodes into categories:

@Mod("spc_create")
public class SpcCreateAddon {

    // ── Categories ──
    static final SpcNodeCategory ROTATIONAL =
        new SpcNodeCategory("spc_create:rotational", "Create: Rotational", 2000,
            "spc_create:textures/gui/cogwheel.png");

    static final SpcNodeCategory FLUID =
        new SpcNodeCategory("spc_create:fluid", "Create: Fluid", 2100);

    public SpcCreateAddon(IEventBus modEventBus) {
        // Check API version compatibility
        if (SpcApi.API_VERSION < 3) {
            LOGGER.warn("SPC API is too old! Expected 1.1.2, found v{}", SpcApi.API_VERSION);
            return;
        }

        // Register rotational nodes
        SpcNodeRegistry.register(RPM_SENSOR_SCHEMA,    new RpmSensorFactory(),    ROTATIONAL);
        SpcNodeRegistry.register(STRESS_SENSOR_SCHEMA, new StressSensorFactory(), ROTATIONAL);
        SpcNodeRegistry.register(SPEED_CTRL_SCHEMA,    new SpeedCtrlFactory(),    ROTATIONAL);

        // Register fluid nodes
        SpcNodeRegistry.register(TANK_LEVEL_SCHEMA,    new TankLevelFactory(),   FLUID);
        SpcNodeRegistry.register(FLOW_RATE_SCHEMA,     new FlowRateFactory(),    FLUID);
    }
}

Best Practices

• Namespace your category IDs — always use "yourmod:name" format
• Use descriptive display names — include your mod name: "Create: Rotational" not just "Rotational"
• Group related nodes together — sensors in one category, actuators in another
• Keep sort orders in the 2000–4000 range — above built-in, below the default 5000
• Limit categories to 3–8 nodes — too many nodes in one category makes it hard to find things
• Icons are optional — don't force a bad icon; no icon is better than a confusing one
• Re-use the same category instance — define it once as a static final field