ExampleModClient.java

package com.example.examplemod;

import com.mojang.blaze3d.systems.RenderSystem;
import net.fabricmc.api.ClientModInitializer;
import net.fabricmc.fabric.api.client.event.lifecycle.v1.ClientTickEvents;
import net.fabricmc.fabric.api.client.keybinding.v1.KeyBindingHelper;
import net.fabricmc.fabric.api.client.rendering.v1.HudRenderCallback;
import net.minecraft.client.MinecraftClient;
import net.minecraft.client.option.KeyBinding;
import net.minecraft.client.util.InputUtil;
import net.minecraft.text.Text;
import org.lwjgl.glfw.GLFW;

/**
 * Client-only entrypoint. Registered in fabric.mod.json under
 * "entrypoints" -> "client". Keybinding + HUD render APIs unchanged
 * across 1.21.7 - 1.21.11.
 */
public class ExampleModClient implements ClientModInitializer {

    private static KeyBinding toggleHudKey;
    private static boolean hudVisible = true;

    @Override
    public void onInitializeClient() {

        // Register a keybinding (default: 'H'), shown in Controls menu under "key.categories.examplemod"
        toggleHudKey = KeyBindingHelper.registerKeyBinding(new KeyBinding(
                "key.examplemod.toggle_hud",
                InputUtil.Type.KEYSYM,
                GLFW.GLFW_KEY_H,
                "key.categories.examplemod"
        ));

        // Check every client tick whether the key was pressed
        ClientTickEvents.END_CLIENT_TICK.register(client -> {
            while (toggleHudKey.wasPressed()) {
                hudVisible = !hudVisible;
                if (client.player != null) {
                    client.player.sendMessage(
                            Text.literal("HUD " + (hudVisible ? "enabled" : "disabled")), true);
                }
            }
        });

        // Draw a simple overlay each frame
        HudRenderCallback.EVENT.register(this::onHudRender);
    }

    private void onHudRender(net.minecraft.client.gui.DrawContext context, net.minecraft.client.render.RenderTickCounter tickCounter) {
        if (!hudVisible) return;

        MinecraftClient client = MinecraftClient.getInstance();
        if (client.player == null) return;

        RenderSystem.enableBlend();
        int x = 10;
        int y = 10;
        context.drawText(client.textRenderer,
                Text.literal("ExampleMod active"),
                x, y, 0xFFFFFF, true);

        // Show current held item name below it
        var heldStack = client.player.getMainHandStack();
        if (!heldStack.isEmpty()) {
            context.drawText(client.textRenderer,
                    Text.literal("Holding: " + heldStack.getName().getString()),
                    x, y + 12, 0xAAAAAA, true);
        }
    }
}