Command Registering Example

CommandGamma.java

package nathanMeyer.mods.tmpi.command;

import com.mojang.brigadier.CommandDispatcher;
import com.mojang.brigadier.arguments.FloatArgumentType;
import nathanMeyer.mods.tmpi.constants.ChatFormatting;
import nathanMeyer.mods.tmpi.util.ChatUtils;
import net.minecraft.client.Minecraft;
import net.minecraft.command.CommandSource;

import static net.minecraft.command.Commands.argument;
import static net.minecraft.command.Commands.literal;

public class CommandGamma{
    public static final CommandGamma INSTANCE = new CommandGamma();

    public static void register(CommandDispatcher<CommandSource> dispatcher){
        dispatcher.register(
            literal("gamma").then(
                argument("newGamma", FloatArgumentType.floatArg(0, 1000)).executes(
                    ctx -> setGamma(ctx.getSource(), FloatArgumentType.getFloat(ctx,"newGamma"))
                )
            ).executes(ctx -> getGamma(ctx.getSource()))
        );
    }

    private static int getGamma(CommandSource source){
        ChatUtils.respond(source,ChatFormatting.PREFIX + "Gamma: " + Minecraft.getInstance().gameSettings.gammaSetting);
        return 1;
    }

    private static int setGamma(CommandSource source, float amount){
        Minecraft.getInstance().gameSettings.gammaSetting = amount;
        ChatUtils.respond(source,ChatFormatting.PREFIX + ChatFormatting.valid("Gamma Updated: ") + Minecraft.getInstance().gameSettings.gammaSetting);
        return 1;
    }
}