ItemScubaTank.java

package net.tropicraft.item.scuba;

import java.util.List;

import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.util.StatCollector;
import net.minecraft.world.World;
import net.tropicraft.item.ItemTropicraft;
import net.tropicraft.item.scuba.ItemScubaGear.AirType;
import net.tropicraft.registry.TCCreativeTabRegistry;
import net.tropicraft.util.ColorHelper;
import cpw.mods.fml.relauncher.Side;
import cpw.mods.fml.relauncher.SideOnly;

public class ItemScubaTank extends ItemTropicraft {

    public ItemScubaTank() {
        this.setHasSubtypes(true);
        this.setMaxDamage(0);
        this.maxStackSize = 1;
        this.setCreativeTab(TCCreativeTabRegistry.tabMisc);
    }

    /**
     * Called when item is crafted/smelted. Used only by maps so far.
     */
    public void onCreated(ItemStack par1ItemStack, World par2World, EntityPlayer par3EntityPlayer) {

    }

    /**
     * allows items to add custom lines of information to the mouseover description
     */
    @SuppressWarnings({ "rawtypes", "unchecked" })
    @SideOnly(Side.CLIENT)
    @Override
    public void addInformation(ItemStack itemstack, EntityPlayer player, List list, boolean par4) {
        AirType airType = itemstack.getItemDamage() == 1 ? AirType.TRIMIX : AirType.REGULAR;
        String airRemaining = getTagCompound(itemstack).getInteger("AirContained") + " psi";

        list.add(ColorHelper.color(9) + StatCollector.translateToLocal("gui.tropicraft:airType") + ": " + ColorHelper.color(7) + airType.getDisplayName());
        list.add(ColorHelper.color(9) + StatCollector.translateToLocal("gui.tropicraft:maxAirCapacity") + ": " + ColorHelper.color(7) + airType.getMaxCapacity() + " psi");
        list.add(ColorHelper.color(9) + StatCollector.translateToLocal("gui.tropicraft:airRemaining") + ": " + ColorHelper.color(7) + airRemaining);
        list.add(ColorHelper.color(9) + String.format("%s: %s%.3f psi/sec", StatCollector.translateToLocal("gui.tropicraft:useEfficiency"),  ColorHelper.color(7), (airType.getUsageRate() * 20)));
    }

    /**
     * returns a list of items with the same ID, but different meta (eg: dye returns 16 items)
     */
    @SuppressWarnings({ "unchecked", "rawtypes" })
    @Override
    @SideOnly(Side.CLIENT)
    public void getSubItems(Item item, CreativeTabs tab, List list) {
        ItemStack singleTankRegular = new ItemStack(item, 1, 0);
        getTagCompound(singleTankRegular).setInteger("AirContained", ItemScubaGear.AirType.REGULAR.getMaxCapacity());
        list.add(singleTankRegular);

        ItemStack singleTankTrimix = new ItemStack(item, 1, 1);
        getTagCompound(singleTankTrimix).setInteger("AirContained", ItemScubaGear.AirType.TRIMIX.getMaxCapacity());
        list.add(singleTankTrimix);

        ItemStack singleTankTrimix2 = new ItemStack(item, 1, 2);
        getTagCompound(singleTankTrimix2).setInteger("AirContained", 0);
        list.add(singleTankTrimix2);
    }

    /**
     * Retrives an existing nbt tag compound or creates a new one if it is null
     * @param stack
     */
    public NBTTagCompound getTagCompound(ItemStack stack) {
        if (!stack.hasTagCompound())
            stack.setTagCompound(new NBTTagCompound());

        return stack.getTagCompound();
    }

}