How to add a tooltip using ItemTooltipEvent?

[Xander402]

Hello,
I'm going to add tooltips to vanilla items in my mod.

 

I've actually added tooltips to the items I wanted..., but you'll clutch your head in disbelief how stupid is what I've done, it definitely can't take a place in a mod.
In my ItemInit class:

public static final ModItem DIAMOND = new ModItem("minecraft:diamond", new String[]{"description line 1", "description line 2"});

and the ModItem class:

package ...

import ...

public class ModItem extends Item implements IHasModel {

    private String[] itemDescription;

    public ModItem(String name, String[] description) {
        itemDescription = description;
        setMaxDamage(0);
        maxStackSize = 64;
        if (name.startsWith("minecraft:")) {
            setUnlocalizedName(Translate.toVanillaNaming(name.substring(10)));
        } else {
            setUnlocalizedName(name);
        }
        setRegistryName(name);
        setCreativeTab(CreativeTabs.MISC);

        ItemInit.ITEMS.add(this);
    }

    @Override
    public void addInformation(ItemStack itemstack, World world, List<String> list, ITooltipFlag flag) {
        if (itemDescription != null) {
            for (String line : itemDescription) {
                list.add(line);
            }
        }
    }

    @Override
    public void registerModels() {
        Main.proxy.registerItemRenderer(this, 0, "inventory");
    }
}

Yeah... a vanilla item override. Let's not comment this.

But I found something called ItemTooltipEvent. I think it should be used like so:
In my RegistryHandler class:

@SuppressWarnings("unused")
@SubscribeEvent
@SideOnly(Side.CLIENT)
public static void itemToolTip(ItemTooltipEvent event) {
	...
}

 

But what I have no idea is what to write inside this method to make it working. I couldn't find any clear example anywhere. Could somebody provide me one..?
Thanks in advance!

Edited February 18, 2019 by Xander402
Correction

[DavidM]

1. Do NOT use static initializers.

2. 

1.12.2:

event.getTooltip.add(String);

 

1.13.2:

event.getTooltip.add(ITextComponent);

 

Edited February 18, 2019 by DavidM

[Xander402]

7 minutes ago, DavidM said:

1. Do NOT use static initializers.

Okay, so I'll do.

7 minutes ago, DavidM said:

2. In your custom item class, override Item#addInformation and add strings to the "tooltip" parameter.

I know what to do with my custom mod items, I don't have any trouble with adding tooltips to them.
I do similarly to what you said, but I have all the tooltips in my lang file in case I wanted to translate the mod.
But I don't think I'm allowed to re-initialize and override a VANILLA item, like minecraft:diamond...

Edited February 18, 2019 by Xander402

[DavidM]

Check my updated reply (I misunderstood your question at first).

Edited February 18, 2019 by DavidM

[Xander402]

Yeah, thank you. Everything works fine.