[1.8][SOLVED] setInventorySlotContents getting the wrong item

[HappyKiller1O1]

So, in my Inventory class for my custom inventory, I am using #setInventorySlotContents to detect an item in the slot, and perform an action accordingly. Problem is, it is only detecting one item. here is what my method looks like:

public void setInventorySlotContents(int slot, ItemStack stack) {
	this.inventory[slot] = stack;

	if(stack != null && stack.stackSize > this.getInventoryStackLimit()) {
		stack.stackSize = this.getInventoryStackLimit();
	}

	if(getStackInSlot(SLOT_BACKPACK) != null && getStackInSlot(SLOT_BACKPACK).getItem() instanceof ItemBackpack) {
		if(!player.worldObj.isRemote) {
			System.out.println("World is not remote");

			ExtendedPlayer props = ExtendedPlayer.get(player);

			if(props.get(player) != null) {

				System.out.println("Player props are not null");

				if(getStackInSlot(SLOT_BACKPACK).getItem() instanceof ItemSmallBackpack) {
					System.out.println("Small Backpack detected!");

					props.setMaxWeight(200);
				} 

				if(getStackInSlot(SLOT_BACKPACK).getItem() instanceof ItemMediumBackpack) {
					System.out.println("Medium Backpack detected!");

					props.setMaxWeight(250);
				}

				if(getStackInSlot(SLOT_BACKPACK).getItem() instanceof ItemLargeBackpack) {
					System.out.println("Large Backpack detected!");

					props.setMaxWeight(300);
				}
			}
		}

		System.out.println("BACKPACK IN SLOT!");
	}else {
		if(!player.worldObj.isRemote) {

			ExtendedPlayer props = ExtendedPlayer.get(player);

			if(props.get(player) != null) {
				props.setMaxWeight(150);
			}
		}
	}

	this.markDirty();
}

 

The problem is where I am checking for an item in "SLOT_BACKPACK" (it is 0. I just use a constant for organization). The items I check for all extend a base called "ItemBackpack", and I would think using "instanceof" to check for it would be enough. But no matter what of the three items I put, it will always seem to return as the ItemSmallBackpack being in the slot. Am I checking for the items wrong? Would using a switch fix the problem?

[Draco18s]

Why not create a getMaxWeight() method to ItemBackpack, get the item, cast it, then ask the backpack what it's max weight is.

[coolAlias]

In addition to what Draco said, why not use the 'slot' and 'stack' parameters from the method? Is 'SLOT_BACKPACK' the only slot that will affect weight? If so:

if (slot == SLOT_BACKPACK) {
  // you already have the ItemStack in the slot, it is 'stack':
  if (stack == null || !(stack.getItem() instanceof ItemBackpack)) {
    // reset player's carry weight
  } else {
     // example only
     player.carryWeight += ((ItemBackpack) stack.getItem()).getCarryWeight(stack);
  }
}

Even better would be to create an interface such as ICarryWeight - then you could have any number of item types that provide carry weight modifiers.

 

Even better than that would be to create a SharedMonsterAttribute for carry weight, then those same items could be in ANY armor or held-item slot (and possibly Baubles slots, haven't worked with it though) and they would affect your carry weight.

[HappyKiller1O1]

I was working on this at 4am, so no wonder I forgot about the parameters. I honestly have never understood how Interfaces truly work. I know they can help me greatly, but all I know is they are abstract, and used to implement methods I am guessing you call in other classes?

[HappyKiller1O1]

Alright, I researched interfaces a tad bit, and made one for my base class. And, after all of that, THE SAME ERROR PERSISTS. Like I said, I have three Backpacks that extend the base of ItemBackpack (ItemSmallBackpack, ItemMediumBackpack, and ItemLargeBackpack). Now, I would think, considering these are three separate classes, it wouldn't be too difficult to actually get the right item, I would be wrong. Here are the item classes, the base, the interface, and the new #setInventorySlotContents. Thank you for any help you can provide.

 

ItemSmallBackpack:

package com.happykiller.weightlimit.items;

public class ItemSmallBackpack extends ItemBackpack {

public ItemSmallBackpack() {
	this.setMaxCarryWeight(200);
}
}

 

ItemMediumBackpack:

package com.happykiller.weightlimit.items;

public class ItemMediumBackpack extends ItemBackpack {

public ItemMediumBackpack() {
	this.setMaxCarryWeight(280);
}
}

 

ItemLargeBackpack:

package com.happykiller.weightlimit.items;

public class ItemLargeBackpack extends ItemBackpack {

public ItemLargeBackpack() {
	this.setMaxCarryWeight(380);
}
}

 

ItemBackpack:

package com.happykiller.weightlimit.items;

import java.util.List;

import com.happykiller.weightlimit.main.interfaces.ICarryWeightModifier;
import com.happykiller.weightlimit.player.ExtendedPlayer;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.world.World;
import net.minecraftforge.fml.relauncher.Side;
import net.minecraftforge.fml.relauncher.SideOnly;

public class ItemBackpack extends Item implements ICarryWeightModifier {

protected int maxWeightModifier = 150;

public ItemStack onItemRightClick(ItemStack stack, World world, EntityPlayer player) {
	if(!world.isRemote) {
		ExtendedPlayer props = ExtendedPlayer.get(player);

		if(!player.isSneaking()) {
			props.addWeight(1);
			System.out.println("Current Weight: " + props.getCurrentWeight());
		}else {
			props.removeAllWeight();
			System.out.println("Current Weight: " + props.getCurrentWeight());
		}
	}

	return stack;
}

@SideOnly(Side.CLIENT)
public void addInformation(ItemStack stack, EntityPlayer player, List list, boolean advanced) {

}

public int setMaxCarryWeight(int newMaxWeight) {
	if(newMaxWeight > 0) {
		this.maxWeightModifier = newMaxWeight;
	}else {
		this.maxWeightModifier = 150;
	}

	return this.maxWeightModifier;
}

public int getMaxCarryWeight() {
	return this.maxWeightModifier;
}

public int getMaxCarryWeightForStack(ItemStack stack) {
	int stackModifier = 150;

	if(stack.getItem() instanceof ItemBackpack) {
		stackModifier = ((ItemBackpack)stack.getItem()).getMaxCarryWeight();
	}else {
		System.out.println("ERROR: Stack was not an extension of ItemBackpack in SLOT_BACKPACK!");
	}

	return stackModifier;
}
}

 

ICarryWeightModifier:

package com.happykiller.weightlimit.main.interfaces;

import net.minecraft.item.ItemStack;

public interface ICarryWeightModifier {

public int setMaxCarryWeight(int newMaxWeight);

public int getMaxCarryWeightForStack(ItemStack stack);

public int getMaxCarryWeight();
}

 

New #setInventorySlotContents:

public void setInventorySlotContents(int slot, ItemStack stack) {
	this.inventory[slot] = stack;

	if(stack != null && stack.stackSize > this.getInventoryStackLimit()) {
		stack.stackSize = this.getInventoryStackLimit();
	}

	if(slot == SLOT_BACKPACK) {
		if(!player.worldObj.isRemote) {

			ExtendedPlayer props = ExtendedPlayer.get(player);

			if(props.get(player) != null) {
				if(stack == null || !(stack.getItem() instanceof ItemBackpack)) {
					props.setMaxWeight(150);
				}else {
					int newMaxWeight = ((ItemBackpack)stack.getItem()).getMaxCarryWeightForStack(stack);

					System.out.println("Stack in use: " + stack.getItem());

					System.out.println("Max weight from interface is: " + newMaxWeight);

					props.setMaxWeight(newMaxWeight);
				}
			}
		}
	}

	this.markDirty();
}

[HappyKiller1O1]

My God, all this time and effort to realize I was registering all three items with the ItemSmallBackpack class. Thank you for showing me an easier way of modifying weight limits, sorry for my idiocy!

[Draco18s]

I was working on this at 4am, so no wonder I forgot about the parameters. I honestly have never understood how Interfaces truly work. I know they can help me greatly, but all I know is they are abstract, and used to implement methods I am guessing you call in other classes?

 

Interfaces exist to allow multiple objects with different inheritance hierarchies to be treated as "the same" due to the contract granted by the interface.

[HappyKiller1O1]

Yes, I went through some Java docs online to figure it out after hearing I should use it. Basically, if we have an interface called "IVehicle", and our class "Car" implements it, if a method requires a class from IVehicle as a param, you can give it the Car class and it works, correct?

[Draco18s]

Yes, I went through some Java docs online to figure it out after hearing I should use it. Basically, if we have an interface called "IVehicle", and our class "Car" implements it, if a method requires a class from IVehicle as a param, you can give it the Car class and it works, correct?

 

Yep. You could also pass CardboardBoxSpaceShip as long as it also implements IVehicle.

[HappyKiller1O1]

Thanks for the help. Will help me a lot throughout my current mod creation.