Add two variations of a read only item stack handler for input and output

src/main/java/dev/zontreck/libzontreck/items/InputItemStackHandler.java

@@ -0,0 +1,47 @@
+package dev.zontreck.libzontreck.items;
+
+import net.minecraft.core.NonNullList;
+import net.minecraft.world.item.ItemStack;
+import net.minecraftforge.items.ItemStackHandler;
+
+public class InputItemStackHandler extends ItemStackHandler {
+    private final ItemStackHandler internalSlot;
+
+    public InputItemStackHandler(ItemStackHandler hidden) {
+        super();
+        internalSlot = hidden;
+    }
+
+    @Override
+    public void setSize(int size) {
+        stacks = NonNullList.<ItemStack>withSize(size, ItemStack.EMPTY);
+    }
+
+    @Override
+    public void setStackInSlot(int slot, ItemStack stack) {
+        internalSlot.setStackInSlot(slot, stack);
+    }
+
+    @Override
+    public int getSlots() {
+        return internalSlot.getSlots();
+    }
+
+    @Override
+    public ItemStack getStackInSlot(int slot) {
+        return internalSlot.getStackInSlot(slot);
+    }
+
+    @Override
+    public ItemStack insertItem(int slot, ItemStack stack, boolean simulate) {
+        setStackInSlot(slot, stack);
+
+        return ItemStack.EMPTY;
+    }
+
+    @Override
+    public ItemStack extractItem(int slot, int amount, boolean simulate) {
+        return ItemStack.EMPTY;
+    }
+}
+

src/main/java/dev/zontreck/libzontreck/items/OutputItemStackHandler.java

@@ -0,0 +1,45 @@
+package dev.zontreck.libzontreck.items;
+
+import net.minecraft.core.NonNullList;
+import net.minecraft.world.item.ItemStack;
+import net.minecraftforge.items.ItemStackHandler;
+
+public class OutputItemStackHandler extends ItemStackHandler {
+    private final ItemStackHandler internalSlot;
+
+    public OutputItemStackHandler(ItemStackHandler hidden) {
+        super();
+        internalSlot = hidden;
+    }
+
+    @Override
+    public void setSize(int size) {
+        stacks = NonNullList.<ItemStack>withSize(size, ItemStack.EMPTY);
+    }
+
+    @Override
+    public void setStackInSlot(int slot, ItemStack stack) {
+        internalSlot.setStackInSlot(slot, stack);
+    }
+
+    @Override
+    public int getSlots() {
+        return internalSlot.getSlots();
+    }
+
+    @Override
+    public ItemStack getStackInSlot(int slot) {
+        return internalSlot.getStackInSlot(slot);
+    }
+
+    @Override
+    public ItemStack insertItem(int slot, ItemStack stack, boolean simulate) {
+        return stack;
+    }
+
+    @Override
+    public ItemStack extractItem(int slot, int amount, boolean simulate) {
+        return internalSlot.extractItem(slot, amount, simulate);
+    }
+}
+