Some things...

src/main/java/de/ellpeck/actuallyadditions/mod/inventory/AAContainer.java

@@ -0,0 +1,68 @@
+package de.ellpeck.actuallyadditions.mod.inventory;
+
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.inventory.AbstractContainerMenu;
+import net.minecraft.world.inventory.MenuType;
+import net.minecraft.world.inventory.Slot;
+import net.minecraft.world.item.ItemStack;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.function.Function;
+
+public abstract class AAContainer extends AbstractContainerMenu {
+    public final int numSlots;
+    public final Function<ItemStack, Boolean> VALIDATOR;
+
+    protected AAContainer(@Nullable MenuType<?> menuType, int containerId, int numSlots, Function<ItemStack, Boolean> validator) {
+        super(menuType, containerId);
+        this.numSlots = numSlots;
+        VALIDATOR = validator;
+    }
+
+    @Nonnull
+    @Override
+    public ItemStack quickMoveStack(@Nonnull Player player, int index) {
+        int inventoryEnd = numSlots + 26;
+        int hotbarStart = inventoryEnd + 1;
+        int hotbarEnd = hotbarStart + 8;
+
+        Slot theSlot = this.slots.get(index);
+
+        if (theSlot.hasItem()) {
+            ItemStack newStack = theSlot.getItem();
+            ItemStack currentStack = newStack.copy();
+
+            if (index >= numSlots) { //Shift from inventory to container.
+                if (numSlots > 0 && VALIDATOR.apply(newStack)) { //Check if the item is valid.
+                    if (!this.moveItemStackTo(newStack, 0, numSlots, false)) { // try to move to container.
+                        return ItemStack.EMPTY;
+                    }
+                }
+                else if (index <= inventoryEnd) { //Shift from inventory to hotbar.
+                    if (!this.moveItemStackTo(newStack, hotbarStart, hotbarEnd + 1, false)) { // try to move to hotbar.
+                        return ItemStack.EMPTY;
+                    }
+                } else if (index >= inventoryEnd + 1 && index < hotbarEnd + 1 && !this.moveItemStackTo(newStack, numSlots, inventoryEnd + 1, false)) { //Shift from hotbar to inventory.
+                    return ItemStack.EMPTY;
+                }
+            } else if (!this.moveItemStackTo(newStack, numSlots, hotbarEnd + 1, false)) { //Shift from container to inventory.
+                return ItemStack.EMPTY;
+            }
+
+            if (newStack.isEmpty()) {
+                theSlot.set(ItemStack.EMPTY);
+            } else {
+                theSlot.setChanged();
+            }
+
+            if (newStack.getCount() == currentStack.getCount()) {
+                return ItemStack.EMPTY;
+            }
+            theSlot.onTake(player, newStack);
+
+            return currentStack;
+        }
+        return ItemStack.EMPTY;
+    }
+}

src/main/java/de/ellpeck/actuallyadditions/mod/items/DrillItem.java

@@ -10,41 +10,35 @@
 
 package de.ellpeck.actuallyadditions.mod.items;
 
-import com.google.common.collect.ArrayListMultimap;
-import com.google.common.collect.Multimap;
 import de.ellpeck.actuallyadditions.api.ActuallyTags;
 import de.ellpeck.actuallyadditions.mod.ActuallyAdditions;
+import de.ellpeck.actuallyadditions.mod.components.ActuallyComponents;
 import de.ellpeck.actuallyadditions.mod.config.CommonConfig;
 import de.ellpeck.actuallyadditions.mod.inventory.ContainerDrill;
 import de.ellpeck.actuallyadditions.mod.items.base.ItemEnergy;
-import de.ellpeck.actuallyadditions.mod.tile.TileEntityInventoryBase;
 import de.ellpeck.actuallyadditions.mod.util.ItemStackHandlerAA;
 import de.ellpeck.actuallyadditions.mod.util.ItemUtil;
 import de.ellpeck.actuallyadditions.mod.util.Util;
 import de.ellpeck.actuallyadditions.mod.util.WorldUtil;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
-import net.minecraft.core.Holder;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.core.registries.BuiltInRegistries;
-import net.minecraft.nbt.CompoundTag;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
-import net.minecraft.tags.BlockTags;
 import net.minecraft.world.InteractionHand;
 import net.minecraft.world.InteractionResult;
 import net.minecraft.world.InteractionResultHolder;
 import net.minecraft.world.SimpleMenuProvider;
-import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.entity.EquipmentSlotGroup;
 import net.minecraft.world.entity.LivingEntity;
-import net.minecraft.world.entity.ai.attributes.Attribute;
 import net.minecraft.world.entity.ai.attributes.AttributeModifier;
 import net.minecraft.world.entity.ai.attributes.Attributes;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.Tier;
 import net.minecraft.world.item.Tiers;
 import net.minecraft.world.item.component.ItemAttributeModifiers;
+import net.minecraft.world.item.component.ItemContainerContents;
 import net.minecraft.world.item.context.UseOnContext;
 import net.minecraft.world.item.enchantment.Enchantments;
 import net.minecraft.world.level.Level;
@@ -67,15 +61,25 @@ public class DrillItem extends ItemEnergy {
     private static final int ENERGY_USE = 100;
     private static final List<ItemAbility> ACTIONS = List.of(ItemAbilities.SHOVEL_DIG, ItemAbilities.PICKAXE_DIG);
 
-    private final Multimap<Holder<Attribute>, AttributeModifier> attributes_unpowered = ArrayListMultimap.create();
+    private final ItemAttributeModifiers attributes_unpowered;
-    private final Multimap<Holder<Attribute>, AttributeModifier> attributes_powered = ArrayListMultimap.create();
+    private final ItemAttributeModifiers attributes_powered;
 
     public DrillItem() {
-        super(ActuallyItems.defaultProps().durability(0).stacksTo(1).component(DataComponents.TOOL, Tiers.NETHERITE.createToolProperties(ActuallyTags.Blocks.MINEABLE_WITH_DRILL)), 250000, 1000);
+        super(ActuallyItems.defaultProps()
-        attributes_powered.put(Attributes.ATTACK_DAMAGE, new AttributeModifier(ActuallyAdditions.modLoc("drill_speed_powered"), 8.0F, AttributeModifier.Operation.ADD_VALUE));
+                .durability(0)
-        attributes_powered.put(Attributes.ATTACK_SPEED, new AttributeModifier(ActuallyAdditions.modLoc("drill_speed_powered"), 1.5F, AttributeModifier.Operation.ADD_VALUE));
+                .stacksTo(1)
-        attributes_unpowered.put(Attributes.ATTACK_DAMAGE, new AttributeModifier(ActuallyAdditions.modLoc("drill_attack"), 0.1F, AttributeModifier.Operation.ADD_VALUE));
+                .component(DataComponents.TOOL, Tiers.NETHERITE.createToolProperties(ActuallyTags.Blocks.MINEABLE_WITH_DRILL))
-        attributes_unpowered.put(Attributes.ATTACK_SPEED, new AttributeModifier(ActuallyAdditions.modLoc("drill_speed"), 1.5F, AttributeModifier.Operation.ADD_VALUE));
+                , 250000, 1000);
+
+        attributes_unpowered = ItemAttributeModifiers.builder()
+                .add(Attributes.ATTACK_DAMAGE, new AttributeModifier(ActuallyAdditions.modLoc("drill_attack"), 0.1F, AttributeModifier.Operation.ADD_VALUE), EquipmentSlotGroup.MAINHAND)
+                .add(Attributes.ATTACK_SPEED, new AttributeModifier(ActuallyAdditions.modLoc("drill_speed"), 1.5F, AttributeModifier.Operation.ADD_VALUE), EquipmentSlotGroup.MAINHAND)
+                .build();
+
+        attributes_powered = ItemAttributeModifiers.builder()
+                .add(Attributes.ATTACK_DAMAGE, new AttributeModifier(ActuallyAdditions.modLoc("drill_attack"), 8.0F, AttributeModifier.Operation.ADD_VALUE), EquipmentSlotGroup.MAINHAND)
+                .add(Attributes.ATTACK_SPEED, new AttributeModifier(ActuallyAdditions.modLoc("drill_speed"), 1.5F, AttributeModifier.Operation.ADD_VALUE), EquipmentSlotGroup.MAINHAND)
+                .build();
     }
 
     @Override
@@ -103,8 +107,13 @@ public class DrillItem extends ItemEnergy {
      * @param stack The Drill
      */
     public static void loadSlotsFromNBT(IItemHandlerModifiable slots, ItemStack stack) {
-        CompoundTag compound = stack.getOrCreateTag();
+        if (stack.has(ActuallyComponents.CONTENTS)) {
-        TileEntityInventoryBase.loadSlots(slots, compound);
+            ItemContainerContents containerContents = stack.getOrDefault(ActuallyComponents.CONTENTS, ItemContainerContents.EMPTY);
+            int slotCount = slots.getSlots();
+            for (int i = 0; i < slotCount; i++) {
+                slots.setStackInSlot(i, i < containerContents.getSlots()? containerContents.getStackInSlot(i): ItemStack.EMPTY);
+            }
+        }
     }
 
     /**
@@ -114,10 +123,11 @@ public class DrillItem extends ItemEnergy {
      * @param stack The Drill
      */
     public static void writeSlotsToNBT(IItemHandler slots, ItemStack stack) {
-        CompoundTag compound = stack.getOrCreateTag();
+        List<ItemStack> stacks = new ArrayList<>();
-
+        for (int i = 0; i < slots.getSlots(); i++) {
-        TileEntityInventoryBase.saveSlots(slots, compound);
+            stacks.add(slots.getStackInSlot(i));
-        stack.setTag(compound);
+        }
+        stack.set(ActuallyComponents.CONTENTS, ItemContainerContents.fromItems(stacks));
     }
 
     @Nonnull

src/main/java/de/ellpeck/actuallyadditions/mod/items/ItemFilter.java

@@ -23,7 +23,7 @@ import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.TooltipFlag;
 import net.minecraft.world.level.Level;
 
-import javax.annotation.Nullable;
+import javax.annotation.Nonnull;
 import java.util.List;
 
 public class ItemFilter extends ItemBase {
@@ -43,11 +43,11 @@ public class ItemFilter extends ItemBase {
 
     
     @Override
-    public void appendHoverText(ItemStack stack, @Nullable TooltipContext pContext, List<Component> tooltip, TooltipFlag flagIn) {
+    public void appendHoverText(ItemStack stack, @Nonnull TooltipContext pContext, List<Component> tooltip, TooltipFlag flagIn) {
         super.appendHoverText(stack, pContext, tooltip, flagIn);
 
         ItemStackHandlerAA inv = new ItemStackHandlerAA(ContainerFilter.SLOT_AMOUNT);
-        DrillItem.loadSlotsFromNBT(inv, stack);
+        DrillItem.loadSlotsFromNBT(inv, stack, pContext.registries());
         for (int i = 0; i < inv.getSlots(); i++) {
             ItemStack slot = inv.getStackInSlot(i);
             if (StackUtil.isValid(slot)) {

src/main/java/de/ellpeck/actuallyadditions/mod/items/Sack.java

@@ -16,8 +16,6 @@ import de.ellpeck.actuallyadditions.mod.inventory.VoidSackContainer;
 import de.ellpeck.actuallyadditions.mod.items.base.ItemBase;
 import de.ellpeck.actuallyadditions.mod.sack.SackData;
 import de.ellpeck.actuallyadditions.mod.sack.SackManager;
-import de.ellpeck.actuallyadditions.mod.util.ItemStackHandlerAA;
-import net.minecraft.core.BlockPos;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.server.level.ServerPlayer;
@@ -30,11 +28,8 @@ import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.component.CustomData;
 import net.minecraft.world.item.context.UseOnContext;
 import net.minecraft.world.level.Level;
-import net.minecraft.world.level.block.entity.BlockEntity;
-import net.neoforged.neoforge.capabilities.Capabilities;
 
 import javax.annotation.Nonnull;
-import java.util.Optional;
 import java.util.UUID;
 
 public class Sack extends ItemBase {
@@ -49,7 +44,7 @@ public class Sack extends ItemBase {
     @Override
     public InteractionResult useOn(UseOnContext context) {
         ItemStack stack = context.getPlayer().getItemInHand(context.getHand());
-        if (!this.isVoid) {
+/*        if (!this.isVoid) { //TODO oh boy this is still old... needs to be converted to the new UUID system.
             Level level = context.getLevel();
             BlockPos clickedPos = context.getClickedPos();
             BlockEntity tile = level.getBlockEntity(clickedPos);
@@ -88,7 +83,7 @@ public class Sack extends ItemBase {
                 }
                 return InteractionResult.SUCCESS;
             }
-        }
+        }*/
         return InteractionResult.PASS;
     }