Attempted to make slots dynamic and failed

src/main/java/ru/windcorp/progressia/client/graphics/world/hud/CursorHUD.java

@@ -28,7 +28,7 @@ import ru.windcorp.progressia.client.world.entity.SpeciesRender;
 import ru.windcorp.progressia.client.world.entity.SpeciesRenderRegistry;
 import ru.windcorp.progressia.common.world.entity.EntityDataPlayer;
 import ru.windcorp.progressia.common.world.entity.SpeciesData.Hand;
-import ru.windcorp.progressia.common.world.item.ItemContainerHand;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainerHand;
 
 public class CursorHUD extends Component {
 

src/main/java/ru/windcorp/progressia/client/graphics/world/hud/HUDManager.java

@@ -28,8 +28,8 @@ import ru.windcorp.progressia.client.world.item.inventory.InventoryRender;
 import ru.windcorp.progressia.client.world.item.inventory.InventoryRenderRegistry;
 import ru.windcorp.progressia.common.util.crash.CrashReports;
 import ru.windcorp.progressia.common.world.item.inventory.Inventory;
-import ru.windcorp.progressia.common.world.item.inventory.InventoryClosingEvent;
+import ru.windcorp.progressia.common.world.item.inventory.event.InventoryClosingEvent;
-import ru.windcorp.progressia.common.world.item.inventory.InventoryOpenedEvent;
+import ru.windcorp.progressia.common.world.item.inventory.event.InventoryOpenedEvent;
 
 public class HUDManager implements HUDWorkspace {
 	

src/main/java/ru/windcorp/progressia/client/graphics/world/hud/HUDWorkspace.java

@@ -21,7 +21,7 @@ import ru.windcorp.progressia.client.Client;
 import ru.windcorp.progressia.client.graphics.world.LocalPlayer;
 import ru.windcorp.progressia.client.world.item.inventory.InventoryComponent;
 import ru.windcorp.progressia.common.world.entity.EntityDataPlayer;
-import ru.windcorp.progressia.common.world.item.ItemContainerHand;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainerHand;
 
 public interface HUDWorkspace {
 	

src/main/java/ru/windcorp/progressia/client/graphics/world/hud/InteractiveSlotComponent.java

@@ -24,47 +24,48 @@ import ru.windcorp.progressia.client.graphics.gui.layout.LayoutFill;
 import ru.windcorp.progressia.client.graphics.input.KeyMatcher;
 import ru.windcorp.progressia.client.graphics.input.WheelScrollEvent;
 import ru.windcorp.progressia.common.Units;
-import ru.windcorp.progressia.common.world.item.ItemContainer;
 import ru.windcorp.progressia.common.world.item.ItemDataContainer;
-import ru.windcorp.progressia.common.world.item.ItemSlot;
 import ru.windcorp.progressia.common.world.item.Items;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainer;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainerMixed;
+import ru.windcorp.progressia.common.world.item.inventory.ItemSlot;
 
 public class InteractiveSlotComponent extends Button {
 
 	private static final double MIN_PICK_ALL_DELAY = Units.get("0.5 s");
 
 	private double lastMainAction = Double.NEGATIVE_INFINITY;
-	
+
 	private final SlotComponent slotComponent;
 	private final HUDWorkspace workspace;
 
 	public InteractiveSlotComponent(String name, ItemContainer container, int index, HUDWorkspace workspace) {
 		this(name, new SlotComponent(name, container, index), workspace);
 	}
-	
+
 	public InteractiveSlotComponent(SlotComponent component, HUDWorkspace workspace) {
 		this(component.getName() + ".Interactive", component, workspace);
 	}
-	
+
 	public InteractiveSlotComponent(String name, SlotComponent component, HUDWorkspace workspace) {
 		super(name, null, null);
 		this.slotComponent = component;
 		this.workspace = workspace;
-		
+
 		Vec2i size = slotComponent.getPreferredSize().add(2 * BORDER);
 		setPreferredSize(size);
-		
+
 		addChild(this.slotComponent);
 		setLayout(new LayoutFill(MARGIN));
-		
+
 		addListeners();
 	}
 
 	private void addListeners() {
 		addAction(button -> onMainAction());
-		
+
 		addListener(KeyMatcher.ofRightMouseButton(), this::onAltAction);
-		
+
 		addListener(WheelScrollEvent.class, event -> {
 			if (event.hasVerticalMovement()) {
 				onSingleMoveAction(event.isDown());
@@ -73,10 +74,13 @@ public class InteractiveSlotComponent extends Button {
 			return false;
 		});
 	}
-	
+
 	private void onMainAction() {
 		ItemSlot handSlot = workspace.getHand().slot();
-		ItemSlot invSlot = getSlot();
+		ItemSlot invSlot = getSlotOrAllocate();
+		if (invSlot == null) {
+			return;
+		}
 
 		boolean success = false;
 
@@ -104,6 +108,8 @@ public class InteractiveSlotComponent extends Button {
 		if (success) {
 			requestReassembly();
 		}
+		
+		cleanContainerUpIfNecessary();
 	}
 
 	private void pickAll(ItemSlot handSlot) {
@@ -114,13 +120,16 @@ public class InteractiveSlotComponent extends Button {
 			}
 		}
 	}
-	
+
 	private void onAltAction() {
 		ItemSlot handSlot = workspace.getHand().slot();
-		ItemSlot invSlot = getSlot();
+		ItemSlot invSlot = getSlotOrAllocate();
-
+		if (invSlot == null) {
-		boolean success = false;
+			return;
+		}
 		
+		boolean success = false;
+
 		if (handSlot.isEmpty()) {
 			success = tryToOpen(invSlot);
 		}
@@ -140,6 +149,8 @@ public class InteractiveSlotComponent extends Button {
 		if (success) {
 			requestReassembly();
 		}
+
+		cleanContainerUpIfNecessary();
 	}
 
 	private boolean tryToOpen(ItemSlot invSlot) {
@@ -149,7 +160,7 @@ public class InteractiveSlotComponent extends Button {
 		if (!(invSlot.getContents() instanceof ItemDataContainer)) {
 			return false;
 		}
-		
+
 		ItemDataContainer item = (ItemDataContainer) invSlot.getContents();
 		return item.open(workspace.getPlayerEntity()) != null;
 	}
@@ -170,4 +181,38 @@ public class InteractiveSlotComponent extends Button {
 		return slotComponent.getSlot();
 	}
 
+	private ItemSlot getSlotOrAllocate() {
+		ItemSlot slot = slotComponent.getSlot();
+		
+		if (slot == null) {
+
+			int slotIndex = slotComponent.getSlotIndex();
+			ItemContainer uncastContainer = slotComponent.getSlotContainer();
+
+			assert slotIndex >= 0 : "Slot index is negative: " + slotIndex;
+			assert slotIndex >= uncastContainer.getSlotCount()
+				: "Slot index is valid (" + slotIndex + ") but container does not provide a slot";
+
+			if (uncastContainer instanceof ItemContainerMixed) {
+				ItemContainerMixed container = (ItemContainerMixed) uncastContainer;
+				container.addSlots(slotIndex - container.getSlotCount() + 1);
+				
+				slot = slotComponent.getSlot();
+				assert slot != null : "Could not allocate slot for index " + slotIndex;
+			} else {
+				// Leave slot null
+			}
+			
+		}
+		
+		return slot;
+	}
+
+	private void cleanContainerUpIfNecessary() {
+		ItemContainer container = slotComponent.getSlotContainer();
+		if (container instanceof ItemContainerMixed) {
+			((ItemContainerMixed) container).cleanUpSlots();
+		}
+	}
+
 }

src/main/java/ru/windcorp/progressia/client/graphics/world/hud/SlotComponent.java

@@ -33,14 +33,20 @@ import ru.windcorp.progressia.client.graphics.model.Shapes.PgmBuilder;
 import ru.windcorp.progressia.client.graphics.texture.Texture;
 import ru.windcorp.progressia.client.world.item.ItemRenderRegistry;
 import ru.windcorp.progressia.client.world.item.ItemRenderable;
-import ru.windcorp.progressia.common.world.item.ItemContainer;
 import ru.windcorp.progressia.common.world.item.ItemData;
 import ru.windcorp.progressia.common.world.item.ItemDataContainer;
-import ru.windcorp.progressia.common.world.item.ItemSlot;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainer;
+import ru.windcorp.progressia.common.world.item.inventory.ItemSlot;
 
 public class SlotComponent extends Component {
 
 	static final float TEXTURE_SIZE = 24;
+	
+	private static boolean drawVirtualSlots;
+	static {
+		String key = SlotComponent.class.getName() + ".drawVirtualSlots";
+		drawVirtualSlots = Boolean.parseBoolean(System.getProperty(key, "true"));
+	}
 
 	private static Renderable containerOpenDecoration = null;
 	private static Renderable containerOpenableDecoration = null;
@@ -84,6 +90,20 @@ public class SlotComponent extends Component {
 			).setSize(TEXTURE_SIZE + 2).setOrigin(-1, -1, 0).create();
 		}
 	}
+	
+	/**
+	 * @return the container
+	 */
+	public ItemContainer getSlotContainer() {
+		return container;
+	}
+	
+	/**
+	 * @return the index
+	 */
+	public int getSlotIndex() {
+		return index;
+	}
 
 	public ItemSlot getSlot() {
 		return container.getSlot(index);
@@ -121,7 +141,15 @@ public class SlotComponent extends Component {
 	}
 
 	private void updateItemRenderer() {
-		ItemData contents = getSlot().getContents();
+		ItemData contents;
+		
+		ItemSlot slot = getSlot();
+		
+		if (slot == null) {
+			contents = null;
+		} else {
+			contents = slot.getContents();
+		}
 
 		if (contents == null) {
 			itemRenderer = null;
@@ -132,7 +160,7 @@ public class SlotComponent extends Component {
 				itemRenderer = ItemRenderRegistry.getInstance().get(contents.getId()).createRenderable(contents);
 			}
 
-			int newAmount = getSlot().getAmount();
+			int newAmount = slot.getAmount();
 			if (newAmount != amountDisplayInt) {
 				amountDisplayInt = newAmount;
 				amountDisplayString = newAmount == 1 ? "" : Integer.toString(newAmount);
@@ -145,6 +173,13 @@ public class SlotComponent extends Component {
 		target.addCustomRenderer(renderer -> {
 
 			updateItemRenderer();
+			
+			if (drawVirtualSlots && getSlot() == null) {
+				renderer.pushColorMultiplier().set(Colors.DEBUG_GREEN);
+				containerOpenDecoration.render(renderer);
+				renderer.popColorMultiplier();
+				return;
+			}
 
 			if (itemRenderer != null) {
 				itemRenderer.render(renderer);

src/main/java/ru/windcorp/progressia/client/world/item/inventory/ContainerComponent.java

@@ -21,7 +21,7 @@ import java.util.Collection;
 
 import ru.windcorp.progressia.client.graphics.gui.Component;
 import ru.windcorp.progressia.client.graphics.world.hud.InteractiveSlotComponent;
-import ru.windcorp.progressia.common.world.item.ItemContainer;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainer;
 
 public abstract class ContainerComponent extends Component {
 

src/main/java/ru/windcorp/progressia/client/world/item/inventory/ContainerComponentSimple.java

@@ -20,6 +20,8 @@ package ru.windcorp.progressia.client.world.item.inventory;
 import java.util.ArrayList;
 import java.util.Collection;
 
+import com.google.common.eventbus.Subscribe;
+
 import glm.vec._2.i.Vec2i;
 import ru.windcorp.progressia.client.graphics.Colors;
 import ru.windcorp.progressia.client.graphics.gui.Component;
@@ -30,7 +32,9 @@ import ru.windcorp.progressia.client.graphics.gui.layout.LayoutGrid;
 import ru.windcorp.progressia.client.graphics.world.hud.Bar;
 import ru.windcorp.progressia.client.graphics.world.hud.HUDWorkspace;
 import ru.windcorp.progressia.client.graphics.world.hud.InteractiveSlotComponent;
-import ru.windcorp.progressia.common.world.item.ItemContainer;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainer;
+import ru.windcorp.progressia.common.world.item.inventory.event.ItemSlotAddedEvent;
+import ru.windcorp.progressia.common.world.item.inventory.event.ItemSlotRemovedEvent;
 
 public class ContainerComponentSimple extends ContainerComponent {
 
@@ -42,6 +46,10 @@ public class ContainerComponentSimple extends ContainerComponent {
 	public ContainerComponentSimple(ItemContainer container, HUDWorkspace workspace) {
 		super("Inventory");
 		this.container = container;
+		
+		if (container.getInventory() != null) {
+			container.getInventory().subscribe(this);
+		}
 
 		setLayout(new LayoutBorderHorizontal(15));
 
@@ -94,5 +102,15 @@ public class ContainerComponentSimple extends ContainerComponent {
 	public Collection<InteractiveSlotComponent> getSlots() {
 		return slotCollection;
 	}
+	
+	@Subscribe
+	private void onSlotAdded(ItemSlotAddedEvent e) {
+		
+	}
+	
+	@Subscribe
+	private void onSlotAdded(ItemSlotRemovedEvent e) {
+		
+	}
 
 }

src/main/java/ru/windcorp/progressia/client/world/item/inventory/InventoryComponentSimple.java

@@ -22,8 +22,8 @@ import java.util.Collection;
 
 import ru.windcorp.progressia.client.graphics.gui.layout.LayoutFill;
 import ru.windcorp.progressia.client.graphics.world.hud.HUDWorkspace;
-import ru.windcorp.progressia.common.world.item.ItemContainer;
 import ru.windcorp.progressia.common.world.item.inventory.Inventory;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainer;
 
 public class InventoryComponentSimple extends InventoryComponent {
 	

src/main/java/ru/windcorp/progressia/common/world/entity/EntityDataPlayer.java

@@ -23,11 +23,11 @@ import com.google.common.eventbus.Subscribe;
 import ru.windcorp.progressia.common.state.IntStateField;
 import ru.windcorp.progressia.common.state.ObjectStateField;
 import ru.windcorp.progressia.common.util.crash.ReportingEventBus;
-import ru.windcorp.progressia.common.world.item.ItemContainerEquipment;
-import ru.windcorp.progressia.common.world.item.ItemContainerHand;
-import ru.windcorp.progressia.common.world.item.inventory.InventoryClosingEvent;
-import ru.windcorp.progressia.common.world.item.inventory.InventoryOpenedEvent;
 import ru.windcorp.progressia.common.world.item.inventory.InventoryUser;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainerEquipment;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainerHand;
+import ru.windcorp.progressia.common.world.item.inventory.event.InventoryClosingEvent;
+import ru.windcorp.progressia.common.world.item.inventory.event.InventoryOpenedEvent;
 
 public class EntityDataPlayer extends EntityData implements InventoryUser {
 

src/main/java/ru/windcorp/progressia/common/world/entity/SpeciesDatalet.java

@@ -25,8 +25,8 @@ import ru.windcorp.progressia.common.state.Encodable;
 import ru.windcorp.progressia.common.state.IOContext;
 import ru.windcorp.progressia.common.world.entity.SpeciesData.EquipmentSlot;
 import ru.windcorp.progressia.common.world.entity.SpeciesData.Hand;
-import ru.windcorp.progressia.common.world.item.ItemContainerEquipment;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainerEquipment;
-import ru.windcorp.progressia.common.world.item.ItemContainerHand;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainerHand;
 
 public class SpeciesDatalet implements Encodable {
 

src/main/java/ru/windcorp/progressia/common/world/item/ItemDataContainer.java

@@ -20,6 +20,7 @@ package ru.windcorp.progressia.common.world.item;
 import ru.windcorp.progressia.common.state.ObjectStateField;
 import ru.windcorp.progressia.common.world.item.inventory.InventorySimple;
 import ru.windcorp.progressia.common.world.item.inventory.InventoryUser;
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainerMixedSimple;
 
 public class ItemDataContainer extends ItemData {
 

src/main/java/ru/windcorp/progressia/common/world/item/Items.java

@@ -17,6 +17,8 @@
  */
 package ru.windcorp.progressia.common.world.item;
 
+import ru.windcorp.progressia.common.world.item.inventory.ItemSlot;
+
 public class Items {
 
 	/**

src/main/java/ru/windcorp/progressia/common/world/item/inventory/Inventory.java

@@ -31,7 +31,8 @@ import ru.windcorp.progressia.common.state.Encodable;
 import ru.windcorp.progressia.common.state.IOContext;
 import ru.windcorp.progressia.common.util.crash.ReportingEventBus;
 import ru.windcorp.progressia.common.util.namespaces.Namespaced;
-import ru.windcorp.progressia.common.world.item.ItemContainer;
+import ru.windcorp.progressia.common.world.item.inventory.event.InventoryClosingEvent;
+import ru.windcorp.progressia.common.world.item.inventory.event.InventoryOpenedEvent;
 
 public class Inventory extends Namespaced implements Encodable {
 	
@@ -77,6 +78,13 @@ public class Inventory extends Namespaced implements Encodable {
 		eventBus.unregister(listener);
 	}
 	
+	/**
+	 * @return the eventBus
+	 */
+	public EventBus getEventBus() {
+		return eventBus;
+	}
+	
 	public synchronized boolean isUser(InventoryUser user) {
 		return users.contains(user);
 	}

src/main/java/ru/windcorp/progressia/common/world/item/inventory/InventorySimple.java

@@ -17,8 +17,6 @@
  */
 package ru.windcorp.progressia.common.world.item.inventory;
 
-import ru.windcorp.progressia.common.world.item.ItemContainer;
-
 public class InventorySimple extends Inventory {
 
 	public InventorySimple(String id, ItemContainer container) {

src/main/java/ru/windcorp/progressia/common/world/item/inventory/ItemContainer.java

@@ -15,7 +15,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item;
+package ru.windcorp.progressia.common.world.item.inventory;
 
 import java.util.Iterator;
 import java.util.NoSuchElementException;
@@ -23,7 +23,6 @@ import java.util.function.Consumer;
 
 import ru.windcorp.progressia.common.state.Encodable;
 import ru.windcorp.progressia.common.util.namespaces.Namespaced;
-import ru.windcorp.progressia.common.world.item.inventory.Inventory;
 
 /**
  * A collection of {@link ItemSlot}s representing a single storage unit. A
@@ -46,7 +45,7 @@ public abstract class ItemContainer extends Namespaced implements Encodable, Ite
 		return inventory;
 	}
 	
-	public void setInventory(Inventory inventory) {
+	protected void setInventory(Inventory inventory) {
 		this.inventory = inventory;
 	}
 

src/main/java/ru/windcorp/progressia/common/world/item/inventory/ItemContainerEquipment.java

@@ -15,7 +15,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item;
+package ru.windcorp.progressia.common.world.item.inventory;
 
 import ru.windcorp.progressia.common.Units;
 import ru.windcorp.progressia.common.world.entity.SpeciesData;

src/main/java/ru/windcorp/progressia/common/world/item/inventory/ItemContainerHand.java

@@ -15,7 +15,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item;
+package ru.windcorp.progressia.common.world.item.inventory;
 
 import ru.windcorp.progressia.common.Units;
 import ru.windcorp.progressia.common.world.entity.SpeciesData;

src/main/java/ru/windcorp/progressia/common/world/item/inventory/ItemContainerMixed.java

@@ -15,16 +15,23 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item;
+package ru.windcorp.progressia.common.world.item.inventory;
 
 import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.function.Consumer;
 
+import com.google.common.eventbus.Subscribe;
+
 import ru.windcorp.progressia.common.state.Encodable;
 import ru.windcorp.progressia.common.state.IOContext;
+import ru.windcorp.progressia.common.world.item.inventory.event.ItemSlotAddedEvent;
+import ru.windcorp.progressia.common.world.item.inventory.event.ItemSlotChangedEvent;
+import ru.windcorp.progressia.common.world.item.inventory.event.ItemSlotRemovedEvent;
 
 /**
  * An {@link ItemContainer} capable of storing multiple item stacks. The set
@@ -32,18 +39,25 @@ import ru.windcorp.progressia.common.state.IOContext;
  * at will.
  */
 public abstract class ItemContainerMixed extends ItemContainer {
+	
+	private final List<ItemSlot> slots = new ArrayList<>();
 
 	public ItemContainerMixed(String id) {
 		super(id);
 	}
-
+	
-	/**
+	@Override
-	 * Retrieves the modifiable {@link List} of all slots. Edits commissioned
+	protected void setInventory(Inventory inventory) {
-	 * through the returned object update the state of the container.
+		if (getInventory() != null) {
-	 * 
+			getInventory().unsubscribe(this);
-	 * @return a list view of this container
+		}
-	 */
+		
-	protected abstract List<ItemSlot> getSlots();
+		super.setInventory(inventory);
+		
+		if (getInventory() != null) {
+			getInventory().subscribe(this);
+		}
+	}
 
 	/**
 	 * Appends additional empty slots to the end of this container.
@@ -51,12 +65,16 @@ public abstract class ItemContainerMixed extends ItemContainer {
 	 * @param amount the amount of slots to add
 	 */
 	public synchronized void addSlots(int amount) {
-		List<ItemSlot> slots = getSlots();
+		Inventory inventory = getInventory();
 		
 		for (int i = 0; i < amount; ++i) {
 			ItemSlot slot = createSlot(slots.size());
 			slots.add(slot);
 			slot.setContainer(this);
+			
+			if (inventory != null) {
+				inventory.getEventBus().post(new ItemSlotAddedEvent(slot));
+			}
 		}
 	}
 	
@@ -68,24 +86,58 @@ public abstract class ItemContainerMixed extends ItemContainer {
 	 */
 	protected abstract ItemSlot createSlot(int index);
 	
+	@Subscribe
+	private void onSlotChanged(ItemSlotChangedEvent e) {
+		cleanUpSlots();
+	}
+	
+	public void cleanUpSlots() {
+		Inventory inventory = getInventory();
+		Collection<ItemSlotRemovedEvent> events = null;
+		
+		// Do not remove slot 0
+		for (int i = slots.size() - 1; i > 0; --i) {
+			ItemSlot slot = slots.get(i);
+			if (slot.isEmpty()) {
+				slots.remove(i);
+				
+				if (inventory != null) {
+					if (events == null) {
+						events = new ArrayList<>(slots.size() - i);
+					}
+					events.add(new ItemSlotRemovedEvent(slot));
+				}
+			} else {
+				break;
+			}
+		}
+		
+		if (events != null) {
+			// events != null only if inventory != null 
+			events.forEach(inventory.getEventBus()::post);
+		}
+	}
+	
 	@Override
 	public ItemSlot getSlot(int index) {
-		return getSlots().get(index);
+		if (index < 0 || index >= slots.size()) {
+			return null;
+		}
+		return slots.get(index);
 	}
 	
 	@Override
 	public int getSlotCount() {
-		return getSlots().size();
+		return slots.size();
 	}
 	
 	@Override
 	public void forEach(Consumer<? super ItemSlot> action) {
-		getSlots().forEach(action);
+		slots.forEach(action);
 	}
 
 	@Override
 	public synchronized void read(DataInput input, IOContext context) throws IOException {
-		List<ItemSlot> slots = getSlots();
 		synchronized (slots) {
 
 			int needSlots = input.readInt();
@@ -99,7 +151,7 @@ public abstract class ItemContainerMixed extends ItemContainer {
 				addSlots(needSlots);
 			} else {
 				while (slots.size() > needSlots) {
-					getSlots().remove(slots.size() - 1);
+					slots.remove(slots.size() - 1);
 				}
 
 				if (slots.size() < needSlots) {
@@ -116,7 +168,6 @@ public abstract class ItemContainerMixed extends ItemContainer {
 
 	@Override
 	public synchronized void write(DataOutput output, IOContext context) throws IOException {
-		List<ItemSlot> slots = getSlots();
 		synchronized (slots) {
 
 			output.writeInt(slots.size());
@@ -130,8 +181,8 @@ public abstract class ItemContainerMixed extends ItemContainer {
 	@Override
 	public void copy(Encodable destination) {
 		ItemContainerMixed container = (ItemContainerMixed) destination;
-		List<ItemSlot> mySlots = this.getSlots();
+		List<ItemSlot> mySlots = this.slots;
-		List<ItemSlot> containerSlots = container.getSlots();
+		List<ItemSlot> containerSlots = container.slots;
 
 		synchronized (mySlots) {
 			synchronized (containerSlots) {
@@ -147,7 +198,7 @@ public abstract class ItemContainerMixed extends ItemContainer {
 					container.addSlots(needSlots);
 				} else {
 					while (containerSlots.size() > needSlots) {
-						getSlots().remove(containerSlots.size() - 1);
+						slots.remove(containerSlots.size() - 1);
 					}
 
 					if (containerSlots.size() < needSlots) {

src/main/java/ru/windcorp/progressia/common/world/item/inventory/ItemContainerMixedSimple.java

@@ -15,15 +15,10 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item;
+package ru.windcorp.progressia.common.world.item.inventory;
-
-import java.util.ArrayList;
-import java.util.List;
 
 public class ItemContainerMixedSimple extends ItemContainerMixed {
 	
-	private final List<ItemSlot> list;
-	
 	private final float massLimit;
 	private final float volumeLimit;
 
@@ -33,17 +28,11 @@ public class ItemContainerMixedSimple extends ItemContainerMixed {
 	
 	public ItemContainerMixedSimple(String id, float massLimit, float volumeLimit, int startingSlots) {
 		super(id);
-		this.list = new ArrayList<>();
 		this.massLimit = massLimit;
 		this.volumeLimit = volumeLimit;
 		
 		addSlots(startingSlots);
 	}
-	
-	@Override
-	protected List<ItemSlot> getSlots() {
-		return list;
-	}
 
 	@Override
 	public ItemSlot createSlot(int index) {

src/main/java/ru/windcorp/progressia/common/world/item/inventory/ItemContainerSingle.java

@@ -15,7 +15,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item;
+package ru.windcorp.progressia.common.world.item.inventory;
 
 import java.io.DataInput;
 import java.io.DataOutput;

src/main/java/ru/windcorp/progressia/common/world/item/inventory/ItemSlot.java

@@ -15,7 +15,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item;
+package ru.windcorp.progressia.common.world.item.inventory;
 
 import java.io.DataInput;
 import java.io.DataOutput;
@@ -23,6 +23,9 @@ import java.io.IOException;
 
 import ru.windcorp.progressia.common.state.Encodable;
 import ru.windcorp.progressia.common.state.IOContext;
+import ru.windcorp.progressia.common.world.item.ItemData;
+import ru.windcorp.progressia.common.world.item.ItemDataRegistry;
+import ru.windcorp.progressia.common.world.item.inventory.event.ItemSlotChangedEvent;
 
 /**
  * An entity optionally containing an {@link ItemData}. Item slots are typically
@@ -42,6 +45,10 @@ public class ItemSlot implements Encodable {
 		return container;
 	}
 	
+	public Inventory getInventory() {
+		return getContainer().getInventory();
+	}
+	
 	/**
 	 * @param container the container to set
 	 */
@@ -76,6 +83,11 @@ public class ItemSlot implements Encodable {
 		this.amount = amount;
 		
 		checkState();
+		
+		Inventory inventory = getInventory();
+		if (inventory != null) {
+			inventory.getEventBus().post(new ItemSlotChangedEvent(this));
+		}
 	}
 
 	/**

src/main/java/ru/windcorp/progressia/common/world/item/inventory/event/InventoryClosingEvent.java

@@ -15,7 +15,10 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item.inventory;
+package ru.windcorp.progressia.common.world.item.inventory.event;
+
+import ru.windcorp.progressia.common.world.item.inventory.Inventory;
+import ru.windcorp.progressia.common.world.item.inventory.InventoryUser;
 
 public class InventoryClosingEvent extends InventoryEvent {
 	

src/main/java/ru/windcorp/progressia/common/world/item/inventory/event/InventoryEvent.java

@@ -15,7 +15,9 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item.inventory;
+package ru.windcorp.progressia.common.world.item.inventory.event;
+
+import ru.windcorp.progressia.common.world.item.inventory.Inventory;
 
 public abstract class InventoryEvent {
 	

src/main/java/ru/windcorp/progressia/common/world/item/inventory/event/InventoryOpenedEvent.java

@@ -15,7 +15,10 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
-package ru.windcorp.progressia.common.world.item.inventory;
+package ru.windcorp.progressia.common.world.item.inventory.event;
+
+import ru.windcorp.progressia.common.world.item.inventory.Inventory;
+import ru.windcorp.progressia.common.world.item.inventory.InventoryUser;
 
 public class InventoryOpenedEvent extends InventoryEvent {
 	

src/main/java/ru/windcorp/progressia/common/world/item/inventory/event/ItemContainerEvent.java

@@ -0,0 +1,38 @@
+/*
+ * Progressia
+ * Copyright (C)  2020-2021  Wind Corporation and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package ru.windcorp.progressia.common.world.item.inventory.event;
+
+import ru.windcorp.progressia.common.world.item.inventory.ItemContainer;
+
+public abstract class ItemContainerEvent extends InventoryEvent {
+	
+	private final ItemContainer container;
+
+	public ItemContainerEvent(ItemContainer container) {
+		super(container.getInventory());
+		this.container = container;
+	}
+	
+	/**
+	 * @return the container
+	 */
+	public ItemContainer getContainer() {
+		return container;
+	}
+
+}

src/main/java/ru/windcorp/progressia/common/world/item/inventory/event/ItemSlotAddedEvent.java

@@ -0,0 +1,28 @@
+/*
+ * Progressia
+ * Copyright (C)  2020-2021  Wind Corporation and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package ru.windcorp.progressia.common.world.item.inventory.event;
+
+import ru.windcorp.progressia.common.world.item.inventory.ItemSlot;
+
+public class ItemSlotAddedEvent extends ItemSlotEvent {
+
+	public ItemSlotAddedEvent(ItemSlot slot) {
+		super(slot);
+	}
+
+}

src/main/java/ru/windcorp/progressia/common/world/item/inventory/event/ItemSlotChangedEvent.java

@@ -0,0 +1,28 @@
+/*
+ * Progressia
+ * Copyright (C)  2020-2021  Wind Corporation and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package ru.windcorp.progressia.common.world.item.inventory.event;
+
+import ru.windcorp.progressia.common.world.item.inventory.ItemSlot;
+
+public class ItemSlotChangedEvent extends ItemSlotEvent {
+
+	public ItemSlotChangedEvent(ItemSlot slot) {
+		super(slot);
+	}
+
+}

src/main/java/ru/windcorp/progressia/common/world/item/inventory/event/ItemSlotEvent.java

@@ -0,0 +1,38 @@
+/*
+ * Progressia
+ * Copyright (C)  2020-2021  Wind Corporation and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package ru.windcorp.progressia.common.world.item.inventory.event;
+
+import ru.windcorp.progressia.common.world.item.inventory.ItemSlot;
+
+public abstract class ItemSlotEvent extends ItemContainerEvent {
+	
+	private final ItemSlot slot;
+
+	public ItemSlotEvent(ItemSlot slot) {
+		super(slot.getContainer());
+		this.slot = slot;
+	}
+	
+	/**
+	 * @return the slot
+	 */
+	public ItemSlot getSlot() {
+		return slot;
+	}
+
+}

src/main/java/ru/windcorp/progressia/common/world/item/inventory/event/ItemSlotRemovedEvent.java

@@ -0,0 +1,28 @@
+/*
+ * Progressia
+ * Copyright (C)  2020-2021  Wind Corporation and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package ru.windcorp.progressia.common.world.item.inventory.event;
+
+import ru.windcorp.progressia.common.world.item.inventory.ItemSlot;
+
+public class ItemSlotRemovedEvent extends ItemSlotEvent {
+
+	public ItemSlotRemovedEvent(ItemSlot slot) {
+		super(slot);
+	}
+
+}