keep backpack content by tags in compound

src/main/java/de/jottyfan/minecraft/quickiefabric/container/BackpackInventory.java

@@ -1,5 +1,8 @@
 package de.jottyfan.minecraft.quickiefabric.container;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 import de.jottyfan.minecraft.quickiefabric.items.ItemBackpack;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.inventory.Inventories;
@@ -9,16 +12,23 @@ import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.ListTag;
 import net.minecraft.sound.SoundCategory;
 import net.minecraft.sound.SoundEvents;
+import net.minecraft.util.Hand;
 import net.minecraft.util.collection.DefaultedList;
 
+/**
+ * 
+ * @author jotty
+ *
+ */
 public class BackpackInventory implements Inventory {
-	public static final int SECTION_SIZE = 9;
+	private final static Logger LOGGER = LogManager.getLogger(BackpackInventory.class);
 	private final DefaultedList<ItemStack> stacks;
 	private final BackpackScreenHandler handler;
+	private Hand hand;
 
 	private BackpackInventory(CompoundTag tag, BackpackScreenHandler handler) {
 		this.handler = handler;
-		this.stacks = DefaultedList.ofSize(SECTION_SIZE * ItemBackpack.SLOTSIZE, ItemStack.EMPTY);
+		this.stacks = DefaultedList.ofSize(ItemBackpack.SLOTSIZE, ItemStack.EMPTY);
 		readItemsFromTag(this.stacks, tag);
 	}
 
@@ -35,35 +45,6 @@ public class BackpackInventory implements Inventory {
 		return new BackpackInventory(stack.getTag().getCompound("backpack"), handler);
 	}
 
-	private void readItemsFromTag(DefaultedList<ItemStack> inventory, CompoundTag tag) {
-		ListTag listTag = tag.getList("items", 10);
-		for (int i = 0; i < listTag.size(); ++i) {
-			CompoundTag compoundTag = listTag.getCompound(i);
-			int j = compoundTag.getInt("slot");
-
-			if (j >= 0 && j < inventory.size()) {
-				inventory.set(j, ItemStack.fromTag(compoundTag));
-			}
-		}
-	}
-
-	private CompoundTag writeItemsToTag() {
-		DefaultedList<ItemStack> inventory = stacks;
-		ListTag listTag = new ListTag();
-		for (int i = 0; i < inventory.size(); ++i) {
-			ItemStack itemStack = (ItemStack) inventory.get(i);
-			if (!itemStack.isEmpty()) {
-				CompoundTag compoundTag = new CompoundTag();
-				compoundTag.putInt("slot", i);
-				itemStack.toTag(compoundTag);
-				listTag.add(compoundTag);
-			}
-		}
-		CompoundTag tag = new CompoundTag();
-		tag.put("items", listTag);
-		return tag;
-	}
-
 	public DefaultedList<ItemStack> getList() {
 		return stacks;
 	}
@@ -110,6 +91,7 @@ public class BackpackInventory implements Inventory {
 
 	@Override
 	public void setStack(int slot, ItemStack stack) {
+//		LOGGER.info("set slot {} item stack {}x {}", slot, stack.getCount(), stack.getItem().getName());
 		this.stacks.set(slot, stack);
 		markDirty();
 	}
@@ -121,7 +103,8 @@ public class BackpackInventory implements Inventory {
 
 	@Override
 	public void markDirty() {
-		handler.onContentChanged(this);
+//		LOGGER.info("dirty marked");
+//		handler.onContentChanged(this);
 	}
 
 	@Override
@@ -133,13 +116,47 @@ public class BackpackInventory implements Inventory {
 	@Override
 	public void onClose(PlayerEntity player) {
 		Inventory.super.onClose(player);
-		ItemStack stack = handler.getStack();
+		ItemStack stack = player.getStackInHand(hand);
 		if (stack != null) {
 			if (!stack.hasTag()) {
 				stack.setTag(new CompoundTag());
 			}
 			stack.getTag().put("backpack", writeItemsToTag());
 		}
+		player.getStackInHand(hand).setTag(stack.getTag());
 		player.playSound(SoundEvents.BLOCK_WOOL_PLACE, SoundCategory.PLAYERS, 1f, 1f);
 	}
+
+	private void readItemsFromTag(DefaultedList<ItemStack> inventory, CompoundTag tag) {
+		ListTag listTag = tag.getList("items", 10);
+		for (int i = 0; i < listTag.size(); ++i) {
+			CompoundTag compoundTag = listTag.getCompound(i);
+			int j = compoundTag.getInt("slot");
+
+			if (j >= 0 && j < inventory.size()) {
+				inventory.set(j, ItemStack.fromTag(compoundTag));
+			}
+		}
+	}
+
+	private CompoundTag writeItemsToTag() {
+		DefaultedList<ItemStack> inventory = stacks;
+		ListTag listTag = new ListTag();
+		for (int i = 0; i < inventory.size(); ++i) {
+			ItemStack itemStack = (ItemStack) inventory.get(i);
+			if (!itemStack.isEmpty()) {
+				CompoundTag compoundTag = new CompoundTag();
+				compoundTag.putInt("slot", i);
+				compoundTag = itemStack.toTag(compoundTag);
+				listTag.add(compoundTag);
+			}
+		}
+		CompoundTag tag = new CompoundTag();
+		tag.put("items", listTag);
+		return tag;
+	}
+	
+	public void setHand(Hand hand) {
+		this.hand = hand;
+	}
 }

src/main/java/de/jottyfan/minecraft/quickiefabric/container/BackpackScreen.java

@@ -15,9 +15,12 @@ import net.minecraft.text.TranslatableText;
 import net.minecraft.util.Identifier;
 
 @Environment(EnvType.CLIENT)
-public class BackpackScreen extends HandledScreen<BackpackScreenHandler> implements ScreenHandlerProvider<BackpackScreenHandler> {
+public class BackpackScreen extends HandledScreen<BackpackScreenHandler>
-	private final static Identifier TEXTURE = new Identifier(RegistryManager.QUICKIEFABRIC, "textures/gui/backpack.png");
+		implements ScreenHandlerProvider<BackpackScreenHandler> {
-	private final static Identifier SLOT_TEXTURE = new Identifier(RegistryManager.QUICKIEFABRIC, "textures/gui/slot.png");
+	private final static Identifier TEXTURE = new Identifier(RegistryManager.QUICKIEFABRIC,
+			"textures/gui/backpack.png");
+	private final static Identifier SLOT_TEXTURE = new Identifier(RegistryManager.QUICKIEFABRIC,
+			"textures/gui/slot.png");
 	private int slots;
 	private final Integer containerHeight = 222;
 	private final Integer containerWidth = 176;
@@ -65,8 +68,7 @@ public class BackpackScreen extends HandledScreen<BackpackScreenHandler> impleme
 	}
 
 	@Override
-  protected void drawForeground(MatrixStack matrixStack, int i, int j)
+	protected void drawForeground(MatrixStack matrixStack, int i, int j) {
-  {
 		this.textRenderer.draw(matrixStack, this.title, 8.0F, -20.0F, 4210752);
 		this.textRenderer.draw(matrixStack, this.playerInventory.getDisplayName(), 8.0F, 101f, 4210752);
 	}

src/main/java/de/jottyfan/minecraft/quickiefabric/container/BackpackScreenHandler.java

@@ -4,17 +4,17 @@ import de.jottyfan.minecraft.quickiefabric.init.RegistryManager;
 import de.jottyfan.minecraft.quickiefabric.items.ItemBackpack;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.entity.player.PlayerInventory;
-import net.minecraft.inventory.Inventory;
 import net.minecraft.item.ItemStack;
 import net.minecraft.network.PacketByteBuf;
 import net.minecraft.screen.ScreenHandler;
 import net.minecraft.screen.slot.Slot;
-import net.minecraft.util.collection.DefaultedList;
+import net.minecraft.util.Hand;
 
 public class BackpackScreenHandler extends ScreenHandler {
 
 	private final BackpackInventory backpackInventory;
 	private final PlayerEntity player;
+	private final Hand hand;
 	private final ItemStack stack; // the stack of the backpack item
 	private int backpackSlotSize;
 
@@ -22,6 +22,7 @@ public class BackpackScreenHandler extends ScreenHandler {
 		super(RegistryManager.BACKPACK_SCREEN_HANDLER, syncId);
 		this.player = playerInventory.player;
 		this.stack = buf.readItemStack();
+		this.hand = buf.readByte() > 0 ? Hand.MAIN_HAND : Hand.OFF_HAND;
 		this.backpackInventory = BackpackInventory.getInventory(this, player, stack);
 		backpackSlotSize = ItemBackpack.SLOTSIZE;
 
@@ -41,20 +42,6 @@ public class BackpackScreenHandler extends ScreenHandler {
 		for (int x = 0; x < 9; ++x) {
 			this.addSlot(new Slot(playerInventory, x, 8 + x * 18, 58 + spacing));
 		}
-		playerInventory.onOpen(player);
-		
-		DefaultedList<ItemStack> backpackSlots = backpackInventory.getList();
-		if (backpackSlots.size() == 0) {
-			return;
-		}
-		for (int x = 0; x < 9; x++) {
-			for (int y = 0; y < backpackSlotSize / 9; y++) {
-				this.getSlot(x + y * 9).setStack(backpackSlots.get(x + y * 9));
-			}
-		}
-		for (int x = 0; x < (backpackSlotSize % 9); x++) {
-			this.getSlot(x + (backpackSlotSize / 9) * 9).setStack(backpackSlots.get(x + (backpackSlotSize / 9) * 9));
-		}
 	}
 
 	public PlayerEntity getPlayer() {
@@ -66,24 +53,13 @@ public class BackpackScreenHandler extends ScreenHandler {
 		return true;
 	}
 
-	@Override
-	public void onContentChanged(Inventory inv) {
-		super.onContentChanged(inv);
-		if (inv == this.backpackInventory) {
-			this.updateInv();
-		}
-	}
-
 	@Override
 	public void close(PlayerEntity player) {
 		super.close(player);
+		this.backpackInventory.setHand(hand);
 		this.backpackInventory.onClose(player);
 	}
 
-	public void updateInv() {
-		this.sendContentUpdates();
-	}
-
 	@Override
 	public ItemStack transferSlot(PlayerEntity player, int slotNum) {
 		ItemStack copy = ItemStack.EMPTY;

src/main/java/de/jottyfan/minecraft/quickiefabric/items/ItemBackpack.java

@@ -39,6 +39,7 @@ public class ItemBackpack extends Item implements DyeableItem {
 				@Override
 				public void writeScreenOpeningData(ServerPlayerEntity serverPlayerEntity, PacketByteBuf packetByteBuf) {
 					packetByteBuf.writeItemStack(itemStack);
+					packetByteBuf.writeByte(hand == Hand.MAIN_HAND ? 1 : 0);
 				}
 
 				@Override
@@ -50,6 +51,7 @@ public class ItemBackpack extends Item implements DyeableItem {
 				public ScreenHandler createMenu(int syncId, PlayerInventory inv, PlayerEntity player) {
 					PacketByteBuf buf = new PacketByteBuf(Unpooled.buffer());
 					buf.writeItemStack(itemStack);
+					buf.writeByte(hand == Hand.MAIN_HAND ? 1 : 0);
 					return new BackpackScreenHandler(syncId, inv, buf);
 				}
 			});