Implements opening containers from items with and without a block context.

src/main/java/appeng/container/ContainerLocator.java

@@ -23,16 +23,16 @@ import appeng.api.parts.IPartHost;
 import appeng.api.util.AEPartLocation;
 import appeng.api.util.DimensionalCoord;
 import appeng.parts.AEBasePart;
-import appeng.parts.misc.PartInterface;
 import com.google.common.base.Preconditions;
 import io.netty.handler.codec.DecoderException;
 import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.ItemUseContext;
 import net.minecraft.network.PacketBuffer;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.Direction;
 import net.minecraft.util.Hand;
 import net.minecraft.util.math.BlockPos;
-import org.apache.commons.lang3.NotImplementedException;
 
 /**
  * Describes how a container the player has opened was originally
@@ -47,7 +47,16 @@ import org.apache.commons.lang3.NotImplementedException;
 public final class ContainerLocator {
 
     private enum Type {
-        ITEM,
+        /**
+         * An item used from the player's inventory.
+         */
+        PLAYER_INVENTORY,
+        /**
+         * An item used from the player's inventory, but right-clicked
+         * on a block face, has block position and side in addition to the
+         * above.
+         */
+        PLAYER_INVENTORY_WITH_BLOCK_CONTEXT,
         BLOCK,
         PART
     }
@@ -82,9 +91,38 @@ public final class ContainerLocator {
         return new ContainerLocator(Type.PART, -1, dimensionId, te.getPos(), AEPartLocation.fromFacing(side));
     }
 
-    public static ContainerLocator forHand(Hand hand) {
-        // FIXME can we get an inventory location for the hand?
-        throw new IllegalStateException();
+    /**
+     * Construct a container locator for an item being used on a block. The item could still open a container
+     * for itself, but it might also open a special container for the block being right-clicked.
+     */
+    public static ContainerLocator forItemUseContext(ItemUseContext context) {
+        PlayerEntity player = context.getPlayer();
+        if (player == null) {
+            throw new IllegalArgumentException("Cannot open a container without a player");
+        }
+        int dimensionId = player.world.getDimension().getType().getId();
+        int slot = getPlayerInventorySlotFromHand(player, context.getHand());
+        AEPartLocation side = AEPartLocation.fromFacing(context.getFace());
+        return new ContainerLocator(Type.PLAYER_INVENTORY_WITH_BLOCK_CONTEXT, slot, dimensionId, context.getPos(), side);
+    }
+
+    public static ContainerLocator forHand(PlayerEntity player, Hand hand) {
+        int slot = getPlayerInventorySlotFromHand(player, hand);
+        return new ContainerLocator(Type.PLAYER_INVENTORY, slot, -1, null, null);
+    }
+
+    private static int getPlayerInventorySlotFromHand(PlayerEntity player, Hand hand) {
+        ItemStack is = player.getHeldItem(hand);
+        if (is.isEmpty()) {
+            throw new IllegalArgumentException("Cannot open an item-inventory with empty hands");
+        }
+        int invSize = player.inventory.getSizeInventory();
+        for (int i = 0; i < invSize; i++) {
+            if (player.inventory.getStackInSlot(i) == is) {
+                return i;
+            }
+        }
+        throw new IllegalArgumentException("Could not find item held in hand " + hand + " in player inventory");
     }
 
     public static ContainerLocator forPart(AEBasePart part) {
@@ -100,11 +138,11 @@ public final class ContainerLocator {
     }
 
     public boolean hasItemIndex() {
-        return type == Type.ITEM;
+        return type == Type.PLAYER_INVENTORY || type == Type.PLAYER_INVENTORY_WITH_BLOCK_CONTEXT;
     }
 
     public int getItemIndex() {
-        Preconditions.checkState(type == Type.ITEM);
+        Preconditions.checkState(hasItemIndex());
         return itemIndex;
     }
 
@@ -113,36 +151,43 @@ public final class ContainerLocator {
     }
 
     public boolean hasBlockPos() {
-        return type == Type.BLOCK || type == Type.PART;
+        return type == Type.BLOCK || type == Type.PART || type == Type.PLAYER_INVENTORY_WITH_BLOCK_CONTEXT;
     }
 
     public BlockPos getBlockPos() {
-        Preconditions.checkState(type == Type.BLOCK || type == Type.PART);
+        Preconditions.checkState(hasBlockPos());
         return blockPos;
     }
 
     public boolean hasSide() {
-        return type == Type.PART;
+        return type == Type.PART || type == Type.PLAYER_INVENTORY_WITH_BLOCK_CONTEXT;
     }
 
     public AEPartLocation getSide() {
-        Preconditions.checkState(type == Type.PART);
+        Preconditions.checkState(hasSide());
         return side;
     }
 
     public void write(PacketBuffer buf) {
         switch (type) {
-            case ITEM:
+            case PLAYER_INVENTORY:
                 buf.writeByte(0);
                 buf.writeInt(itemIndex);
                 break;
-            case BLOCK:
+            case PLAYER_INVENTORY_WITH_BLOCK_CONTEXT:
                 buf.writeByte(1);
+                buf.writeInt(itemIndex);
+                buf.writeInt(dimensionId);
+                buf.writeBlockPos(blockPos);
+                buf.writeByte(side.ordinal());
+                break;
+            case BLOCK:
+                buf.writeByte(22);
                 buf.writeInt(dimensionId);
                 buf.writeBlockPos(blockPos);
                 break;
             case PART:
-                buf.writeByte(2);
+                buf.writeByte(3);
                 buf.writeInt(dimensionId);
                 buf.writeBlockPos(blockPos);
                 buf.writeByte(side.ordinal());
@@ -157,13 +202,21 @@ public final class ContainerLocator {
         switch (type) {
             case 0:
                 return new ContainerLocator(
-                        Type.ITEM,
+                        Type.PLAYER_INVENTORY,
                         buf.readInt(),
                         -1,
                         null,
                         null
                 );
             case 1:
+                return new ContainerLocator(
+                        Type.PLAYER_INVENTORY_WITH_BLOCK_CONTEXT,
+                        buf.readInt(),
+                        buf.readInt(),
+                        buf.readBlockPos(),
+                        AEPartLocation.values()[buf.readByte()]
+                );
+            case 2:
                 return new ContainerLocator(
                         Type.BLOCK,
                         -1,
@@ -171,7 +224,7 @@ public final class ContainerLocator {
                         buf.readBlockPos(),
                         null
                 );
-            case 2:
+            case 3:
                 return new ContainerLocator(
                         Type.PART,
                         -1,
@@ -184,4 +237,25 @@ public final class ContainerLocator {
         }
     }
 
+    @Override
+    public String toString() {
+        StringBuilder result = new StringBuilder(type.name());
+        result.append('{');
+        if (hasItemIndex()) {
+            result.append("slot=").append(itemIndex).append(',');
+        }
+        if (hasBlockPos()) {
+            result.append("dim=").append(dimensionId).append(',');
+            result.append("pos=").append(blockPos).append(',');
+        }
+        if (hasSide()) {
+            result.append("side=").append(side).append(',');
+        }
+        if (result.charAt(result.length() - 1) == ',') {
+            result.setLength(result.length() - 1);
+        }
+        result.append('}');
+        return result.toString();
+    }
+
 }