Differences

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--- tutorial:inventory [2019/08/06 15:31] – fudge
+++ tutorial:inventory [2019/08/07 06:59] – fudge
@@ Line 1: / Line 1: @@
 ====== Storing items in a block as an Inventory ======
+Make sure you've [[tutorial:blockentity|made a block entity]] before reading this tutorial.
 The standard way to store items in a BlockEntity is to make it an ''Inventory''.
 This allows hoppers (or other mods) to insert and extract items from your BlockEntity without any extra work.
@@ Line 110: / Line 112: @@
 }
 </code>
 Now in your ''BlockEntity'' Implement ''ImplementedInventory'',
 and provide it with an instance of ''DefaultedList<ItemStack> items'' that stores the items.
@@ Line 121: / Line 124: @@
         return items;
     }
-    ...
+    [...]
 }
 </code>
--->>>>>>>Remember markDirty() <<<<<<<<<--
 We're also gonna need to save the inventories to tag and load it from there.
 ''Inventories'' has helper methods that makes this very easy:
 <code java>
 public class DemoBlockEntity extends BlockEntity implements ImplementedInventory {
-    ...
+    [...]
     @Override
     public void fromTag(CompoundTag tag) {
@@ Line 145: / Line 147: @@
 }
 </code>
-===== Extracting and inserting from your inventory =====
+===== Extracting and inserting from your inventory (or any inventory) =====
-Remember that the same thing can be done with any inventory...
+In our block class, we'll override the `activate` behavior to insert and extract items from our inventory.
+Note that this can be done to any ''Inventory'' instance, not just our own (so you could do the same thing to a chest block, for example).
+First we'll handle inserting into the inventory. The player will insert the item he is holding if he is holding one.
+It'll go into the first slot if it is empty, or to the second slot if the first one is empty,
+or if the second is empty too we'll print some information about the inventory.
+Note that we call ''copy()'' when inserting the ''ItemStack'' into the inventory so it doesn't get destroyed alongside the player's ''ItemStack''.
+<code java>
+public class ExampleBlock extends Block implements BlockEntityProvider {
+    [...]
+    @Override
+    public boolean activate(BlockState blockState, World world, BlockPos blockPos, PlayerEntity player, Hand hand, BlockHitResult blockHitResult) {
+        if (world.isClient) return true;
+        Inventory blockEntity = (Inventory) world.getBlockEntity(blockPos);
+        if (!player.getStackInHand(hand).isEmpty()) {
+            // Check what is the first open slot and put an item from the player's hand there
+            if (blockEntity.getInvStack(0).isEmpty()) {
+                // Put the stack the player is holding into the inventory
+                blockEntity.setInvStack(0, player.getStackInHand(hand).copy());
+                // Remove the stack from the player's hand
+                player.getStackInHand(hand).setCount(0);
+            } else if (blockEntity.getInvStack(1).isEmpty()) {
+                blockEntity.setInvStack(1, player.getStackInHand(hand).copy());
+                player.getStackInHand(hand).setCount(0);
+            } else {
+                // If the inventory is full we'll print it's contents
+                System.out.println("The first slot holds "
+                        + blockEntity.getInvStack(0) + " and the second slot holds " + blockEntity.getInvStack(1));
+            }
+        }
+        return true;
+    }
+}
+</code>
+We'll have the opposite behavior when the player is not holding an item. We'll take the item from the second slot, and then the first one of the second is empty.
+If the first is empty as well we won't do anything.
+<code java>
+public class ExampleBlock extends Block implements BlockEntityProvider {
+    [...]
+    @Override
+    public boolean activate(BlockState blockState, World world, BlockPos blockPos, PlayerEntity player, Hand hand, BlockHitResult blockHitResult) {
+        ...
+        if (!player.getStackInHand(hand).isEmpty()) {
+            ...
+        } else {
+            // If the player is not holding anything we'll get give him the items in the block entity one by one
+            // Find the first slot that has an item and give it to the player
+            if (!blockEntity.getInvStack(1).isEmpty()) {
+                // Give the player the stack in the inventory
+                player.giveItemStack(blockEntity.getInvStack(1));
+                // Remove the stack from the inventory
+                blockEntity.removeInvStack(1);
+            } else if (!blockEntity.getInvStack(0).isEmpty()) {
+                player.giveItemStack(blockEntity.getInvStack(0));
+                blockEntity.removeInvStack(0);
+            }
+        }
+        return true;
+    }
+}
+</code>
+===== Implementing SidedInventory =====
+If you want to have different logic based on what side things (hopper or other mods) interact with your block
+you need to implement ''SidedInventory''.
+If say you wanted to make it so you cannot insert from the upper side of the block, you would do this:
+<code java>
+public class DemoBlockEntity extends BlockEntity implements ImplementedInventory, SidedInventory {
+    [...]
+    @Override
+    public int[] getInvAvailableSlots(Direction var1) {
+        // Just return an array of all slots
+        int[] result = new int[getItems().size()];
+        for (int i = 0; i < result.length; i++) {
+            result[i] = i;
+        }
+        return result;
+    }
+    @Override
+    public boolean canInsertInvStack(int slot, ItemStack stack, Direction direction) {
+        return direction != Direction.UP;
+    }
+    @Override
+    public boolean canExtractInvStack(int slot, ItemStack stack, Direction direction) {
+        return true;
+    }
+}
+</code>