feat: add selection direction

Author: mrtz6

paper-api/src/main/java/io/papermc/paper/event/inventory/PlayerBundleItemSelectEvent.java

@@ -29,9 +29,10 @@ public final class PlayerBundleItemSelectEvent extends InventoryEvent {
 
     private final int previousIndex;
     private final int selectedIndex;
+    private final int direction;
 
     @ApiStatus.Internal
-    public PlayerBundleItemSelectEvent(final InventoryView view, final ItemStack bundle, final int rawSlot, final ItemStack previousItem, final ItemStack selectedItem, final int previousIndex, final int selectedIndex) {
+    public PlayerBundleItemSelectEvent(final InventoryView view, final ItemStack bundle, final int rawSlot, final ItemStack previousItem, final ItemStack selectedItem, final int previousIndex, final int selectedIndex, final int direction) {
         super(view);
 
         this.bundle = bundle;
@@ -43,6 +44,7 @@ public PlayerBundleItemSelectEvent(final InventoryView view, final ItemStack bun
 
         this.previousIndex = previousIndex;
         this.selectedIndex = selectedIndex;
+        this.direction = direction;
     }
 
     /**
@@ -119,6 +121,15 @@ public int getSelectedIndex() {
         return this.selectedIndex;
     }
 
+    /**
+     * Gets the direction from the previous selection to the new one.
+     *
+     * @return +1 if forwards, -1 if backwards
+     */
+    public int getDirection() {
+        return this.direction;
+    }
+
     @Override
     public HandlerList getHandlers() {
         return HANDLER_LIST;

paper-server/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java

@@ -1613,7 +1613,7 @@ public static void callPlayerBundleItemSelectEvent(final net.minecraft.world.ent
             return;
         }
 
-        if (slotId < 0 || slotId >= player.containerMenu.slots.size() || selectedIndex == net.minecraft.world.item.component.BundleContents.NO_SELECTED_ITEM_INDEX) {
+        if (slotId < 0 || slotId >= player.containerMenu.slots.size() || selectedIndex <= net.minecraft.world.item.component.BundleContents.NO_SELECTED_ITEM_INDEX) {
             return;
         }
 
@@ -1623,18 +1623,36 @@ public static void callPlayerBundleItemSelectEvent(final net.minecraft.world.ent
         }
 
         final net.minecraft.world.item.component.BundleContents contents = item.get(net.minecraft.core.component.DataComponents.BUNDLE_CONTENTS);
-        if (contents == null || selectedIndex < 0 || selectedIndex >= contents.size()) {
+        if (contents == null) {
             return;
         }
 
+        final int previousIndex = contents.getSelectedItemIndex();
+        if (selectedIndex >= contents.size() || selectedIndex == previousIndex) {
+            return;
+        }
+
+        int direction;
+        if (previousIndex == -1) {
+            direction = selectedIndex == 0 ? 1 : -1;
+        } else {
+            int diff = selectedIndex - previousIndex;
+            direction = diff > 0 ? 1 : -1;
+
+            if (Math.abs(diff) == contents.size() - 1) {
+                direction = -direction;
+            }
+        }
+
         new io.papermc.paper.event.inventory.PlayerBundleItemSelectEvent(
             player.containerMenu.getBukkitView(),
             item.asBukkitMirror(),
             slotId,
             contents.getSelectedItem() != null ? contents.getSelectedItem().create().asBukkitMirror() : org.bukkit.inventory.ItemStack.empty(),
             contents.items().get(selectedIndex).create().asBukkitMirror(),
-            contents.getSelectedItemIndex(),
-            selectedIndex
+            previousIndex,
+            selectedIndex,
+            direction
         ).callEvent();
     }