Merge branch 'fix/equip-one-not-whole' into 'main'

fix: equipping stackable items now equips one item of stack

See merge request cable-mc/cobblemon!2469

CHANGELOG.md

@@ -169,7 +169,7 @@
 - Fixed crashes for addon species with non-Cobblemon namespaces, in evolution, fishing bait and Pokédex lookups.
 - Bees now grow Apricorns and the Galarica Nut Bush, which were in the bee growables tag but never handled, and correctly spend their nectar when they do
 - Saccharine Leaves can now be bone mealed
-
+- Fixed equipping a stack of items instead of one item of a stack
 ### Developer
 - Evolution requirements can now set `pokedexIcon` and `pokedexTooltip` directly in their JSON to control how they're shown on the Pokédex's evolution tree, for example:
   ```json

common/src/main/kotlin/com/cobblemon/mod/common/item/WearableHatItem.kt

@@ -19,14 +19,13 @@ import net.minecraft.world.level.Level
 
 class WearableHatItem(override val name: String): CobblemonItem(Properties()), WearableItem {
     override fun use(level: Level, player: Player, usedHand: InteractionHand): InteractionResultHolder<ItemStack> {
-        val itemStack = player.getItemInHand(usedHand)
         val hitPokemon = player.traceFirstEntityCollision(
             entityClass = PokemonEntity::class.java,
             maxDistance = player.entityInteractionRange().toFloat()
         )
         // If the player is looking at a Pokémon within range, block the ability to swap the item onto their head
-        return if (player.isCrouching && hitPokemon != null && hitPokemon.isOwnedBy(player)) {
-            InteractionResultHolder.fail(itemStack)
-        } else this.swapWithEquipmentSlot(this, level, player, usedHand)
+        if (player.isCrouching && hitPokemon != null && hitPokemon.isOwnedBy(player)) return InteractionResultHolder.fail(player.getItemInHand(usedHand))
+
+        return this.swapStackWithEquipmentSlot(level, player, usedHand)
     }
-}
+}

common/src/main/kotlin/com/cobblemon/mod/common/item/WearableItem.kt

@@ -10,10 +10,18 @@ package com.cobblemon.mod.common.item
 
 import com.cobblemon.mod.common.util.cobblemonResource
 import net.minecraft.resources.ResourceLocation
+import net.minecraft.stats.Stats
+import net.minecraft.world.InteractionHand
+import net.minecraft.world.InteractionResultHolder
 import net.minecraft.world.entity.EquipmentSlot
+import net.minecraft.world.entity.player.Player
 import net.minecraft.world.item.Equipable
+import net.minecraft.world.item.ItemStack
+import net.minecraft.world.item.enchantment.EnchantmentEffectComponents.PREVENT_ARMOR_CHANGE
+import net.minecraft.world.item.enchantment.EnchantmentHelper
+import net.minecraft.world.level.Level
 
-interface WearableItem: Equipable {
+interface WearableItem : Equipable {
     val name: String
 
     companion object {
@@ -23,5 +31,43 @@ interface WearableItem: Equipable {
     fun getModel3d(): ResourceLocation = cobblemonResource("${MODEL_PATH}/${this.name}")
     fun getModel2d(): ResourceLocation = cobblemonResource(this.name)
 
-    override fun getEquipmentSlot(): EquipmentSlot { return EquipmentSlot.HEAD }
-}
+    override fun getEquipmentSlot(): EquipmentSlot {
+        return EquipmentSlot.HEAD
+    }
+
+    /**
+     * Swap stack with equipment slot
+     * Copied from vanilla, modified to account for stackable items
+     * @see Equipable.swapWithEquipmentSlot
+     *
+     * @param item
+     * @param level
+     * @param player
+     * @param hand
+     * @return the interaction result holder
+     */
+    fun swapStackWithEquipmentSlot(
+        level: Level,
+        player: Player,
+        hand: InteractionHand
+    ): InteractionResultHolder<ItemStack> {
+        var itemStack = player.getItemInHand(hand)
+        val equipmentSlot = player.getEquipmentSlotForItem(itemStack)
+
+        if (!player.canUseSlot(equipmentSlot)) return InteractionResultHolder.pass(itemStack)
+
+        val slotStack = player.getItemBySlot(equipmentSlot)
+
+        if (!(!EnchantmentHelper.has(slotStack, PREVENT_ARMOR_CHANGE) || player.isCreative) || ItemStack.matches(itemStack, slotStack)) return InteractionResultHolder.fail(itemStack)
+        if (!level.isClientSide()) player.awardStat(Stats.ITEM_USED.get(itemStack.item))
+
+        val equipStack = itemStack.split(1)
+        when {
+            itemStack.isEmpty -> itemStack = slotStack.copyAndClear()
+            else -> player.addItem(slotStack.copyAndClear())
+        }
+
+        player.setItemSlot(equipmentSlot, equipStack)
+        return InteractionResultHolder.sidedSuccess(itemStack, level.isClientSide())
+    }
+}