Tracking forms in held item manager

src/battle-scene.ts

@@ -3167,17 +3167,11 @@ export default class BattleScene extends SceneBase {
       let matchingFormChange: SpeciesFormChange | null;
       if (pokemon.species.speciesId === SpeciesId.NECROZMA && matchingFormChangeOpts.length > 1) {
         // Ultra Necrozma is changing its form back, so we need to figure out into which form it devolves.
-        const formChangeItemModifiers = (
+        const formChangeItems = pokemon.heldItemManager.getActiveFormChangeItems();
-          this.findModifiers(
-            m => m instanceof PokemonFormChangeItemModifier && m.pokemonId === pokemon.id,
-          ) as PokemonFormChangeItemModifier[]
-        )
-          .filter(m => m.active)
-          .map(m => m.formChangeItem);
 
-        matchingFormChange = formChangeItemModifiers.includes(FormChangeItem.N_LUNARIZER)
+        matchingFormChange = formChangeItems.includes(FormChangeItem.N_LUNARIZER)
           ? matchingFormChangeOpts[0]
-          : formChangeItemModifiers.includes(FormChangeItem.N_SOLARIZER)
+          : formChangeItems.includes(FormChangeItem.N_SOLARIZER)
             ? matchingFormChangeOpts[1]
             : null;
       } else {

src/data/pokemon-forms.ts

@@ -1,4 +1,3 @@
-import { PokemonFormChangeItemModifier } from "../modifier/modifier";
 import type Pokemon from "../field/pokemon";
 import { StatusEffect } from "#enums/status-effect";
 import { allMoves } from "./data-lists";
@@ -135,6 +134,10 @@ export enum FormChangeItem {
   NORMAL_MEMORY, // TODO: Find a potential use for this
 }
 
+export function formChangeItemName(id: FormChangeItem) {
+  return i18next.t(`modifierType:FormChangeItem.${FormChangeItem[id]}`);
+}
+
 export type SpeciesFormChangeConditionPredicate = (p: Pokemon) => boolean;
 export type SpeciesFormChangeConditionEnforceFunc = (p: Pokemon) => void;
 
@@ -277,13 +280,11 @@ export class SpeciesFormChangeItemTrigger extends SpeciesFormChangeTrigger {
   }
 
   canChange(pokemon: Pokemon): boolean {
-    return !!globalScene.findModifier(
+    const matchItem = pokemon.heldItemManager.hasFormChangeItem(this.item);
-      m =>
+    if (!matchItem) {
-        m instanceof PokemonFormChangeItemModifier &&
+      return false;
-        m.pokemonId === pokemon.id &&
+    }
-        m.formChangeItem === this.item &&
+    return pokemon.heldItemManager.formChangeItems[this.item].active === this.active;
-        m.active === this.active,
-    );
   }
 }
 

src/field/pokemon-held-item-manager.ts

@@ -1,5 +1,6 @@
 import { allHeldItems } from "#app/items/all-held-items";
 import type { HeldItemId } from "#app/enums/held-item-id";
+import type { FormChangeItem } from "#app/data/pokemon-forms";
 
 interface HeldItemProperties {
   stack: number;
@@ -11,8 +12,17 @@ type HeldItemPropertyMap = {
   [key in HeldItemId]: HeldItemProperties;
 };
 
+interface FormChangeItemProperties {
+  active: boolean;
+}
+
+type FormChangeItemPropertyMap = {
+  [key in FormChangeItem]: FormChangeItemProperties;
+};
+
 export class PokemonItemManager {
   public heldItems: HeldItemPropertyMap;
+  public formChangeItems: FormChangeItemPropertyMap;
 
   constructor() {
     this.heldItems = {};
@@ -53,4 +63,32 @@ export class PokemonItemManager {
       delete this.heldItems[itemType];
     }
   }
+
+  addFormChangeItem(id: FormChangeItem) {
+    if (!(id in this.formChangeItems)) {
+      this.formChangeItems[id] = { active: false };
+    }
+  }
+
+  hasFormChangeItem(id: FormChangeItem): boolean {
+    return id in this.formChangeItems;
+  }
+
+  hasActiveFormChangeItem(id: FormChangeItem): boolean {
+    return id in this.formChangeItems && this.formChangeItems[id].active;
+  }
+
+  getFormChangeItems(): FormChangeItem[] {
+    return Object.keys(this.formChangeItems).map(k => Number(k));
+  }
+
+  getActiveFormChangeItems(): FormChangeItem[] {
+    return this.getFormChangeItems().filter(m => this.formChangeItems[m].active);
+  }
+
+  toggleActive(id: FormChangeItem) {
+    if (id in this.formChangeItems) {
+      this.formChangeItems[id].active = !this.formChangeItems[id].active;
+    }
+  }
 }

src/modifier/modifier-type.ts

@@ -8,6 +8,7 @@ import { getNatureName, getNatureStatMultiplier } from "#app/data/nature";
 import { getPokeballCatchMultiplier, getPokeballName, MAX_PER_TYPE_POKEBALLS } from "#app/data/pokeball";
 import {
   FormChangeItem,
+  formChangeItemName,
   pokemonFormChanges,
   SpeciesFormChangeCondition,
   SpeciesFormChangeItemTrigger,
@@ -1400,7 +1401,7 @@ export class FormChangeItemModifierType extends PokemonModifierType implements G
   }
 
   get name(): string {
-    return i18next.t(`modifierType:FormChangeItem.${FormChangeItem[this.formChangeItem]}`);
+    return formChangeItemName(this.formChangeItem);
   }
 
   getDescription(): string {

src/ui/party-ui-handler.ts

@@ -6,7 +6,7 @@ import { Command } from "#app/ui/command-ui-handler";
 import MessageUiHandler from "#app/ui/message-ui-handler";
 import { UiMode } from "#enums/ui-mode";
 import { BooleanHolder, toReadableString, randInt, getLocalizedSpriteKey } from "#app/utils/common";
-import { PokemonFormChangeItemModifier, PokemonHeldItemModifier } from "#app/modifier/modifier";
+import { PokemonHeldItemModifier } from "#app/modifier/modifier";
 import { ForceSwitchOutAttr } from "#app/data/moves/move";
 import { allMoves } from "#app/data/data-lists";
 import { Gender, getGenderColor, getGenderSymbol } from "#app/data/gender";
@@ -14,7 +14,7 @@ import { StatusEffect } from "#enums/status-effect";
 import PokemonIconAnimHandler, { PokemonIconAnimMode } from "#app/ui/pokemon-icon-anim-handler";
 import { pokemonEvolutions } from "#app/data/balance/pokemon-evolutions";
 import { addWindow } from "#app/ui/ui-theme";
-import { SpeciesFormChangeItemTrigger, FormChangeItem } from "#app/data/pokemon-forms";
+import { SpeciesFormChangeItemTrigger, FormChangeItem, formChangeItemName } from "#app/data/pokemon-forms";
 import { getVariantTint } from "#app/sprites/variant";
 import { Button } from "#enums/buttons";
 import { applyChallenges, ChallengeType } from "#app/data/challenge";
@@ -750,9 +750,9 @@ export default class PartyUiHandler extends MessageUiHandler {
       globalScene.phaseManager.getCurrentPhase()?.is("SelectModifierPhase") &&
       this.partyUiMode === PartyUiMode.CHECK
     ) {
-      const formChangeItemModifiers = this.getFormChangeItemsModifiers(pokemon);
+      const formChangeItems = this.getFormChangeItems(pokemon);
-      const modifier = formChangeItemModifiers[option - PartyOption.FORM_CHANGE_ITEM];
+      const item = formChangeItems[option - PartyOption.FORM_CHANGE_ITEM];
-      modifier.active = !modifier.active;
+      pokemon.heldItemManager.toggleActive(item);
       globalScene.triggerPokemonFormChange(pokemon, SpeciesFormChangeItemTrigger, false, true);
     }
 
@@ -1332,8 +1332,8 @@ export default class PartyUiHandler extends MessageUiHandler {
         break;
       case PartyUiMode.CHECK:
         if (globalScene.phaseManager.getCurrentPhase()?.is("SelectModifierPhase")) {
-          const formChangeItemModifiers = this.getFormChangeItemsModifiers(pokemon);
+          const formChangeItems = this.getFormChangeItems(pokemon);
-          for (let i = 0; i < formChangeItemModifiers.length; i++) {
+          for (let i = 0; i < formChangeItems.length; i++) {
             this.options.push(PartyOption.FORM_CHANGE_ITEM + i);
           }
         }
@@ -1393,10 +1393,10 @@ export default class PartyUiHandler extends MessageUiHandler {
             }
             break;
           default:
-            const formChangeItemModifiers = this.getFormChangeItemsModifiers(pokemon);
+            const formChangeItems = this.getFormChangeItems(pokemon);
-            if (formChangeItemModifiers && option >= PartyOption.FORM_CHANGE_ITEM) {
+            if (formChangeItems && option >= PartyOption.FORM_CHANGE_ITEM) {
-              const modifier = formChangeItemModifiers[option - PartyOption.FORM_CHANGE_ITEM];
+              const item = formChangeItems[option - PartyOption.FORM_CHANGE_ITEM];
-              optionName = `${modifier.active ? i18next.t("partyUiHandler:DEACTIVATE") : i18next.t("partyUiHandler:ACTIVATE")} ${modifier.type.name}`;
+              optionName = `${pokemon.heldItemManager.hasActiveFormChangeItem(item) ? i18next.t("partyUiHandler:DEACTIVATE") : i18next.t("partyUiHandler:ACTIVATE")} ${formChangeItemName(item)}`;
             } else if (option === PartyOption.UNPAUSE_EVOLUTION) {
               optionName = `${pokemon.pauseEvolutions ? i18next.t("partyUiHandler:UNPAUSE_EVOLUTION") : i18next.t("partyUiHandler:PAUSE_EVOLUTION")}`;
             } else {
@@ -1555,29 +1555,24 @@ export default class PartyUiHandler extends MessageUiHandler {
     });
   }
 
-  getFormChangeItemsModifiers(pokemon: Pokemon) {
+  getFormChangeItems(pokemon: Pokemon) {
-    let formChangeItemModifiers = globalScene.findModifiers(
+    let formChangeItems = pokemon.heldItemManager.getFormChangeItems();
-      m => m instanceof PokemonFormChangeItemModifier && m.pokemonId === pokemon.id,
+    const hasActiveFormChangeItems = pokemon.heldItemManager.getFormChangeItems().length;
-    ) as PokemonFormChangeItemModifier[];
+    const ultraNecrozmaActive = pokemon.heldItemManager.hasActiveFormChangeItem(FormChangeItem.ULTRANECROZIUM_Z);
-    const ultraNecrozmaModifiers = formChangeItemModifiers.filter(
+    if (ultraNecrozmaActive) {
-      m => m.active && m.formChangeItem === FormChangeItem.ULTRANECROZIUM_Z,
-    );
-    if (ultraNecrozmaModifiers.length > 0) {
       // ULTRANECROZIUM_Z is active and deactivating it should be the only option
-      return ultraNecrozmaModifiers;
+      return [FormChangeItem.ULTRANECROZIUM_Z];
     }
-    if (formChangeItemModifiers.find(m => m.active)) {
+    if (hasActiveFormChangeItems) {
       // a form is currently active. the user has to disable the form or activate ULTRANECROZIUM_Z
-      formChangeItemModifiers = formChangeItemModifiers.filter(
+      formChangeItems = formChangeItems.filter(
-        m => m.active || m.formChangeItem === FormChangeItem.ULTRANECROZIUM_Z,
+        m => pokemon.heldItemManager.hasActiveFormChangeItem(m) || m === FormChangeItem.ULTRANECROZIUM_Z,
       );
     } else if (pokemon.species.speciesId === SpeciesId.NECROZMA) {
       // no form is currently active. the user has to activate some form, except ULTRANECROZIUM_Z
-      formChangeItemModifiers = formChangeItemModifiers.filter(
+      formChangeItems = formChangeItems.filter(m => m !== FormChangeItem.ULTRANECROZIUM_Z);
-        m => m.formChangeItem !== FormChangeItem.ULTRANECROZIUM_Z,
-      );
     }
-    return formChangeItemModifiers;
+    return formChangeItems;
   }
 
   getOptionsCursorWithScroll(): number {