How to use

ChangelingAbility

in

mage.abilities.keyword

@Override
public void watch(GameEvent event, Game game) {
  if (event.getType() == EventType.DAMAGED_PLAYER) {
    DamagedPlayerEvent dEvent = (DamagedPlayerEvent) event;
    if (dEvent.isCombatDamage()) {
      Permanent creature = game.getPermanent(dEvent.getSourceId());
      if (creature != null && !allSubtypes.contains(creature.getControllerId())) {
        if (creature.getAbilities().containsKey(ChangelingAbility.getInstance().getId()) || creature.isAllCreatureTypes()) {
          allSubtypes.add(creature.getControllerId());
        } else {
          Set<SubType> subtypes = damagingSubtypes.getOrDefault(creature.getControllerId(), new LinkedHashSet<>());
          subtypes.addAll(creature.getSubtype(game));
          damagingSubtypes.put(creature.getControllerId(), subtypes);
        }
      }
    }
  }
}

  @Override
  public boolean apply(Game game, Ability source) {
    for (Iterator<MageObjectReference> it = affectedObjectList.iterator(); it.hasNext();) {
      Permanent permanent = it.next().getPermanent(game);
      if (permanent != null) {
        permanent.addAbility(ChangelingAbility.getInstance(), source.getSourceId(), game, false);
      } else {
        it.remove();
      }
    }
    return true;
  }
}

public CribSwapShapeshifterWhiteToken() {
  super("Shapeshifter", "1/1 colorless Shapeshifter creature token with changeling");
  this.setOriginalExpansionSetCode("LRW");
  cardType.add(CardType.CREATURE);
  subtype.add(SubType.SHAPESHIFTER);
  power = new MageInt(1);
  toughness = new MageInt(1);
  addAbility(ChangelingAbility.getInstance());
}

public DrJuliusJumblemorph(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{2}{G}{W}");
  this.addSuperType(SuperType.LEGENDARY);
  this.power = new MageInt(4);
  this.toughness = new MageInt(4);
  // Dr. Julius Jumblemorph is every creature type (even if this card isn't on the battlefield).
  this.addAbility(ChangelingAbility.getInstance());
  
  // Whenever a host enters the battlefield under your control, you may search your library and/or graveyard for a card with augment and combine it with that host. If you search your library this way, shuffle it.
  // TODO: Host currently isn't implemented, so this ability currently would never trigger
}

boolean changeling = false;
boolean changeling2 = false;
if (creature.getAbilities().containsKey(ChangelingAbility.getInstance().getId()) || creature.isAllCreatureTypes()) {
  changeling = true;
if (creature2.getAbilities().containsKey(ChangelingAbility.getInstance().getId()) || creature2.isAllCreatureTypes()) {
  changeling2 = true;

public WoodlandChangeling(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{1}{G}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(2);
  this.toughness = new MageInt(2);
  // Changeling
  this.addAbility(ChangelingAbility.getInstance());
}

public MistformUltimus(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{3}{U}");
  
  this.addSuperType(SuperType.LEGENDARY);
  this.subtype.add(SubType.ILLUSION);
  this.power = new MageInt(3);
  this.toughness = new MageInt(3);
  // Mistform Ultimus is every creature type.
  this.addAbility(ChangelingAbility.getInstance());
}

default boolean shareSubtypes(Card otherCard, Game game) {
  if (otherCard == null) {
    throw new IllegalArgumentException("Params can't be null");
  }
  if (this.isCreature() && otherCard.isCreature()) {
    if (this.getAbilities().contains(ChangelingAbility.getInstance())
        || this.isAllCreatureTypes()
        || otherCard.getAbilities().contains(ChangelingAbility.getInstance())
        || otherCard.isAllCreatureTypes()) {
      return true;
    }
  }
  for (SubType subtype : this.getSubtype(game)) {
    if (otherCard.hasSubtype(subtype, game)) {
      return true;
    }
  }
  return false;
}

  private int getAmount(List<Permanent> permanents, Permanent target, Game game) {
    int amount = 0;
    SubTypeList targetSubtype = target.getSubtype(game);
    if (target.getAbilities().contains(ChangelingAbility.getInstance()) || target.isAllCreatureTypes()) {
      return permanents.size() - 1;
    }
    for (Permanent permanent : permanents) {
      if (!permanent.getId().equals(target.getId())) {
        for (SubType subtype : targetSubtype) {
          if (subtype.getSubTypeSet() == SubTypeSet.CreatureType) {
            if (permanent.hasSubtype(subtype, game)) {
              amount++;
              break;
            }
          }
        }
      }
    }
    return amount;
  }
}

public ChangelingSentinel(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{3}{W}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(3);
  this.toughness = new MageInt(2);
  this.addAbility(ChangelingAbility.getInstance());
  this.addAbility(VigilanceAbility.getInstance());
}

public BladesOfVelisVel(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.TRIBAL,CardType.INSTANT},"{1}{R}");
  this.subtype.add(SubType.SHAPESHIFTER);
  // Changeling
  this.addAbility(ChangelingAbility.getInstance());
  
  // Up to two target creatures each get +2/+0 and gain all creature types until end of turn.
  Effect effect = new BoostTargetEffect(2,0, Duration.EndOfTurn);
  effect.setText("Up to two target creatures each get +2/+0");
  this.getSpellAbility().addEffect(effect);
  effect = new GainAbilityTargetEffect(ChangelingAbility.getInstance(), Duration.EndOfTurn, "and gain all creature types until end of turn");
  this.getSpellAbility().addEffect(effect);
  this.getSpellAbility().addTarget(new TargetCreaturePermanent(0,2));        
}

public GameTrailChangeling(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{3}{G}{G}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(4);
  this.toughness = new MageInt(4);
  this.addAbility(ChangelingAbility.getInstance());
  this.addAbility(TrampleAbility.getInstance());
}

public ChangelingTitan(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{4}{G}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(7);
  this.toughness = new MageInt(7);
  // Changeling
  this.addAbility(ChangelingAbility.getInstance());
  // Champion a creature
  this.addAbility(new ChampionAbility(this, true));
}

public AvianChangeling(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{2}{W}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(2);
  this.toughness = new MageInt(2);
  this.addAbility(ChangelingAbility.getInstance());
  this.addAbility(FlyingAbility.getInstance());
}

@Override
public boolean hasSubtype(SubType value, Game game) {
  if (value == null) {
    return false;
  }
  SubTypeList subtypes = this.getSubtype(game);
  if (subtypes.contains(value)) {
    return true;
  } else {
    // checking for Changeling
    // first make sure input parameter is a creature subtype
    // if not, then ChangelingAbility doesn't matter
    if (value.getSubTypeSet() != SubTypeSet.CreatureType) {
      return false;
    }
    // as it is creature subtype, then check the existence of Changeling
    return abilities.contains(ChangelingAbility.getInstance()) || isAllCreatureTypes();
  }
}

public ChangelingBerserker(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{3}{R}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(5);
  this.toughness = new MageInt(3);
  // Changeling
  this.addAbility(ChangelingAbility.getInstance());
  
  // Haste
  this.addAbility(HasteAbility.getInstance());
  
  // Champion a creature
  this.addAbility(new ChampionAbility(this, true));
}

public ChangelingHero(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{4}{W}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(4);
  this.toughness = new MageInt(4);
  // Changeling
  this.addAbility(ChangelingAbility.getInstance());
  
  // Champion a creature
  this.addAbility(new ChampionAbility(this, true));
  
  // Lifelink
  this.addAbility(LifelinkAbility.getInstance());
}

public MirrorEntity(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{2}{W}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(1);
  this.toughness = new MageInt(1);
  // Changeling
  this.addAbility(ChangelingAbility.getInstance());
  // {X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.
  DynamicValue variableMana = ManacostVariableValue.instance;
  Effect effect = new SetPowerToughnessAllEffect(variableMana, variableMana, Duration.EndOfTurn, filter, true);
  effect.setText("Until end of turn, creatures you control have base power and toughness X/X");
  Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, effect, new VariableManaCost());
  effect = new GainAbilityAllEffect(ChangelingAbility.getInstance(), Duration.EndOfTurn, filter, false, Layer.TypeChangingEffects_4, SubLayer.NA);
  effect.setText("and gain all creature types");
  ability.addEffect(effect);
  this.addAbility(ability);
}

public CairnWanderer(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{4}{B}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(4);
  this.toughness = new MageInt(4);
  // Changeling
  this.addAbility(ChangelingAbility.getInstance());
  // As long as a creature card with flying is in a graveyard, Cairn Wanderer has flying. The same is true for fear, first strike, double strike, deathtouch, haste, landwalk, lifelink, protection, reach, trample, shroud, and vigilance.
  this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new CairnWandererEffect()));
}

public TaureanMauler(UUID ownerId, CardSetInfo setInfo) {
  super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{2}{R}");
  this.subtype.add(SubType.SHAPESHIFTER);
  this.power = new MageInt(2);
  this.toughness = new MageInt(2);
  // Changeling
  this.addAbility(ChangelingAbility.getInstance());
  
  // Whenever an opponent casts a spell, you may put a +1/+1 counter on Taurean Mauler.
  this.addAbility(new SpellCastOpponentTriggeredAbility(new AddCountersSourceEffect(CounterType.P1P1.createInstance()), true));
  
}