How to use

declareAttacker

method

in

mage.players.Player

  player.declareAttacker(creature.getId(), defenders.iterator().next(), game, false);
} else {
  if (!player.isHuman()) { // computer only for multiple defenders
    player.declareAttacker(creature.getId(), defenders.iterator().next(), game, false);
  } else {  // human players only for multiple defenders
    TargetDefender target = new TargetDefender(defenders, creature.getId());
    if (player.chooseTarget(Outcome.Damage, target, null, game)) {
      player.declareAttacker(creature.getId(), target.getFirstTarget(), game, false);
  player.declareAttacker(creature.getId(), defendersForcedToAttack.iterator().next(), game, false);
} else {
  TargetDefender target = new TargetDefender(defendersForcedToAttack, creature.getId());
  target.setRequired(true);
  if (player.chooseTarget(Outcome.Damage, target, null, game)) {
    player.declareAttacker(creature.getId(), target.getFirstTarget(), game, false);

@Override
public boolean apply(Game game, Ability source) {
  Player controller = game.getPlayer(source.getControllerId());
  TargetOpponent targetDefender = new TargetOpponent();
  if (controller != null) {
    game.getBattlefield().getAllActivePermanents(CardType.CREATURE).stream().filter((permanent) -> (filter.match(permanent, source.getSourceId(), source.getControllerId(), game))).forEachOrdered((permanent) -> {
      if (game.getOpponents(controller.getId()).size() > 1) {
        controller.choose(outcome.Benefit, targetDefender, source.getSourceId(), game);
      } else {
        targetDefender.add(game.getOpponents(controller.getId()).iterator().next(), game);
      }
      if (permanent.canAttack(targetDefender.getFirstTarget(), game)) {
        controller.declareAttacker(permanent.getId(), targetDefender.getFirstTarget(), game, false);
      }
    });
  }
  return false;
}

@Override
public boolean apply(Game game, Ability source) {
  Player opponent = game.getPlayer(game.getPermanent(getTargetPointer().getFirst(game, source)).getControllerId());
  if (opponent != null) {
    filterOpponentCreatures.add(new ControllerIdPredicate(opponent.getId()));
    game.getBattlefield().getAllActivePermanents(CardType.CREATURE).stream().filter((permanent) -> (filterOpponentCreatures.match(permanent, source.getSourceId(), source.getControllerId(), game))).forEachOrdered((permanent) -> {
      //TODO: allow the player to choose between a planeswalker and player
      if (permanent.canAttack(source.getControllerId(), game)) {
        opponent.declareAttacker(permanent.getId(), source.getControllerId(), game, false);
      }
    });
    return true;
  }
  return false;
}

sim.getPlayer(attackerId).declareAttacker(attackId, defenderId, sim, false);

if (!killers.isEmpty()) {
  for (Permanent attacker : killers) {
    attackingPlayer.declareAttacker(attacker.getId(), defenderId, game, false);
    attackingPlayer.declareAttacker(attacker.getId(), defenderId, game, true);

for (CombatGroup group: engagement.getGroups()) {
  for (UUID attackerId: group.getAttackers()) {
    sim.getPlayer(activePlayerId).declareAttacker(attackerId, defenderId, sim, false);