IEvent

Represents an event.

Type	Name	Interface Description
Variables	args: any[]	• Function: Arguments passed to the event. The payload shape depends on the event type: EventType.Touch uses [TouchData], pinch events use [IPinchInfo], collision events use [CollisionInfo] or [CollisionInfo2D].
Variables	type: number | UserEventType	• Function: The type of the event, which can be either a number or a UserEventType.

Use Case

Example 1 — Tap to drop a ball/coin that bounces multiple times on a static floor — full Physics Matter resource flow (DSL: add_builtin_resource → set_resource_properties →…

@component()
export class TapToDropBouncy extends APJS.BasicScriptComponent {
  private rb: APJS.RigidBody2D | null = null;
  private collider: APJS.CircleCollider2D | null = null;
  private touchCallback: ((event: APJS.IEvent) => void) | null = null;
  private collisionCallback: ((event: APJS.IEvent) => void) | null = null;
  private dropped = false;
  private bounceCount = 0;

  onStart(): void {
    const obj = this.getSceneObject();
    this.rb = obj.getComponent("RigidBody2D") as APJS.RigidBody2D;
    this.collider = obj.getComponent("CircleCollider2D") as APJS.CircleCollider2D;
    if (!this.rb || !this.collider) return;

    // emitCollisionEvent is APJS-runtime-only — must set in onStart, not in DSL.
    this.collider.emitCollisionEvent = true;

    this.touchCallback = (event: APJS.IEvent) => {
      const touch = event.args[0] as APJS.TouchData;
      if (touch.phase === APJS.TouchPhase.Began && !this.dropped && this.rb) {
        this.dropped = true;
        this.rb.static = false;  // gravity now applies
      }
    };
    APJS.EventManager.getGlobalEmitter().on(APJS.EventType.Touch, this.touchCallback);

    this.collisionCallback = (event: APJS.IEvent) => {
      this.bounceCount++;
      // Optional: stop tracking after 5 bounces, or play SFX, or update score, etc.
      if (this.bounceCount === 1) console.log("[Bouncy] first impact");
    };
    const emitter = APJS.EventManager.getObjectEmitter(this.collider);
    emitter.on(APJS.CollisionEvent2D.Enter, this.collisionCallback, this);
  }

  onDestroy(): void {
    if (this.touchCallback) {
      APJS.EventManager.getGlobalEmitter().off(APJS.EventType.Touch, this.touchCallback);
    }
    if (this.collisionCallback && this.collider) {
      APJS.EventManager.getObjectEmitter(this.collider).off(APJS.CollisionEvent2D.Enter, this.collisionCallback, this);
    }
  }
}

Example 2 — Tap screen to clone/spawn a copy of this object at the touch position

@component()
export class TapSpawnAtTouch extends APJS.BasicScriptComponent {
  private touchCallback: (event: APJS.IEvent) => void;
  private spawned: APJS.SceneObject[] = [];

  // RecordStart: remove every spawned clone. See GameState §"RecordStart / RecordEnd Lifecycle".
  private onRecordStart = (_event: APJS.IEvent) => {
    const scene = this.getSceneObject().scene;
    for (const s of this.spawned) {
      scene.removeSceneObject(s);
    }
    this.spawned = [];
  };

  onStart(): void {
    this.touchCallback = (event: APJS.IEvent) => {
      const touchInfo = event.args[0] as APJS.TouchData;
      if (touchInfo.phase === APJS.TouchPhase.Began) {
        const clone = this.getSceneObject().clone();
        const screenPos = new APJS.Vector2f(
          touchInfo.position.x * 720,
          (1.0 - touchInfo.position.y) * 1280
        );
        const st = clone.getComponent("ScreenTransform") as APJS.ScreenTransform;
        if (st) {
          st.anchoredPosition = screenPos.clone().subtract(new APJS.Vector2f(360, 640));
        }
        this.spawned.push(clone);
      }
    };
    APJS.EventManager.getGlobalEmitter().on(APJS.EventType.Touch, this.touchCallback, this);
    APJS.EventManager.getGlobalEmitter().on(APJS.EventType.RecordStart, this.onRecordStart);
  }

  onDestroy(): void {
    if (this.touchCallback) {
      APJS.EventManager.getGlobalEmitter().off(APJS.EventType.Touch, this.touchCallback, this);
    }
    APJS.EventManager.getGlobalEmitter().off(APJS.EventType.RecordStart, this.onRecordStart);
  }
}