Method on

packages/core/components/shared/emitter.ts:4–9

(eventName: U, callback: (data: Partial<T>) => void)

  private listeners: { [key in U]?: Array<(data: Partial<T>) => void> } = {};

  on(eventName: U, callback: (data: Partial<T>) => void) {
    if (!this.listeners[eventName]) {
      this.listeners[eventName] = [];
    }
    this.listeners[eventName]?.push(callback);
  }

  off(eventName: U, callback: (data: Partial<T>) => void) {
    if (this.listeners[eventName]) {