utils.ts

export function addClass(element: Element, className: string) {
  if (element.classList) {
    element.classList.add(className)
  } else {
    element.className += ` ${className}`
  }
}

export function removeClass(element: Element, className: string) {
  if (element.classList) {
    element.classList.remove(className)
  } else {
    const re = new RegExp(
      "(^|\\b)" + className.split(" ").join("|") + "(\\b|$)",
      "gi"
    )
    element.className = element.className.replace(re, " ")
  }
}

export function addEventListener(element: Element, event: string, cb: any) {
  if (element.addEventListener) {
    element.addEventListener(event, cb)
  } else {
    (element as any).attachEvent(`on${event}`, () => {
      cb.call(element)
    })
  }
}

export function removeEventListener(element: Element, event: string, cb: any) {
  if (element.removeEventListener) {
    element.removeEventListener(event, cb)
  } else {
    (element as any).detachEvent(`on${event}`, cb)
  }
}