messenger-sitcker-changer.js

/*
* 2017/10/31 Happy Helloween
* Author: LeeXun leexun.official@gmail.com
* Just copy and paste it on console
* Notice: It's really dangerous if you don't know that this means!
*
*/
function handleNewElement() {
  var nodeList = document.getElementById('js_1').querySelectorAll("[aria-label='貼圖']");
  var s = nodeList[nodeList.length-1].style;
  s.width = "150px"
  s.height = "129px"
  s.background = "url('https://stickershop.line-scdn.net/stickershop/v1/sticker/1802683/android/sticker.png;compress=true')"
  s.backgroundPosition = "center"
  s.backgroundSize = "contain"
  s.backgroundRepeat = "no-repeat"
}
document.getElementById('js_1').addEventListener('DOMNodeInserted', handleNewElement, false);