assistant-android/app/src/main/assets/content.js

function requestContentFocus() {
  $("#editor").focus();
}

function setupWhenContentEditable() {
  var editor = $("#editor");
  if (!editor[0].hasAttribute("contenteditable")) {
    return;
  }

  // paste
  editor.on("paste", function(e) {
    e.preventDefault();
    var text = (e.originalEvent || e).clipboardData.getData("text/plain");
    text = text.replace(/\n/g, "<br>");
    if ("" != text) {
      document.execCommand("insertHTML", false, text);
    } else {
      window.onPasteListener.onPaste();
    }
  });

  requestContentFocus();
}

function getStyle(dom, name) {
  return window.getComputedStyle(dom)[name];
}

function customLinkgo(self) {
  var datas = self.dataset.datas;
  console.log(datas)
  window.OnLinkClickListener.onClick(datas);
}

var typeClassList = [
  "community_article-container",
  "answer-container",
  "game-container"
];

function removeDomByParent(curDom) {
  if (curDom.parentElement) {
    curDom.parentElement.removeChild(curDom);
  }
}

window.addEventListener("load", function() {
  var EditorDom = document.querySelector("#editor");
  setupWhenContentEditable();

  document.addEventListener("keydown", function(e) {
    var event = e || window.event;

    if (event.keyCode === 8) {
      var s = document.getSelection();
      var r = s.getRangeAt(0);

      if (r.startOffset === r.endOffset && r.endOffset === 0) {
        var preDOM = s.focusNode.previousElementSibling;

        if (
          preDOM &&
          preDOM instanceof Element &&
          preDOM.nodeName === "IMG" &&
          getStyle(preDOM, "display") === "block"
        ) {
          preDOM.parentElement.removeChild(preDOM);
        }
      }

      var customDom = s.focusNode;
      if (customDom) {
        if (
          r.startContainer.nodeName.toLowerCase() === "blockquote" &&
          r.startOffset === 0
        ) {
          RE.formatBlock();
          e.preventDefault();
        } else if (
          customDom.nodeName === "#text" &&
          customDom.previousElementSibling &&
          typeClassList.indexOf(customDom.previousElementSibling.className) >
            -1 &&
          r.startOffset === 1
        ) {
          var needDeleteDom = customDom.previousElementSibling;
          needDeleteDom.insertAdjacentElement(
            "afterend",
            document.createElement("br")
          );
        } else if (
          customDom instanceof Element &&
          customDom.childNodes[s.focusOffset] &&
          customDom.childNodes[s.focusOffset].previousElementSibling &&
          typeClassList.indexOf(
            customDom.childNodes[s.focusOffset].previousElementSibling.className
          ) > -1
        ) {
          customDom =
            customDom.childNodes[s.focusOffset].previousElementSibling;
          customDom.parentElement.removeChild(customDom);
        }
      }
    }
  });

  document.addEventListener("keyup", function(e) {
    var event = e || window.event;
    if (event.keyCode === 13) {
      var s = document.getSelection();
      var curDom = s.focusNode;
      var preDom = curDom.previousElementSibling;

      if (
        curDom.nodeName.toLowerCase() === "blockquote" &&
        preDom.nodeName.toLowerCase() === "blockquote"
      ) {
        if (
          preDom.childNodes.length > 1 ||
          (preDom.childNodes.length === 1 &&
            preDom.childNodes[0].tagName !== "BR")
        ) {
          curDom.style.marginTop = 0;
          preDom.style.marginBottom = 0;
        } else if (
          (curDom.childNodes.length === 0 ||
            (curDom.childNodes.length === 1 &&
              curDom.childNodes[0].tagName === "BR")) &&
          (preDom.childNodes.length === 0 ||
            (preDom.childNodes.length === 1 &&
              preDom.childNodes[0].tagName === "BR"))
        ) {

          removeDomByParent(curDom);

          var startQuoteDom = preDom.previousElementSibling;
          startQuoteDom && startQuoteDom.nodeName.toLowerCase() === "blockquote"
            ? (startQuoteDom.style.marginBottom = "10px")
            : null;

          var range = document.createRange();
          range.selectNode(preDom);
          s.removeAllRanges();
          s.addRange(range);

          RE.formatBlock();
        }
      }
    }
  });

  document.addEventListener("selectionchange", function(e) {
    var event = e || window.event;
    var targetDom = event.target.activeElement;
    if (targetDom.id === "editor" && targetDom.lastElementChild) {
      if (typeClassList.indexOf(targetDom.lastElementChild.className) > -1) {
        var brDom = document.createElement("br");
        EditorDom.appendChild(brDom);
      }
    }
  });
});