Copy a Gerrit link for querying CR And add a button to browse branch code

快捷浏览分支代码以及快捷拷贝查询CR的链接
当前为 2023-07-07 提交的版本，查看最新版本。
换行
// ==UserScript==
// @name         Copy a Gerrit link for querying CR And add a button to browse branch code
// @namespace    http://tampermonkey.net/
// @version      0.4
// @description  快捷浏览分支代码以及快捷拷贝查询CR的链接
// @author       Jackie
// @match        https://gerrit.mot.com*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=mot.com
// @run-at       document-end
// @grant        GM.addStyle
// ==/UserScript==

(function() {
    'use strict';

    let action = ()=>{
        sleep(100).then(()=>{
            addButtons();
        });
    }
    //action();
    sleep(1000).then(()=>{
        let c = document.getElementById("gerrit_header");
        observeDOM(c, /*onAdd*/ action, /*onRemove*/ action);
    });
})();

function addButtons() {
    console.log(`=======================addButtons`)
    let btnCopyCrQueryLink = document.getElementById("btnCopyCrQueryLink");
    if(!btnCopyCrQueryLink){
        btnCopyCrQueryLink = createButton("CopyQueryLink");
        btnCopyCrQueryLink.id = "btnCopyCrQueryLink";
        btnCopyCrQueryLink.onclick = () => {
            let msg = "CR not found!"
            let crDiv = document.getElementsByClassName("com-google-gerrit-client-change-CommitBox_BinderImpl_GenCss_style-text")[0];
            if(crDiv && crDiv.firstElementChild){
                msg = "https://gerrit.mot.com/#/q/" + crDiv.firstElementChild.text;
            }
            navigator.clipboard.writeText(msg);
            showSnackbar(msg);
        }
        let parent = document.getElementsByClassName("com-google-gerrit-client-change-ChangeScreen_BinderImpl_GenCss_style-infoLineHeaderButtons")[0];
        if(parent) {
            parent.appendChild(btnCopyCrQueryLink);
        }
    }

    let btnBrowseBranch = document.getElementById("btnBrowseBranch");
    if(!btnBrowseBranch){
        btnBrowseBranch = createElement({
            name:"a",
            class:"com-google-gerrit-client-change-ChangeScreen_BinderImpl_GenCss_style-projectSettings",
            innerHTML: "Browse Branch"
        });
        btnBrowseBranch.target = `_blank`;
        btnBrowseBranch.id = "btnBrowseBranch";

        let branchTd = document.querySelector('#change_infoTable > tbody > tr:nth-of-type(7) > td:nth-of-type(1)');
        let branchName = branchTd.firstChild.text;
        let project = document.querySelector('#change_infoTable > tbody > tr:nth-of-type(6) > td:nth-of-type(1)').firstChild.text;
        btnBrowseBranch.href = `https://gerrit.mot.com/plugins/gitiles/${project}/+/refs/heads/${branchName}`;
        branchTd.appendChild(btnBrowseBranch);
    }

}

function showSnackbar(msg) {
    let snackbar = getSnackbar();
    snackbar.className = "show";
    setTimeout(function(){
        snackbar.className = snackbar.className.replace("show", "");
    }, 1500);
}

function getSnackbar() {
    let snackbar = document.getElementById('snackbar');
    if(!snackbar) {
        snackbar = document.createElement("div");
        snackbar.id="snackbar";
        snackbar.innerHTML="Copied succesfully"
        document.getElementsByClassName('screen')[0].appendChild(snackbar);
        GM.addStyle(`
      #snackbar {
  visibility: hidden;
  min-width: 250px;
  margin-left: -125px;
  background-color: #333;
  color: #fff;
  text-align: center;
  border-radius: 2px;
  padding: 16px;
  position: fixed;
  z-index: 1;
  left: 50%;
  top: 50px;
  font-size: 17px;
}

#snackbar.show {
  visibility: visible;
  -webkit-animation: fadein 0.5s, fadeout 0.5s 2.5s;
  animation: fadein 0.5s, fadeout 0.5s 2.5s;
}

@-webkit-keyframes fadein {
  from {top: 0; opacity: 0;}
  to {top: 50px; opacity: 1;}
}

@keyframes fadein {
  from {top: 0; opacity: 0;}
  to {top: 50px; opacity: 1;}
}

@-webkit-keyframes fadeout {
  from {top: 50px; opacity: 1;}
  to {top: 0; opacity: 0;}
}

@keyframes fadeout {
  from {top: 50px; opacity: 1;}
  to {top: 0; opacity: 0;}
}
    `);
    }
    return snackbar;
}

function createButton(text) {
    let button = createElement(
        {
            name:"button",
            class:"com-google-gerrit-client-change-ChangeScreen_BinderImpl_GenCss_style-highlight",
        }
    );
    button.type = "button";
    button.title = text;
    let div = document.createElement('div');
    div.innerHTML=text;
    button.appendChild(div);
    return button;
}

function createElement(info) {
    if(!info.name) return undefined;
    let element = document.createElement(info.name);
    if(info.innerHTML) element.innerHTML = info.innerHTML;
    if(info.class) {
        /*if(info.class.__proto__ == String.prototype) {
            element.classList.add(info.class);
        } else {
            for (let cls of info.class) {
                element.classList.add(cls);
            }
        }*/
        element.classList.add(info.class);
    }
    return element;
}

function sleep (time) {
    return new Promise((resolve) => setTimeout(resolve, time));
}

const observeDOM = (function () {
    let MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
    let eventListenerSupported = window.addEventListener;

    return function (obj, onAddCallback, onRemoveCallback) {
        if (MutationObserver) {
            // define a new observer
            let mutationObserver = new MutationObserver(function (mutations, observer) {
                if (mutations[0].addedNodes.length && onAddCallback != undefined) {
                    onAddCallback();
                }
            });
            // have the observer observe foo for changes in children
            mutationObserver.observe(obj, { attributes: true, childList: true, subtree: true });
        } else if (eventListenerSupported) {
            obj.addEventListener('DOMNodeInserted', onAddCallback, false);
        }
    };
})();