22.JavaScript制作一个简单的提示框插件

window.myPlugin = window.myPlugin || {};

window.myPlugin.showMsg = (function () {
    var mongolia, //蒙层
        promptBox, //提示框
        closeSpan, //关闭按钮
        titleSpan, //提示标题
        contextSpan, //提示信息
        okBtn, //确定按钮
        cancelBtn, //取消按钮
        isRegEvent, //是否注册事件
        option; //传入的参数



    /**
     * 初始化蒙层
     */
    function initMongolia() {
        if (!mongolia) { //没有蒙层则初始化
            //蒙层：覆盖整个窗口，半透明的黑色
            mongolia = document.createElement("div");
            mongolia.style.position = "fixed";
            mongolia.style.width = mongolia.style.height = "100%";
            mongolia.style.left = mongolia.style.top = 0;
            mongolia.style.background = "rgba(0,0,0,.5)";
            document.body.appendChild(mongolia);
        }
        mongolia.style.display = "block"; //展示蒙层
    }

    /**
     * 初始化提示框
     */
    function initPromptBox() {
        //提示框：宽高300，位置居中
        if (!promptBox) {
            promptBox = document.createElement("div");
            promptBox.style.width = promptBox.style.height = "300px";
            promptBox.style.background = "#fff";
            promptBox.style.fontSize = "14px";
            promptBox.style.position = "absolute";
            promptBox.style.top = promptBox.style.left = "50%";
            promptBox.style.marginLeft = promptBox.style.marginTop = "-150px";
            promptBox.style["data-myplugin-id"] = "promptBox";
            initPromptContext();
            mongolia.appendChild(promptBox);
            titleSpan = document.querySelector("[data-myplugin-id=‘title‘]"); //提示标题
            contextSpan = document.querySelector("[data-myplugin-id=‘message‘]"); //提示信息
            closeSpan = document.querySelector("[data-myplugin-id=‘close‘]"); //关闭按钮
            okBtn = document.querySelector("[data-myplugin-id=‘ok‘]"); //确定按钮
            cancelBtn = document.querySelector("[data-myplugin-id=‘cancel‘]"); //取消按钮
        }

        okBtn.innerText = option.okText || "确定";
        cancelBtn.innerText = option.cancelText || "取消";
        titleSpan.innerText = option.title || "提示";
        contextSpan.innerText = option.context || "";
    }

    /**
     * 初始化提示框中的内容
     */
    function initPromptContext() {
        //内容包含：标题，关闭按钮，提示信息，确定按钮，取消按钮

        //创建标题，关闭按钮
        var div = document.createElement("div");
        div.innerHTML = `<span style="float:left;" data-myplugin-id="title"></span>
        <span  style="float:right;cursor:pointer;" data-myplugin-id="close">X</span>`;
        div.style.height = "50px";
        div.style.padding = "10px 20px";
        div.style.background = "#eee";
        div.style.boxSizing = "border-box";
        promptBox.appendChild(div);

        //创建提示信息
        div = document.createElement("div");
        div.innerHTML = `<span  data-myplugin-id="message"></span>`;
        div.style.height = "200px";
        div.style.padding = "10px 20px";
        div.style.boxSizing = "border-box";
        promptBox.appendChild(div);

        //创建确定按钮，取消按钮
        div = document.createElement("div");
        div.innerHTML = `<button style="float:right;margin:10px;cursor:pointer;" data-myplugin-id="cancel"></button><button style="float:right;margin:10px;cursor:pointer;" data-myplugin-id="ok"></button>`;
        div.style.height = "50px";
        div.style.padding = "10px 20px";
        div.style.boxSizing = "border-box";
        promptBox.appendChild(div);
    }

    //注册事件
    function regEvent() {
        if (!isRegEvent) { //未注册事件
            //1.点击关闭，点击蒙层，点击取消按钮
            closeSpan.onclick = mongolia.onclick = function () {
                mongolia.style.display = "none"; //隐藏蒙层
            };

            okBtn.onclick = function () {
                option && option.okFunction && option.okFunction();
                mongolia.style.display = "none"; //隐藏蒙层
            }

            cancelBtn.onclick = function () {
                option && option.cancelFunction && option.cancelFunction();
                mongolia.style.display = "none"; //隐藏蒙层
            }

            //2.拖动提示框事件
            window.onmousedown = function (e) {
                var target = getTarget(e.target); //是否包含目标元素

                if (target) {
                    var style = window.getComputedStyle(target);
                    var left = parseInt(style.left);
                    var top = parseInt(style.top);
                    var disX = parseInt(e.pageX) - left;
                    var disY = parseInt(e.pageY) - top;

                    window.onmousemove = function (e) {
                        var newLeft = parseInt(e.pageX) - disX;
                        var newTop = parseInt(e.pageY) - disY;

                        promptBox.style.left = newLeft + "px";
                        promptBox.style.top = newTop + "px";

                    };
                    window.onmouseup = window.onmouseleave = function () {
                        window.onmousemove = null;
                    }
                }
            };

            function getTarget(target) {
                while (target) {
                    if (target.tagName === "DIV" && target.style["data-myplugin-id"] === "promptBox") {
                        return target;
                    } else {
                        target = target.parentElement;
                    }
                }
                return false;
            }
        }
    }




    /**
     * @param {object} opts 
     * opts.title : 提示标题
     * opts.context : 提示信息
     * opts.cancelText:取消按钮内容
     * opts.okText:确定按钮内容
     * opts.cancelText:取消按钮内容
     * opts.okFunction:确定按钮的回调函数
     * opts.cancelFunction:取消按钮的回调函数
     */
    function showMsg(opts) {
        if (typeof opts === "string") {
            option = {
                context: opts
            }
        } else {
            option = opts || {};
        }
        initMongolia();
        initPromptBox();
        regEvent();
    }

    return showMsg;
}());

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script src="./js/myPlugin.js"></script>
    <script>
        window.myPlugin.showMsg({
            title: "信息",
            context: "确定删除吗",
            okText: "OK",
            cancelText: "Cancel",
            okFunction: function(){
                console.log("点击OK按钮");
            },
            cancelFunction:function(){
                console.log("点击Cancel按钮");
            }
        });
    </script>
</body>

</html>