向JS对象添加和删除事件

Posted 2020-08-16 大胡子毛绒老头

this.removeEventListener = function (obj, ename, func) {
    var store = obj[this.addEventListener.pre + ename];
    if (!store) {
        return;
    }
    var i = store.indexOf(func);
    if (i < 0) {
        return;
    }
    obj[this.addEventListener.pre + ename].splice(i, 1);
};
this.addEventListener = function (obj, enames) {
    if (arguments.length < 2) {
        return;
    }
    if (!this.addEventListener.pre) {
        this.addEventListener.pre = "god_" + Math.random() * Number.MAX_VALUE;
    }
    if (typeof arguments[1] == "string") {
        var ename = arguments[1];
        var fullname = "on" + ename;
        if (!(fullname in obj)) {
            var store = this.addEventListener.pre + ename;
            if (!obj[store]) {
                obj[store] = [];
            }
            Object.defineProperty(obj, fullname, {
                set: function (v) {
                    obj[store].push(v);
                }
            });
            var notice = ename === "notice" ? "notice" : "notice" + ename;
            obj[notice] = function () {
                for (var i = 0; i < obj[store].length; i++) {
                    try {
                        obj[store][i].apply(obj, arguments);
                    } catch (e) {
                        console.log(e.message);
                    }
                }
            };
        }
    }
    if (typeof arguments[2] === "string") {
        var narguments = [obj];
        for (var i = 2; i < arguments.length; i++) {
            narguments.push(arguments[i]);
        }
        this.addEventListener.apply(this, narguments);
    }
};