watermark 水印

watermark.js

```javascript
function checkWaterStatus(domain){
	var otdiv = document.getElementById('joychou');
	if(!otdiv) {
		watermark.load({watermark_txt: domain})
		watermark.load({watermark_txt: domain, watermark_x:100, watermark_y:100, watermark_alpha: 0.01})
	}
}

// 定时器
setInterval(checkWaterStatus, 100, "JoyChou's Blog")


(function(watermark){
    window.watermarkdivs = [];
    // 加载水印
    var loadMark = function(settings) {
        var defaultSettings={
            watermark_id: 'joychou',       //水印总体的id
            watermark_txt:"测试水印",        //水印的内容
            watermark_x:20,                 //水印起始位置x轴坐标
            watermark_y:20,                 //水印起始位置Y轴坐标
            watermark_rows:0,               //水印行数
            watermark_cols:0,               //水印列数
            watermark_x_space:100,          //水印x轴间隔
            watermark_y_space:50,           //水印y轴间隔
            watermark_font:'微软雅黑',      //水印字体
            watermark_color:'black',       //水印字体颜色
            watermark_fontsize:'20px',     //水印字体大小
            watermark_alpha:0.07,          //水印透明度，要求设置在大于等于0.003
            watermark_width:150,           //水印宽度
            watermark_height:100,          //水印长度
            watermark_angle:25,            //水印倾斜度数
        };

        //采用配置项替换默认值，作用类似jquery.extend
        if(arguments.length === 1&&typeof arguments[0] ==="object" )
        {
            var src = arguments[0]||{};
            for(key in src)
            {
                if(src[key]&&defaultSettings[key]&&src[key]===defaultSettings[key])
                    continue;
                else if(src[key])
                    defaultSettings[key]=src[key];
            }
        }
        //如果元素存在就移除
        // var watermark_element = document.getElementById(defaultSettings.watermark_id);
        // if(watermark_element){
        //     var _parentElement = watermark_element.parentNode;
        //     if(_parentElement){
        //         _parentElement.removeChild(watermark_element);
        //     }
        // }

        //获取页面最大宽度
        var page_width = Math.max(document.body.scrollWidth,document.body.clientWidth);
        //获取页面最大长度
        var page_height = Math.max(document.body.scrollHeight,document.body.clientHeight);

        // 创建文档碎片
        var oTemp = document.createDocumentFragment();

        //创建水印外壳div
        var otdiv = document.getElementById(defaultSettings.watermark_id);
        if(!otdiv){
            otdiv = document.createElement('div');
            //创建shadow dom
            otdiv.id = defaultSettings.watermark_id;
            otdiv.style.pointerEvents = "none";
            //判断浏览器是否支持createShadowRoot方法
            if(typeof otdiv.createShadowRoot === 'function'){
                shadowRoot = otdiv.createShadowRoot();
            }else{
                shadowRoot = otdiv;
            }
            //将shadow dom随机插入到body内的任意位置
            var nodeList = document.body.children;
            var index = Math.floor(Math.random()*(nodeList.length-1));
            if(nodeList[index]){
                document.body.insertBefore(otdiv,nodeList[index]);
            }else{
                document.body.appendChild(otdiv);
            }
        }else if(otdiv,shadowRoot){
            shadowRoot = otdiv.shadowRoot;
        }

        //如果将水印列数设置为0，或水印列数设置过大，超过页面最大宽度，则重新计算水印列数和水印x轴间隔
        if (defaultSettings.watermark_cols == 0 || (parseInt(defaultSettings.watermark_x + defaultSettings.watermark_width *defaultSettings.watermark_cols + defaultSettings.watermark_x_space * (defaultSettings.watermark_cols - 1)) > page_width)) {
            defaultSettings.watermark_cols = parseInt((page_width - defaultSettings.watermark_x + defaultSettings.watermark_x_space) / (defaultSettings.watermark_width + defaultSettings.watermark_x_space));
            defaultSettings.watermark_x_space = parseInt((page_width - defaultSettings.watermark_x - defaultSettings.watermark_width * defaultSettings.watermark_cols) / (defaultSettings.watermark_cols - 1));
        }
        //如果将水印行数设置为0，或水印行数设置过大，超过页面最大长度，则重新计算水印行数和水印y轴间隔
        if (defaultSettings.watermark_rows == 0 || (parseInt(defaultSettings.watermark_y + defaultSettings.watermark_height * defaultSettings.watermark_rows + defaultSettings.watermark_y_space * (defaultSettings.watermark_rows - 1)) > page_height)) {
            defaultSettings.watermark_rows = parseInt((defaultSettings.watermark_y_space + page_height - defaultSettings.watermark_y) / (defaultSettings.watermark_height + defaultSettings.watermark_y_space));
            defaultSettings.watermark_y_space = parseInt(((page_height - defaultSettings.watermark_y) - defaultSettings.watermark_height * defaultSettings.watermark_rows) / (defaultSettings.watermark_rows - 1));
        }

        var x;
        var y;
        for (var i = 0; i < defaultSettings.watermark_rows; i++) {
            y = defaultSettings.watermark_y + (defaultSettings.watermark_y_space + defaultSettings.watermark_height) * i;
            for (var j = 0; j < defaultSettings.watermark_cols; j++) {
                x = defaultSettings.watermark_x + (defaultSettings.watermark_width + defaultSettings.watermark_x_space) * j;

                var mask_div = document.createElement('div');
                var oText=document.createTextNode(defaultSettings.watermark_txt);
                mask_div.appendChild(oText);
                // 设置水印相关属性start
                mask_div.id = defaultSettings.watermark_id + i + j;
                //设置水印div倾斜显示
                mask_div.style.webkitTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
                mask_div.style.MozTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
                mask_div.style.msTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
                mask_div.style.OTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
                mask_div.style.transform = "rotate(-" + defaultSettings.watermark_angle + "deg)";
                mask_div.style.visibility = "";
                mask_div.style.position = "absolute";
                //选不中
                mask_div.style.left = x + 'px';
                mask_div.style.top = y + 'px';
                mask_div.style.overflow = "hidden";
                mask_div.style.zIndex = "9999";
                //mask_div.style.border="solid #eee 1px";
                mask_div.style.opacity = defaultSettings.watermark_alpha;
                mask_div.style.fontSize = defaultSettings.watermark_fontsize;
                mask_div.style.fontFamily = defaultSettings.watermark_font;
                mask_div.style.color = defaultSettings.watermark_color;
                mask_div.style.textAlign = "center";
                mask_div.style.width = defaultSettings.watermark_width + 'px';
                mask_div.style.height = defaultSettings.watermark_height + 'px';
                mask_div.style.display = "block";
                //设置水印相关属性end
                //附加到文档碎片中
                shadowRoot.appendChild(mask_div);
            };
        };
    };
    //初始化水印，添加load和resize事件
    watermark.init = function(settings) {
        window.addEventListener('load',function () {
            loadMark(settings);
        });
        window.addEventListener('resize',function () {
            loadMark(settings);
        });
        window.addEventListener('DOMContentLoaded',function () {
            loadMark(settings);
        })
    };
    //手动加载水印
    watermark.load = function(settings){
        loadMark(settings);
    };

})(window.watermark = {} );
```