js实现给html固定区域增加水印

背景

给视频和文档的div区域增加水印。以下代码可以在任意位置增加水印。

js代码实现

var now = getNow();watermark({\"watermark_txt\":\"A B C X Y Z \"+now});function watermark(settings) {//此处可以更改自己想要初始化的id。var ele = document.getElementById(\"myBody\");//默认设置var defaultSettings = {watermark_txt: \"text\",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: 20, //水印行数watermark_cols: 20, //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_color: \'#aaa\', //水印字体颜色watermark_alpha: 0.4, //水印透明度watermark_fontsize: \'15px\', //水印字体大小watermark_font: \'微软雅黑\', //水印字体watermark_width: 210, //水印宽度watermark_height: 80, //水印长度watermark_angle: 20 //水印倾斜度数};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];}}var oTemp = document.createDocumentFragment();//获取页面最大宽度var page_width = Math.max(ele.scrollWidth, ele.clientWidth);var cutWidth = page_width * 0.0150;var page_width = page_width - cutWidth;//获取页面最大高度var page_height = Math.max(ele.scrollHeight, ele.clientHeight) ;//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\');mask_div.id = \'mask_div\' + i + j;mask_div.className = \'mask_div\';mask_div.appendChild(document.createTextNode(defaultSettings.watermark_txt));//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\";mask_div.style.left = x + \'px\';mask_div.style.top = y + \'px\';mask_div.style.overflow = \"hidden\";mask_div.style.zIndex = \"9999\";//让水印不遮挡页面的点击事件mask_div.style.pointerEvents = \'none\';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\";ad8mask_div.style.width = defaultSettings.watermark_width + \'px\';mask_div.style.height = defaultSettings.watermark_height + \'px\';mask_div.style.display = \"block\";oTemp.appendChild(mask_div);};};ele.appendChild(oTemp);}function getNow() {var d = new Date();var year = d.getFullYear();var month = change(d.getMonth() + 1);var day = change(d.getDate());var hour = change(d.getHours());var minute = change(d.getMinutes());var second = change(d.getSeconds());function change(t) {if (t < 10) {return \"0\" + t;} else {return t;}}var time = year + \'年\' + month + \'月\' + day + \'日 \' + hour + \'时\' + minute + \'分\' + second + \'秒\';return time;}