Tools-设置背景水印

Posted 2020-12-08 hlssz

目的

背景是需要在网页中根据用户名设置水印

<script>
    function watermark(settings) {
        debugger;
        //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:10,//水印行数
            watermark_cols:20,//水印列数
            watermark_x_space:50,//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:0.3,//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:15//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];
            }
        }

        var oTemp = document.createDocumentFragment();

        //获取页面最大宽度
        var page_width = Math.max(document.body.scrollWidth,document.body.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(document.body.scrollHeight,document.body.clientHeight);
        // var page_height = document.body.scrollHeight+document.body.scrollTop;
        //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 = "0";
                mask_div.style.pointerEvents=‘none‘;//pointer-events:none  让水印不遮挡页面的点击事件
                //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";
                oTemp.appendChild(mask_div);
            };
        };
        document.body.appendChild(oTemp);
    }
    watermark({
    　　"watermark_txt": getCookie("username")
    });

    function getCookie(cname) {
        var name = cname + "=";
        var ca = document.cookie.split(‘;‘);
        for(var i = 0; i < ca.length; i++) {
            var c = ca[i];
            while (c.charAt(0) == ‘ ‘) {
                c = c.substring(1);
            }
            if (c.indexOf(name)  == 0) {
                return c.substring(name.length, c.length);
            }
        }
        return "";
    };
</script>