我正在Leaflet.js地图上绘制SVG标记图标.图标代表气象站,它们根据风向旋转并显示平均风速作为叠加.
我已经能够在Chrome中按照需要运行此功能,但Firefox中的文本位置已关闭.
左边是Chrome(55.0.2883.95),右边是Firefox(50.0.1).
这是Leaflet.Icon
我正在使用的自定义类:
window.RemoteWind = window.RemoteWind || {}; // This uses Chroma.js to build a color scale which is used for wind speed. // http://gka.github.io/chroma.js RemoteWind.color_scale = chroma.scale([ 'lightblue', 'green', 'red', 'purple' ]) .mode('hsl') // the blending mode .domain([0, 7, 15, 25]); // the distinct steps for each. RemoteWind.VectorIcon = L.Icon.extend({ options: { height: 26, width: 26, stroke: 'white', strokeWidth: 2, circle: { cx: 13, cy: 13, r: 13 } }, _createSVG: function(){ var svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg'); svg.setAttributeNS(null, 'version', '1.1') svg.setAttribute("xmlns", "http://www.w3.org/2000/svg"); svg.setAttribute("xmlns:xlink", "http://www.w3.org/1999/xlink"); svg.setAttribute('height', this.options.height); svg.setAttribute('width', this.options.width); return svg; } }); /* * Vector based icon for a station */ RemoteWind.StationIcon = RemoteWind.VectorIcon.extend({ options: { className: 'leaflet-station-icon active', speed: 0, direction: 0, path: { d: "M26,19c0-2.2-0.6-4.4-1.6-6.2C22.2,8.8,13,0,13,0S3.8,8.7,1.6,12.8c-1,1.8-1.6,4-1.6,6.2c0,7.2,5.8,13,13,13 S26,26.2,26,19z" } }, createIcon: function (oldIcon) { var div = (oldIcon && oldIcon.tagName === 'DIV') ? oldIcon : document.createElement('div'), svg = this._createSVG(), g = document.createElementNS('http://www.w3.org/2000/svg', 'g'), txt_g = document.createElementNS('http://www.w3.org/2000/svg', 'g'), options = this.options, path, txt; g.setAttributeNS(null, "transform", "translate(0,-6)"); path = document.createElementNS('http://www.w3.org/2000/svg', 'path'); path.setAttributeNS(null, 'd', "M26,19c0-2.2-0.6-4.4-1.6-6.2C22.2,8.8,13,0,13,0S3.8,8.7,1.6,12.8c-1,1.8-1.6,4-1.6,6.2c0,7.2,5.8,13,13,13 S26,26.2,26,19z"); path.setAttributeNS(null, 'stroke', this.options.stroke); path.setAttributeNS(null, 'stroke-width', this.options.strokeWidth); path.setAttributeNS(null, 'fill', RemoteWind.color_scale(options.speed).name() ); path.setAttributeNS(null, 'transform', 'rotate(% 13 19)'.replace('%', options.direction)); txt = document.createElementNS('http://www.w3.org/2000/svg', 'text'); txt.innerHTML = Math.round(options.speed).toString(); txt.setAttributeNS(null, 'fill', 'white'); txt.setAttributeNS(null, 'x', this.options.height / 2); txt.setAttributeNS(null, 'y', this.options.width / 2); txt.setAttributeNS(null, 'text-anchor', 'middle'); txt.setAttributeNS(null, 'alignment-baseline', 'central'); g.appendChild(path); txt_g.appendChild(txt); svg.appendChild(g); svg.appendChild(txt_g); div.appendChild(svg); this._setIconStyles(div, 'icon'); return div; }, createShadow: function () { return null; } }); RemoteWind.stationIcon = function (options) { return new RemoteWind.StationIcon(options); };
我通过设置text-anchor="middle"
和alignment-baseline="central"
加上x
和y
坐标来定位文本.
这是添加标记时在DOM中创建的HTML:
为什么firefox没有正确定位文本?
Firefox目前不支持alignment-baseline
.它确实支持dominant-baseline
,对于您的用例来说几乎相同.