Я добавил два метода к Детектору Лалита Пателя выше:
- addFont (family, stylesheetUrl, ruleString) -> определяет, существует ли шрифт 'family', если нет, добавляет таблицу стилей, загружающую шрифт, используя либо stylesheetUrl, если он задан, либо иным образом ruleString
- addFontsArr (arr) -> добавляет массив шрифтов
С этим вы можете сделать:
fonts = [ 'Arial', 'Arial Black', { family: 'Lato', stylesheetUrl: 'https://fonts.googleapis.com/css?family=Lato'}, 'Leelawadee UI']
(new FontDetector()).addFontsArr(fonts);
код:
/**
* JavaScript code to detect available availability of a
* particular font in a browser using JavaScript and CSS.
*
* Author : Lalit Patel
* Website: http://www.lalit.org/lab/javascript-css-font-detect/
* License: Apache Software License 2.0
* http://www.apache.org/licenses/LICENSE-2.0
* Version: 0.15 (21 Sep 2009)
* Changed comparision font to default from sans-default-default,
* as in FF3.0 font of child element didn't fallback
* to parent element if the font is missing.
* Version: 0.2 (04 Mar 2012)
* Comparing font against all the 3 generic font families ie,
* 'monospace', 'sans-serif' and 'sans'. If it doesn't match all 3
* then that font is 100% not available in the system
* Version: 0.3 (24 Mar 2012)
* Replaced sans with serif in the list of baseFonts
*/
/**
* Usage: d = new Detector();
* d.detect('font name');
*/
function FontDetector() {
this.detect = detect;
this.addFont = addFont;
this.addFontsArr = addFontsArr;
// a font will be compared against all the three default fonts.
// and if it doesn't match all 3 then that font is not available.
var baseFonts = ['monospace', 'sans-serif', 'serif'];
//we use m or w because these two characters take up the maximum width.
// And we use a LLi so that the same matching fonts can get separated
var testString = "mmmmmmmmmmlli";
//we test using 72px font size, we may use any size. I guess larger the better.
var testSize = '72px';
var h = document.getElementsByTagName("body")[0];
// create a SPAN in the document to get the width of the text we use to test
var s = document.createElement("span");
s.style.fontSize = testSize;
s.innerHTML = testString;
var defaultWidth = {};
var defaultHeight = {};
for (var index in baseFonts) {
//get the default width for the three base fonts
s.style.fontFamily = baseFonts[index];
h.appendChild(s);
defaultWidth[baseFonts[index]] = s.offsetWidth; //width for the default font
defaultHeight[baseFonts[index]] = s.offsetHeight; //height for the defualt font
h.removeChild(s);
}
function detect(font) {
var detected = false;
for (var index in baseFonts) {
s.style.fontFamily = font + ',' + baseFonts[index]; // name of the font along with the base font for fallback.
h.appendChild(s);
var matched = (s.offsetWidth != defaultWidth[baseFonts[index]] || s.offsetHeight != defaultHeight[baseFonts[index]]);
h.removeChild(s);
detected = detected || matched;
}
return detected;
}
function addFont(family, stylesheetUrl, ruleString) {
if (detect(family)) {
//console.log('using internal font '+family);
return true;
}
if (stylesheetUrl) {
console.log('added stylesheet '+stylesheetUrl);
var head = document.head, link = document.createElement('link');
link.type = 'text/css';
link.rel = 'stylesheet';
link.href = stylesheetUrl;
head.appendChild(link);
return true;
}
if (ruleString) {
console.log('adding font rule:'+rule);
var newStyle = document.createElement('style');
newStyle.appendChild(document.createTextNode(rule));
document.head.appendChild(newStyle);
return true;
}
console.log('could not add font '+family);
}
function addFontsArr(arr) {
arr.forEach(a => typeof a==='string' ? addFont(a) : addFont(a.family, a.stylesheetUrl, a.ruleString));
}
};