lzyd-map-h/node_modules/html2canvas/dist/lib/render/font-metrics.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var util_1 = require("../core/util");
var SAMPLE_TEXT = 'Hidden Text';
var FontMetrics = /** @class */ (function () {
    function FontMetrics(document) {
        this._data = {};
        this._document = document;
    }
    FontMetrics.prototype.parseMetrics = function (fontFamily, fontSize) {
        var container = this._document.createElement('div');
        var img = this._document.createElement('img');
        var span = this._document.createElement('span');
        var body = this._document.body;
        container.style.visibility = 'hidden';
        container.style.fontFamily = fontFamily;
        container.style.fontSize = fontSize;
        container.style.margin = '0';
        container.style.padding = '0';
        body.appendChild(container);
        img.src = util_1.SMALL_IMAGE;
        img.width = 1;
        img.height = 1;
        img.style.margin = '0';
        img.style.padding = '0';
        img.style.verticalAlign = 'baseline';
        span.style.fontFamily = fontFamily;
        span.style.fontSize = fontSize;
        span.style.margin = '0';
        span.style.padding = '0';
        span.appendChild(this._document.createTextNode(SAMPLE_TEXT));
        container.appendChild(span);
        container.appendChild(img);
        var baseline = img.offsetTop - span.offsetTop + 2;
        container.removeChild(span);
        container.appendChild(this._document.createTextNode(SAMPLE_TEXT));
        container.style.lineHeight = 'normal';
        img.style.verticalAlign = 'super';
        var middle = img.offsetTop - container.offsetTop + 2;
        body.removeChild(container);
        return { baseline: baseline, middle: middle };
    };
    FontMetrics.prototype.getMetrics = function (fontFamily, fontSize) {
        var key = fontFamily + " " + fontSize;
        if (typeof this._data[key] === 'undefined') {
            this._data[key] = this.parseMetrics(fontFamily, fontSize);
        }
        return this._data[key];
    };
    return FontMetrics;
}());
exports.FontMetrics = FontMetrics;
//# sourceMappingURL=font-metrics.js.map