js-draw
Version:
Draw pictures using a pen, touchscreen, or mouse! JS-draw is a drawing library for JavaScript and TypeScript.
28 lines (27 loc) • 1.24 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
/** Computes the font size of a text element, based on style information. */
const determineFontSize = (elem, computedStyles,
// output: Written to to update supported style attributes
supportedStyleAttrs) => {
const fontSizeExp = /^([-0-9.e]+)px/i;
// In some environments, computedStyles.fontSize can be increased by the system.
// Thus, to prevent text from growing on load/save, prefer .style.fontSize.
let fontSizeMatch = fontSizeExp.exec(elem.style?.fontSize ?? '');
if (!fontSizeMatch && elem.tagName.toLowerCase() === 'tspan' && elem.parentElement) {
// Try to inherit the font size of the parent text element.
fontSizeMatch = fontSizeExp.exec(elem.parentElement.style?.fontSize ?? '');
}
// If we still couldn't find a font size, try to use computedStyles (which can be
// wrong).
if (!fontSizeMatch && computedStyles) {
fontSizeMatch = fontSizeExp.exec(computedStyles.fontSize);
}
let fontSize = 12;
if (fontSizeMatch) {
supportedStyleAttrs.add('fontSize');
fontSize = parseFloat(fontSizeMatch[1]);
}
return fontSize;
};
exports.default = determineFontSize;