3f67f411d8
Bug: skia: Change-Id: I2ffd54cf81c974f3a80103e1726a06067cc90d82 Reviewed-on: https://skia-review.googlesource.com/c/skia/+/200044 Reviewed-by: Mike Reed <reed@google.com> Reviewed-by: Florin Malita <fmalita@chromium.org> Commit-Queue: Kevin Lubick <kjlubick@google.com>
113 lines
3.0 KiB
JavaScript
113 lines
3.0 KiB
JavaScript
// Functions dealing with parsing/stringifying fonts go here.
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var fontStringRegex = new RegExp(
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'(italic|oblique|normal|)\\s*' + // style
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'(small-caps|normal|)\\s*' + // variant
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'(bold|bolder|lighter|[1-9]00|normal|)\\s*' + // weight
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'([\\d\\.]+)' + // size
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'(px|pt|pc|in|cm|mm|%|em|ex|ch|rem|q)' + // unit
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// line-height is ignored here, as per the spec
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'(.+)' // family
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);
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function stripWhitespace(str) {
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return str.replace(/^\s+|\s+$/, '');
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}
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var defaultHeight = 16;
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// Based off of node-canvas's parseFont
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// returns font size in px, which represents the em width.
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function parseFontString(fontStr) {
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var font = fontStringRegex.exec(fontStr);
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if (!font) {
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SkDebug('Invalid font string ' + fontStr);
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return null;
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}
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var size = parseFloat(font[4]);
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var sizePx = defaultHeight;
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var unit = font[5];
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switch (unit) {
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case 'em':
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case 'rem':
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sizePx = size * defaultHeight;
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break;
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case 'pt':
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sizePx = size * 4/3;
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break;
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case 'px':
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sizePx = size;
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break;
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case 'pc':
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sizePx = size * defaultHeight;
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break;
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case 'in':
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sizePx = size * 96;
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break;
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case 'cm':
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sizePx = size * 96.0 / 2.54;
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break;
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case 'mm':
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sizePx = size * (96.0 / 25.4);
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break;
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case 'q': // quarter millimeters
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sizePx = size * (96.0 / 25.4 / 4);
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break;
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case '%':
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sizePx = size * (defaultHeight / 75);
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break;
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}
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return {
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'style': font[1],
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'variant': font[2],
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'weight': font[3],
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'sizePx': sizePx,
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'family': font[6].trim()
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};
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}
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function getTypeface(fontstr) {
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var descriptors = parseFontString(fontstr);
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var typeface = getFromFontCache(descriptors);
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descriptors['typeface'] = typeface;
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return descriptors;
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}
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// null means use the default typeface (which is currently NotoMono)
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var fontCache = {
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'Noto Mono': {
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'*': null, // is used if we have this font family, but not the right style/variant/weight
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},
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'monospace': {
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'*': null,
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}
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};
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// descriptors is like https://developer.mozilla.org/en-US/docs/Web/API/FontFace/FontFace
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// The ones currently supported are family, style, variant, weight.
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function addToFontCache(typeface, descriptors) {
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var key = (descriptors['style'] || 'normal') + '|' +
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(descriptors['variant'] || 'normal') + '|' +
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(descriptors['weight'] || 'normal');
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var fam = descriptors['family'];
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if (!fontCache[fam]) {
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// preload with a fallback to this typeface
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fontCache[fam] = {
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'*': typeface,
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};
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}
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fontCache[fam][key] = typeface;
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}
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function getFromFontCache(descriptors) {
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var key = (descriptors['style'] || 'normal') + '|' +
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(descriptors['variant'] || 'normal') + '|' +
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(descriptors['weight'] || 'normal');
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var fam = descriptors['family'];
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if (!fontCache[fam]) {
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return null;
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}
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return fontCache[fam][key] || fontCache[fam]['*'];
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}
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CanvasKit._testing['parseFontString'] = parseFontString; |