From cfdaa5735330cda74df01a0a95a64f5428270771 Mon Sep 17 00:00:00 2001
From: Calixte Denizet <calixte.denizet@gmail.com>
Date: Sat, 27 Nov 2021 15:49:57 +0100
Subject: [PATCH] Handle sub/super-scripts in rich text - it aims to fix
#14317; - change the fontSize and the verticalAlign properties according to
the position of the text.
---
src/core/xfa/xhtml.js | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/src/core/xfa/xhtml.js b/src/core/xfa/xhtml.js
index 510747db4..273cc93bc 100644
--- a/src/core/xfa/xhtml.js
+++ b/src/core/xfa/xhtml.js
@@ -107,13 +107,14 @@ const StyleMapping = new Map([
["margin-top", value => measureToString(getMeasurement(value))],
["text-indent", value => measureToString(getMeasurement(value))],
["font-family", value => value],
+ ["vertical-align", value => measureToString(getMeasurement(value))],
]);
const spacesRegExp = /\s+/g;
const crlfRegExp = /[\r\n]+/g;
const crlfForRichTextRegExp = /\r\n?/g;
-function mapStyle(styleStr, node) {
+function mapStyle(styleStr, node, richText) {
const style = Object.create(null);
if (!styleStr) {
return style;
@@ -158,6 +159,29 @@ function mapStyle(styleStr, node) {
);
}
+ if (
+ richText &&
+ style.verticalAlign &&
+ style.verticalAlign !== "0px" &&
+ style.fontSize
+ ) {
+ // A non-zero verticalAlign means that we've a sub/super-script and
+ // consequently the font size must be decreased.
+ // https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf#G11.2097514
+ // And the two following factors to position the scripts have been
+ // found here:
+ // https://en.wikipedia.org/wiki/Subscript_and_superscript#Desktop_publishing
+ const SUB_SUPER_SCRIPT_FACTOR = 0.583;
+ const VERTICAL_FACTOR = 0.333;
+ const fontSize = getMeasurement(style.fontSize);
+ style.fontSize = measureToString(fontSize * SUB_SUPER_SCRIPT_FACTOR);
+ style.verticalAlign = measureToString(
+ Math.sign(getMeasurement(style.verticalAlign)) *
+ fontSize *
+ VERTICAL_FACTOR
+ );
+ }
+
fixTextIndent(style);
return style;
}
@@ -333,7 +357,7 @@ class XhtmlObject extends XmlObject {
name: this[$nodeName],
attributes: {
href: this.href,
- style: mapStyle(this.style, this),
+ style: mapStyle(this.style, this, this[$richText]),
},
children,
value,