mirror of
https://codeberg.org/forgejo/forgejo.git
synced 2024-11-30 12:17:47 +01:00
fd4e7447e7
Backport #21642 Browsers introduce a opaque background on iframes if the iframe element's color-scheme does not match the document's color scheme which in case of a dark theme results in a mismatch and the browser adds a white background. Avoid this by specifying the same color scheme outside and inside the iframe. See https://fvsch.com/transparent-iframes for more info. My initial attempt was to make the iframe document the same color-scheme as the parent page (light or dark) but with that, there was a ugly background flash on load in Chrome because Chrome apparently always loads iframe in light scheme initially. Firefox still shows a background flash on load but this is not possible to get rid of and it's certainly a browser bug. Before: <img width="1147" alt="Screen Shot 2022-10-31 at 13 30 55" src="https://user-images.githubusercontent.com/115237/199017132-9828aace-bdd0-4ede-8118-359e72bcf2fe.png"> After: <img width="1152" alt="Screen Shot 2022-10-31 at 13 30 36" src="https://user-images.githubusercontent.com/115237/199017137-989a9e67-3fe0-445f-a191-df5bf290dabf.png">
67 lines
2.3 KiB
JavaScript
67 lines
2.3 KiB
JavaScript
import {isDarkTheme} from '../utils.js';
|
|
const {mermaidMaxSourceCharacters} = window.config;
|
|
|
|
const iframeCss = `
|
|
:root {color-scheme: normal}
|
|
body {margin: 0; padding: 0}
|
|
#mermaid {display: block; margin: 0 auto}
|
|
`;
|
|
|
|
function displayError(el, err) {
|
|
el.closest('pre').classList.remove('is-loading');
|
|
const errorNode = document.createElement('div');
|
|
errorNode.setAttribute('class', 'ui message error markup-block-error mono');
|
|
errorNode.textContent = err.str || err.message || String(err);
|
|
el.closest('pre').before(errorNode);
|
|
}
|
|
|
|
export async function renderMermaid() {
|
|
const els = document.querySelectorAll('.markup code.language-mermaid');
|
|
if (!els.length) return;
|
|
|
|
const {default: mermaid} = await import(/* webpackChunkName: "mermaid" */'mermaid');
|
|
|
|
mermaid.initialize({
|
|
startOnLoad: false,
|
|
theme: isDarkTheme() ? 'dark' : 'neutral',
|
|
securityLevel: 'strict',
|
|
});
|
|
|
|
for (const el of els) {
|
|
const source = el.textContent;
|
|
|
|
if (mermaidMaxSourceCharacters >= 0 && source.length > mermaidMaxSourceCharacters) {
|
|
displayError(el, new Error(`Mermaid source of ${source.length} characters exceeds the maximum allowed length of ${mermaidMaxSourceCharacters}.`));
|
|
continue;
|
|
}
|
|
|
|
let valid;
|
|
try {
|
|
valid = mermaid.parse(source);
|
|
} catch (err) {
|
|
displayError(el, err);
|
|
}
|
|
|
|
if (!valid) {
|
|
el.closest('pre').classList.remove('is-loading');
|
|
continue;
|
|
}
|
|
|
|
try {
|
|
// can't use bindFunctions here because we can't cross the iframe boundary. This
|
|
// means js-based interactions won't work but they aren't intended to work either
|
|
mermaid.mermaidAPI.render('mermaid', source, (svgStr) => {
|
|
const heightStr = (svgStr.match(/viewBox="(.+?)"/) || ['', ''])[1].split(/\s+/)[3];
|
|
if (!heightStr) return displayError(el, new Error('Could not determine chart height'));
|
|
const iframe = document.createElement('iframe');
|
|
iframe.classList.add('markup-render');
|
|
iframe.sandbox = 'allow-scripts';
|
|
iframe.style.height = `${Math.ceil(parseFloat(heightStr))}px`;
|
|
iframe.srcdoc = `<html><head><style>${iframeCss}</style></head><body>${svgStr}</body></html>`;
|
|
el.closest('pre').replaceWith(iframe);
|
|
});
|
|
} catch (err) {
|
|
displayError(el, err);
|
|
}
|
|
}
|
|
}
|