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86 行
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4 年前
// Set these to how you want inline and display math to be delimited.
const defaultCopyDelimiters = {
inline: ['$', '$'],
// alternative: ['\(', '\)']
display: ['$$', '$$'] // alternative: ['\[', '\]']
}; // Replace .katex elements with their TeX source (<annotation> element).
// Modifies fragment in-place. Useful for writing your own 'copy' handler,
// as in copy-tex.js.
const katexReplaceWithTex = function katexReplaceWithTex(fragment, copyDelimiters) {
if (copyDelimiters === void 0) {
copyDelimiters = defaultCopyDelimiters;
}
// Remove .katex-html blocks that are preceded by .katex-mathml blocks
// (which will get replaced below).
const katexHtml = fragment.querySelectorAll('.katex-mathml + .katex-html');
for (let i = 0; i < katexHtml.length; i++) {
const element = katexHtml[i];
if (element.remove) {
element.remove(null);
} else {
element.parentNode.removeChild(element);
}
} // Replace .katex-mathml elements with their annotation (TeX source)
// descendant, with inline delimiters.
const katexMathml = fragment.querySelectorAll('.katex-mathml');
for (let i = 0; i < katexMathml.length; i++) {
const element = katexMathml[i];
const texSource = element.querySelector('annotation');
if (texSource) {
if (element.replaceWith) {
element.replaceWith(texSource);
} else {
element.parentNode.replaceChild(texSource, element);
}
texSource.innerHTML = copyDelimiters.inline[0] + texSource.innerHTML + copyDelimiters.inline[1];
}
} // Switch display math to display delimiters.
const displays = fragment.querySelectorAll('.katex-display annotation');
for (let i = 0; i < displays.length; i++) {
const element = displays[i];
element.innerHTML = copyDelimiters.display[0] + element.innerHTML.substr(copyDelimiters.inline[0].length, element.innerHTML.length - copyDelimiters.inline[0].length - copyDelimiters.inline[1].length) + copyDelimiters.display[1];
}
return fragment;
};
document.addEventListener('copy', function (event) {
const selection = window.getSelection();
if (selection.isCollapsed) {
return; // default action OK if selection is empty
}
const fragment = selection.getRangeAt(0).cloneContents();
if (!fragment.querySelector('.katex-mathml')) {
return; // default action OK if no .katex-mathml elements
} // Preserve usual HTML copy/paste behavior.
const html = [];
for (let i = 0; i < fragment.childNodes.length; i++) {
html.push(fragment.childNodes[i].outerHTML);
}
event.clipboardData.setData('text/html', html.join('')); // Rewrite plain-text version.
event.clipboardData.setData('text/plain', katexReplaceWithTex(fragment).textContent); // Prevent normal copy handling.
event.preventDefault();
});