signal-desktop/ts/quill/signal-clipboard/util.ts

108 lines
2.9 KiB
TypeScript

// Copyright 2023 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
const QUILL_EMBED_GUARD = '\uFEFF';
export function createEventHandler({
deleteSelection,
}: {
deleteSelection: boolean;
}) {
return (event: ClipboardEvent): void => {
// If we're attempting to cut, and focus is not in one of our composer elements, we
// let the browser do its default behavior. We don't need formatting from them.
if (deleteSelection) {
const { activeElement } = document;
if (
!activeElement ||
activeElement.matches('input, textarea') ||
!activeElement.closest('[contenteditable=true]')
) {
return;
}
}
if (!event.clipboardData) {
return;
}
const selection = window.getSelection();
if (!selection) {
return;
}
// Create synthetic html with the full selection we can put into clipboard
const container = document.createElement('div');
for (let i = 0, max = selection.rangeCount; i < max; i += 1) {
const range = selection.getRangeAt(i);
container.appendChild(range.cloneContents());
}
// We fail over to selection.toString() because we can't pull values from the DOM if
// the selection is within an <input/> or <textarea/>. But the browser can!
const plaintext = getStringFromNode(container) || selection.toString();
// Note: we can't leave text/plain alone and just add text/signal; if we update
// clipboardData at all, all other data is reset.
event.clipboardData?.setData('text/plain', plaintext);
event.clipboardData?.setData('text/signal', container.innerHTML);
if (deleteSelection) {
selection.deleteFromDocument();
}
event.preventDefault();
event.stopPropagation();
};
}
function getStringFromNode(
node: Node,
parent?: Node,
nextSibling?: Node
): string {
if (node.nodeType === Node.TEXT_NODE) {
if (node.textContent === QUILL_EMBED_GUARD) {
return '';
}
return node.textContent || '';
}
if (node.nodeType !== Node.ELEMENT_NODE) {
return '';
}
const element = node as Element;
if (
element.nodeName === 'IMG' &&
(element.classList.contains('emoji') ||
element.classList.contains('emoji-blot'))
) {
return element.ariaLabel || '';
}
if (nextSibling && element.nodeName === 'BR') {
return '\n';
}
const childCount = element.childNodes.length;
if (childCount === 0) {
return element.textContent || '';
}
let result = '';
for (let i = 0; i < childCount; i += 1) {
const child = element.childNodes[i];
const nextChild = element.childNodes[i + 1];
result += getStringFromNode(child, node, nextChild);
}
if (
parent &&
parent.childNodes.length > 1 &&
(element.nodeName === 'P' ||
element.nodeName === 'DIV' ||
element.nodeName === 'TIME')
) {
if (result.length > 0 && !result.endsWith('\n\n')) {
result += '\n';
}
}
return result;
}