owncast/webroot/js/chat/content-editable.js

132 lines
3.6 KiB
JavaScript

/*
Since we can't really import react-contenteditable here, I'm borrowing code for this component from here:
github.com/lovasoa/react-contenteditable/
and here:
https://stackoverflow.com/questions/22677931/react-js-onchange-event-for-contenteditable/27255103#27255103
*/
import { Component, createRef, createElement } from 'https://unpkg.com/preact?module';
function replaceCaret(el) {
// Place the caret at the end of the element
const target = document.createTextNode('');
el.appendChild(target);
// do not move caret if element was not focused
const isTargetFocused = document.activeElement === el;
if (target !== null && target.nodeValue !== null && isTargetFocused) {
var sel = window.getSelection();
if (sel !== null) {
var range = document.createRange();
range.setStart(target, target.nodeValue.length);
range.collapse(true);
sel.removeAllRanges();
sel.addRange(range);
}
if (el) el.focus();
}
}
function normalizeHtml(str) {
return str && str.replace(/ |\u202F|\u00A0/g, ' ');
}
export default class ContentEditable extends Component {
constructor(props) {
super(props);
this.el = createRef();
this.lastHtml = '';
this.emitChange = this.emitChange.bind(this);
this.getDOMElement = this.getDOMElement.bind(this);
}
shouldComponentUpdate(nextProps) {
const { props } = this;
const el = this.getDOMElement();
// We need not rerender if the change of props simply reflects the user's edits.
// Rerendering in this case would make the cursor/caret jump
// Rerender if there is no element yet... (somehow?)
if (!el) return true;
// ...or if html really changed... (programmatically, not by user edit)
if (
normalizeHtml(nextProps.html) !== normalizeHtml(el.innerHTML)
) {
return true;
}
// Handle additional properties
return props.disabled !== nextProps.disabled ||
props.tagName !== nextProps.tagName ||
props.className !== nextProps.className ||
props.innerRef !== nextProps.innerRef;
}
componentDidUpdate() {
const el = this.getDOMElement();
if (!el) return;
// Perhaps React (whose VDOM gets outdated because we often prevent
// rerendering) did not update the DOM. So we update it manually now.
if (this.props.html !== el.innerHTML) {
el.innerHTML = this.props.html;
}
this.lastHtml = this.props.html;
replaceCaret(el);
}
getDOMElement() {
return (this.props.innerRef && typeof this.props.innerRef !== 'function' ? this.props.innerRef : this.el).current;
}
emitChange(originalEvt) {
const el = this.getDOMElement();
if (!el) return;
const html = el.innerHTML;
if (this.props.onChange && html !== this.lastHtml) {
// Clone event with Object.assign to avoid
// "Cannot assign to read only property 'target' of object"
const evt = Object.assign({}, originalEvt, {
target: {
value: html
}
});
this.props.onChange(evt);
}
this.lastHtml = html;
}
render(props) {
const { html, innerRef } = props;
return createElement(
'div',
{
...props,
ref: typeof innerRef === 'function' ? (current) => {
innerRef(current)
this.el.current = current
} : innerRef || this.el,
onInput: this.emitChange,
onBlur: this.props.onBlur || this.emitChange,
onKeyup: this.props.onKeyUp || this.emitChange,
onKeydown: this.props.onKeyDown || this.emitChange,
contentEditable: !this.props.disabled,
dangerouslySetInnerHTML: { __html: html },
},
this.props.children,
);
}
}