cybre-space/app/javascript/mastodon/features/ui/util/optional_motion.js

57 lines
1.6 KiB
JavaScript

// Like react-motion's Motion, but checks to see if the user prefers
// reduced motion and uses a cross-fade in those cases.
import React from 'react';
import Motion from 'react-motion/lib/Motion';
import PropTypes from 'prop-types';
const stylesToKeep = ['opacity', 'backgroundOpacity'];
let reduceMotion;
const extractValue = (value) => {
// This is either an object with a "val" property or it's a number
return (typeof value === 'object' && value && 'val' in value) ? value.val : value;
};
class OptionalMotion extends React.Component {
static propTypes = {
defaultStyle: PropTypes.object,
style: PropTypes.object,
children: PropTypes.func,
}
render() {
const { style, defaultStyle, children } = this.props;
if (typeof reduceMotion !== 'boolean') {
// This never changes without a page reload, so we can just grab it
// once from the body classes as opposed to using Redux's connect(),
// which would unnecessarily update every state change
reduceMotion = document.body.classList.contains('reduce-motion');
}
if (reduceMotion) {
Object.keys(style).forEach(key => {
if (stylesToKeep.includes(key)) {
return;
}
// If it's setting an x or height or scale or some other value, we need
// to preserve the end-state value without actually animating it
style[key] = defaultStyle[key] = extractValue(style[key]);
});
}
return (
<Motion style={style} defaultStyle={defaultStyle}>
{children}
</Motion>
);
}
}
export default OptionalMotion;