1 files changed, 44 insertions, 0 deletions
diff --git a/app/javascript/flavours/glitch/util/reduced_motion.js b/app/javascript/flavours/glitch/util/reduced_motion.js
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index 000000000..95519042b
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+++ b/app/javascript/flavours/glitch/util/reduced_motion.js
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+// Like react-motion's Motion, but reduces all animations to cross-fades
+// for the benefit of users with motion sickness.
+import React from 'react';
+import Motion from 'react-motion/lib/Motion';
+import PropTypes from 'prop-types';
+
+const stylesToKeep = ['opacity', 'backgroundOpacity'];
+
+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 ReducedMotion extends React.Component {
+
+  static propTypes = {
+    defaultStyle: PropTypes.object,
+    style: PropTypes.object,
+    children: PropTypes.func,
+  }
+
+  render() {
+
+    const { style, defaultStyle, children } = this.props;
+
+    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 ReducedMotion;