Remove fade-in animation from modals in web UI (#15199)

app/javascript/mastodon/components/modal_root.js

@@ -9,11 +9,7 @@ export default class ModalRoot extends React.PureComponent {
     onClose: PropTypes.func.isRequired,
   };
 
-  state = {
-    revealed: !!this.props.children,
-  };
-
-  activeElement = this.state.revealed ? document.activeElement : null;
+  activeElement = this.props.children ? document.activeElement : null;
 
   handleKeyUp = (e) => {
     if ((e.key === 'Escape' || e.key === 'Esc' || e.keyCode === 27)
@@ -53,8 +49,6 @@ export default class ModalRoot extends React.PureComponent {
       this.activeElement = document.activeElement;
 
       this.getSiblings().forEach(sibling => sibling.setAttribute('inert', true));
-    } else if (!nextProps.children) {
-      this.setState({ revealed: false });
     }
   }
 
@@ -72,11 +66,6 @@ export default class ModalRoot extends React.PureComponent {
         console.error(error);
       });
     }
-    if (this.props.children) {
-      requestAnimationFrame(() => {
-        this.setState({ revealed: true });
-      });
-    }
   }
 
   componentWillUnmount () {
@@ -94,7 +83,6 @@ export default class ModalRoot extends React.PureComponent {
 
   render () {
     const { children, onClose } = this.props;
-    const { revealed } = this.state;
     const visible = !!children;
 
     if (!visible) {
@@ -104,7 +92,7 @@ export default class ModalRoot extends React.PureComponent {
     }
 
     return (
-      <div className='modal-root' ref={this.setRef} style={{ opacity: revealed ? 1 : 0 }}>
+      <div className='modal-root' ref={this.setRef}>
         <div style={{ pointerEvents: visible ? 'auto' : 'none' }}>
           <div role='presentation' className='modal-root__overlay' onClick={onClose} />
           <div role='dialog' className='modal-root__container'>{children}</div>

app/javascript/styles/mastodon/components.scss

@@ -4439,8 +4439,6 @@ a.status-card.compact:hover {
 
 .modal-root {
   position: relative;
-  transition: opacity 0.3s linear;
-  will-change: opacity;
   z-index: 9999;
 }