Play animated custom emoji on hover (#11348)

* Play animated custom emoji on hover in status

* Play animated custom emoji on hover in display names

* Play animated custom emoji on hover in bios/bio fields

* Add support for animation on hover on public pages emojis too

* Fix tests

* Code style cleanup

5 files changed, 127 insertions, 3 deletions

diff --git a/app/javascript/mastodon/components/display_name.js b/app/javascript/mastodon/components/display_name.js
index 6b9dd6f81..70ef82789 100644
--- a/app/javascript/mastodon/components/display_name.js
+++ b/app/javascript/mastodon/components/display_name.js
@@ -1,6 +1,7 @@
 import React from 'react';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import PropTypes from 'prop-types';
+import { autoPlayGif } from 'mastodon/initial_state';
 
 export default class DisplayName extends React.PureComponent {
 
@@ -10,6 +11,47 @@ export default class DisplayName extends React.PureComponent {
     localDomain: PropTypes.string,
   };
 
+  _updateEmojis () {
+    const node = this.node;
+
+    if (!node || autoPlayGif) {
+      return;
+    }
+
+    const emojis = node.querySelectorAll('.custom-emoji');
+
+    for (var i = 0; i < emojis.length; i++) {
+      let emoji = emojis[i];
+      if (emoji.classList.contains('status-emoji')) {
+        continue;
+      }
+      emoji.classList.add('status-emoji');
+
+      emoji.addEventListener('mouseenter', this.handleEmojiMouseEnter, false);
+      emoji.addEventListener('mouseleave', this.handleEmojiMouseLeave, false);
+    }
+  }
+
+  componentDidMount () {
+    this._updateEmojis();
+  }
+
+  componentDidUpdate () {
+    this._updateEmojis();
+  }
+
+  handleEmojiMouseEnter = ({ target }) => {
+    target.src = target.getAttribute('data-original');
+  }
+
+  handleEmojiMouseLeave = ({ target }) => {
+    target.src = target.getAttribute('data-static');
+  }
+
+  setRef = (c) => {
+    this.node = c;
+  }
+
   render () {
     const { others, localDomain } = this.props;
 
@@ -39,7 +81,7 @@ export default class DisplayName extends React.PureComponent {
     }
 
     return (
-      <span className='display-name'>
+      <span className='display-name' ref={this.setRef}>
         {displayName} {suffix}
       </span>
     );
diff --git a/app/javascript/mastodon/components/status_content.js b/app/javascript/mastodon/components/status_content.js
index 06f5b4aad..8a05415af 100644
--- a/app/javascript/mastodon/components/status_content.js
+++ b/app/javascript/mastodon/components/status_content.js
@@ -7,6 +7,7 @@ import Permalink from './permalink';
 import classnames from 'classnames';
 import PollContainer from 'mastodon/containers/poll_container';
 import Icon from 'mastodon/components/icon';
+import { autoPlayGif } from 'mastodon/initial_state';
 
 const MAX_HEIGHT = 642; // 20px * 32 (+ 2px padding at the top)
 
@@ -71,12 +72,35 @@ export default class StatusContent extends React.PureComponent {
     }
   }
 
+  _updateStatusEmojis () {
+    const node = this.node;
+
+    if (!node || autoPlayGif) {
+      return;
+    }
+
+    const emojis = node.querySelectorAll('.custom-emoji');
+
+    for (var i = 0; i < emojis.length; i++) {
+      let emoji = emojis[i];
+      if (emoji.classList.contains('status-emoji')) {
+        continue;
+      }
+      emoji.classList.add('status-emoji');
+
+      emoji.addEventListener('mouseenter', this.handleEmojiMouseEnter, false);
+      emoji.addEventListener('mouseleave', this.handleEmojiMouseLeave, false);
+    }
+  }
+
   componentDidMount () {
     this._updateStatusLinks();
+    this._updateStatusEmojis();
   }
 
   componentDidUpdate () {
     this._updateStatusLinks();
+    this._updateStatusEmojis();
   }
 
   onMentionClick = (mention, e) => {
@@ -95,6 +119,14 @@ export default class StatusContent extends React.PureComponent {
     }
   }
 
+  handleEmojiMouseEnter = ({ target }) => {
+    target.src = target.getAttribute('data-original');
+  }
+
+  handleEmojiMouseLeave = ({ target }) => {
+    target.src = target.getAttribute('data-static');
+  }
+
   handleMouseDown = (e) => {
     this.startXY = [e.clientX, e.clientY];
   }
diff --git a/app/javascript/mastodon/features/account/components/header.js b/app/javascript/mastodon/features/account/components/header.js
index e5b60e33e..cab67c607 100644
--- a/app/javascript/mastodon/features/account/components/header.js
+++ b/app/javascript/mastodon/features/account/components/header.js
@@ -79,6 +79,47 @@ class Header extends ImmutablePureComponent {
     return !location.pathname.match(/\/(followers|following)\/?$/);
   }
 
+  _updateEmojis () {
+    const node = this.node;
+
+    if (!node || autoPlayGif) {
+      return;
+    }
+
+    const emojis = node.querySelectorAll('.custom-emoji');
+
+    for (var i = 0; i < emojis.length; i++) {
+      let emoji = emojis[i];
+      if (emoji.classList.contains('status-emoji')) {
+        continue;
+      }
+      emoji.classList.add('status-emoji');
+
+      emoji.addEventListener('mouseenter', this.handleEmojiMouseEnter, false);
+      emoji.addEventListener('mouseleave', this.handleEmojiMouseLeave, false);
+    }
+  }
+
+  componentDidMount () {
+    this._updateEmojis();
+  }
+
+  componentDidUpdate () {
+    this._updateEmojis();
+  }
+
+  handleEmojiMouseEnter = ({ target }) => {
+    target.src = target.getAttribute('data-original');
+  }
+
+  handleEmojiMouseLeave = ({ target }) => {
+    target.src = target.getAttribute('data-static');
+  }
+
+  setRef = (c) => {
+    this.node = c;
+  }
+
   render () {
     const { account, intl, domain, identity_proofs } = this.props;
 
@@ -200,7 +241,7 @@ class Header extends ImmutablePureComponent {
     const acct            = account.get('acct').indexOf('@') === -1 && domain ? `${account.get('acct')}@${domain}` : account.get('acct');
 
     return (
-      <div className={classNames('account__header', { inactive: !!account.get('moved') })}>
+      <div className={classNames('account__header', { inactive: !!account.get('moved') })} ref={this.setRef}>
         <div className='account__header__image'>
           <div className='account__header__info'>
             {info}
diff --git a/app/javascript/mastodon/features/emoji/emoji.js b/app/javascript/mastodon/features/emoji/emoji.js
index 01b5a6664..359bb7ffd 100644
--- a/app/javascript/mastodon/features/emoji/emoji.js
+++ b/app/javascript/mastodon/features/emoji/emoji.js
@@ -29,7 +29,7 @@ const emojify = (str, customEmojis = {}) => {
         // if you want additional emoji handler, add statements below which set replacement and return true.
         if (shortname in customEmojis) {
           const filename = autoPlayGif ? customEmojis[shortname].url : customEmojis[shortname].static_url;
-          replacement = `<img draggable="false" class="emojione" alt="${shortname}" title="${shortname}" src="${filename}" />`;
+          replacement = `<img draggable="false" class="emojione custom-emoji" alt="${shortname}" title="${shortname}" src="${filename}" data-original="${customEmojis[shortname].url}" data-static="${customEmojis[shortname].static_url}" />`;
           return true;
         }
         return false;
diff --git a/app/javascript/packs/public.js b/app/javascript/packs/public.js
index 0c60d828e..b58622a8d 100644
--- a/app/javascript/packs/public.js
+++ b/app/javascript/packs/public.js
@@ -44,6 +44,12 @@ function main() {
     }
   };
 
+  const getEmojiAnimationHandler = (swapTo) => {
+    return ({ target }) => {
+      target.src = target.getAttribute(swapTo);
+    };
+  };
+
   ready(() => {
     const locale = document.documentElement.lang;
 
@@ -108,6 +114,9 @@ function main() {
     if (parallaxComponents.length > 0 ) {
       new Rellax('.parallax', { speed: -1 });
     }
+
+    delegate(document, '.custom-emoji', 'mouseover', getEmojiAnimationHandler('data-original'));
+    delegate(document, '.custom-emoji', 'mouseout', getEmojiAnimationHandler('data-static'));
   });
 
   delegate(document, '.webapp-btn', 'click', ({ target, button }) => {