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

7 files changed, 149 insertions, 22 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 }) => {
diff --git a/app/lib/formatter.rb b/app/lib/formatter.rb
index 6c1239963..65059efa0 100644
--- a/app/lib/formatter.rb
+++ b/app/lib/formatter.rb
@@ -137,11 +137,7 @@ class Formatter
   def encode_custom_emojis(html, emojis, animate = false)
     return html if emojis.empty?
 
-    emoji_map = if animate
-                  emojis.each_with_object({}) { |e, h| h[e.shortcode] = full_asset_url(e.image.url) }
-                else
-                  emojis.each_with_object({}) { |e, h| h[e.shortcode] = full_asset_url(e.image.url(:static)) }
-                end
+    emoji_map = emojis.each_with_object({}) { |e, h| h[e.shortcode] = [full_asset_url(e.image.url), full_asset_url(e.image.url(:static))] }
 
     i                     = -1
     tag_open_index        = nil
@@ -157,7 +153,14 @@ class Formatter
         emoji     = emoji_map[shortcode]
 
         if emoji
-          replacement = "<img draggable=\"false\" class=\"emojione\" alt=\":#{encode(shortcode)}:\" title=\":#{encode(shortcode)}:\" src=\"#{encode(emoji)}\" />"
+          original_url, static_url = emoji
+          replacement = begin
+            if animate
+              "<img draggable=\"false\" class=\"emojione\" alt=\":#{encode(shortcode)}:\" title=\":#{encode(shortcode)}:\" src=\"#{encode(original_url)}\" />"
+            else
+              "<img draggable=\"false\" class=\"emojione custom-emoji\" alt=\":#{encode(shortcode)}:\" title=\":#{encode(shortcode)}:\" src=\"#{encode(static_url)}\" data-original=\"#{original_url}\" data-static=\"#{static_url}\" />"
+            end
+          end
           before_html = shortname_start_index.positive? ? html[0..shortname_start_index - 1] : ''
           html        = before_html + replacement + html[i + 1..-1]
           i          += replacement.size - (shortcode.size + 2) - 1
diff --git a/spec/lib/formatter_spec.rb b/spec/lib/formatter_spec.rb
index 96d2fc7e0..b8108a247 100644
--- a/spec/lib/formatter_spec.rb
+++ b/spec/lib/formatter_spec.rb
@@ -261,7 +261,7 @@ RSpec.describe Formatter do
       let(:text) { ':coolcat: Beep boop' }
 
       it 'converts the shortcode to an image tag' do
-        is_expected.to match(/<img draggable="false" class="emojione" alt=":coolcat:"/)
+        is_expected.to match(/<img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
       end
     end
   end
@@ -330,7 +330,7 @@ RSpec.describe Formatter do
           let(:text) { ':coolcat: Beep boop' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/<p><img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/<p><img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
 
@@ -338,7 +338,7 @@ RSpec.describe Formatter do
           let(:text) { 'Beep :coolcat: boop' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/Beep <img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/Beep <img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
 
@@ -354,7 +354,7 @@ RSpec.describe Formatter do
           let(:text) { 'Beep boop :coolcat:' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/boop <img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/boop <img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
       end
@@ -377,7 +377,7 @@ RSpec.describe Formatter do
           let(:text) { '<p>:coolcat: Beep boop<br />' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/<p><img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/<p><img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
 
@@ -385,7 +385,7 @@ RSpec.describe Formatter do
           let(:text) { '<p>Beep :coolcat: boop</p>' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/Beep <img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/Beep <img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
 
@@ -401,7 +401,7 @@ RSpec.describe Formatter do
           let(:text) { '<p>Beep boop<br />:coolcat:</p>' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/<br><img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/<br><img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
       end
@@ -500,7 +500,7 @@ RSpec.describe Formatter do
           let(:text) { ':coolcat: Beep boop' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/<p><img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/<p><img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
 
@@ -508,7 +508,7 @@ RSpec.describe Formatter do
           let(:text) { 'Beep :coolcat: boop' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/Beep <img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/Beep <img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
 
@@ -524,7 +524,7 @@ RSpec.describe Formatter do
           let(:text) { 'Beep boop :coolcat:' }
 
           it 'converts the shortcode to an image tag' do
-            is_expected.to match(/boop <img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/boop <img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
       end
@@ -551,7 +551,7 @@ RSpec.describe Formatter do
           let(:text) { '<p>:coolcat: Beep boop<br />' }
 
           it 'converts shortcode to image tag' do
-            is_expected.to match(/<p><img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/<p><img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
 
@@ -559,7 +559,7 @@ RSpec.describe Formatter do
           let(:text) { '<p>Beep :coolcat: boop</p>' }
 
           it 'converts shortcode to image tag' do
-            is_expected.to match(/Beep <img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/Beep <img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
 
@@ -575,7 +575,7 @@ RSpec.describe Formatter do
           let(:text) { '<p>Beep boop<br />:coolcat:</p>' }
 
           it 'converts shortcode to image tag' do
-            is_expected.to match(/<br><img draggable="false" class="emojione" alt=":coolcat:"/)
+            is_expected.to match(/<br><img draggable="false" class="emojione custom-emoji" alt=":coolcat:"/)
           end
         end
       end