Add option to reduce motion (#5393)

* Add option to reduce motion

* Use HOC to wrap all Motion calls

* fix case-sensitive issue

* Avoid updating too frequently

* Get rid of unnecessary change to _simple_status.html.haml

13 files changed, 46 insertions, 12 deletions

diff --git a/app/javascript/mastodon/components/collapsable.js b/app/javascript/mastodon/components/collapsable.js
index ad1453589..42ea37ec2 100644
--- a/app/javascript/mastodon/components/collapsable.js
+++ b/app/javascript/mastodon/components/collapsable.js
@@ -1,5 +1,5 @@
 import React from 'react';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../features/ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import PropTypes from 'prop-types';
 
diff --git a/app/javascript/mastodon/components/dropdown_menu.js b/app/javascript/mastodon/components/dropdown_menu.js
index 73ad46bb7..3a3ebf487 100644
--- a/app/javascript/mastodon/components/dropdown_menu.js
+++ b/app/javascript/mastodon/components/dropdown_menu.js
@@ -3,7 +3,7 @@ import PropTypes from 'prop-types';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import IconButton from './icon_button';
 import Overlay from 'react-overlays/lib/Overlay';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../features/ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import detectPassiveEvents from 'detect-passive-events';
 
diff --git a/app/javascript/mastodon/components/icon_button.js b/app/javascript/mastodon/components/icon_button.js
index 68d1a2735..d8e445cef 100644
--- a/app/javascript/mastodon/components/icon_button.js
+++ b/app/javascript/mastodon/components/icon_button.js
@@ -1,5 +1,5 @@
 import React from 'react';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../features/ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import PropTypes from 'prop-types';
 import classNames from 'classnames';
diff --git a/app/javascript/mastodon/features/account/components/header.js b/app/javascript/mastodon/features/account/components/header.js
index 9ee7a56d9..07a6c5dec 100644
--- a/app/javascript/mastodon/features/account/components/header.js
+++ b/app/javascript/mastodon/features/account/components/header.js
@@ -3,7 +3,7 @@ import ImmutablePropTypes from 'react-immutable-proptypes';
 import PropTypes from 'prop-types';
 import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
 import IconButton from '../../../components/icon_button';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import { connect } from 'react-redux';
 import ImmutablePureComponent from 'react-immutable-pure-component';
diff --git a/app/javascript/mastodon/features/compose/components/privacy_dropdown.js b/app/javascript/mastodon/features/compose/components/privacy_dropdown.js
index e38ed38c1..c1e85aee3 100644
--- a/app/javascript/mastodon/features/compose/components/privacy_dropdown.js
+++ b/app/javascript/mastodon/features/compose/components/privacy_dropdown.js
@@ -3,7 +3,7 @@ import PropTypes from 'prop-types';
 import { injectIntl, defineMessages } from 'react-intl';
 import IconButton from '../../../components/icon_button';
 import Overlay from 'react-overlays/lib/Overlay';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import detectPassiveEvents from 'detect-passive-events';
 import classNames from 'classnames';
diff --git a/app/javascript/mastodon/features/compose/components/search.js b/app/javascript/mastodon/features/compose/components/search.js
index f57d54618..398fc44ce 100644
--- a/app/javascript/mastodon/features/compose/components/search.js
+++ b/app/javascript/mastodon/features/compose/components/search.js
@@ -2,7 +2,7 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import { defineMessages, injectIntl, FormattedMessage } from 'react-intl';
 import Overlay from 'react-overlays/lib/Overlay';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 
 const messages = defineMessages({
diff --git a/app/javascript/mastodon/features/compose/components/upload.js b/app/javascript/mastodon/features/compose/components/upload.js
index cd9e08360..5d8d66cf7 100644
--- a/app/javascript/mastodon/features/compose/components/upload.js
+++ b/app/javascript/mastodon/features/compose/components/upload.js
@@ -2,7 +2,7 @@ import React from 'react';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import PropTypes from 'prop-types';
 import IconButton from '../../../components/icon_button';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import ImmutablePureComponent from 'react-immutable-pure-component';
 import { defineMessages, injectIntl } from 'react-intl';
diff --git a/app/javascript/mastodon/features/compose/components/upload_progress.js b/app/javascript/mastodon/features/compose/components/upload_progress.js
index 3e49098c7..d5e6f19cd 100644
--- a/app/javascript/mastodon/features/compose/components/upload_progress.js
+++ b/app/javascript/mastodon/features/compose/components/upload_progress.js
@@ -1,6 +1,6 @@
 import React from 'react';
 import PropTypes from 'prop-types';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import { FormattedMessage } from 'react-intl';
 
diff --git a/app/javascript/mastodon/features/compose/components/warning.js b/app/javascript/mastodon/features/compose/components/warning.js
index a0814e984..803b7f86a 100644
--- a/app/javascript/mastodon/features/compose/components/warning.js
+++ b/app/javascript/mastodon/features/compose/components/warning.js
@@ -1,6 +1,6 @@
 import React from 'react';
 import PropTypes from 'prop-types';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 
 export default class Warning extends React.PureComponent {
diff --git a/app/javascript/mastodon/features/compose/containers/sensitive_button_container.js b/app/javascript/mastodon/features/compose/containers/sensitive_button_container.js
index 8624849f3..e4bd5a743 100644
--- a/app/javascript/mastodon/features/compose/containers/sensitive_button_container.js
+++ b/app/javascript/mastodon/features/compose/containers/sensitive_button_container.js
@@ -4,7 +4,7 @@ import PropTypes from 'prop-types';
 import classNames from 'classnames';
 import IconButton from '../../../components/icon_button';
 import { changeComposeSensitivity } from '../../../actions/compose';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import { injectIntl, defineMessages } from 'react-intl';
 
diff --git a/app/javascript/mastodon/features/compose/index.js b/app/javascript/mastodon/features/compose/index.js
index 6166fce3c..0c66585c9 100644
--- a/app/javascript/mastodon/features/compose/index.js
+++ b/app/javascript/mastodon/features/compose/index.js
@@ -8,7 +8,7 @@ import { mountCompose, unmountCompose } from '../../actions/compose';
 import { Link } from 'react-router-dom';
 import { injectIntl, defineMessages } from 'react-intl';
 import SearchContainer from './containers/search_container';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import SearchResultsContainer from './containers/search_results_container';
 import { changeComposing } from '../../actions/compose';
diff --git a/app/javascript/mastodon/features/ui/components/upload_area.js b/app/javascript/mastodon/features/ui/components/upload_area.js
index dda28feeb..c19065be6 100644
--- a/app/javascript/mastodon/features/ui/components/upload_area.js
+++ b/app/javascript/mastodon/features/ui/components/upload_area.js
@@ -1,6 +1,6 @@
 import React from 'react';
 import PropTypes from 'prop-types';
-import Motion from 'react-motion/lib/Motion';
+import Motion from '../../ui/util/optional_motion';
 import spring from 'react-motion/lib/spring';
 import { FormattedMessage } from 'react-intl';
 
diff --git a/app/javascript/mastodon/features/ui/util/optional_motion.js b/app/javascript/mastodon/features/ui/util/optional_motion.js
new file mode 100644
index 000000000..4276eeaa4
--- /dev/null
+++ b/app/javascript/mastodon/features/ui/util/optional_motion.js
@@ -0,0 +1,34 @@
+// Like react-motion's Motion, but checks to see if the user prefers
+// reduced motion and uses a cross-fade in those cases.
+
+import Motion from 'react-motion/lib/Motion';
+import { connect } from 'react-redux';
+
+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;
+};
+
+const mapStateToProps = (state, ownProps) => {
+  const reduceMotion = state.getIn(['meta', 'reduce_motion']);
+
+  if (reduceMotion) {
+    const { style, defaultStyle } = ownProps;
+
+    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 { style, defaultStyle };
+  }
+  return {};
+};
+
+export default connect(mapStateToProps)(Motion);