Display existing reactions below the message

This displays the existing reactions a message has from all users below the
message.

Since we don't currently have an API to actually get these events yet,
adds a temporary hook that looks for a specific message to inject some sample
data. This helps build out the UI for now and can be removed once it exists.

Fixes https://github.com/vector-im/riot-web/issues/9573

res/css/_components.scss

@@ -115,6 +115,8 @@
 @import "./views/messages/_MTextBody.scss";
 @import "./views/messages/_MessageActionBar.scss";
 @import "./views/messages/_MessageTimestamp.scss";
+@import "./views/messages/_ReactionsRow.scss";
+@import "./views/messages/_ReactionsRowButton.scss";
 @import "./views/messages/_RoomAvatarEvent.scss";
 @import "./views/messages/_SenderProfile.scss";
 @import "./views/messages/_TextualEvent.scss";

res/css/views/messages/_ReactionsRow.scss

@@ -0,0 +1,19 @@
+/*
+Copyright 2019 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_ReactionsRow {
+    margin: 6px 0;
+}

res/css/views/messages/_ReactionsRowButton.scss

@@ -0,0 +1,30 @@
+/*
+Copyright 2019 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_ReactionsRowButton {
+    display: inline-block;
+    height: 20px;
+    line-height: 21px;
+    margin-right: 6px;
+    padding: 0 6px;
+    border: 1px solid $reaction-row-button-border-color;
+    border-radius: 10px;
+    background-color: $reaction-row-button-bg-color;
+
+    &:hover {
+        border-color: $reaction-row-button-hover-border-color;
+    }
+}

res/themes/dark/css/_dark.scss

@@ -151,6 +151,10 @@ $message-action-bar-fg-color: $header-panel-text-primary-color;
 $message-action-bar-border-color: #616b7f;
 $message-action-bar-hover-border-color: $header-panel-text-primary-color;
 
+$reaction-row-button-bg-color: $header-panel-bg-color;
+$reaction-row-button-border-color: #616b7f;
+$reaction-row-button-hover-border-color: $header-panel-text-primary-color;
+
 // ***** Mixins! *****
 
 @define-mixin mx_DialogButton {

res/themes/light/css/_light.scss

@@ -259,6 +259,10 @@ $message-action-bar-fg-color: $primary-fg-color;
 $message-action-bar-border-color: #e9edf1;
 $message-action-bar-hover-border-color: #b8c1d2;
 
+$reaction-row-button-bg-color: $header-panel-bg-color;
+$reaction-row-button-border-color: #e9edf1;
+$reaction-row-button-hover-border-color: #bebebe;
+
 // ***** Mixins! *****
 
 @define-mixin mx_DialogButton {

src/components/views/messages/ReactionsRow.js

@@ -0,0 +1,65 @@
+/*
+Copyright 2019 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from 'react';
+import PropTypes from 'prop-types';
+
+import sdk from '../../../index';
+import { isContentActionable } from '../../../utils/EventUtils';
+
+// TODO: Actually load reactions from the timeline
+// Since we don't yet load reactions, let's inject some dummy data for testing the UI
+// only. The UI assumes these are already sorted into the order we want to present,
+// presumably highest vote first.
+const SAMPLE_REACTIONS = {
+    "👍": 4,
+    "👎": 2,
+    "🙂": 1,
+};
+
+export default class ReactionsRow extends React.PureComponent {
+    static propTypes = {
+        // The event we're displaying reactions for
+        mxEvent: PropTypes.object.isRequired,
+    }
+
+    render() {
+        const { mxEvent } = this.props;
+
+        if (!isContentActionable(mxEvent)) {
+            return null;
+        }
+
+        const content = mxEvent.getContent();
+        // TODO: Remove this once we load real reactions
+        if (!content.body || content.body !== "reactions test") {
+            return null;
+        }
+
+        const ReactionsRowButton = sdk.getComponent('messages.ReactionsRowButton');
+        const items = Object.entries(SAMPLE_REACTIONS).map(([content, count]) => {
+            return <ReactionsRowButton
+                key={content}
+                content={content}
+                count={count}
+            />;
+        });
+
+        return <div className="mx_ReactionsRow">
+            {items}
+        </div>;
+    }
+}

src/components/views/messages/ReactionsRowButton.js

@@ -0,0 +1,33 @@
+/*
+Copyright 2019 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from 'react';
+import PropTypes from 'prop-types';
+
+export default class ReactionsRowButton extends React.PureComponent {
+    static propTypes = {
+        content: PropTypes.string.isRequired,
+        count: PropTypes.number.isRequired,
+    }
+
+    render() {
+        const { content, count } = this.props;
+
+        return <span className="mx_ReactionsRowButton">
+            {content} {count}
+        </span>;
+    }
+}

src/components/views/rooms/EventTile.js

@@ -622,6 +622,14 @@ module.exports = withMatrixClient(React.createClass({
                 <ToolTipButton helpText={keyRequestHelpText} />
             </div> : null;
 
+        let reactions;
+        if (SettingsStore.isFeatureEnabled("feature_reactions")) {
+            const ReactionsRow = sdk.getComponent('messages.ReactionsRow');
+            reactions = <ReactionsRow
+                mxEvent={this.props.mxEvent}
+            />;
+        }
+
         switch (this.props.tileShape) {
             case 'notif': {
                 const EmojiText = sdk.getComponent('elements.EmojiText');
@@ -734,6 +742,7 @@ module.exports = withMatrixClient(React.createClass({
                                            showUrlPreview={this.props.showUrlPreview}
                                            onHeightChanged={this.props.onHeightChanged} />
                             { keyRequestInfo }
+                            { reactions }
                             { actionBar }
                         </div>
                         {