Implement tooltip for group rooms

src/components/structures/GroupView.js

@@ -661,6 +661,14 @@ export default React.createClass({
         const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
         const TintableSvg = sdk.getComponent('elements.TintableSvg');
         const Spinner = sdk.getComponent('elements.Spinner');
+        const ToolTipButton = sdk.getComponent('elements.ToolTipButton');
+
+        const roomsHelpNode = this.state.editing ? <ToolTipButton helpText={
+            _t(
+                'These rooms are displayed to community members on the community page. '+
+                'Community members can join the rooms by clicking on them.',
+            )
+        } /> : <div />;
 
         const addRoomRow = this.state.editing ?
             (<AccessibleButton className="mx_GroupView_rooms_header_addRow"
@@ -675,7 +683,10 @@ export default React.createClass({
             </AccessibleButton>) : <div />;
         return <div className="mx_GroupView_rooms">
             <div className="mx_GroupView_rooms_header">
-                <h3>{ _t('Rooms') }</h3>
+                <h3>
+                    { _t('Rooms') }
+                    { roomsHelpNode }
+                </h3>
                 { addRoomRow }
             </div>
             { this.state.groupRoomsLoading ?

src/components/views/elements/ToolTipButton.js

@@ -0,0 +1,55 @@
+/*
+Copyright 2017 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 sdk from '../../../index';
+
+module.exports = React.createClass({
+    displayName: 'ToolTipButton',
+
+    getInitialState: function() {
+        return {
+            hover: false,
+        };
+    },
+
+    onMouseOver: function() {
+        this.setState({
+            hover: true,
+        });
+    },
+
+    onMouseOut: function() {
+        this.setState({
+            hover: false,
+        });
+    },
+
+    render: function() {
+        const RoomTooltip = sdk.getComponent("rooms.RoomTooltip");
+        const tip = this.state.hover ? <RoomTooltip
+            className="mx_ToolTipButton_container"
+            tooltipClassName="mx_ToolTipButton_helpText"
+            label={this.props.helpText}
+        /> : <div />;
+        return (
+            <div className="mx_ToolTipButton" onMouseOver={this.onMouseOver} onMouseOut={this.onMouseOut} >
+                ?
+                { tip }
+            </div>
+        );
+    },
+});

src/i18n/strings/en_EN.json

@@ -694,6 +694,7 @@
     "Leave": "Leave",
     "Unable to leave room": "Unable to leave room",
     "Community Settings": "Community Settings",
+    "These rooms are displayed to community members on the community page. Community members can join the rooms by clicking on them.": "These rooms are displayed to community members on the community page. Community members can join the rooms by clicking on them.",
     "Add rooms to this community": "Add rooms to this community",
     "Featured Rooms:": "Featured Rooms:",
     "Featured Users:": "Featured Users:",