Tweak appearance of invite reason

This adjusts the display of invite reasons to match design feedback.

Fixes https://github.com/vector-im/element-web/issues/16869

src/components/views/elements/EventTilePreview.tsx

@@ -55,22 +55,10 @@ interface IProps {
      * The mxc:// avatar URL of the displayed user
      */
     avatarUrl?: string;
-
-    /**
-     * Whether the EventTile should appear faded
-     */
-    faded?: boolean;
-
-    /**
-     * Callback for when the component is clicked
-     */
-    onClick?: () => void;
 }
 
 interface IState {
     message: string;
-    faded: boolean;
-    eventTileKey: number;
 }
 
 const AVATAR_SIZE = 32;
@@ -81,23 +69,9 @@ export default class EventTilePreview extends React.Component<IProps, IState> {
         super(props);
         this.state = {
             message: props.message,
-            faded: !!props.faded,
-            eventTileKey: 0,
         };
     }
 
-    changeMessage(message: string) {
-        this.setState({
-            message,
-            // Change the EventTile key to force React to create a new instance
-            eventTileKey: this.state.eventTileKey + 1,
-        });
-    }
-
-    unfade() {
-        this.setState({ faded: false });
-    }
-
     private fakeEvent({message}: IState) {
         // Fake it till we make it
         /* eslint-disable quote-props */
@@ -147,12 +121,10 @@ export default class EventTilePreview extends React.Component<IProps, IState> {
         const className = classnames(this.props.className, {
             "mx_IRCLayout": this.props.layout == Layout.IRC,
             "mx_GroupLayout": this.props.layout == Layout.Group,
-            "mx_EventTilePreview_faded": this.state.faded,
         });
 
-        return <div className={className} onClick={this.props.onClick}>
+        return <div className={className}>
             <EventTile
-                key={this.state.eventTileKey}
                 mxEvent={event}
                 layout={this.props.layout}
                 enableFlair={SettingsStore.getValue(UIFeature.Flair)}

src/components/views/elements/InviteReason.tsx

@@ -0,0 +1,62 @@
+/*
+Copyright 2021 The Matrix.org Foundation C.I.C.
+
+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 classNames from "classnames";
+import React from "react";
+import { _t } from "../../../languageHandler";
+import { replaceableComponent } from "../../../utils/replaceableComponent";
+
+interface IProps {
+    reason: string;
+}
+
+interface IState {
+    hidden: boolean;
+}
+
+@replaceableComponent("views.elements.InviteReason")
+export default class InviteReason extends React.PureComponent<IProps, IState> {
+    constructor(props) {
+        super(props);
+        this.state = {
+            // We hide the reason for invitation by default, since it can be a
+            // vector for spam/harassment.
+            hidden: true,
+        };
+    }
+
+    onToggleClick = () => {
+        this.setState({
+            hidden: false,
+        });
+    }
+
+    render() {
+        const classes = classNames({
+            "mx_InviteReason": true,
+            "mx_InviteReason_hidden": this.state.hidden,
+        });
+
+        return <div className={classes}>
+            <div className="mx_InviteReason_reason">{this.props.reason}</div>
+            <div className="mx_InviteReason_toggle"
+                onClick={this.onToggleClick}
+            >
+                {_t("View message")}
+            </div>
+        </div>;
+    }
+}