Add "Copy" to room context menu.

This menu item creates a matrix.to link for the room and copies it to the clipboard.

src/components/structures/MatrixChat.tsx

@@ -105,6 +105,8 @@ import VerificationRequestToast from '../views/toasts/VerificationRequestToast';
 import PerformanceMonitor, { PerformanceEntryNames } from "../../performance";
 import UIStore, { UI_EVENTS } from "../../stores/UIStore";
 import SoftLogout from './auth/SoftLogout';
+import { makeRoomPermalink } from "../../utils/permalinks/Permalinks";
+import { copyPlaintext } from "../../utils/strings";
 
 /** constants for MatrixChat.state.view */
 export enum Views {
@@ -627,6 +629,9 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
             case 'forget_room':
                 this.forgetRoom(payload.room_id);
                 break;
+            case 'copy_room':
+                this.copyRoom(payload.room_id);
+                break;
             case 'reject_invite':
                 Modal.createTrackedDialog('Reject invitation', '', QuestionDialog, {
                     title: _t('Reject invitation'),
@@ -1193,6 +1198,17 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
         });
     }
 
+    private async copyRoom(roomId: string) {
+        const roomLink = makeRoomPermalink(roomId);
+        const success = await copyPlaintext(roomLink);
+        if (!success) {
+            Modal.createTrackedDialog("Unable to copy room", "", ErrorDialog, {
+                title: _t("Unable to copy room"),
+                description: _t("Unable to copy room"),
+            });
+        }
+    }
+
     /**
      * Starts a chat with the welcome user, if the user doesn't already have one
      * @returns {string} The room ID of the new room, or null if no room was created

src/components/views/rooms/RoomTile.tsx

@@ -358,6 +358,17 @@ export default class RoomTile extends React.PureComponent<IProps, IState> {
         this.setState({ generalMenuPosition: null }); // hide the menu
     };
 
+    private onCopyRoomClick = (ev: ButtonEvent) => {
+        ev.preventDefault();
+        ev.stopPropagation();
+
+        dis.dispatch({
+            action: 'copy_room',
+            room_id: this.props.room.roomId,
+        });
+        this.setState({ generalMenuPosition: null }); // hide the menu
+    };
+
     private onInviteClick = (ev: ButtonEvent) => {
         ev.preventDefault();
         ev.stopPropagation();
@@ -522,6 +533,11 @@ export default class RoomTile extends React.PureComponent<IProps, IState> {
                         label={_t("Settings")}
                         iconClassName="mx_RoomTile_iconSettings"
                     />
+                    <IconizedContextMenuOption
+                        onClick={this.onCopyRoomClick}
+                        label={_t("Copy")}
+                        iconClassName="mx_RoomTile_iconSettings"
+                    />
                 </IconizedContextMenuOptionList>
                 <IconizedContextMenuOptionList red>
                     <IconizedContextMenuOption