Vary resume link text

Use 'Switch' if unholding that call would hold another

src/CallHandler.tsx

@@ -616,6 +616,18 @@ export default class CallHandler {
         }
     }
 
+    /**
+     * @returns true if we are currently in anu call where we haven't put the remote party on hold
+     */
+    hasAnyUnheldCall() {
+        for (const call of this.calls.values()) {
+            if (call.state === CallState.Ended) continue;
+            if (!call.isRemoteOnHold()) return true;
+        }
+
+        return false;
+    }
+
     private async startCallApp(roomId: string, type: string) {
         dis.dispatch({
             action: 'appsDrawer',

src/components/views/voip/CallView.tsx

@@ -19,7 +19,7 @@ import React, { createRef, CSSProperties, ReactNode } from 'react';
 import dis from '../../../dispatcher/dispatcher';
 import CallHandler from '../../../CallHandler';
 import {MatrixClientPeg} from '../../../MatrixClientPeg';
-import { _t } from '../../../languageHandler';
+import { _t, _td } from '../../../languageHandler';
 import VideoFeed, { VideoFeedType } from "./VideoFeed";
 import RoomAvatar from "../avatars/RoomAvatar";
 import { CallState, CallType, MatrixCall } from 'matrix-js-sdk/src/webrtc/call';
@@ -423,7 +423,9 @@ export default class CallView extends React.Component<IProps, IState> {
         const isOnHold = this.state.isLocalOnHold || this.state.isRemoteOnHold;
         let onHoldText = null;
         if (this.state.isRemoteOnHold) {
-            onHoldText = _t("You held the call <a>Resume</a>", {}, {
+            const holdString = CallHandler.sharedInstance().hasAnyUnheldCall() ?
+                _td("You held the call <a>Switch</a>") : _td("You held the call <a>Resume</a>");
+            onHoldText = _t(holdString, {}, {
                 a: sub => <AccessibleButton kind="link" onClick={this.onCallResumeClick}>
                     {sub}
                 </AccessibleButton>,

src/i18n/strings/en_EN.json

@@ -851,6 +851,7 @@
     "sends fireworks": "sends fireworks",
     "Sends the given message with snowfall": "Sends the given message with snowfall",
     "sends snowfall": "sends snowfall",
+    "You held the call <a>Switch</a>": "You held the call <a>Switch</a>",
     "You held the call <a>Resume</a>": "You held the call <a>Resume</a>",
     "%(peerName)s held the call": "%(peerName)s held the call",
     "Video Call": "Video Call",