In prerelease, enable background throttling when not on a call

main.js

@@ -403,7 +403,10 @@ async function createWindow() {
       ),
       nativeWindowOpen: true,
       spellcheck: await getSpellCheckSetting(),
-      backgroundThrottling: false,
+      // We are evaluating background throttling in prerelease versions. If we decide to
+      //   move forward, we can remove this line (as `backgroundThrottling` is true by
+      //   default).
+      backgroundThrottling: !isProduction(app.getVersion()),
       enablePreferredSizeMode: true,
     },
     icon: windowIcon,
@@ -664,6 +667,29 @@ ipc.on('title-bar-double-click', () => {
   }
 });
 
+ipc.on('set-is-call-active', (_event, isCallActive) => {
+  if (!mainWindow) {
+    return;
+  }
+
+  // We are evaluating background throttling in prerelease versions. If we decide to move
+  //   forward, we can remove this check.
+  if (isProduction(app.getVersion())) {
+    return;
+  }
+
+  let backgroundThrottling;
+  if (isCallActive) {
+    console.log('Background throttling disabled because a call is active');
+    backgroundThrottling = false;
+  } else {
+    console.log('Background throttling enabled because no call is active');
+    backgroundThrottling = true;
+  }
+
+  mainWindow.webContents.setBackgroundThrottling(backgroundThrottling);
+});
+
 ipc.on('convert-image', async (event, uuid, data) => {
   const { error, response } = await heicConverter(uuid, data);
   event.reply(`convert-image:${uuid}`, { error, response });

ts/components/CallManager.stories.tsx

@@ -87,6 +87,7 @@ const createProps = (storyProps: Partial<PropsType> = {}): PropsType => ({
   renderDeviceSelection: () => <div />,
   renderSafetyNumberViewer: (_: SafetyNumberViewerProps) => <div />,
   setGroupCallVideoRequest: action('set-group-call-video-request'),
+  setIsCallActive: action('set-is-call-active'),
   setLocalAudio: action('set-local-audio'),
   setLocalPreview: action('set-local-preview'),
   setLocalVideo: action('set-local-video'),

ts/components/CallManager.tsx

@@ -86,6 +86,7 @@ export type PropsType = {
   openSystemPreferencesAction: () => unknown;
   playRingtone: () => unknown;
   setGroupCallVideoRequest: (_: SetGroupCallVideoRequestType) => void;
+  setIsCallActive: (_: boolean) => void;
   setLocalAudio: (_: SetLocalAudioType) => void;
   setLocalVideo: (_: SetLocalVideoType) => void;
   setLocalPreview: (_: SetLocalPreviewType) => void;
@@ -366,9 +367,15 @@ export const CallManager: React.FC<PropsType> = props => {
     notifyForCall,
     playRingtone,
     stopRingtone,
+    setIsCallActive,
     setOutgoingRing,
   } = props;
 
+  const isCallActive = Boolean(activeCall);
+  useEffect(() => {
+    setIsCallActive(isCallActive);
+  }, [isCallActive, setIsCallActive]);
+
   const shouldRing = getShouldRing(props);
   useEffect(() => {
     if (shouldRing) {

ts/context/createNativeThemeListener.ts

@@ -7,6 +7,9 @@ import { NativeThemeState } from '../types/NativeThemeNotifier.d';
 export type Callback = (change: NativeThemeState) => void;
 
 export interface MinimalIPC {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  send(channel: string, ...args: ReadonlyArray<any>): void;
+
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   sendSync(channel: string): any;
 

ts/context/index.ts

@@ -15,7 +15,11 @@ export class Context {
 
   public readonly nativeThemeListener;
 
-  constructor(ipc: MinimalIPC) {
+  constructor(private readonly ipc: MinimalIPC) {
     this.nativeThemeListener = createNativeThemeListener(ipc, window);
   }
+
+  setIsCallActive(isCallActive: boolean): void {
+    this.ipc.send('set-is-call-active', isCallActive);
+  }
 }

ts/state/ducks/calling.ts

@@ -960,6 +960,14 @@ function returnToActiveCall(): ReturnToActiveCallActionType {
   };
 }
 
+function setIsCallActive(
+  isCallActive: boolean
+): ThunkAction<void, RootStateType, unknown, never> {
+  return () => {
+    window.SignalContext.setIsCallActive(isCallActive);
+  };
+}
+
 function setLocalPreview(
   payload: SetLocalPreviewType
 ): ThunkAction<void, RootStateType, unknown, never> {
@@ -1203,6 +1211,7 @@ export const actions = {
   remoteVideoChange,
   returnToActiveCall,
   setGroupCallVideoRequest,
+  setIsCallActive,
   setLocalAudio,
   setLocalPreview,
   setLocalVideo,

ts/test-electron/context/createNativeThemeListener_test.ts

@@ -20,6 +20,13 @@ class FakeIPC extends EventEmitter implements MinimalIPC {
     assert.strictEqual(channel, 'native-theme:init');
     return this.state;
   }
+
+  // eslint-disable-next-line class-methods-use-this
+  public send() {
+    throw new Error(
+      'This should not be called. It is only here to satisfy the interface'
+    );
+  }
 }
 
 describe('NativeThemeListener', () => {