Cleanup + use a better check for blurring support

src/livekit/TrackProcessorContext.tsx

@@ -7,18 +7,10 @@ Please see LICENSE in the repository root for full details.
 
 import {
   ProcessorWrapper,
+  supportsBackgroundProcessors,
   type BackgroundOptions,
 } from "@livekit/track-processors";
-import {
-  createContext,
-  type FC,
-  useCallback,
-  useContext,
-  useEffect,
-  useRef,
-  useState,
-} from "react";
-import { logger } from "matrix-js-sdk/src/logger";
+import { createContext, type FC, useContext, useEffect, useMemo } from "react";
 import { type LocalVideoTrack } from "livekit-client";
 
 import {
@@ -30,23 +22,23 @@ import { BlurBackgroundTransformer } from "./BlurBackgroundTransformer";
 type ProcessorState = {
   supported: boolean | undefined;
   processor: undefined | ProcessorWrapper<BackgroundOptions>;
-  /**
-   * Call this method to try to initialize a processor.
-   * This only needs to happen if supported is undefined.
-   * If the backgroundBlur setting is set to true this does not need to be called
-   * and the processorState.supported will update automatically to the correct value.
-   */
-  checkSupported: () => void;
 };
+
 const ProcessorContext = createContext<ProcessorState | undefined>(undefined);
 
-export const useTrackProcessor = (): ProcessorState | undefined =>
-  useContext(ProcessorContext);
+export function useTrackProcessor(): ProcessorState {
+  const state = useContext(ProcessorContext);
+  if (state === undefined)
+    throw new Error(
+      "useTrackProcessor must be used within a ProcessorProvider",
+    );
+  return state;
+}
 
 export const useTrackProcessorSync = (
   videoTrack: LocalVideoTrack | null,
 ): void => {
-  const { processor } = useTrackProcessor() || {};
+  const { processor } = useTrackProcessor();
   useEffect(() => {
     if (!videoTrack) return;
     if (processor && !videoTrack.getProcessor()) {
@@ -61,53 +53,28 @@ export const useTrackProcessorSync = (
 interface Props {
   children: JSX.Element;
 }
+
 export const ProcessorProvider: FC<Props> = ({ children }) => {
   // The setting the user wants to have
   const [blurActivated] = useSetting(backgroundBlurSettings);
-
-  // If `ProcessorState.supported` is undefined the user can activate that we want
-  // to have it at least checked (this is useful to show the settings menu properly)
-  // We dont want to try initializing the blur if the user is not even looking at the setting
-  const [shouldCheckSupport, setShouldCheckSupport] = useState(blurActivated);
-
-  // Cache the processor so we only need to initialize it once.
-  const blur = useRef<ProcessorWrapper<BackgroundOptions> | undefined>(
-    undefined,
+  const supported = useMemo(() => supportsBackgroundProcessors(), []);
+  const blur = useMemo(
+    () =>
+      new ProcessorWrapper(
+        new BlurBackgroundTransformer({ blurRadius: 15 }),
+        "background-blur",
+      ),
+    [],
   );
 
-  const checkSupported = useCallback(() => {
-    setShouldCheckSupport(true);
-  }, []);
   // This is the actual state exposed through the context
-  const [processorState, setProcessorState] = useState<ProcessorState>(() => ({
-    supported: false,
-    processor: undefined,
-    checkSupported,
-  }));
-
-  useEffect(() => {
-    if (!shouldCheckSupport) return;
-    try {
-      if (!blur.current) {
-        blur.current = new ProcessorWrapper(
-          new BlurBackgroundTransformer({ blurRadius: 15 }),
-          "background-blur",
-        );
-      }
-      setProcessorState({
-        checkSupported,
-        supported: true,
-        processor: blurActivated ? blur.current : undefined,
-      });
-    } catch (e) {
-      setProcessorState({
-        checkSupported,
-        supported: false,
-        processor: undefined,
-      });
-      logger.error("disable background blur", e);
-    }
-  }, [blurActivated, checkSupported, shouldCheckSupport]);
+  const processorState = useMemo(
+    () => ({
+      supported,
+      processor: supported && blurActivated ? blur : undefined,
+    }),
+    [supported, blurActivated, blur],
+  );
 
   return (
     <ProcessorContext.Provider value={processorState}>

src/livekit/useLiveKit.ts

@@ -88,7 +88,7 @@ export function useLiveKit(
   const devices = useMediaDevices();
   const initialDevices = useRef<MediaDevices>(devices);
 
-  const { processor } = useTrackProcessor() || {};
+  const { processor } = useTrackProcessor();
   const initialProcessor = useInitial(() => processor);
   const roomOptions = useMemo(
     (): RoomOptions => ({

src/room/LobbyView.tsx

@@ -120,7 +120,7 @@ export const LobbyView: FC<Props> = ({
       muteStates.audio.enabled && { deviceId: devices.audioInput.selectedId },
   );
 
-  const { processor } = useTrackProcessor() || {};
+  const { processor } = useTrackProcessor();
 
   const initialProcessor = useInitial(() => processor);
   const localTrackOptions = useMemo<CreateLocalTracksOptions>(

src/settings/SettingsModal.tsx

@@ -5,10 +5,10 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { type FC, type ReactNode, useEffect, useState } from "react";
+import { type FC, type ReactNode, useState } from "react";
 import { useTranslation } from "react-i18next";
 import { type MatrixClient } from "matrix-js-sdk";
-import { Root as Form ,Separator} from "@vector-im/compound-web";
+import { Root as Form, Separator } from "@vector-im/compound-web";
 import { type Room as LivekitRoom } from "livekit-client";
 
 import { Modal } from "../Modal";
@@ -69,8 +69,7 @@ export const SettingsModal: FC<Props> = ({
 
   // Generate a `Checkbox` input to turn blur on or off.
   const BlurCheckbox: React.FC = (): ReactNode => {
-    const { supported, checkSupported } = useTrackProcessor() || {};
-    useEffect(() => checkSupported?.(), [checkSupported]);
+    const { supported } = useTrackProcessor();
 
     const [blurActive, setBlurActive] = useSetting(backgroundBlurSetting);