接入宿主生命周期暂停背景音乐

useBackgroundMusic 订阅 app.lifecycle 统一事件

宿主进后台或桌面失焦时暂停音频循环并 suspend WebAudio

宿主恢复 active 后按用户原音乐状态继续播放

更新测试和原生壳架构文档

src/hooks/useBackgroundMusic.test.tsx

@@ -0,0 +1,142 @@
+/* @vitest-environment jsdom */
+
+import { act, renderHook } from '@testing-library/react';
+import { afterEach, expect, test, vi } from 'vitest';
+
+import { subscribeHostAppLifecycle } from '../services/host-bridge/hostBridge';
+import { useBackgroundMusic } from './useBackgroundMusic';
+
+vi.mock('../services/host-bridge/hostBridge', () => ({
+  subscribeHostAppLifecycle: vi.fn(() => () => undefined),
+}));
+
+const subscribeHostAppLifecycleMock = vi.mocked(subscribeHostAppLifecycle);
+
+class MockAudioParam {
+  value = 0;
+
+  setValueAtTime = vi.fn((value: number) => {
+    this.value = value;
+  });
+
+  linearRampToValueAtTime = vi.fn((value: number) => {
+    this.value = value;
+  });
+
+  exponentialRampToValueAtTime = vi.fn((value: number) => {
+    this.value = value;
+  });
+
+  cancelScheduledValues = vi.fn();
+}
+
+class MockGainNode {
+  gain = new MockAudioParam();
+
+  connect = vi.fn();
+}
+
+class MockOscillatorNode {
+  frequency = new MockAudioParam();
+  detune = new MockAudioParam();
+  type: OscillatorType = 'sine';
+
+  connect = vi.fn();
+  start = vi.fn();
+  stop = vi.fn();
+}
+
+const audioContextInstances: MockAudioContext[] = [];
+
+class MockAudioContext {
+  currentTime = 0;
+  destination = {};
+  state: AudioContextState = 'suspended';
+  resume = vi.fn(async () => {
+    this.state = 'running';
+  });
+  suspend = vi.fn(async () => {
+    this.state = 'suspended';
+  });
+  close = vi.fn(async () => {
+    this.state = 'closed';
+  });
+  createGain = vi.fn(() => new MockGainNode());
+  createOscillator = vi.fn(() => new MockOscillatorNode());
+
+  constructor() {
+    audioContextInstances.push(this);
+  }
+}
+
+afterEach(() => {
+  vi.useRealTimers();
+  vi.clearAllMocks();
+  audioContextInstances.length = 0;
+  Reflect.deleteProperty(window, 'AudioContext');
+  Reflect.deleteProperty(window, 'webkitAudioContext');
+});
+
+function installAudioContextMock() {
+  Object.defineProperty(window, 'AudioContext', {
+    configurable: true,
+    value: MockAudioContext,
+  });
+}
+
+test('background music suspends and resumes with native host lifecycle', async () => {
+  vi.useFakeTimers();
+  installAudioContextMock();
+  let lifecycleListener: Parameters<typeof subscribeHostAppLifecycle>[0] | null =
+    null;
+  subscribeHostAppLifecycleMock.mockImplementation((listener) => {
+    lifecycleListener = listener;
+    return () => undefined;
+  });
+
+  renderHook(() => useBackgroundMusic({ active: true, volume: 0.6 }));
+
+  await act(async () => {
+    window.dispatchEvent(new KeyboardEvent('keydown'));
+    await Promise.resolve();
+  });
+  const context = audioContextInstances[0];
+  expect(context).toBeTruthy();
+  expect(context?.resume).toHaveBeenCalledTimes(1);
+
+  await act(async () => {
+    lifecycleListener?.({
+      state: 'background',
+      focused: false,
+      nativeState: 'background',
+    });
+    await Promise.resolve();
+  });
+  expect(context?.suspend).toHaveBeenCalledTimes(1);
+
+  await act(async () => {
+    lifecycleListener?.({
+      state: 'active',
+      focused: true,
+      nativeState: 'active',
+    });
+    await Promise.resolve();
+  });
+  expect(context?.resume).toHaveBeenCalledTimes(2);
+});
+
+test('background music keeps browser fallback behavior when native lifecycle is unsupported', async () => {
+  installAudioContextMock();
+
+  renderHook(() => useBackgroundMusic({ active: true, volume: 0.6 }));
+
+  await act(async () => {
+    window.dispatchEvent(new Event('pointerdown'));
+    await Promise.resolve();
+  });
+
+  const context = audioContextInstances[0];
+  expect(subscribeHostAppLifecycleMock).toHaveBeenCalledTimes(1);
+  expect(context?.resume).toHaveBeenCalledTimes(1);
+  expect(context?.suspend).not.toHaveBeenCalled();
+});

src/hooks/useBackgroundMusic.ts

@@ -1,5 +1,7 @@
 import { useCallback, useEffect, useRef } from 'react';
 
+import { subscribeHostAppLifecycle } from '../services/host-bridge/hostBridge';
+
 type AudioWindow = Window & {
   webkitAudioContext?: typeof AudioContext;
 };
@@ -88,6 +90,7 @@ export function useBackgroundMusic({
   const stepRef = useRef(0);
   const activeRef = useRef(active);
   const volumeRef = useRef(volume);
+  const hostLifecycleActiveRef = useRef(true);
 
   const stopLoop = useCallback(() => {
     if (loopTimerRef.current !== null) {
@@ -126,7 +129,12 @@ export function useBackgroundMusic({
 
   const scheduleLoop = useCallback(() => {
     const graph = ensureAudioGraph();
-    if (!graph || !activeRef.current || volumeRef.current <= 0) {
+    if (
+      !graph ||
+      !activeRef.current ||
+      !hostLifecycleActiveRef.current ||
+      volumeRef.current <= 0
+    ) {
       stopLoop();
       return;
     }
@@ -162,21 +170,46 @@ export function useBackgroundMusic({
     loopTimerRef.current = window.setTimeout(scheduleLoop, 2200);
   }, [ensureAudioGraph, stopLoop]);
 
-  const updateMasterVolume = useCallback((graph?: { context: AudioContext; masterGain: GainNode } | null) => {
-    const audioGraph = graph ?? ensureAudioGraph();
-    if (!audioGraph) return;
+  const updateMasterVolume = useCallback(
+    (graph?: { context: AudioContext; masterGain: GainNode } | null) => {
+      const audioGraph =
+        graph ??
+        (contextRef.current && masterGainRef.current
+          ? {
+              context: contextRef.current,
+              masterGain: masterGainRef.current,
+            }
+          : null);
+      if (!audioGraph) return;
 
-    const targetGain = activeRef.current && volumeRef.current > 0
-      ? Math.max(0.0001, volumeRef.current * 0.18)
-      : 0.0001;
+      const targetGain =
+        activeRef.current &&
+        hostLifecycleActiveRef.current &&
+        volumeRef.current > 0
+          ? Math.max(0.0001, volumeRef.current * 0.18)
+          : 0.0001;
 
-    audioGraph.masterGain.gain.cancelScheduledValues(audioGraph.context.currentTime);
-    audioGraph.masterGain.gain.linearRampToValueAtTime(targetGain, audioGraph.context.currentTime + 0.24);
-  }, [ensureAudioGraph]);
+      audioGraph.masterGain.gain.cancelScheduledValues(
+        audioGraph.context.currentTime,
+      );
+      audioGraph.masterGain.gain.linearRampToValueAtTime(
+        targetGain,
+        audioGraph.context.currentTime + 0.24,
+      );
+    },
+    [],
+  );
 
   const startPlayback = useCallback(async () => {
     const graph = ensureAudioGraph();
-    if (!graph || !activeRef.current || volumeRef.current <= 0) return;
+    if (
+      !graph ||
+      !activeRef.current ||
+      !hostLifecycleActiveRef.current ||
+      volumeRef.current <= 0
+    ) {
+      return;
+    }
 
     if (graph.context.state === 'suspended') {
       await graph.context.resume();
@@ -189,11 +222,21 @@ export function useBackgroundMusic({
     }
   }, [ensureAudioGraph, scheduleLoop, updateMasterVolume]);
 
+  const suspendPlaybackForHostLifecycle = useCallback(() => {
+    updateMasterVolume();
+    stopLoop();
+
+    const context = contextRef.current;
+    if (context?.state === 'running') {
+      void context.suspend().catch(() => undefined);
+    }
+  }, [stopLoop, updateMasterVolume]);
+
   useEffect(() => {
     activeRef.current = active;
     volumeRef.current = volume;
 
-    if (!active || volume <= 0) {
+    if (!active || !hostLifecycleActiveRef.current || volume <= 0) {
       updateMasterVolume();
       stopLoop();
       return;
@@ -214,6 +257,25 @@ export function useBackgroundMusic({
     };
   }, [active, startPlayback, stopLoop, updateMasterVolume, volume]);
 
+  useEffect(
+    () =>
+      subscribeHostAppLifecycle((payload) => {
+        const isHostActive = payload.state === 'active' && payload.focused;
+        if (hostLifecycleActiveRef.current === isHostActive) {
+          return;
+        }
+
+        hostLifecycleActiveRef.current = isHostActive;
+        if (!isHostActive) {
+          suspendPlaybackForHostLifecycle();
+          return;
+        }
+
+        void startPlayback();
+      }),
+    [startPlayback, suspendPlaybackForHostLifecycle],
+  );
+
   useEffect(() => () => {
     stopLoop();