feat: 添加媒体权限请求处理；更新 H5ShellPage 以支持音视频权限管理

lib/main.dart

@@ -3,6 +3,7 @@ import 'dart:convert';
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
+import 'package:permission_handler/permission_handler.dart';
 import 'package:url_launcher/url_launcher.dart';
 import 'package:webview_flutter/webview_flutter.dart';
 
@@ -119,12 +120,21 @@ class _H5ShellPageState extends State<H5ShellPage> {
   }
 
   WebViewController _buildController(int lineIndex) {
-    return WebViewController()
+    return WebViewController(
+      onPermissionRequest: (request) {
+        unawaited(_handleWebViewPermissionRequest(request));
+      },
+    )
       ..setJavaScriptMode(JavaScriptMode.unrestricted)
       ..addJavaScriptChannel(
         'OpenIMShell',
         onMessageReceived: (message) => _handleShellMessage(lineIndex, message),
       )
+      ..addJavaScriptChannel(
+        'OpenIMFlutterShell',
+        onMessageReceived: (message) =>
+            _handleFlutterShellMessage(lineIndex, message),
+      )
       ..setBackgroundColor(_shellBackground)
       ..setNavigationDelegate(
         NavigationDelegate(
@@ -211,6 +221,35 @@ class _H5ShellPageState extends State<H5ShellPage> {
     }
   }
 
+  void _handleFlutterShellMessage(int lineIndex, JavaScriptMessage message) {
+    try {
+      final decoded = jsonDecode(message.message);
+      if (decoded is! Map) {
+        return;
+      }
+
+      switch (decoded['type']) {
+        case 'requestMediaPermissions':
+          final requestId = decoded['requestId']?.toString();
+          if (requestId == null || requestId.isEmpty) {
+            return;
+          }
+          unawaited(
+            _handleShellMediaPermissionRequest(
+              lineIndex: lineIndex,
+              requestId: requestId,
+              audio: decoded['audio'] == true,
+              video: decoded['video'] == true,
+            ),
+          );
+        case 'openAppSettings':
+          unawaited(openAppSettings());
+      }
+    } catch (_) {
+      // Ignore malformed shell messages from web content.
+    }
+  }
+
   void _scheduleShellCoverFallback(int lineIndex) {
     final slot = _lineSlots[lineIndex];
     slot.shellCoverFallbackTimer?.cancel();
@@ -309,6 +348,88 @@ class _H5ShellPageState extends State<H5ShellPage> {
     return _runJavaScriptSafely(lineIndex, script);
   }
 
+  Future<void> _handleShellMediaPermissionRequest({
+    required int lineIndex,
+    required String requestId,
+    required bool audio,
+    required bool video,
+  }) async {
+    final result = await _requestNativeMediaPermissions(
+      audio: audio,
+      video: video,
+    );
+    final payload = jsonEncode({
+      'requestId': requestId,
+      'granted': result.granted,
+      'permanentlyDenied': result.permanentlyDenied,
+      'restricted': result.restricted,
+    });
+    final script = '''
+(() => {
+  try {
+    window.dispatchEvent(new CustomEvent('openim-shell-media-permission-result', { detail: $payload }));
+  } catch (_) {}
+})();
+''';
+    await _runJavaScriptSafely(lineIndex, script);
+  }
+
+  Future<void> _handleWebViewPermissionRequest(
+    WebViewPermissionRequest request,
+  ) async {
+    final requestsOnlySupportedMediaTypes = request.types.every(
+      (type) =>
+          type == WebViewPermissionResourceType.camera ||
+          type == WebViewPermissionResourceType.microphone,
+    );
+    if (!requestsOnlySupportedMediaTypes) {
+      await request.deny();
+      return;
+    }
+
+    final result = await _requestNativeMediaPermissions(
+      audio: request.types.contains(WebViewPermissionResourceType.microphone),
+      video: request.types.contains(WebViewPermissionResourceType.camera),
+    );
+
+    if (result.granted) {
+      await request.grant();
+    } else {
+      await request.deny();
+    }
+  }
+
+  Future<_NativeMediaPermissionResult> _requestNativeMediaPermissions({
+    required bool audio,
+    required bool video,
+  }) async {
+    final permissions = <Permission>[
+      if (audio) Permission.microphone,
+      if (video) Permission.camera,
+    ];
+
+    if (permissions.isEmpty) {
+      return const _NativeMediaPermissionResult(granted: true);
+    }
+
+    var granted = true;
+    var permanentlyDenied = false;
+    var restricted = false;
+
+    for (final permission in permissions) {
+      final status = await permission.request();
+      granted = granted && status.isGranted;
+      permanentlyDenied = permanentlyDenied || status.isPermanentlyDenied;
+      restricted = restricted || status.isRestricted;
+    }
+
+    return _NativeMediaPermissionResult(
+      granted: granted,
+      permanentlyDenied: permanentlyDenied,
+      restricted: restricted,
+    );
+  }
+
   void _updateSlotUrl(int lineIndex, String? url) {
     if (url == null || lineIndex < 0 || lineIndex >= _lineSlots.length) {
       return;
@@ -499,6 +620,18 @@ class _H5ShellPageState extends State<H5ShellPage> {
   }
 }
 
+class _NativeMediaPermissionResult {
+  const _NativeMediaPermissionResult({
+    required this.granted,
+    this.permanentlyDenied = false,
+    this.restricted = false,
+  });
+
+  final bool granted;
+  final bool permanentlyDenied;
+  final bool restricted;
+}
+
 class _H5LineWebViewSlot {
   _H5LineWebViewSlot({
     required this.line,