System font and newer dependencies

lib/providers/native_provider.dart

@@ -0,0 +1,72 @@
+import 'dart:async';
+import 'dart:io';
+import 'package:flutter/services.dart';
+
+class NativeFeatures {
+  static const MethodChannel _channel = MethodChannel('native');
+  static bool _callbacksApplied = false;
+  static int _resPermShizuku = -2;  // not set
+
+  static Future<ByteData> _readFileBytes(String path) async {
+    var file = File(path);
+    var bytes = await file.readAsBytes();
+    return ByteData.view(bytes.buffer);
+  }
+
+  static Future _handleCalls(MethodCall call) async {
+    if (call.method == 'resPermShizuku') {
+      _resPermShizuku = call.arguments['res'];
+    }
+  }
+
+  static Future _waitWhile(bool Function() test,
+      [Duration pollInterval = const Duration(milliseconds: 250)]) {
+    var completer = Completer();
+    check() {
+      if (test()) {
+        Timer(pollInterval, check);
+      } else {
+        completer.complete();
+      }
+    }
+    check();
+    return completer.future;
+  }
+
+  static Future<bool> tryLoadSystemFont() async {
+    var font = await _channel.invokeMethod('getSystemFont');
+    if (font == null) { return false; }
+    var fontLoader = FontLoader('SystemFont');
+    fontLoader.addFont(_readFileBytes(font));
+    await fontLoader.load();
+    return true;
+  }
+
+  static Future<int> checkPermissionShizuku() async {
+    if (!_callbacksApplied) {
+      _channel.setMethodCallHandler(_handleCalls);
+      _callbacksApplied = true;
+    }
+    int res = await _channel.invokeMethod('checkPermissionShizuku');
+    if (res == -2) {
+      await _waitWhile(() => _resPermShizuku == -2);
+      res = _resPermShizuku;
+      _resPermShizuku = -2;
+    }
+    return res;
+  }
+
+  static Future<bool> checkPermissionRoot() async {
+    return await _channel.invokeMethod('checkPermissionRoot');
+  }
+
+  static Future<bool> installWithShizuku({required String apkFileUri}) async {
+    return await _channel.invokeMethod(
+        'installWithShizuku', {'apkFileUri': apkFileUri});
+  }
+
+  static Future<bool> installWithRoot({required String apkFilePath}) async {
+    return await _channel.invokeMethod(
+        'installWithRoot', {'apkFilePath': apkFilePath});
+  }
+}