Flutter support

.gitignore

@@ -27,6 +27,7 @@ doc/api/
 .history
 .vscode
 compile_commands.json
+*.log
 
 # IntelliJ
 *.iml

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.0.4
+
+* Added support for Android and Flutter Desktops (Windows/Linux).
+
 ## 0.0.3
 
 * Using `package:args` for handling CLI arguments.

README.md

@@ -6,13 +6,14 @@ This is a [GSoC 2021 project](https://summerofcode.withgoogle.com/projects/#4757
 
 ## Supported Platforms
 
-Currently, 64 bit Desktop Platforms (Linux, Windows and MacOS) are supported.
+Currently, Android and 64 bit Desktop Platforms (Linux, Windows and MacOS) are supported.
 
 ## Requirements
 
 1. Dart SDK 2.12.0 or above.
 2. CMake 3.15 or above. (If on windows, Visual Studio 2019 with C++ tools)
 3. C++ compiler. (g++/clang/msvc)
+4. Android NDK if targeting Android.
 
 ## Usage
 
@@ -27,6 +28,22 @@ Currently, 64 bit Desktop Platforms (Linux, Windows and MacOS) are supported.
    dart run cronet:setup # Downloads the cronet binaries.
    ```
 
+   **Flutter**
+
+   ```bash
+   flutter pub get
+   flutter run cronet:setup # Downloads the cronet binaries.
+   ```
+
+   ***Note for Android:** Remember to add the following permissions in `AndroidManifest.xml` file.
+
+   ```xml
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+   ```
+
+   You may also like to enable cleartext traffic by adding `android:usesCleartextTraffic="true"` to `AndroidManifest.xml` file.
+
 3. Import
 
    ```dart
@@ -56,8 +73,20 @@ Currently, 64 bit Desktop Platforms (Linux, Windows and MacOS) are supported.
 
 ## Run Example
 
+### Flutter
+
 ```bash
-cd example
+cd example/flutter
+flutter pub get
+flutter run cronet:setup # Downloads the cronet binaries.
+flutter run
+```
+
+### Dart CLI
+
+```bash
+cd example/cli
+dart pub get
 dart run cronet:setup # Downloads the cronet binaries.
 dart run
 ```
@@ -98,3 +127,5 @@ Note: Test results may get affected by: <https://github.com/google/cronet.dart/i
 2. Run `dart run cronet:setup build` from the root of your project.
 
 **Note for Windows:** Run `step 2` from `x64 Native Tools Command Prompt for VS 2019` shell.
+
+**Note for Android:** Copy the produced jar files in `android/libs` and `.so` files in `android/src/main/jniLibs` subdirectory from the root of this package.

analysis_options.yaml

@@ -5,6 +5,7 @@
 include: package:lints/recommended.yaml
 
 analyzer:
+  exclude: [example/flutter/**]
   strong-mode:
     implicit-casts: false
     implicit-dynamic: false

android/.gitignore

@@ -0,0 +1,8 @@
+*.iml
+.gradle
+/local.properties
+/.idea/workspace.xml
+/.idea/libraries
+.DS_Store
+/build
+/captures

android/build.gradle

@@ -0,0 +1,50 @@
+group 'dev.google.cronet'
+version '1.0-SNAPSHOT'
+
+buildscript {
+    ext.kotlin_version = '1.3.50'
+    repositories {
+        google()
+        jcenter()
+    }
+
+    dependencies {
+        classpath 'com.android.tools.build:gradle:4.1.0'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+    }
+}
+
+rootProject.allprojects {
+    repositories {
+        google()
+        jcenter()
+    }
+}
+
+apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
+
+android {
+    compileSdkVersion 30
+
+    sourceSets {
+        main.java.srcDirs += 'src/main/kotlin'
+    }
+
+    externalNativeBuild {
+        // Encapsulates your CMake build configurations.
+        cmake {
+            // Provides a relative path to your CMake build script.
+            path "../src/CMakeLists.txt"
+        }
+    }
+
+    defaultConfig {
+        minSdkVersion 16
+    }
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation files(fileTree(dir: 'libs', includes: ['*.jar']))
+}

android/gradle.properties

@@ -0,0 +1,3 @@
+org.gradle.jvmargs=-Xmx1536M
+android.useAndroidX=true
+android.enableJetifier=true

android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7-all.zip

android/settings.gradle

@@ -0,0 +1 @@
+rootProject.name = 'cronet'

android/src/main/AndroidManifest.xml

@@ -0,0 +1,5 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+  package="dev.google.cronet">
+  <uses-permission android:name="android.permission.INTERNET" />
+  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+</manifest>

android/src/main/kotlin/dev/google/cronet/CronetPlugin.kt

@@ -0,0 +1,41 @@
+package dev.google.cronet
+
+import androidx.annotation.NonNull
+
+import io.flutter.embedding.engine.plugins.FlutterPlugin
+import io.flutter.plugin.common.MethodCall
+import io.flutter.plugin.common.MethodChannel
+import io.flutter.plugin.common.MethodChannel.MethodCallHandler
+import io.flutter.plugin.common.MethodChannel.Result
+import io.flutter.plugin.common.PluginRegistry.Registrar
+
+import org.chromium.base.ContextUtils
+
+/** CronetPlugin */
+class CronetPlugin: FlutterPlugin, MethodCallHandler {
+  /// The MethodChannel that will the communication between Flutter and native Android
+  ///
+  /// This local reference serves to register the plugin with the Flutter Engine and unregister it
+  /// when the Flutter Engine is detached from the Activity
+  private lateinit var channel : MethodChannel
+
+  override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
+    System.loadLibrary("cronet.86.0.4240.198")
+    System.loadLibrary("wrapper")
+    ContextUtils.initApplicationContext(flutterPluginBinding.applicationContext)
+    channel = MethodChannel(flutterPluginBinding.binaryMessenger, "cronet")
+    channel.setMethodCallHandler(this)
+  }
+
+  override fun onMethodCall(@NonNull call: MethodCall, @NonNull result: Result) {
+    if (call.method == "getPlatformVersion") {
+      result.success("Android ${android.os.Build.VERSION.RELEASE}")
+    } else {
+      result.notImplemented()
+    }
+  }
+
+  override fun onDetachedFromEngine(@NonNull binding: FlutterPlugin.FlutterPluginBinding) {
+    channel.setMethodCallHandler(null)
+  }
+}

bin/setup.dart

@@ -9,6 +9,7 @@ import 'package:args/command_runner.dart';
 import 'package:cli_util/cli_logging.dart' show Ansi, Logger;
 import 'package:cronet/src/constants.dart';
 import 'package:cronet/src/third_party/ffigen/find_resource.dart';
+import 'package:path/path.dart';
 
 // Extracts a tar.gz file.
 void extract(String fileName, [String dir = '']) {
@@ -28,13 +29,37 @@ void extract(String fileName, [String dir = '']) {
   }
 }
 
+/// Places downloaded mobile binaries to proper location.
+void placeMobileBinaries(String platform, String fileName) {
+  Directory(androidPaths['cronet.jar']!).createSync(recursive: true);
+  Directory(tempAndroidDownloadPath['cronet.jar']!).listSync().forEach((jar) {
+    if (jar is File) {
+      jar.renameSync(join(androidPaths['cronet.jar']!, basename(jar.path)));
+    }
+  });
+  Directory(androidPaths['cronet.so']!).createSync(recursive: true);
+  Directory(tempAndroidDownloadPath['cronet.so']!)
+      .listSync(recursive: true)
+      .forEach((cronet) {
+    if (cronet is File) {
+      Directory(join(androidPaths['cronet.so']!, basename(cronet.parent.path)))
+          .createSync(recursive: true);
+      cronet.renameSync(join(androidPaths['cronet.so']!,
+          basename(cronet.parent.path), basename(cronet.path)));
+    }
+  });
+}
+
 /// Places downloaded binaries to proper location.
 void placeBinaries(String platform, String fileName) {
   final logger = Logger.standard();
   final ansi = Ansi(Ansi.terminalSupportsAnsi);
   logger.stdout('${ansi.yellow}Extracting Cronet for $platform${ansi.none}');
   Directory(binaryStorageDir).createSync(recursive: true);
   extract(fileName, binaryStorageDir);
+  if (mobilePlatforms.contains(platform)) {
+    placeMobileBinaries(platform, fileName);
+  }
   logger.stdout('Done! Cleaning up...');
 
   File(fileName).deleteSync();
@@ -75,9 +100,10 @@ Future<void> downloadCronetBinaries(String platform) async {
 String _makeBuildOutputPath(String buildFolderPath, String fileName,
     {bool isDebug = false}) {
   if (Platform.isWindows) {
-    return '$buildFolderPath\\out\\${Platform.operatingSystem}\\${isDebug ? "Debug" : "Release"}\\$fileName';
+    return join(buildFolderPath, 'out', Platform.operatingSystem,
+        isDebug ? 'Debug' : 'Release', fileName);
   } else if (Platform.isMacOS || Platform.isLinux) {
-    return '$buildFolderPath/out/${Platform.operatingSystem}/$fileName';
+    return join(buildFolderPath, 'out', Platform.operatingSystem, fileName);
   } else {
     throw Exception('Unsupported Platform.');
   }
@@ -95,7 +121,7 @@ void buildWrapper() {
     final result = Process.runSync('cmake', [
       'CMakeLists.txt',
       '-B',
-      'out/${Platform.operatingSystem}',
+      join('out', Platform.operatingSystem),
       '-DCMAKE_BUILD_TYPE=Release'
     ]);
     print(result.stdout);
@@ -111,16 +137,20 @@ void buildWrapper() {
     }
     return;
   }
-  var result = Process.runSync('cmake',
-      ['--build', 'out/${Platform.operatingSystem}', '--config', 'Release']);
+  var result = Process.runSync('cmake', [
+    '--build',
+    join('out', Platform.operatingSystem),
+    '--config',
+    'Release'
+  ]);
   print(result.stdout);
   print(result.stderr);
   if (result.exitCode != 0) return;
   Directory.current = pwd;
   final moveLocation = '$binaryStorageDir${Platform.operatingSystem}64';
   Directory(moveLocation).createSync(recursive: true);
   final buildOutputPath = _makeBuildOutputPath(wrapperPath, getWrapperName());
-  File(buildOutputPath).copySync('$moveLocation/${getWrapperName()}');
+  File(buildOutputPath).copySync(join(moveLocation, getWrapperName()));
   logger.stdout(
       '${ansi.green}Wrapper moved to $moveLocation. Success!${ansi.none}');
   return;
@@ -141,7 +171,7 @@ void verifyCronetBinary() {
   final logger = Logger.standard();
   final ansi = Ansi(Ansi.terminalSupportsAnsi);
   final sampleSource = findPackageRoot()
-      .resolve('third_party/cronet_sample')
+      .resolve(join('third_party', 'cronet_sample'))
       .toFilePath(windows: Platform.isWindows);
   final buildName = _getCronetSampleBuildName();
   final pwd = Directory.current;
@@ -153,29 +183,30 @@ void verifyCronetBinary() {
 
   logger.stdout('Building Sample...');
   var result = Process.runSync('cmake', [
-    '$sampleSource/CMakeLists.txt',
+    join(sampleSource, 'CMakeLists.txt'),
     '-B',
-    '$sampleSource/out/${Platform.operatingSystem}'
+    join(sampleSource, 'out', Platform.operatingSystem)
   ], environment: {
     'CURRENTDIR': pwd.path
   });
   print(result.stdout);
   print(result.stderr);
   result = Process.runSync(
-      'cmake', ['--build', '$sampleSource/out/${Platform.operatingSystem}'],
+      'cmake', ['--build', join(sampleSource, 'out', Platform.operatingSystem)],
       environment: {'CURRENTDIR': pwd.path});
   print(result.stdout);
   print(result.stderr);
   final buildOutputPath =
       _makeBuildOutputPath(sampleSource, buildName, isDebug: true);
 
   logger.stdout('Copying...');
-  final sample = File(buildOutputPath)
-      .copySync('.dart_tool/cronet/${Platform.operatingSystem}64/$buildName');
+  final sample = File(buildOutputPath).copySync(
+      join('.dart_tool', 'cronet', Platform.operatingSystem + '64', buildName));
 
   logger.stdout('Verifying...');
   result = Process.runSync(
-      '.dart_tool/cronet/${Platform.operatingSystem}64/$buildName', []);
+      join('.dart_tool', 'cronet', Platform.operatingSystem + '64', buildName),
+      []);
   if (result.exitCode == 0) {
     logger.stdout('${ansi.green}Verified! Cronet is working fine.${ansi.none}');
   } else {
@@ -238,6 +269,9 @@ Future<void> main(List<String> args) async {
     if (validPlatforms.contains('${Platform.operatingSystem}64')) {
       await downloadCronetBinaries('${Platform.operatingSystem}64');
     }
+    if (Directory('android').existsSync()) {
+      await downloadCronetBinaries('android');
+    }
   } else {
     await runner.run(args);
   }

example/README.md

@@ -1,4 +1,5 @@
 ## Examples
 
 - [Bare Minimum](https://github.com/google/cronet.dart#example)
-- [Simple (Dart CLI)](https://github.com/google/cronet.dart/tree/main/example/)
+- [Simple (Dart CLI)](https://github.com/google/cronet.dart/tree/main/example/cli)
+- [Simple (Flutter)](https://github.com/google/cronet.dart/tree/main/example/flutter)

example/cli/analysis_options.yaml

@@ -0,0 +1,14 @@
+# Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+include: package:lints/recommended.yaml
+
+analyzer:
+  strong-mode:
+    implicit-casts: false
+    implicit-dynamic: false
+linter:
+  rules:
+    - directives_ordering
+    - lines_longer_than_80_chars