added an initial sample Flutter ffi plugin

.gitignore

@@ -0,0 +1,7 @@
+.DS_Store
+.dart_tool/
+
+.packages
+.pub/
+
+build/

.metadata

@@ -0,0 +1,10 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: adc687823a831bbebe28bdccfac1a628ca621513
+  channel: stable
+
+project_type: plugin

CHANGELOG.md

@@ -0,0 +1,3 @@
+## 0.0.1
+
+* TODO: Describe initial release.

LICENSE

@@ -0,0 +1,27 @@
+Copyright © 2021, HypnosisI2P.
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are
+permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this list of
+conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice, this list of
+conditions and the following disclaimer in the documentation and/or other materials
+provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors may be used
+to endorse or promote products derived from this software without specific prior written
+permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

@@ -0,0 +1,16 @@
+# native_add
+
+A Flutter FFI plugin allowing to launch, terminate, and access gostcoind.
+
+## Getting Started
+
+This project is a starting point for a Flutter
+[plug-in package](https://flutter.dev/developing-packages/),
+a specialized package that includes platform-specific implementation code for
+Android and/or iOS.
+
+For help getting started with Flutter, view our
+[online documentation](https://flutter.dev/docs), which offers tutorials,
+samples, guidance on mobile development, and a full API reference.
+
+Follow the [Add C and C++ code to your project](https://developer.android.com/studio/projects/add-native-code) instructions in the Android docs to add native code and support for the native code toolchain (either CMake or `ndk-build`).

android/.gitignore

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

android/CMakeLists.txt

@@ -0,0 +1,9 @@
+cmake_minimum_required(VERSION 3.4.1)  # for example
+
+add_library( native_add
+
+             # Sets the library as a shared library.
+             SHARED
+
+             # Provides a relative path to your source file(s).
+             ../ios/Classes/native_add.cpp )

android/build.gradle

@@ -0,0 +1,47 @@
+group 'com.example.native_add'
+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:$kotlin_version"
+    }
+}
+
+rootProject.allprojects {
+    repositories {
+        google()
+        jcenter()
+    }
+}
+
+apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
+
+android {
+    compileSdkVersion 30
+
+    sourceSets {
+        main.java.srcDirs += 'src/main/kotlin'
+    }
+    defaultConfig {
+        minSdkVersion 16
+    }
+
+    externalNativeBuild {
+        cmake {
+          // Provides a relative path to a CMake build script.
+          path "CMakeLists.txt"
+        }
+    }
+}
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+}

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 = 'native_add'

android/src/main/AndroidManifest.xml

@@ -0,0 +1,3 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+  package="com.example.native_add">
+</manifest>

android/src/main/kotlin/com/example/native_add/NativeAddPlugin.kt

@@ -0,0 +1,36 @@
+package com.example.native_add
+
+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
+
+/** NativeAddPlugin */
+class NativeAddPlugin: 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) {
+    channel = MethodChannel(flutterPluginBinding.binaryMessenger, "native_add")
+    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)
+  }
+}

example/.gitignore

@@ -0,0 +1,46 @@
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins
+.flutter-plugins-dependencies
+.packages
+.pub-cache/
+.pub/
+/build/
+
+# Web related
+lib/generated_plugin_registrant.dart
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release

example/.metadata

@@ -0,0 +1,10 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: adc687823a831bbebe28bdccfac1a628ca621513
+  channel: stable
+
+project_type: app

example/README.md

@@ -0,0 +1,16 @@
+# native_add_example
+
+Demonstrates how to use the native_add plugin.
+
+## Getting Started
+
+This project is a starting point for a Flutter application.
+
+A few resources to get you started if this is your first Flutter project:
+
+- [Lab: Write your first Flutter app](https://flutter.dev/docs/get-started/codelab)
+- [Cookbook: Useful Flutter samples](https://flutter.dev/docs/cookbook)
+
+For help getting started with Flutter, view our
+[online documentation](https://flutter.dev/docs), which offers tutorials,
+samples, guidance on mobile development, and a full API reference.

example/android/.gitignore

@@ -0,0 +1,11 @@
+gradle-wrapper.jar
+/.gradle
+/captures/
+/gradlew
+/gradlew.bat
+/local.properties
+GeneratedPluginRegistrant.java
+
+# Remember to never publicly share your keystore.
+# See https://flutter.dev/docs/deployment/android#reference-the-keystore-from-the-app
+key.properties