Android

Introduction

Here you will learn how to prepare your environment to such an extent that you will be able to successfully build the application and enable yourself to work on the code through, for example, Android Studio.

This tutorial is based on latest working workflow file, to ensure that everything will just works. If you encounter any problems feel free to contact us on our Discord or by other communication channel.

It is possible to build, run end edit Android version on Windows, but it requires patched flutter directory.

By “patched” I mean directory in state like before running flutter build on Linux machine.

Assumptions

• You are using Ubuntu 20.04 or later (due to fact that this tutorial is based on this version)
• You have working internet connection
• You already installed Flutter, Rust and vcpkg
• You cloned RustDesk repository
• You know what are you doing

System

This part of tutorial is based on clean Ubuntu 20.04 instance with prerequisites like Flutter, Rust and vcpkg already installed and configured.

If you missing any of these prerequisites, obtain and configure them, then return back here.

Instruction

This is step-to-step instruction.

Generating Bridge 🌉

Due to fact that this project is based on Flutter Rust Bridge you should first generate it, you can achieve it by running following commands.

Change your current directory into rustdesk directory:

cd rustdesk

If you did not have one, clone RustDesk repository, you can achieve that by running:

git clone https://github.com/rustdesk/rustdesk

Then you’ll be able to change your directory into rustdesk:

cd rustdesk

You also might be required to install some prerequisites if you are doing this first time:

sudo apt install ca-certificates -y
sudo apt update -y
sudo apt install -y g++ gcc git curl wget nasm yasm libgtk-3-dev clang cmake libclang-dev ninja-build llvm-dev libclang-10-dev llvm-10-dev pkg-config rustfmt

Installing Flutter Rust Bridge dependencies

At this step you’ll install additional dependencies required by Flutter Rust Bridge also you’ll download Flutter dependencies from pubspec.yaml file.

This might take some time depending on your internet connection speed and overall desktop performance:

cargo install flutter_rust_bridge_codegen
pushd flutter && flutter pub get && popd

Generating bridge files

In order for everything to work you’ll need to generate Flutter Rust Bridge, in order to do it simply run:

~/.cargo/bin/flutter_rust_bridge_codegen --rust-input ./src/flutter_ffi.rs --dart-output ./flutter/lib/generated_bridge.dart

If everything worked fine, you should see something like this in your terminal window:

2023/02/27 20:44:39 [INFO] Success!
2023/02/27 20:44:39 [INFO] Now go and use it :)

Building RustDesk for Android 📱

Installing dependencies

At this step you might require some additional dependencies, you could install them by running this:

sudo apt update -y
sudo apt-get -qq install -y  git curl wget nasm yasm libgtk-3-dev clang libxcb-randr0-dev libxdo-dev libxfixes-dev libxcb-shape0-dev libxcb-xfixes0-dev libasound2-dev libpulse-dev cmake libclang-dev ninja-build libappindicator3-dev libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev libvdpau-dev libva-dev libclang-dev llvm-dev libclang-10-dev llvm-10-dev pkg-config tree g++ libc6-dev gcc-multilib g++-multilib openjdk-11-jdk-headless

You might also need to activate ffigen:

dart pub global activate ffigen 5.0.1

Downloading additional dependencies

For this tutorial we prepared some dependencies for you, feel free to use them. It requires vcpkg to be installed, in this case at /opt:

pushd /opt
sudo wget https://github.com/rustdesk/doc.rustdesk.com/releases/download/console/dep.tar.gz
sudo tar xzf dep.tar.gz
popd

Warning: It requires vcpkg directory to be at $HOME, if Building rustdesk lib part of this instruction will throw errors like:

error: failed to run custom build command for `magnum-opus v0.4.0 (https://github.com/rustdesk/magnum-opus#79be072c)`

Caused by:
  process didn't exit successfully: `/home/user/rustdesk/target/release/build/magnum-opus-05dc0023b86da8fc/build-script-build` (exit status: 101)
  --- stdout
  cargo:info=arm64-android
  cargo:rustc-link-lib=static=opus
  cargo:rustc-link-search=/home/user/vcpkg/installed/arm64-android/lib
  cargo:include=/home/user/vcpkg/installed/arm64-android/include
  rerun-if-changed=/home/user/.cargo/git/checkouts/magnum-opus-4bb999f3bcbf6ab0/79be072/opus_ffi.h
  rerun-if-changed=/home/user/vcpkg/installed/arm64-android/include

Consider installing vcpkg in your home directory, then run:

pushd $HOME
sudo wget https://github.com/rustdesk/doc.rustdesk.com/releases/download/console/dep.tar.gz
sudo tar xzf dep.tar.gz
popd

Disabling Flutter Rust Bridge build

You’ll might need to disable building Flutter Rust Bridge from build.rs file, you can do it by running:

sed -i "s/gen_flutter_rust_bridge();/\/\//g" build.rs

Building RustDesk library

At this step you’ll build librustdesk.so file.

First, add triplet to rust:

rustup target add aarch64-linux-android

Then install cargo-ndk it is required to generate librustdesk.so file:

cargo install cargo-ndk

Now it’s time to run ndk_arm64.sh. This script contains code that builds Rust for Flutter, it requires NDK in version r23c.

You could download it here. You’ll be required to install it manually or follow this instruction. This file is quite heavy so this process might take a while, it mostly depends on your internet connection.

Just remember to set ANDROID_NDK_HOME variable and check if it’s valid.

Then simply run:

./flutter/ndk_arm64.sh

Moving generated library into jniLibs directory

If you generated librustdesk.so then create proper directory:

mkdir -p ./flutter/android/app/src/main/jniLibs/arm64-v8a

And just copy it there:

cp ./target/aarch64-linux-android/release/liblibrustdesk.so ./flutter/android/app/src/main/jniLibs/arm64-v8a/librustdesk.so

Building RustDesk

It’s the last step, now you will build your version of RustDesk apk.

If you done everything correctly you’ll be able to build it with ease.

First you need to download so.tar.gz:

pushd flutter
sudo wget -O so.tar.gz https://github.com/rustdesk/doc.rustdesk.com/releases/download/console/so.tar.gz

Then unpack it:

tar xzvf so.tar.gz
popd

We’ll temporary use debug sign config:

sed -i "s/signingConfigs.release/signingConfigs.debug/g" ./flutter/android/app/build.gradle

Then you need to copy librustdesk.so file into proper directory:

mkdir -p ./flutter/android/app/src/main/jniLibs/arm64-v8a
cp ./target/aarch64-linux-android/release/liblibrustdesk.so ./flutter/android/app/src/main/jniLibs/arm64-v8a/librustdesk.so

Now we’ll finally build Flutter:

pushd flutter
flutter build apk --release --target-platform android-arm64 --split-per-abi

Optional

If you want you might move builded app somewhere else, feel free to run:

mv build/app/outputs/flutter-apk/app-arm64-v8a-release.apk ../rustdesk-release.apk