building android apps with haskell

a basic overview on how to build android apps with haskell

Transcript

1. building android apps with haskell Moritz Angermann, Haskell.sg November Meetup, Singapore
2. Who • Moritz Angermann / zw3rk • mobile and dekstop apps blog: https:/ /medium.com/@zw3rk twitter: @angerman_io, @zw3rktech, @mobilehaskell Moritz Angermann, Haskell.sg November Meetup, Singapore
3. Prerequisites • LLVM 5 - http:/ /releases.llvm.org/download.html#5.0.1 • Android Cross Compiler - http:/ /hackage.mobilehaskell.org • Toolchain Wrapper - https:/ /github.com/zw3rk/toolchain-wrapper • Android Studio - https:/ /developer.android.com/studio/index.html • (A recent cabal - https:/ /github.com/haskell/cabal/) Moritz Angermann, Haskell.sg November Meetup, Singapore
4. Installing LLVM & GHC Cross Compiler $ curl -L -O http://releases.llvm.org/5.0.0/clang+llvm-5.0.0-x86_64-apple-darwin.tar.xz $ tar xjf clang+llvm-5.0.0-x86_64-apple-darwin.tar.xz $ export PATH=$PWD/clang+llvm-5.0.0-x86_64-apple-darwin/bin:$PATH $ curl -L -O http://hackage.mobilehaskell.org/.../ghc-8.4.0.20180109-x86_64-linux-android.tar.xz $ curl -L -O http://hackage.mobilehaskell.org/.../ghc-8.4.0.20180109-armv7-linux-androideabi.tar.xz $ curl -L -O http://hackage.mobilehaskell.org/.../ghc-8.4.0.20180109-aarch64-linux-android.tar.xz $ mkdir ghc-{x86_64,armv7,aarch64} $ tar xjf ghc-8.4.0.20180109-x86_64-linux-android.tar.xz -C ghc-x86_64 $ tar xjf ghc-8.4.0.20180109-armv7-linux-androideabi.tar.xz -C ghc-armv7 $ tar xjf ghc-8.4.0.20180109-aarch64-linux-android.tar.xz -C ghc-aarch64 $ export PATH=$PWD/ghc-x86_64/bin:$PWD/ghc-armv7/bin:$PWD/ghc-aarch64/bin:$PATH Moritz Angermann, Haskell.sg November Meetup, Singapore
5. Installing the Toolchain Wrapper # Clone it, bootstrap it and add it to PATH $ git clone https://github.com/zw3rk/toolchain-wrapper $ (cd toolchain-wrapper && ./bootstrap) $ export PATH=$PWD/toolchain-wrapper:$PATH Modify the toolchain config: - toolchain-wrapper/android-toolchain.config (macOS) - toolchain-wrapper/linux-android-toolchain.config (linux) to match your installed Android NDK. Moritz Angermann, Haskell.sg November Meetup, Singapore
6. The Application • Create the application in Android Studio • Create a small Haskell library • Link the Haskell library with the application • Run some trivial Haskell code Moritz Angermann, Haskell.sg November Meetup, Singapore
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12. The Glorious Haskell library {-# LANGUAGE ForeignFunctionInterface #-} module MeetupDemo where import Foreign.C foreign export ccall "hs_hello" hello :: IO CString hello :: IO CString hello = newCString "Hello from Haskell" Moritz Angermann, Haskell.sg November Meetup, Singapore
13. Building the Static library $ x86_64-linux-android-ghc -fllvmng -staticlib -fPIC \ -o hs-libs/x86_64/libHSmeetupdemo.a \ -odir build/hs/x86_64 -hidir build/hs/x86_64 src/main/hs/Lib.hs [1 of 1] Compiling MeetupDemo ( src/main/hs/Lib.hs, src/main/hs/Lib.o ) Linking hs-libs/x86_64/libHSmeetupdemo.a ... Moritz Angermann, Haskell.sg November Meetup, Singapore
14. Adjust the app/build.gradle: add abiFilters defaultConfig { applicationId "com.zw3rk.meetupdemo" minSdkVersion 21 targetSdkVersion 26 versionCode 1 versionName "1.0" testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" externalNativeBuild { cmake { cppFlags "" } } ndk { abiFilters 'x86_64', 'armeabi-v7a', 'arm64-v8a' } } Moritz Angermann, Haskell.sg November Meetup, Singapore
15. Adjust the CMakeLists.txt cmake_minimum_required(VERSION 3.4.1) add_library( native-lib SHARED src/main/cpp/native-lib.cpp ) find_library( log-lib log ) find_library( c-lib c ) find_library( z-lib z ) find_library( hs-lib HSmeetupdemo PATHS ${PROJECT_SOURCE_DIR}/hs-libs/${ANDROID_ABI} NO_CMAKE_FIND_ROOT_PATH ) target_link_libraries( native-lib ${log-lib} ${hs-lib} ${c-lib} ${z-lib} ) Moritz Angermann, Haskell.sg November Meetup, Singapore
16. Adapting the JNI glue (1) #include <jni.h> #include <string> extern "C" JNIEXPORT jstring JNICALL Java_com_zw3rk_meetupdemo_MainActivity_stringFromJNI( JNIEnv *env, jobject /* this */) { std::string hello = "Hello from C++"; return env->NewStringUTF(hello.c_str()); } Moritz Angermann, Haskell.sg November Meetup, Singapore
17. Adapting the JNI glue (2) extern "C" { extern void hs_init(int * argc, char ** argv[]); extern void hs_hello(); } extern "C" JNIEXPORT void JNICALL Java_com_zw3rk_meetupdemo_MainActivity_hsInit(JNIEnv *env, jobject /* this */) { hs_init(NULL,NULL); } Moritz Angermann, Haskell.sg November Meetup, Singapore
18. Adapting the JNI glue (3) extern "C" JNIEXPORT jstring JNICALL Java_com_zw3rk_meetupdemo_MainActivity_stringFromJNI( JNIEnv *env, jobject /* this */) { return env->NewStringUTF(hs_hello()); } Moritz Angermann, Haskell.sg November Meetup, Singapore
19. Adapting the Main Activity class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { hsInit() super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) sample_text.text = stringFromJNI() } external fun stringFromJNI(): String external fun hsInit() companion object { init { System.loadLibrary("native-lib") } } } Moritz Angermann, Haskell.sg November Meetup, Singapore
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21. Notes • Building for iOS is very similar. Just drag the archive into Xcode and link; glue code easier in Obj-C. • Building with cabal It is possible, requires a very recent cabal from git and some manual intervention (haskell/cabal#4939; haskell/cabal#4972) • Make sure you keep your package databases separate! This could and should be handled better by cabal and ghc. • User Guide and Tutorials are coming mobile-haskell-user-guilde.rtfd.io Moritz Angermann, Haskell.sg November Meetup, Singapore
22. Code Source code can be found at - github.com/angerman/2018-01-MeetupDemo Run the Makefile in the app folder then building with Android Studio. Moritz Angermann, Haskell.sg November Meetup, Singapore
23. Thank you! Questions? Moritz Angermann, Haskell.sg November Meetup, Singapore