How to create the needed Android project in android studio

[iwanbk]

Hi All,

I'm currently try to run my rust app on android.

I've followed the na-mainloop from rust-android-examples,
then build and run the app using

cargo apk build
cargo apk run

From the log printed in console, i can see that my app is running, but failed because of some permission.

Now, i want to add the UI and some permission (which i believe will be in the manifest file).
I've tried these:

1. create native C++ project from Android Studio: but i don't think it is the right way
2. copy java/android related files from na-subclass-jni, i can do :
   • adjust System.loadLibrary to load my libary
   • gradlew build
   • gradlew installBuild
   • adb shell am start -n co.realfit.nasubclassjni/.MainActivity
     but i see almost nothing in the logcat.
     and i just realized that this example doesn't have UI, so i move to another example
3. copy java/android related files from agdk-mainloop:
   • do the same with above
   • adjust <meta-data android:name="android.app.lib_name" android:value="mylib" />

• if my .so is libsomething.so, i do this System.loadLibrary("something")

but i got this in the logcat

2024-04-04 20:31:59.112  4138-4138  AndroidRuntime          co.realfit.agdkmainloop              E  FATAL EXCEPTION: main
                                                                                                    Process: co.realfit.agdkmainloop, PID: 4138
                                                                                                    java.lang.UnsatisfiedLinkError: No implementation found for long com.google.androidgamesdk.GameActivity.loadNativeCode(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String, android.content.res.AssetManager, byte[]) (tried Java_com_google_androidgamesdk_GameActivity_loadNativeCode and Java_com_google_androidgamesdk_GameActivity_loadNativeCode__Ljava_lang_String_2Ljava_lang_String_2Ljava_lang_String_2Ljava_lang_String_2Ljava_lang_String_2Landroid_content_res_AssetManager_2_3B) - is the library loaded, e.g. System.loadLibrary?
                                                                                                    	at com.google.androidgamesdk.GameActivity.loadNativeCode(Native Method)
                                                                                                    	at com.google.androidgamesdk.GameActivity.onCreate(GameActivity.java:265)
                                                                                                    	at co.realfit.agdkmainloop.MainActivity.onCreate(MainActivity.java:63)
                                                                                                    	at android.app.Activity.performCreate(Activity.java:8595)
                                                                                                    	at android.app.Activity.performCreate(Activity.java:8573)
                                                                                                    	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1456)
                                                                                                    	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3764)
                                                                                                    	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3922)
                                                                                                    	at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:103)
                                                                                                    	at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:139)
                                                                                                    	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:96)
                                                                                                    	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2443)
                                                                                                    	at android.os.Handler.dispatchMessage(Handler.java:106)
                                                                                                    	at android.os.Looper.loopOnce(Looper.java:205)
                                                                                                    	at android.os.Looper.loop(Looper.java:294)
                                                                                                    	at android.app.ActivityThread.main(ActivityThread.java:8177)
                                                                                                    	at java.lang.reflect.Method.invoke(Native Method)
                                                                                                    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:552)
                                                                                                    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:971)

My question:

1. why i got above error, how to fix?
2. how is the proper way to create Android java/kotlin project for our app?

[iwanbk]

Because i use tokio, my android_main is like this

#[tokio::main]
#[no_mangle]
async fn android_main(app: AndroidApp)  {

[iwanbk]

cc @rib @MarijnS95 @madsmtm

[iwanbk]

why i got above error, how to fix?
how is the proper way to create Android java/kotlin project for our app?

for the fist question, i fixed it by fix the lib name in Cargo.toml

[lib]
name="something"
crate_type=["cdylib"]

Still not sure about the second one.

[madsmtm]

I transfered this here from the top-level org, as I felt it might have a greater chance of being answered here (I can't provide any input to the discussion myself).

[MarijnS95]

For me it is unclear what the author is asking. If anything, using Java/Kotlin activities, and Android Studio/Gradle makes this completely incompatible and irrelevant to cargo-apk. Depending on the use-case the author should look into cargo-ndk (but beware of consistent breakage), rust-android-gradle (deprecated and not compatible with the latest Android Gradle Plugin (AGP)), or perhaps any of the many other spin-offs that provide interoperability or templated Android Studio projects with some Rust in it.