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Attention | Topic was automatically imported from the old Question2Answer platform. |
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Asked By | leo_lau_racefit |
I am new to Godot and I am following the tutorial to add custom function on Android.
https://docs.godotengine.org/en/3.1/development/cpp/creating_android_modules.html
After I add custom code (same as the tutorial), the app crash with the following error.
--------- beginning of crash
2020-02-25 10:54:44.774 927-927/org.godotengine.character E/AndroidRuntime: FATAL EXCEPTION: main
Process: org.godotengine.character, PID: 927
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{org.godotengine.character/com.godot.game.GodotApp}: java.lang.InstantiationException: java.lang.Class<com.godot.game.GodotApp> has no zero argument constructor
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3340)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3594)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2146)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:237)
at android.app.ActivityThread.main(ActivityThread.java:7762)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1047)
Caused by: java.lang.InstantiationException: java.lang.Class<com.godot.game.GodotApp> has no zero argument constructor
at java.lang.Class.newInstance(Native Method)
at android.app.AppComponentFactory.instantiateActivity(AppComponentFactory.java:95)
at android.support.v4.app.CoreComponentFactory.instantiateActivity(CoreComponentFactory.java:43)
at android.app.Instrumentation.newActivity(Instrumentation.java:1251)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3328)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3594)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2146)
at android.os.Handler.dispatchMessage(Handler.java:107)
at android.os.Looper.loop(Looper.java:237)
at android.app.ActivityThread.main(ActivityThread.java:7762)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1047)
This is the code I added (copy and paste A singleton object template):
public class GodotApp extends Godot.SingletonBase {
protected Activity appActivity;
protected Context appContext;
private int instanceId = 0;
public int myFunction(String p_str) {
// a function to bind
return 1;
}
public void getInstanceId(int pInstanceId) {
// You will need to call this method from Godot and pass in the get_instance_id().
instanceId = pInstanceId;
}
static public Godot.SingletonBase initialize(Activity p_activity) {
return new GodotApp(p_activity);
}
public GodotApp(Activity p_activity) {
//register class name and functions to bind
registerClass("MySingleton", new String[]
{
"myFunction",
"getInstanceId"
});
this.appActivity = p_activity;
this.appContext = appActivity.getApplicationContext();
// you might want to try initializing your singleton here, but android
// threads are weird and this runs in another thread, so to interact with Godot you usually have to do
appActivity.runOnUiThread(new Runnable() {
public void run() {
//useful way to get config info from project.godot
String key = GodotLib.getGlobal("plugin/api_key");
//SDK.initializeHere();
}
});
}
// forwarded callbacks you can reimplement, as SDKs often need them
protected void onMainActivityResult(int requestCode, int resultCode, Intent data) {}
protected void onMainRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {}
protected void onMainPause() {}
protected void onMainResume() {}
protected void onMainDestroy() {}
protected void onGLDrawFrame(GL10 gl) {}
protected void onGLSurfaceChanged(GL10 gl, int width, int height) {} // singletons will always miss first onGLSurfaceChanged call
}
Before I add any code on Java file, it runs no problem.
It can also run on PC smoothly.
My configuration:
- Android: Android Studio 3.5.3
- NDK(side by side): 21.0.6113669
- Java: jdk-12.0.2
- Phone: Samsung Galaxy S10 with Android 10.
- The app is run by connecting my phone via USB cable and pressing Android icon on the top-right corner.
Thank you for your patient.