feat: simplify implementation by avoiding returning channel

android/NotificationHelper.java

@@ -9,20 +9,16 @@ import android.graphics.Bitmap;
 import android.graphics.drawable.Icon;
 
 public class NotificationHelper {
-    public static NotificationChannel newChannel(Context ctx) {
-        String tag = "NotificationHelper";
+    private final static String tag = "NotificationHelper";
+    public static void newChannel(Context ctx, String channelID, String name, String description) {
         Log.w(tag,String.format("newChannel invoked"));
-        String CHANNEL_ID = "CHANNEL_ID";
-        CharSequence name = "notification_channel_name";
-        String description = "notification_channel_description";
         int importance = NotificationManager.IMPORTANCE_DEFAULT;
-        NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
+        NotificationChannel channel = new NotificationChannel(channelID, name, importance);
     	Log.e(tag,String.format("channel: %s",channel));
         channel.setDescription(description);
 
         NotificationManager notificationManager = ctx.getSystemService(NotificationManager.class);
     	Log.e(tag,String.format("manager: %s",notificationManager));
         notificationManager.createNotificationChannel(channel);
-        return channel;
     }
 }

android/notify_android.go

@@ -2,18 +2,16 @@ package android
 
 import (
 	"fmt"
-	"runtime"
 
 	"gioui.org/app"
 	"github.com/tailscale/tailscale-android/jni"
 )
 
 type NotificationChannel struct {
-	javaObj jni.Object
+	id string
 }
 
-func NewChannel(name, description string) (*NotificationChannel, error) {
-	var channel jni.Object
+func NewChannel(id, name, description string) (*NotificationChannel, error) {
 	if err := jni.Do(jni.JVMFor(app.JavaVM()), func(env jni.Env) error {
 		appCtx := jni.Object(app.AppContext())
 		classLoader := jni.ClassLoaderFor(env, appCtx)
@@ -21,26 +19,20 @@ func NewChannel(name, description string) (*NotificationChannel, error) {
 		if err != nil {
 			return err
 		}
-		newChannelMethod := jni.GetStaticMethodID(env, notifyClass, "newChannel", "(Landroid/content/Context;)Landroid/app/NotificationChannel;")
-		// jname := jni.Value(jni.JavaString(env, name))
-		// jdescription := jni.Value(jni.JavaString(env, description))
-		channel, err = jni.CallStaticObjectMethod(env, notifyClass, newChannelMethod, jni.Value(app.AppContext()))
+		newChannelMethod := jni.GetStaticMethodID(env, notifyClass, "newChannel", "(Landroid/content/Context;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V")
+		jname := jni.Value(jni.JavaString(env, name))
+		jdescription := jni.Value(jni.JavaString(env, description))
+		jID := jni.Value(jni.JavaString(env, id))
+		err = jni.CallStaticVoidMethod(env, notifyClass, newChannelMethod, jni.Value(app.AppContext()), jID, jname, jdescription)
 		if err != nil {
 			return err
 		}
-		channel = jni.NewGlobalRef(env, channel)
 		return nil
 	}); err != nil {
 		return nil, fmt.Errorf("failed creating notification channel: %w", err)
 	}
 	nc := &NotificationChannel{
-		javaObj: channel,
+		id: id,
 	}
-	runtime.SetFinalizer(nc, func(obj *NotificationChannel) {
-		_ = jni.Do(jni.JVMFor(app.JavaVM()), func(env jni.Env) error {
-			jni.DeleteGlobalRef(env, obj.javaObj)
-			return nil
-		})
-	})
 	return nc, nil
 }

example/hello.go

@@ -31,7 +31,7 @@ func main() {
 		}
 	}()
 	go func() {
-		channel, err := android.NewChannel("hello", "description")
+		channel, err := android.NewChannel("CHANNEL", "hello", "description")
 		if err != nil {
 			log.Printf("channel creation failed: %v", err)
 		}