create new channel (needed for android 8+)

Author: zworkb

pythonforandroid/bootstraps/common/build/src/main/java/org/kivy/android/PythonService.java

@@ -18,6 +18,12 @@
 
 import org.renpy.android.Hardware;
 
+//new imports for channel definition
+import android.app.NotificationManager;
+import android.app.NotificationChannel;
+import android.content.Context;
+import android.graphics.Color;
+import android.os.Build;
 
 public class PythonService extends Service implements Runnable {
 
@@ -116,7 +122,31 @@ protected void doStartForeground(Bundle extras) {
             builder.setSmallIcon(context.getApplicationInfo().icon);
             notification = builder.build();
         }
-        startForeground(1, notification);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
+            Log.v("python service","android 8: start foregrund with new channel");
+            startForegroundWithNewChannel(1, notification);
+        }else{
+            Log.v("python service","android <8: start foregrund withut new channel");
+            startForeground(1, notification);
+        }
+    }
+
+    /**
+     * https://stackoverflow.com/questions/47531742/startforeground-fail-after-upgrade-to-android-8-1
+     *
+     * this change is necessary because from Android 8 on we need our own channel
+     */
+    private void startForegroundWithNewChannel(int id, Notification notification){
+        String NOTIFICATION_CHANNEL_ID = "org.bd.pureservice"; //TODO: dynamically
+        String channelName = "Pureservice";
+        NotificationChannel chan = new NotificationChannel(NOTIFICATION_CHANNEL_ID, channelName, NotificationManager.IMPORTANCE_NONE);
+        chan.setLightColor(Color.BLUE);
+        chan.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
+        NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
+        assert manager != null;
+        manager.createNotificationChannel(chan);
+        startForeground(id, notification);
     }
 
     @Override

pythonforandroid/bootstraps/service_only/build/templates/AndroidManifest.tmpl.xml

@@ -71,11 +71,13 @@
 
         {% if service %}
         <service android:name="org.kivy.android.PythonService"
-                 android:process=":pythonservice" />
+                 android:process=":pythonservice" 
+                 android:exported="true"/>
         {% endif %}
         {% for name in service_names %}
         <service android:name="{{ args.package }}.Service{{ name|capitalize }}"
-                 android:process=":service_{{ name }}" />
+                 android:process=":service_{{ name }}"
+                 android:exported="true" />
         {% endfor %}
 
         {% if args.billing_pubkey %}