Improved android networking

android-project/app/src/main/AndroidManifest.xml

@@ -58,6 +58,9 @@
     <!-- if you want to connect to the network or internet, uncomment this. -->
     <uses-permission android:name="android.permission.INTERNET" />
 
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SPECIAL_USE"/>
+
     <!-- Create a Java class extending SDLActivity and place it in a
          directory under app/src/main/java matching the package, e.g. app/src/main/java/com/gamemaker/game/MyGame.java
 
@@ -76,6 +79,13 @@
         <!-- Example of setting SDL hints from AndroidManifest.xml:
         <meta-data android:name="SDL_ENV.SDL_ANDROID_TRAP_BACK_BUTTON" android:value="0"/>
          -->
+        <service
+            android:name=".InfiniPaintNetworkService"
+            android:foregroundServiceType="specialUse"
+            android:exported="false">
+            <property android:name="android.app.PROPERTY_SPECIAL_USE_FGS_SUBTYPE"
+                android:value="When connected to a server/hosting a server, keep the connection alive even when the application is in the background."/>
+        </service>
 
         <activity android:name="com.erroratline0.infinipaint.InfiniPaint"
             android:label="@string/app_name"

android-project/app/src/main/java/com/erroratline0/infinipaint/InfiniPaint.java

@@ -19,6 +19,7 @@
 package com.erroratline0.infinipaint;
 
 import android.content.Context;
+import android.content.Intent;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
@@ -142,4 +143,10 @@ public class InfiniPaint extends SDLActivity {
     static public void updateTextboxAndCursorPos(String str, int selectionBegin, int selectionEnd) {
         mSingleton.commandHandler.post(new InfiniPaintUpdateTextboxAndCursorPosTask(str, selectionBegin, selectionEnd));
     }
+    static public void startNetworkService() {
+        mSingleton.startForegroundService(new Intent(mSingleton, InfiniPaintNetworkService.class));
+    }
+    static public void stopNetworkService() {
+        mSingleton.stopService(new Intent(mSingleton, InfiniPaintNetworkService.class));
+    }
 }

android-project/app/src/main/java/com/erroratline0/infinipaint/InfiniPaintNetworkService.java

@@ -0,0 +1,58 @@
+package com.erroratline0.infinipaint;
+
+import android.app.ForegroundServiceStartNotAllowedException;
+import android.app.Notification;
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.app.Service;
+import android.content.Intent;
+import android.content.pm.ServiceInfo;
+import android.os.Build;
+import android.os.IBinder;
+import android.view.KeyEvent;
+
+
+public class InfiniPaintNetworkService extends Service {
+    public static native void networkServiceStarted();
+    public static native void networkServiceDestroyed();
+
+    private static final String CHANNEL_ID = "NetworkServiceChannel";
+
+    @Override
+    public void onCreate() {
+        createNotificationChannel();
+    }
+
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        Notification notification = new Notification.Builder(this, CHANNEL_ID)
+                .setContentTitle("Online canvas")
+                .setContentText("Currently online")
+                .build();
+        startForeground(1, notification);
+        networkServiceStarted();
+        // For now, don't try restarting the connection after we've been disconnected
+        return START_NOT_STICKY;
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        // We don't provide binding, so return null
+        return null;
+    }
+
+    @Override
+    public void onDestroy() {
+        networkServiceDestroyed();
+    }
+
+    private void createNotificationChannel() {
+        NotificationChannel serviceChannel = new NotificationChannel(
+                CHANNEL_ID,
+                "Network Service Channel",
+                NotificationManager.IMPORTANCE_DEFAULT
+        );
+        NotificationManager manager = getSystemService(NotificationManager.class);
+        manager.createNotificationChannel(serviceChannel);
+    }
+}