Merge "commons" into the project root directory

app/src/main/java/fr/free/nrw/commons/HandlerService.java

@@ -0,0 +1,68 @@
+package fr.free.nrw.commons;
+
+import android.app.*;
+import android.content.*;
+import android.os.*;
+
+public abstract class HandlerService<T> extends Service {
+    private volatile Looper threadLooper;
+    private volatile ServiceHandler threadHandler;
+    private String serviceName;
+
+    private final class ServiceHandler extends Handler {
+        public ServiceHandler(Looper looper) {
+            super(looper);
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            handle(msg.what, (T)msg.obj);
+            stopSelf(msg.arg1);
+        }
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        threadLooper.quit();
+    }
+
+    public class HandlerServiceLocalBinder extends Binder {
+        public HandlerService getService() {
+            return HandlerService.this;
+        }
+
+    }
+
+    private final IBinder localBinder = new HandlerServiceLocalBinder();
+    @Override
+    public IBinder onBind(Intent intent) {
+        return localBinder;
+    }
+
+    protected HandlerService(String serviceName) {
+        this.serviceName = serviceName;
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        HandlerThread thread = new HandlerThread(serviceName);
+        thread.start();
+
+        threadLooper = thread.getLooper();
+        threadHandler = new ServiceHandler(threadLooper);
+    }
+
+    private void postMessage(int type, Object obj) {
+        Message msg = threadHandler.obtainMessage(type);
+        msg.obj = obj;
+        threadHandler.sendMessage(msg);
+    }
+
+    public void queue(int what, T t) {
+        postMessage(what, t);
+    }
+
+    protected abstract void handle(int what, T t);
+}