Is my Service working properly?

Question

I am attempting to familiarize myself with the android Service, for the purpose of overlaying the screen and drawing to it/interacting with the user outside of the app.

I know services aren't meant to interact with the user, but I can't find another way of accomplishing this.

I have found some resources that were quite a bit of help here on Stack Overflow. Here is another project on GitHub that is an example of something similar, but done in a different way.

As of right now, just because I am learning and want to accomplish this specific useless thing, I want there to be a Toast every time the screen is touched.

From reading and looking, my understanding is I need to start an Intent of a service. I must use the service to add a ViewGroup to the WindowManager. The handling of the touches and what is drawn to the screen is handled on the ViewGroup.

Yes, I have the service and overlay permission properly placed in the AndroidManifest.xml

Here are my 3 classes

public class MainActivity extends Activity
{

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        startService(new Intent(this, MyService.class));
        finish();
    }

}

public class MyService extends Service
{

    @Override
    public IBinder onBind(Intent p1)
    {
        // TODO: Implement this method
        return null;
    }

    private MyView view;
    @Override
    public void onCreate()
    {
        // TODO: Implement this method
        super.onCreate();
        view = new MyView(this);
        WindowManager.LayoutParams params = new WindowManager.LayoutParams(
            WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
            WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
            PixelFormat.TRANSLUCENT);
        params.gravity = Gravity.RIGHT | Gravity.TOP;
        params.setTitle("Load Average");
        WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
        wm.addView(view, params);
    }

}

public class MyView extends ViewGroup
{

    public MyView(Context context){
        super(context);
        setLayoutParams(new LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.MATCH_PARENT));


    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
    }


    @Override
    protected void onLayout(boolean p1, int p2, int p3, int p4, int p5)
    {
        // TODO: Implement this method
    }

    @Override
    public boolean onTouchEvent(MotionEvent event)
    {
        // TODO: Implement this method
        Toast.makeText(getContext(), "Touched", Toast.LENGTH_SHORT).show();
        return true;
    }

}

This code compiles and runs with no errors, and while messing with it, I CAN draw things to the screen in the draw method, but the toast in onTouchEvent never appears on the screen. Why won't it show up?

Edit: Using setOnTouchListener(...): and creating the toast in there didn't work either.

David Crouse · Answer 1 · 2015-02-20T20:11:23.000

0

Your service creation and drawing is OK, as is your toast code. Throw a breakpoint on the Toast.makeText() and see if it is even getting called. My suspicion is that it is not.

Try creating a OnTouchListener and binding it to the ViewGroup, rather than using OnTouchEvent. This has worked for me in the past.

Edit: Corrected to OnTouchListner.

edited Feb 20 '15 at 20:11

answered Feb 20 '15 at 19:49

David Crouse

31
5

I am using AIDE and creating this directly from my phone for convenience. I don't think breakpoints are a thing on this. How would I attach a TouchEventListener to the ViewGroup? – REGAL Feb 20 '15 at 19:59
I meant OnTouchListener (fixed above). Just create a new one and attach with ViewGroup.setOnTouchListener. Make sure to filter events on type, else you get 2 calls, once on touch start and one on touch end. – David Crouse Feb 20 '15 at 20:10
Oh, onTouchListener. That clarifies things – REGAL Feb 20 '15 at 20:17

Is my Service working properly?

1 Answers1