I develop one app. I load everything's using service which is start from my StartActivity class. i want to set showcaseview in my loaded content and I am using this github demo lib for showcaseview. 
please any one can help me,thanks in advance, help is appreciable. 
Problem is :- when is pass the activity context then it's null or i am not sure that how to pass activity context from service class.
when my service start then ui is like this
screen short
StartActivity.java
public class StartActivity extends Activity {
    private static final String SHOWCASE_ID = "com.zennaxx.screenrecorder";
    private ImageView btnCamera;
    private ImageView btnSetting;
    private ImageView btnAlbum;
    private ImageView btnClose;
    Activity activity;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        initView();
    }
    public void initView()
    {
        setContentView(R.layout.floating_view);
        activity = StartActivity.this;
        btnCamera = (ImageView)findViewById(R.id.btn_camera);
        btnSetting = (ImageView)findViewById(R.id.btn_settings);
        btnAlbum = (ImageView)findViewById(R.id.btn_album);
        btnClose = (ImageView)findViewById(R.id.btn_close);
        startShowcaseView();
    }
    private void startShowcaseView()
    {
        ShowcaseConfig config = new ShowcaseConfig();
        config.setDelay(500); // half second between each showcase view
        MaterialShowcaseSequence sequence = new MaterialShowcaseSequence(activity, SHOWCASE_ID);
        sequence.setOnItemShownListener(new MaterialShowcaseSequence.OnSequenceItemShownListener() {
            @Override
            public void onShow(MaterialShowcaseView itemView, int position) {
                Toast.makeText(itemView.getContext(), "Item #" + position, Toast.LENGTH_SHORT).show();
                if (position == 3) {
                    startService();
                }
            }
        });
        sequence.setConfig(config);
        sequence.addSequenceItem(btnCamera, "This is button one", "GOT IT");
        sequence.addSequenceItem(btnSetting, "This is Setting button ", "GOT IT");
        sequence.addSequenceItem(btnAlbum, "This is Album button ", "GOT IT");
        sequence.addSequenceItem(btnClose, "This is Close button ", "GOT IT");
        Log.i("Ready to Showcaseview", "(^'_'^)");
        sequence.start();
    }
    private void startService()
    {
        startService(new Intent(getApplicationContext(), FloatingViewService.class));
        finish();
    }
}
FloatViewService.java
public class FloatingViewService extends Service {
    private static final String SHOWCASE_ID = "example.showcaseview";
    private WindowManager windowManager;
    private View floatingView;
    private TextView mTextCoolDown;
    private WindowManager.LayoutParams params;
    private ImageView btnCamera;
    private ImageView btnSettings;
    private ImageView btnAlbum;
    private ImageView btnExit;
    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        return START_STICKY;
    }
    @Override
    public void onCreate() {
        super.onCreate();
        Log.i("onCreate()...", "...called");
        initView();
    }
    private void initView() {
        Log.i("initView()...","...called");
        windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        int screen_height = getResources().getDisplayMetrics().heightPixels;
        LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        floatingView = inflater.inflate(R.layout.floating_view, null);
        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSLUCENT);
        params.gravity = Gravity.TOP | Gravity.LEFT;
        params.x = 0;
        params.y = 100;
        btnCamera = (ImageView) floatingView.findViewById(R.id.btn_camera);
        btnSettings = (ImageView) floatingView.findViewById(R.id.btn_settings);
        btnAlbum = (ImageView) floatingView.findViewById(R.id.btn_album);
        btnExit = (ImageView) floatingView.findViewById(R.id.btn_close);
        btnExit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stopSelf();
            }
        });
        windowManager.addView(floatingView, params);
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        if (floatingView != null)
        {
            if(windowManager != null )
            {
                windowManager.removeView(floatingView);
            }
        }
    }
}
 
     
    