Android : How to show dialog or activity over lock screen[ not unlock the screen]

Question

I hava a app, it will receive msg from server and make a dialog to user.So when phone is on lock screen i want dialog will show on the top of lock screen but not unlock it.c

Answer 1

I solved something similar in the following way. Create services, to broadcast the action "ACTION_SCREEN_ON & ACTION_USER_PRESENT & ACTION_SCREEN_OFF", create function to show the windows with WINDOW_SERVICE. I use a service for my requirements, but it can adapt.

public class OverlayService extends Service {

    private static final String TAG = OverlayService.class.getSimpleName();
    WindowManager mWindowManager;
    View mView;
    Animation mAnimation;

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        registerOverlayReceiver();
        return super.onStartCommand(intent, flags, startId);
    }

    private void showDialog(String aTitle){
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);

        mView = View.inflate(getApplicationContext(), R.layout.fragment_overlay, null);
        mView.setTag(TAG);

        int top = getApplicationContext().getResources().getDisplayMetrics().heightPixels / 2;

        RelativeLayout dialog = (RelativeLayout) mView.findViewById(R.id.dialog);
        LayoutParams lp = (LayoutParams) dialog.getLayoutParams();
        lp.topMargin = top;
        lp.bottomMargin = top;
        mView.setLayoutParams(lp);

        ImageButton imageButton = (ImageButton) mView.findViewById(R.id.close);
        lp = (LayoutParams) imageButton.getLayoutParams();
        lp.topMargin = top - 58;
        imageButton.setLayoutParams(lp);
        imageButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                mView.setVisibility(View.INVISIBLE);
            }
        });

        TextView title = (TextView) mView.findViewById(R.id.Title);
        title.setText(aTitle);

        final WindowManager.LayoutParams mLayoutParams = new WindowManager.LayoutParams(
        ViewGroup.LayoutParams.MATCH_PARENT,
        ViewGroup.LayoutParams.MATCH_PARENT, 0, 0,
        WindowManager.LayoutParams.TYPE_SYSTEM_ERROR,
        WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
                | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
                | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON ,
        PixelFormat.RGBA_8888);

        mView.setVisibility(View.VISIBLE);
        mAnimation = AnimationUtils.loadAnimation(getApplicationContext(), R.anim.in);
        mView.startAnimation(mAnimation);
        mWindowManager.addView(mView, mLayoutParams);

    }

    private void hideDialog(){
        if(mView != null && mWindowManager != null){
            mWindowManager.removeView(mView);
            mView = null;
        }
    }

    @Override
    public void onDestroy() {
        unregisterOverlayReceiver();
        super.onDestroy();
    }

    private void registerOverlayReceiver() {
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_SCREEN_ON);
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        filter.addAction(Intent.ACTION_USER_PRESENT);
        registerReceiver(overlayReceiver, filter);
    }

    private void unregisterOverlayReceiver() {
        hideDialog();
        unregisterReceiver(overlayReceiver);
    }


    private BroadcastReceiver overlayReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Log.d(TAG, "[onReceive]" + action);
            if (action.equals(Intent.ACTION_SCREEN_ON)) {
                showDialog("Esto es una prueba y se levanto desde");
            }
            else if (action.equals(Intent.ACTION_USER_PRESENT)) {
                hideDialog();
            }
            else if (action.equals(Intent.ACTION_SCREEN_OFF)) {
                hideDialog();
            }
        }
    };
}

I hope it useful!