chat head like facebook programatically in android

You can simply use a service class to show a chat head like button on Screen.

Global access to a service can be enforced when it is declared in its manifest's <service> tag. By doing so, other applications will need to declare a corresponding <uses-permission> element in their own manifest to be able to start, stop, or bind to the service.



Provide this entry as a <service> element that's a child of the <application> element:

    <application
        android:icon="@drawable/icon"
        android:label="@string/app_name">
        ...
        <!--
            Because android:exported is set to "false",
            the service is only available to this app.
        -->
        <service
            android:name=".ServiceMovableCameraBtn"
            android:exported="false"/>
        ...
    <application/>

The attribute android:name specifies the class name of the service.

For example:

public class ServiceMovableCameraBtn extends Service implements View.OnTouchListener
{
    private WindowManager windowManager;

    boolean mHasDoubleClicked = false;
    long lastPressTime;

    WindowManager.LayoutParams container_params;

    private int   initialX;
    private int   initialY;
    private float initialTouchX;
    private float initialTouchY;

    Context con;

    android.support.design.widget.FloatingActionButton btnCapture;

    private GestureDetector gestureDetector;


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

    @Override
    public void onCreate()
    {
        super.onCreate();
        con = this;
        windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        setTheme(R.style.AppTheme);

        gestureDetector = new GestureDetector(this, new SingleTapConfirm());
      

        //  LAYOUT PARAMS
        container_params = new WindowManager.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.TYPE_PHONE,         WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE, PixelFormat.TRANSLUCENT);

        btnCapture = new android.support.design.widget.FloatingActionButton(this);
        btnCapture.setImageResource(R.mipmap.ic_launcher);

        btnCapture.setOnTouchListener(this);

        windowManager.addView(btnCapture, container_params);
    }

    @Override
    public void onDestroy()
    {
        super.onDestroy();
        if (btnCapture != null)
        {
            windowManager.removeView(btnCapture);
        }
    }

    Toast toast;

    @Override
    public boolean onTouch(View view, MotionEvent event)
    {
        WindowManager.LayoutParams paramsF = container_params;

        if (gestureDetector.onTouchEvent(event))
        {
            // single tap
            onSingleClick();
            return true;
        }
        else
        {

            switch (event.getAction())
            {
                case MotionEvent.ACTION_DOWN:
                    long pressTime = System.currentTimeMillis();

                    if (pressTime - lastPressTime <= 300)
                    {
                        generateNotification();
                        mHasDoubleClicked = true;
                    }
                    else
                    {
                        mHasDoubleClicked = false;
                    }
                    lastPressTime = pressTime;
                    initialX = paramsF.x;
                    initialY = paramsF.y;
                    initialTouchX = event.getRawX();
                    initialTouchY = event.getRawY();
                    break;
                case MotionEvent.ACTION_UP:

                    break;
                case MotionEvent.ACTION_MOVE:
                    paramsF.x = initialX + (int) (event.getRawX() - initialTouchX);
                    paramsF.y = initialY + (int) (event.getRawY() - initialTouchY);
                    windowManager.updateViewLayout(btnCapture, paramsF);
                    break;
            }

        }
        return false;
    }




    public void showToast(final String text)
    {
        new Handler().post(new Runnable()
        {
            @Override
            public void run()
            {
                if (toast != null)
                {
                    toast.cancel();
                }
                toast = Toast.makeText(ServiceMovableCameraBtn.this, text, Toast.LENGTH_LONG);
                toast.setGravity(Gravity.CENTER, 0, 0);
                toast.show();
            }
        });


    }


    private class SingleTapConfirm extends GestureDetector.SimpleOnGestureListener
    {

        @Override
        public boolean onSingleTapConfirmed(MotionEvent event)
        {
            return true;
        }
For example:
        @Override
        public boolean onSingleTapUp(MotionEvent e)
        {
            return true;
        }
    }


    public void onSingleClick()
    {

    //perform some task..
    }


    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    private void generateNotification()
    {
        ServiceMovableCameraBtn.this.stopSelf();

        Context context            = ServiceMovableCameraBtn.this;
        String  message            = "Tap to open SpyCam.";
        Intent  notificationIntent = new Intent(ServiceMovableCameraBtn.this, MainActivityG.class);

        int icon = R.mipmap.ic_launcher;
        try
        {


            NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);


            String title = "Title";
            notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);

            PendingIntent intent = PendingIntent.getActivity(context, 0, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);


            Uri defaultSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
            if (defaultSound == null)
            {
                defaultSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE);
                if (defaultSound == null)
                {
                    defaultSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_ALARM);
                }
            }
            Notification.Builder builder = new Notification.Builder(context).setContentTitle(title)

.setContentText(message)

.setContentIntent(intent)

.setSmallIcon(icon)

.setLights(Color.GREEN, 500, 600)

.setAutoCancel(true)

.setSound(defaultSound);

            builder.setOngoing(true);

            Notification not = new Notification.BigTextStyle(builder).bigText(message).build();
            if (defaultSound == null)
            {
                not.defaults |= Notification.DEFAULT_SOUND;
            }


            notificationManager.notify(1, not);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }


}

You can use this service class to display anything floating on the screen,like in this example we use FAB button,but you can use ImageView etc,.according to your requirement.