Nrthugu

I want to create a floating button like Uber. Uber shows a floating button when online and hides it when offline. Also "DU recorder" app has the floating button.

I want the floating button remain on top of all apps and be movable on any place on screen.

I have Samsung Galaxy S7 Edge with Android 8 (Oreo)

use this code 



import android.content.Context;

import android.support.design.widget.FloatingActionButton;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.view.View;



public class MovableFloatingActionButton extends FloatingActionButton implements View.OnTouchListener {



    private final static float CLICK_DRAG_TOLERANCE = 10; // Often, there will be a slight, unintentional, drag when the user taps the FAB, so we need to account for this.



    private float downRawX, downRawY;

    private float dX, dY;



    public MovableFloatingActionButton(Context context) {

        super(context);

        init();

    }



    public MovableFloatingActionButton(Context context, AttributeSet attrs) {

        super(context, attrs);

        init();

    }



    public MovableFloatingActionButton(Context context, AttributeSet attrs, int defStyleAttr) {

        super(context, attrs, defStyleAttr);

        init();

    }



    private void init() {

        setOnTouchListener(this);

    }



    @Override

    public boolean onTouch(View view, MotionEvent motionEvent){



        int action = motionEvent.getAction();

        if (action == MotionEvent.ACTION_DOWN) {



            downRawX = motionEvent.getRawX();

            downRawY = motionEvent.getRawY();

            dX = view.getX() - downRawX;

            dY = view.getY() - downRawY;



            return true; // Consumed



        }

        else if (action == MotionEvent.ACTION_MOVE) {



            int viewWidth = view.getWidth();

            int viewHeight = view.getHeight();



            View viewParent = (View)view.getParent();

            int parentWidth = viewParent.getWidth();

            int parentHeight = viewParent.getHeight();



            float newX = motionEvent.getRawX() + dX;

            newX = Math.max(0, newX); // Don't allow the FAB past the left hand side of the parent

            newX = Math.min(parentWidth - viewWidth, newX); // Don't allow the FAB past the right hand side of the parent



            float newY = motionEvent.getRawY() + dY;

            newY = Math.max(0, newY); // Don't allow the FAB past the top of the parent

            newY = Math.min(parentHeight - viewHeight, newY); // Don't allow the FAB past the bottom of the parent



            view.animate()

                    .x(newX)

                    .y(newY)

                    .setDuration(0)

                    .start();



            return true; // Consumed



        }

        else if (action == MotionEvent.ACTION_UP) {



            float upRawX = motionEvent.getRawX();

            float upRawY = motionEvent.getRawY();



            float upDX = upRawX - downRawX;

            float upDY = upRawY - downRawY;



            if (Math.abs(upDX) < CLICK_DRAG_TOLERANCE && Math.abs(upDY) < CLICK_DRAG_TOLERANCE) { // A click

                return performClick();

            }

            else { // A drag

                return true; // Consumed

            }



        }

        else {

            return super.onTouchEvent(motionEvent);

        }



    }



}



//-------------------this code inside the xml file -----------

<com.example.MovableFloatingActionButton

        android:id="@+id/fab"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_gravity="bottom|end"

        android:layout_margin="@dimen/fab_margin"

        android:src="@drawable/ic_navigate_next_white_24dp"/>

Your question contains multiple questions so let us break it down and take it to step by step.

For Creating Floating Button:

I would say use @Vishal Sharma answer about this question in this page

And about showing and hiding it when the user is online or offline:

public class NetworkStateReceiver extends BroadcastReceiver {



    protected Set<NetworkStateReceiverListener> listeners;

    protected Boolean connected;



    public NetworkStateReceiver() {

        listeners = new HashSet<NetworkStateReceiverListener>();

        connected = null;

    }



    public void onReceive(Context context, Intent intent) {

        if(intent == null || intent.getExtras() == null)

            return;



        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo ni = manager.getActiveNetworkInfo();



        if(ni != null && ni.getState() == NetworkInfo.State.CONNECTED) {

            connected = true;

        } else if(intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY,Boolean.FALSE)) {

            connected = false;

        }



        notifyStateToAll();

    }



    private void notifyStateToAll() {

        for(NetworkStateReceiverListener listener : listeners)

            notifyState(listener);

    }



    private void notifyState(NetworkStateReceiverListener listener) {

        if(connected == null || listener == null)

            return;



        if(connected == true)

            listener.networkAvailable();

        else

            listener.networkUnavailable();

    }



    public void addListener(NetworkStateReceiverListener l) {

        listeners.add(l);

        notifyState(l);

    }



    public void removeListener(NetworkStateReceiverListener l) {

        listeners.remove(l);

    }



    public interface NetworkStateReceiverListener {

        public void networkAvailable();

        public void networkUnavailable();

    }

}

YOUR ACTIVITY:

public class MyActivity implements NetworkStateReceiverListener {

    private NetworkStateReceiver networkStateReceiver;

}

IN YOUR ACTIVITY: INSTANTIATE THE RECEIVER

public void onCreate(Bundle savedInstanceState) {

    networkStateReceiver = new NetworkStateReceiver();

    networkStateReceiver.addListener(this);

    this.registerReceiver(networkStateReceiver, new IntentFilter(android.net.ConnectivityManager.CONNECTIVITY_ACTION));

}



public void onDestroy() {

    super.onDestroy();

    networkStateReceiver.removeListener(this);

    this.unregisterReceiver(networkStateReceiver);

}

IN YOUR ACTIVITY: IMPLEMENTS THE REQUIRED METHODS

@Override

public void networkAvailable() {

    /* TODO: show your button here */

}



@Override

public void networkUnavailable() {

    /* TODO: hide your button here */        

}