Listener for Button press until button is released in android Studio

Question

I am trying to send data via Bluetooth continuously when a button is pressed until it is released, but in my code, I am receiving the data only once when the button is pressed or released.

Here, I am using OnTouchListener with Action_Down and Action_Up. If someone can help me with it, that would be really great, Thank you.

fab1.setOnTouchListener(new View.OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    TextView d;

                    switch (event.getAction())
                    {
                        case MotionEvent.ACTION_DOWN:data[0]='H';
                            if(connection_check)
                            {
                                d =findViewById(R.id.datacheck);
                                String str=String.valueOf(data)+"\n";
                                d.setText(str);
                                sendData.write(str.getBytes());
                            }
                            else
                                Toast.makeText(getApplicationContext(), "Bluetooth not connected", Toast.LENGTH_LONG).show();
                        break;

                        case MotionEvent.ACTION_UP:
                            data[0]='L';
                            if(connection_check)
                            {
                                d =findViewById(R.id.datacheck);
                                String str=String.valueOf(data)+"\n";
                                d.setText(str);
                                sendData.write(str.getBytes());
                            }
                            else
                                Toast.makeText(getApplicationContext(), "Bluetooth not connected", Toast.LENGTH_LONG).show();

                            break;


                    }

Answer 1

Your below code to send the data will be called only once when the user presses the button:

      data[0]='H';      
      if(connection_check)
         {
             d =findViewById(R.id.datacheck);
             String str=String.valueOf(data)+"\n";
             d.setText(str);
             sendData.write(str.getBytes());
         }
      else
        Toast.makeText(getApplicationContext(), "Bluetooth not connected", Toast.LENGTH_LONG).show();

You need to create a handler and runnable to call your send function continuously and start and stop it according to the button events.

Runnable:

Runnable dataSender = new Runnable(){
     @override
     void run(){ 
       if(isPressed && connection_check)
       {
           d =findViewById(R.id.datacheck); 
           String str=String.valueOf(data)+"\n";
           d.setText(str);
           sendData.write(str.getBytes());
           handler.postDelayed(this,100) // for 100 milliseconds
       }
      else
         return
     }
  }

Handler:

Handler handler = new Handler(Looper.getMainLooper())

Now create a global boolean variable isPressed set it to false. Now in your onTouchListener set isPressed accordingly and start the runnable using handler.

fab1.setOnTouchListener(new View.OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    TextView d;

                    switch (event.getAction())
                    {
                        case MotionEvent.ACTION_DOWN:
                             isPressed = true
                             handler.post(dataSender) // start the handler
                             break;

                        case MotionEvent.ACTION_UP:
                            isPressed = false //to stop the handler
                            data[0]='L';
                            if(connection_check)
                            {
                                d =findViewById(R.id.datacheck);
                                String str=String.valueOf(data)+"\n";
                                d.setText(str);
                                sendData.write(str.getBytes());
                            }
                            else
                                Toast.makeText(getApplicationContext(), "Bluetooth not connected", Toast.LENGTH_LONG).show();

                            break;


                    }