java - Simple LibGDX Pong game drag player instead of getting x position

I got a working pong game in LibGDX but when I touch the screen the player x automaticly jumps to the coordinates I touched. I wan't my game to detect I touched and then move the player to the left/right if I swipe my finger to the left or the right.

This is what I tried so far:

if(Gdx.input.isTouched() && Gdx.input.getY()>240*screenheight){
  if(tapped)TouchX = Gdx.input.getX();
    tapped = false;
    DragX = Gdx.input.getX();


    distance = player.getX() - TouchX;

    PlayerX = Gdx.input.getX() + distance;


    Gdx.app.log("PlayerX "+player.getX(), "Distance "+distance);
    Gdx.app.log("DragX ", ""+DragX);
}else{
    tapped = true;

}

Here I update the player X coordinates

player.setX(PlayerX);

Does anyone know how to make this work?