title: Click and hold button in R shiny?
body: <p>I would like to be able to change the value of a parameter by clicking on a R shiny button. So I need to buttons, one for increasing and one for decreasing the value.</p>
  
  <p>I would like to keep the de-/increase  of the value with a certain speed while holding the button.</p>
  
  <p>By releasing the click of the button the action should stop.</p>
  
  <p>So far I have not found this option for the <code>actionButtons</code> in R shiny. Is there another type of button which gives this opportunity?</p>