How to detect keyboard show/ hide event in jquery for mobile web application

You can use resize event to get if keyboard is appearing or not

$(document).ready(function(){
  var _originalSize = $(window).width() + $(window).height()
  $(window).resize(function(){
    if($(window).width() + $(window).height() != _originalSize){
      console.log("keyboard show up");
      $(".copyright_link").css("position","relative");  
    }else{
      console.log("keyboard closed");
      $(".copyright_link").css("position","fixed");  
    }
  });
});

if($(document.activeElement).attr('type') == "text"){
    console.log("Keyboard is visible");
}else{
    console.log("Keyboard is not visible");  
}