Adds Alt+Shift shortcut for swapping languages in Google Translate.

swapper.js

/**
 * Adds Alt+Shift shortcut for swapping languages in Google Translate.
 * Best used with browser JS injectors such as
 * https://chrome.google.com/webstore/detail/custom-javascript-for-web/poakhlngfciodnhlhhgnaaelnpjljija
 */
(function () {

  var shiftKeyPressed = false,
    altKeyPressed = false,
    swap = document.querySelector('#gt-swap');
  
  window.addEventListener('keydown', function (event) {
    var key = event.keyCode;
    
    if (key === 16)
      shiftKeyPressed = true;
    else if (key === 18)
      altKeyPressed = true;
      
    if (shiftKeyPressed && altKeyPressed) {
      swap.dispatchEvent(new MouseEvent('mouseover'));
      swap.dispatchEvent(new MouseEvent('mousedown'));
      swap.dispatchEvent(new MouseEvent('mouseup'));
      
      shiftKeyPressed = false;
      altKeyPressed = false;
    }
  });
  
  window.addEventListener('keyup', function (event) {
    var key = event.keyCode;
    
    if (key === 16)
      shiftKeyPressed = false;
    else if (key === 18)
      altKeyPressed = false;
  });

})();