Firing a dropdownlist event instantaneously (ideally jQuery)

This is related to Fire event each time a DropDownList item is selected with jQuery and How to fire an dropdownlist event instantaneously? but the answers there don't give quite what I need.

Given a dropdown selection in HTML with jQuery+JavaScript, and allowing for either mouse or keyboard interaction, I want to code such that an action will fire not just on final selection (''change'' event) but also when the user uses the keyboard up-arrow or down-arrow to change the selection without yet using the enter key to confirm that selection. In particular, in a dropdown to select color, I'd like to change the color of a swatch continually as the user arrows up or down through the options.

The following code is based in part on the discussion at Fire event each time a DropDownList item is selected with jQuery, but the "winning" version there doesn't work when keyboard is used to make selections, an开发者_开发问答d it is a pretty complete failure on Safari & Google Chrome. My code here works fine in all recent versions of Firefox, and it works fine for mouse-based actions in Chrome and Safari; however, in Chrome when the user works with the keyboard, the only event I seem to be able to capture is the ''change''; ditto for Safari, for what it's worth.

  (function($) {
      $.fn.dropdownSelect = function(fn) {
          return this.each(function() {
              // I'd expect this to be the normal case for selecting with mouse, but only seems to work in Firefox.    
              $('option', this).click(function() {
                  fn();
              });
              // Selection via arrow keys. Only seems to work in Firefox.  
              $(this).keyup(function() {
                  fn();
              });
              // Next case is crucial for Safari and Chrome, should be harmless for Firefox.
              $(this).change(function() {
                  fn();
              });
          });
      }
  })(jQuery);

Then I invoke it like:

$('#color-dropdown').dropdownSelect(function () {
     // Act on it here.
});

I tried checking also for the ''keypress'' event, but to no avail. Any ideas?

You want 'keydown'. The keypress event does not capture control functions like arrows.