weird jQuery UI Slider behavior

Question

I'm developing a simple one page website and I'm integrating the jQuery UI Slider. The website I'm integrating it in is : Website.

It seems like I'm having a little problem with the slider. If you look closely at the slider when navigating with the left and right arrow ( or the left and right keyboard keys ) you will notice that when going backward, before the last step, the min range jumps ahead the handle with a few pixels ( the background image ).

And also the animate property attached to the handle it doesn't work when using the mouse cursor to move the handle, per say the handle is in position 0 and you click on the last position, normally it should animate to the last position but it jumps there.

Could someone tell me how to fix these bugs ? I tried working on the CSS for the first problem but it doesn't seem to be because of that.

Answer 1

1. "min range jumps ahead the handle" - I've reduced the bug here: http://jsfiddle.net/jefferyto/Gd5dn/

   This is a bug in jQuery.animate() when animating non-pixel values; Slider uses percentages. Before animating, jQuery converts the element's starting value (in pixels) into the end value's units, and assigns this non-px starting value to the element (lines 8601-8605 in jQuery 1.7.2 (unminified)).

   The calculation is flawed for small end values (like 0%), and so the range's starting width is larger than what it should be.

   I've opened a pull request with a fix; the same fix can be applied to the current stable version of jQuery.

   Update: You can find a plugin that fixes this bug (for jQuery 1.7.2) here: http://jsfiddle.net/jefferyto/zbkQX/

   Copy from (at the top)

   // Start jQuery.animate() fix
   

   to (before the test code)

   // End jQuery.animate() fix
   

   It should work if you paste this code into your plugins.js.

2. "it should animate to the last position but it jumps there" - this is because the Slider and jPages plugins are connected with circular callbacks.

   When the user clicks on the slider, Slider triggers a slide event then animates the handle and range. The slide event handler calls jPages to change to the new page. jPages calls its assigned callback function, which passes the current page number back to Slider. Slider sets its value and starts to animate the handle/range.

   After the slide event, Slider goes back to animating the handle and range (which is actually the second time it is animating). Slider calls .stop(1, 1) on the elements before animating, which causes the first animation to stop and jump immediately to its end value. (The second .animate() does nothing since the elements are already in the correct position.)

   (I hope that made sense :-) )

   I suggest adding logic in the jPages callback to call Slider with the new page number only if the trigger isn't originally from Slider.

   Update: I think you'll need to update both callbacks:

   For Slider:

   slide: function(event, ui) {
       if (!self.paging) {
           self.paging = true;
           $(self.shop_navigation_class).jPages(ui.value);
           self.paging = false;
       }
   }
   

   For jPages:

   callback: function(pages) {
       var data = {
           current_page: pages.current,
           total_pages: pages.count
       }
       self.set_local_storage_data(self.data_key, JSON.stringify(data));
       if (!self.paging) {
           self.paging = true;
           $(self.shop_slider_class).slider("value", pages.current);
           self.paging = false;
       }
   }
   

   Please let me know if this works for you.

Answer 2

The simplest answer is probably to just not use jQueryUI's slider.

Having looked at your code it looks like you're easily competent enough at JS and CSS to replicate its appearance and core behaviour yourself, and make it work exactly how you want it to.