品牌列表 字母 优化

@@ -10,6 +10,7 @@ var $ = require('jquery'),
     lazyLoad = require('yoho.lazyload');
 
 var swiper,
+    $fixTitleBar,
     $brandList = $('.brand-list');
 
 var searchH = $('.newbrand-search').outerHeight(),
@@ -38,21 +39,30 @@ $('.yoho-header').css({
     top: 0
 });
 
+$fixTitleBar = $('<div class="title-bar fixed-title-bar"><h2></h2></div>');
+$fixTitleBar.hide();
+$('.brand-list').last().append($fixTitleBar);
+
 $(window).scroll(function() {
-    var scrTop = $(window).scrollTop();
+    var scrTop = $(window).scrollTop(),
+        minBrandListTop = brandSwipe + $('.hot-brand').outerHeight() +
+        $('.banner-top').outerHeight();
+
+    if ($brandList.eq(0).offset().top < minBrandListTop) {
+        $fixTitleBar.hide();
+    }
 
-    $('.brand-list').each(function() {
+    $brandList.each(function() {
         var offTop = $(this).offset().top - brandSwipe;
 
         if (scrTop >= offTop) {
-            $brandList.find('.title-bar').css('position', 'static');
-            $(this).find('.title-bar').css({
+            $fixTitleBar.css({
+                display: 'block',
                 position: 'fixed',
                 top: brandSwipe
-            });
-        } else {
-            $(this).find('.title-bar').css('position', 'static');
+            }).find('h2').html($(this).find('.title-bar').text());
         }
+
     });
 });