js: Extract pagination model.

* js/utils.js (guix.clamp): New function.
* js/controller/packages.js (guix.packages.controller): Remove 'pages',
  'currentPageIndex', and 'pageSize' properties.  Add 'pager' prop.
  Delete 'paginate', 'currentPage', 'isFirstPage', 'isLastPage', and
  'isCurrentPage' methods.
* js/model/packages.js (guix.packages.Pager): New function.
* js/view/packages.js (guix.packages.view): Use new Pager API.

1 files changed, 4 insertions, 0 deletions

diff --git a/js/utils.js b/js/utils.js
index b3e4768..c44ee23 100644
--- a/js/utils.js
+++ b/js/utils.js
@@ -17,6 +17,10 @@
 
 var guix = {};
 
+guix.clamp = function(n, min, max) {
+  return Math.max(Math.min(n, max), min);
+};
+
 guix.chunk = function(array, size) {
   return array.reduce(function(memo, value, i) {
     var currentSlice = _(memo).last();