js/css for lines comment (css is only for dev)

public/ng/css/gogs.css

@@ -1445,13 +1445,45 @@ The register and sign-in page style
 .code-view .lines-num span {
   font-family: Monaco, Menlo, Consolas, "Courier New", monospace;
   line-height: 20px;
-  padding: 0 10px;
+  padding: 0 15px;
   cursor: pointer;
   display: block;
 }
+.code-view .lines-code b {
+  position: relative;
+  z-index: 5;
+  float: left;
+  width: 20px;
+  height: 20px;
+  margin: 0px -10px -1px -10px;
+  line-height: 20px;
+  color: #fff;
+  text-align: center;
+  text-indent: 0;
+  cursor: pointer;
+  background-color: #4183c4;
+  background-color: #4183c4;
+  background-image: -webkit-linear-gradient(#5490ca, #4183c4);
+  background-image: linear-gradient(#5490ca, #4183c4);
+  background-repeat: repeat-x;
+  border-radius: 3px;
+  box-shadow: 0 1px 4px rgba(0,0,0,0.15);
+  opacity: 0;
+  -webkit-transform: scale(0.8, 0.8);
+  -ms-transform: scale(0.8, 0.8);
+  transform: scale(0.8, 0.8);
+  -webkit-transition: -webkit-transform 0.1s ease-in-out;
+  transition: transform 0.1s ease-in-out;
+  font-size: 20px;
+}
+.code-view .lines-code b.ishovered {
+  opacity:1;
+}
 .code-view .lines-code > pre {
   border: none;
   border-left: 1px solid #ddd;
+  border-radius: 0;
+  padding-left: 15px;
 }
 .code-view .lines-code > pre > ol.linenums > li {
   padding: 0 10px;

public/ng/js/gogs.js

@@ -261,6 +261,14 @@ var Gogs = {};
             }
         });
 
+        $('.code-diff .lines-code > pre').hover(function () {
+            var $b = $(this).prev();
+            $b.addClass('ishovered');
+        });
+        $('.code-diff tr').mouseleave(function () {
+            $('.code-diff .lines-code > b').removeClass('ishovered');
+        });
+
         $(window).on('hashchange', function (e) {
             var m = window.location.hash.match(/^#diff-(\d+)(L\d+)\-(L\d+)$/);
             var $list = $('.code-diff td.lines-num > span');

templates/repo/diff.tmpl

@@ -110,8 +110,8 @@
                             <td class="lines-num lines-num-new">
                                 <span rel="diff-{{Add $i 1}}L{{$j}}{{$k}}">{{if $line.RightIdx}}{{$line.RightIdx}}{{end}}</span>
                             </td>
-                            
                             <td class="lines-code">
+                                <b>+</b>
                                 <pre>{{$line.Content}}</pre>
                             </td>
                         </tr>