show some indication when updates are available.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@9920 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/model/UpdateCenter.java

@@ -176,6 +176,19 @@ public class UpdateCenter implements ModelObject {
         return r;
     }
 
+    /**
+     * Does any of the plugin has updates?
+     */
+    public boolean hasUpdates() {
+        Data data = getData();
+        if(data==null)      return false;
+
+        for (PluginWrapper pw : Hudson.getInstance().getPluginManager().getPlugins()) {
+            if(pw.getUpdateInfo() !=null) return true;
+        }
+        return false;
+    }
+
     public String getDisplayName() {
         return "Update center";
     }

core/src/main/resources/hudson/model/Hudson/manage.jelly

@@ -31,7 +31,10 @@
         ${%Useful when you modified config files directly on disk.} 
       </local:feature>
       <local:feature icon="gear2.gif"        href="pluginManager/" title="${%Manage Plugins}">
-        ${%Add, remove, disable or enable plugins that can extend the functionality of Hudson.}  
+        ${%Add, remove, disable or enable plugins that can extend the functionality of Hudson.}
+        <j:if test="${it.updateCenter.hasUpdates()}">
+          <span style="color:red; font-weight:bold">(${%updates available})</span>
+        </j:if>
       </local:feature>
       <local:feature icon="computer.gif"     href="systemInfo"  title="${%System Information}">
         ${%Displays various environmental information to assist trouble-shooting.}