[video] show thumbnail for video files in dir-view/favorites/view-shared-dir pages

static/scripts/common.js

@@ -720,6 +720,22 @@ define([
             }
         },
 
+        // check if a file is a video
+        videoCheck: function (filename) {
+            // no file ext
+            if (filename.lastIndexOf('.') == -1) {
+                return false;
+            }
+            var file_ext = filename.substr(filename.lastIndexOf('.') + 1).toLowerCase();
+            var exts = ['mp4', 'ogv', 'webm', 'mov'];
+            if (exts.indexOf(file_ext) != -1) {
+                return true;
+            } else {
+                return false;
+            }
+        },
+
+
         compareTwoWord: function(a_name, b_name) {
             // compare a_name and b_name at lower case
             // if a_name >= b_name, return 1