Fix dblib.centerVertical when the parent element is the body

diff --git a/lib/dblib.js b/lib/dblib.js
index f167d5125b1a3d0e7650af16db54721fdf77fb20..df2189b2e9cb365cbf6eb110cd1e3f5fad976e53 100755 (executable)
--- a/lib/dblib.js
+++ b/lib/dblib.js
@@ -4,7 +4,10 @@ class dblib{
                elem.style.left = elem.parentNode.clientWidth / 2 - parseInt(elem.clientWidth) / 2 + "px";
        }
        static centerVertical(elem){
-               elem.style.top = elem.parentNode.clientHeight / 2 - parseInt(elem.clientHeight) / 2 + "px";
+               let parent = elem.parentNode;
+               if (parent == document.body)
+                       parent = document.documentElement;
+               elem.style.top = parent.clientHeight / 2 - parseInt(elem.clientHeight) / 2 + "px";
        }
        static remove(elem){
                if(elem)
@@ -16,7 +19,7 @@ class dblib{
        static humanFormat(str){
                var str = str.replace("_", " ");
                str = str[0].toUpperCase() + str.slice(1, str.length);
-               return str;     
+               return str;
        }
        static copy(dest, src){
                for(let prop in src){
@@ -64,7 +67,7 @@ class dblib{
                        if(obj[prop] === search)
                                obj[prop] = replace;
                        else if(obj[prop] instanceof Object)
-                               obj[prop] = this.replaceRecursive(obj[prop], search, replace); 
+                               obj[prop] = this.replaceRecursive(obj[prop], search, replace);
                }
                return obj;
        }