diff --git a/WidgetFolderBrowser.m b/WidgetFolderBrowser.m
index c185640..2c0eb51 100644
--- a/WidgetFolderBrowser.m
+++ b/WidgetFolderBrowser.m
@@ -8,90 +8,104 @@
 % sciclist@brain.mpg.de
 % Max-Planck Institute For Brain Research
 %
-    properties
+
+    properties (Dependent)
+        
+        file
+        
+    end
+    
+    properties (Access = private)
         
         ui
         model
         
     end
     
+    events
+        
+        event_file
+        
+    end
+    
     methods
         
         function obj = WidgetFolderBrowser(varargin)
             
             % parse input
             parserObj = inputParser;
-            addParameter(parserObj, 'Parent', [], @(varin) (isempty(varin) || isgraphics(varin)));
+            addParameter(parserObj, 'Parent', [], @(varhandle) (isempty(varhandle) || isgraphics(varhandle)));
             addParameter(parserObj, 'Extension', '*.*', @ischar);
             parse(parserObj, varargin{:});
             
-            
-            % create MVC
+            % ui component
             obj.ui = WidgetFolderBrowserUi(parserObj.Results.Parent);
             if ~isa(obj.ui, 'WidgetFolderBrowserUi')
                 error('WidgetFolderBrowser: initializing ui failed!');
             end
             
+            % model component
             obj.model = WidgetFolderBrowserModel(parserObj.Results.Extension);
             if ~isa(obj.model, 'WidgetFolderBrowserModel')
                 error('WidgetFolderBrowserModel: initailizing model failed!');
             end
             
             
-            % link controler with view and model
-            addlistener(obj.ui, 'event_fileLoad', @obj.fcnCallback_FileLoad);
-            addlistener(obj.ui, 'event_fileNext', @obj.fcnCallback_FileNext);
-            addlistener(obj.ui, 'event_filePrevious', @obj.fcnCallback_FilePrevious);
-            addlistener(obj.ui, 'event_folderLoad', @obj.fcnCallback_FolderLoad);
-            addlistener(obj.model, 'file', 'PostSet', @obj.fcnCallback_FileUpdated);
+            % link ui events
+            addlistener(obj.ui, 'event_fileLoad', @obj.fcnCallback_fileLoad);
+            addlistener(obj.ui, 'event_fileNext', @obj.fcnCallback_fileNext);
+            addlistener(obj.ui, 'event_filePrevious', @obj.fcnCallback_filePrevious);
+            addlistener(obj.ui, 'event_folderLoad', @obj.fcnCallback_folderLoad);
+            
+            % link model events
+            addlistener(obj.model, 'file', 'PostSet', @obj.fcnCallback_fileUpdated);
             
         end
     end
     
     methods
         
-        %%% --- callback functions --- %%%
-        
-        function obj = fcnCallback_FileLoad(obj, ~, ~)
+        %% @ ui event_fileLoad
+        function obj = fcnCallback_fileLoad(obj, ~, ~)
             
             obj.model.fileLoad();
             
-            set(obj.ui.pushButton_PrevFile, 'Enable', 'off');
-            set(obj.ui.pushButton_NextFile, 'Enable', 'off');
-            
         end
         
-        function obj = fcnCallback_FileNext(obj, ~, ~)
+        %% @ ui event_fileNext
+        function obj = fcnCallback_fileNext(obj, ~, ~)
             
             obj.model.fileUpdate(1);
             
         end
         
-        function obj = fcnCallback_FilePrevious(obj, ~, ~)
+        %% @ ui event_filePrevious
+        function obj = fcnCallback_filePrevious(obj, ~, ~)
             
             obj.model.fileUpdate(-1);
             
         end
         
-        function obj = fcnCallback_FolderLoad(obj, ~, ~)
+        %% @ ui event_folderLoad
+        function obj = fcnCallback_folderLoad(obj, ~, ~)
             
             obj.model.folderLoad();
             
-            set(obj.ui.pushButton_PrevFile, 'Enable', 'on');
-            set(obj.ui.pushButton_NextFile, 'Enable', 'on');
-            
         end
         
-        function obj = fcnCallback_FileUpdated(obj, ~, ~)
+        %% @ model event_fileUpdate
+        function obj = fcnCallback_fileUpdated(obj, ~, ~)
             
-            % update status
-            [~, fileTag] = fileparts(obj.model.file);
-            %fprintf('file: %s\n', obj.model.file);
+            obj.ui.updateFileName(obj.model.fileTag);
+            obj.ui.updateFileCounter(obj.model.index, obj.model.listSize);
+            notify(obj, 'event_file');
             
-            set(obj.ui.text_FileName, 'String', fileTag);
-            set(obj.ui.text_FileCounter, 'String', ...
-                sprintf('%d / %d', obj.model.index, obj.model.listSize));
+        end
+        
+        %% @ request file
+        function varfile = get.file(obj)
             
+            varfile = obj.model.file;
             
         end
         
diff --git a/WidgetFolderBrowserModel.m b/WidgetFolderBrowserModel.m
index 05c0127..f4e6e6d 100644
--- a/WidgetFolderBrowserModel.m
+++ b/WidgetFolderBrowserModel.m
@@ -26,6 +26,7 @@
     properties (Dependent)
         
         listSize
+        fileTag
         
     end
     
@@ -119,5 +120,11 @@
             value = length(obj.list);
             
         end
+        
+        function vartag = get.fileTag(obj)
+            
+            [~, vartag] = fileparts(obj.file);
+            
+        end
     end
 end
\ No newline at end of file
diff --git a/WidgetFolderBrowserTest.m b/WidgetFolderBrowserTest.m
new file mode 100644
index 0000000..44aa848
--- /dev/null
+++ b/WidgetFolderBrowserTest.m
@@ -0,0 +1,30 @@
+%% WidgetFolderBrowserTest
+% test script and example usage
+%
+% Aug 2017
+% 
+
+function WidgetFolderBrowserTest()
+
+    %% clean test
+    clc
+    clear variables
+    close all
+
+    
+    %% evoke widget
+    obj = WidgetFolderBrowser();
+    if ~isa(obj, 'WidgetFolderBrowser')
+        error('WidgetFolderBrowser :: test failed!');
+    end
+
+    %% set listener callback
+    addlistener(obj, 'event_file', @fcnCallback_testEvent);
+
+end
+
+function fcnCallback_testEvent(~, ~)
+
+    disp('EVENT_FILE');
+    
+end
diff --git a/WidgetFolderBrowserUi.m b/WidgetFolderBrowserUi.m
index c80a57a..dea189e 100644
--- a/WidgetFolderBrowserUi.m
+++ b/WidgetFolderBrowserUi.m
@@ -9,7 +9,7 @@
 % Max-Planck Institute For Brain Research
 %
     
-    properties
+    properties (Access = private)
         
         parent
         panel
@@ -49,12 +49,12 @@
     
     methods
         
-        function obj = WidgetFolderBrowserUi(ui_parent)
+        function obj = WidgetFolderBrowserUi(varhandle)
             
             
             
             % render parent
-            if isempty(ui_parent)
+            if isempty(varhandle)
                 
                 obj.parent = figure(...
                     'Visible', 'on',...
@@ -66,13 +66,13 @@
                     'Position', obj.UIWINDOW_SIZE);
                 movegui(obj.parent, 'northwest');
                     
-            elseif isgraphics(ui_parent)
+            elseif isgraphics(varhandle)
                 
-                obj.parent = ui_parent;
+                obj.parent = varhandle;
                 
             else
                 
-                error('uirender::invalid input variable for file constructor');
+                error('WidgetFolderBrowserUi::invalid input variable for file constructor');
                 
             end
             
@@ -81,6 +81,24 @@
             
         end
         
+        function obj = updateFileName(obj, vartext)
+            
+            set(obj.text_FileName, 'String', vartext);
+            
+        end
+        
+        function obj = updateFileCounter(obj, varcount, varsize)
+            
+            set(obj.text_FileCounter, 'String', ...
+                sprintf('%d / %d', varcount, varsize));
+            
+        end
+        
+        
+    end
+    
+    methods (Access = private)
+        
         function obj = render(obj)
             
             %%% --- create widget panel --- %%%
@@ -149,12 +167,16 @@
         
         function obj = onClick_pushButton_LoadFile(obj, ~, ~)
             
+            set(obj.pushButton_PrevFile, 'Enable', 'off');
+            set(obj.pushButton_NextFile, 'Enable', 'off');
             notify(obj, 'event_fileLoad');
             
         end
         
         function obj = onClick_pushButton_LoadFolder(obj, ~, ~)
             
+            set(obj.pushButton_PrevFile, 'Enable', 'on');
+            set(obj.pushButton_NextFile, 'Enable', 'on');
             notify(obj, 'event_folderLoad');
             
         end
@@ -173,7 +195,6 @@
             
         end
         
-        
     end
     
 end
diff --git a/test/test.m b/test/test.m
deleted file mode 100644
index b4d0b85..0000000
--- a/test/test.m
+++ /dev/null
@@ -1,18 +0,0 @@
-%% WidgetFolderBrowser
-% test script and example usage
-%
-% Aug 2017
-% 
-
-clc
-clear variables
-close all
-
-
-addpath([pwd, filesep, '..', filesep]);
-
-%% evoke widget
-obj = WidgetFolderBrowser();
-if ~isa(obj, 'WidgetFolderBrowser')
-    error('WidgetFolderBrowser :: test failed!');
-end