diff --git a/examples/calculator.cpp b/examples/calculator.cpp
index 6b059868..1d18c146 100644
--- a/examples/calculator.cpp
+++ b/examples/calculator.cpp
@@ -123,7 +123,7 @@ class Calc : public finalcut::FDialog
     virtual void   onClose (finalcut::FCloseEvent*);
 
     // Callback method
-    void           cb_buttonClicked (finalcut::FWidget*, data_ptr);
+    void           cb_buttonClicked (finalcut::FWidget*, FDataPtr);
 
   private:
     // Typedef and Enumeration
@@ -1053,7 +1053,7 @@ void Calc::onClose (finalcut::FCloseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void Calc::cb_buttonClicked (finalcut::FWidget*, data_ptr data)
+void Calc::cb_buttonClicked (finalcut::FWidget*, FDataPtr data)
 {
   lDouble& x = getValue();
   Calc::button key = *(static_cast<Calc::button*>(data));
diff --git a/examples/checklist.cpp b/examples/checklist.cpp
index 1ee56939..96c87c76 100644
--- a/examples/checklist.cpp
+++ b/examples/checklist.cpp
@@ -59,7 +59,7 @@ class CheckList : public finalcut::FDialog
     virtual void onClose (finalcut::FCloseEvent*);
 
     // Callback method
-    void cb_showList (finalcut::FWidget*, data_ptr);
+    void cb_showList (finalcut::FWidget*, FDataPtr);
 
     // Data Members
     finalcut::FListView  listView{this};
@@ -160,7 +160,7 @@ void CheckList::onClose (finalcut::FCloseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void CheckList::cb_showList (finalcut::FWidget*, data_ptr)
+void CheckList::cb_showList (finalcut::FWidget*, FDataPtr)
 {
   auto iter = listView.beginOfList();
   finalcut::FString shopping_list;
diff --git a/examples/choice.cpp b/examples/choice.cpp
index ad7cdfd6..db05d27f 100644
--- a/examples/choice.cpp
+++ b/examples/choice.cpp
@@ -27,14 +27,14 @@
 typedef std::shared_ptr<finalcut::FRadioButton> FRadioButtonPtr;
 
 // Function prototypes
-void cb_quit (finalcut::FWidget*, finalcut::FWidget::data_ptr);
+void cb_quit (finalcut::FWidget*, FDataPtr);
 void populateChoice (std::vector<FRadioButtonPtr>&, finalcut::FButtonGroup&);
 void preset (std::vector<FRadioButtonPtr>&);
 
 //----------------------------------------------------------------------
 // Callback functions
 //----------------------------------------------------------------------
-void cb_quit (finalcut::FWidget*, finalcut::FWidget::data_ptr data)
+void cb_quit (finalcut::FWidget*, FDataPtr data)
 {
   auto dlg = static_cast<finalcut::FDialog*>(data);
   dlg->close();
diff --git a/examples/dialog.cpp b/examples/dialog.cpp
index a10ec5d5..b0940c6b 100644
--- a/examples/dialog.cpp
+++ b/examples/dialog.cpp
@@ -23,13 +23,13 @@
 #include <final/final.h>
 
 // function prototype
-void cb_quit (finalcut::FWidget*, finalcut::FWidget::data_ptr);
+void cb_quit (finalcut::FWidget*, FDataPtr);
 
 
 //----------------------------------------------------------------------
 // callback function
 //----------------------------------------------------------------------
-void cb_quit (finalcut::FWidget*, finalcut::FWidget::data_ptr data)
+void cb_quit (finalcut::FWidget*, FDataPtr data)
 {
   auto& app = *(static_cast<finalcut::FApplication*>(data));
   app.quit();
diff --git a/examples/input-dialog.cpp b/examples/input-dialog.cpp
index 292ff806..be6f9ea9 100644
--- a/examples/input-dialog.cpp
+++ b/examples/input-dialog.cpp
@@ -24,19 +24,19 @@
 
 
 // function prototypes
-void cb_quit (finalcut::FWidget*, finalcut::FWidget::data_ptr);
-void cb_publish (finalcut::FWidget*, finalcut::FWidget::data_ptr);
+void cb_quit (finalcut::FWidget*, FDataPtr);
+void cb_publish (finalcut::FWidget*, FDataPtr);
 
 //----------------------------------------------------------------------
 // callback functions
 //----------------------------------------------------------------------
-void cb_quit (finalcut::FWidget*, finalcut::FWidget::data_ptr data)
+void cb_quit (finalcut::FWidget*, FDataPtr data)
 {
   auto app = static_cast<finalcut::FApplication*>(data);
   app->quit();
 }
 
-void cb_publish (finalcut::FWidget* widget, finalcut::FWidget::data_ptr data)
+void cb_publish (finalcut::FWidget* widget, FDataPtr data)
 {
   auto cbox1 = static_cast<finalcut::FCheckBox*>(widget);
   auto cbox2 = static_cast<finalcut::FCheckBox*>(data);
diff --git a/examples/listbox.cpp b/examples/listbox.cpp
index ddfb5c31..172195dc 100644
--- a/examples/listbox.cpp
+++ b/examples/listbox.cpp
@@ -35,7 +35,7 @@ static std::shared_ptr<FString> temp_str { nullptr };
 
 // Function prototypes
 void doubleToItem ( FListBoxItem&
-                  , FWidget::data_ptr container
+                  , FDataPtr container
                   , int index);
 FString& doubleToString (std::list<double>::const_iterator iter);
 FString& mapToString ( std::map<FString
@@ -44,14 +44,14 @@ FString& mapToString ( std::map<FString
 
 // Lazy conversion import function
 void doubleToItem ( FListBoxItem& item
-                  , FWidget::data_ptr container, int index)
+                  , FDataPtr container, int index)
 {
   typedef std::list<double>* double_list_ptr;
   double_list_ptr dbllist = static_cast<double_list_ptr>(container);
   std::list<double>::iterator iter = dbllist->begin();
   std::advance (iter, index);
   item.setText (FString() << *iter);
-  item.setData (FWidget::data_ptr(&(*iter)));
+  item.setData (FDataPtr(&(*iter)));
 }
 
 // Import converter functions
diff --git a/examples/listview.cpp b/examples/listview.cpp
index e1f16598..8aa4413e 100644
--- a/examples/listview.cpp
+++ b/examples/listview.cpp
@@ -58,7 +58,7 @@ class Listview : public finalcut::FDialog
     virtual void onClose (finalcut::FCloseEvent*);
 
     // Callback method
-    void cb_showInMessagebox (finalcut::FWidget*, data_ptr);
+    void cb_showInMessagebox (finalcut::FWidget*, FDataPtr);
 
     // Data Members
     finalcut::FListView listView{this};
@@ -189,7 +189,7 @@ void Listview::onClose (finalcut::FCloseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void Listview::cb_showInMessagebox (finalcut::FWidget*, data_ptr)
+void Listview::cb_showInMessagebox (finalcut::FWidget*, FDataPtr)
 {
   const auto& item = listView.getCurrentItem();
   finalcut::FMessageBox info ( "Weather in " + item->getText(1)
diff --git a/examples/menu.cpp b/examples/menu.cpp
index dde19e35..693637d8 100644
--- a/examples/menu.cpp
+++ b/examples/menu.cpp
@@ -60,7 +60,7 @@ class Menu : public finalcut::FDialog
     virtual void onClose (finalcut::FCloseEvent*);
 
     // Callback method
-    void cb_message (finalcut::FWidget*, data_ptr);
+    void cb_message (finalcut::FWidget*, FDataPtr);
 
     // Data Members
     finalcut::FString        line{13, finalcut::fc::BoxDrawingsHorizontal};
@@ -302,7 +302,7 @@ void Menu::onClose (finalcut::FCloseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void Menu::cb_message (finalcut::FWidget* widget, data_ptr)
+void Menu::cb_message (finalcut::FWidget* widget, FDataPtr)
 {
   auto menuitem = static_cast<finalcut::FMenuItem*>(widget);
   auto text = menuitem->getText();
diff --git a/examples/mouse.cpp b/examples/mouse.cpp
index a4f13506..470f9a22 100644
--- a/examples/mouse.cpp
+++ b/examples/mouse.cpp
@@ -342,7 +342,7 @@ class MouseDraw : public finalcut::FDialog
     virtual void onMouseMove (finalcut::FMouseEvent*);
 
     // Callback methods
-    void cb_colorChanged (finalcut::FWidget*, data_ptr);
+    void cb_colorChanged (finalcut::FWidget*, FDataPtr);
 
     // Data Members
     term_area*   canvas{nullptr};
@@ -538,7 +538,7 @@ void MouseDraw::onMouseMove (finalcut::FMouseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void MouseDraw::cb_colorChanged (finalcut::FWidget*, data_ptr)
+void MouseDraw::cb_colorChanged (finalcut::FWidget*, FDataPtr)
 {
   brush.setForeground (c_chooser.getForeground());
   brush.setBackground (c_chooser.getBackground());
diff --git a/examples/scrollview.cpp b/examples/scrollview.cpp
index 9ba2ef4d..30e790e7 100644
--- a/examples/scrollview.cpp
+++ b/examples/scrollview.cpp
@@ -53,10 +53,10 @@ class Scrollview : public finalcut::FScrollView
     virtual void draw();
 
     // Callback methods
-    void cb_go_east (finalcut::FWidget*, data_ptr);
-    void cb_go_south (finalcut::FWidget*, data_ptr);
-    void cb_go_west (finalcut::FWidget*, data_ptr);
-    void cb_go_north (finalcut::FWidget*, data_ptr);
+    void cb_go_east (finalcut::FWidget*, FDataPtr);
+    void cb_go_south (finalcut::FWidget*, FDataPtr);
+    void cb_go_west (finalcut::FWidget*, FDataPtr);
+    void cb_go_north (finalcut::FWidget*, FDataPtr);
 
     // Data Members
     wchar_t pointer_right{finalcut::fc::BlackRightPointingPointer};
@@ -144,7 +144,7 @@ void Scrollview::draw()
 }
 
 //----------------------------------------------------------------------
-void Scrollview::cb_go_east (finalcut::FWidget*, data_ptr)
+void Scrollview::cb_go_east (finalcut::FWidget*, FDataPtr)
 {
   scrollToX (int(getScrollWidth() - getViewportWidth()) + 1);
   go_south.setFocus();
@@ -153,7 +153,7 @@ void Scrollview::cb_go_east (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void Scrollview::cb_go_south (finalcut::FWidget*, data_ptr)
+void Scrollview::cb_go_south (finalcut::FWidget*, FDataPtr)
 {
   scrollToY (int(getScrollHeight() - getViewportHeight()) + 1);
   go_west.setFocus();
@@ -162,7 +162,7 @@ void Scrollview::cb_go_south (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void Scrollview::cb_go_west (finalcut::FWidget*, data_ptr)
+void Scrollview::cb_go_west (finalcut::FWidget*, FDataPtr)
 {
   scrollToX (1);
   go_north.setFocus();
@@ -171,7 +171,7 @@ void Scrollview::cb_go_west (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void Scrollview::cb_go_north (finalcut::FWidget*, data_ptr)
+void Scrollview::cb_go_north (finalcut::FWidget*, FDataPtr)
 {
   scrollToY (1);
   go_east.setFocus();
@@ -200,7 +200,7 @@ class Scrollviewdemo : public finalcut::FDialog
     virtual void onClose (finalcut::FCloseEvent*);
 
     // Callback method
-    void cb_quit (finalcut::FWidget* = nullptr, data_ptr = nullptr);
+    void cb_quit (finalcut::FWidget* = nullptr, FDataPtr = nullptr);
 
     // Data Members
     Scrollview sview{this};
@@ -242,7 +242,7 @@ Scrollviewdemo::~Scrollviewdemo()
 { }
 
 //----------------------------------------------------------------------
-void Scrollviewdemo::cb_quit (finalcut::FWidget*, data_ptr)
+void Scrollviewdemo::cb_quit (finalcut::FWidget*, FDataPtr)
 {
   close();
 }
diff --git a/examples/term-attributes.cpp b/examples/term-attributes.cpp
index 7a770a5b..fdf576fa 100644
--- a/examples/term-attributes.cpp
+++ b/examples/term-attributes.cpp
@@ -52,8 +52,8 @@ class AttribDlg : public finalcut::FDialog
     virtual void onClose (finalcut::FCloseEvent*);
 
     // Callback methods
-    void cb_next (finalcut::FWidget* = nullptr, data_ptr = nullptr);
-    void cb_back (finalcut::FWidget* = nullptr, data_ptr = nullptr);
+    void cb_next (finalcut::FWidget* = nullptr, FDataPtr = nullptr);
+    void cb_back (finalcut::FWidget* = nullptr, FDataPtr = nullptr);
 
     // Data Members
     FColor bgcolor;
@@ -125,7 +125,7 @@ void AttribDlg::onClose (finalcut::FCloseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void AttribDlg::cb_next (finalcut::FWidget*, data_ptr)
+void AttribDlg::cb_next (finalcut::FWidget*, FDataPtr)
 {
   if ( isMonochron() )
     return;
@@ -141,7 +141,7 @@ void AttribDlg::cb_next (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void AttribDlg::cb_back (finalcut::FWidget*, data_ptr)
+void AttribDlg::cb_back (finalcut::FWidget*, FDataPtr)
 {
   if ( isMonochron() )
     return;
diff --git a/examples/ui.cpp b/examples/ui.cpp
index 2f710f6d..1447886a 100644
--- a/examples/ui.cpp
+++ b/examples/ui.cpp
@@ -55,9 +55,9 @@ class ProgressDialog : public finalcut::FDialog
     virtual void onTimer (finalcut::FTimerEvent*);
 
     // Callback methods
-    void cb_reset_bar (finalcut::FWidget*, data_ptr);
-    void cb_more_bar (finalcut::FWidget*, data_ptr);
-    void cb_exit_bar (finalcut::FWidget*, data_ptr);
+    void cb_reset_bar (finalcut::FWidget*, FDataPtr);
+    void cb_more_bar (finalcut::FWidget*, FDataPtr);
+    void cb_exit_bar (finalcut::FWidget*, FDataPtr);
 
     // Data Members
     finalcut::FProgressbar progressBar{this};
@@ -153,20 +153,20 @@ void ProgressDialog::onTimer (finalcut::FTimerEvent*)
 }
 
 //----------------------------------------------------------------------
-void ProgressDialog::cb_reset_bar (finalcut::FWidget*, data_ptr)
+void ProgressDialog::cb_reset_bar (finalcut::FWidget*, FDataPtr)
 {
   progressBar.reset();
 }
 
 //----------------------------------------------------------------------
-void ProgressDialog::cb_more_bar (finalcut::FWidget*, data_ptr)
+void ProgressDialog::cb_more_bar (finalcut::FWidget*, FDataPtr)
 {
   auto p = progressBar.getPercentage();
   progressBar.setPercentage(++p);
 }
 
 //----------------------------------------------------------------------
-void ProgressDialog::cb_exit_bar (finalcut::FWidget*, data_ptr)
+void ProgressDialog::cb_exit_bar (finalcut::FWidget*, FDataPtr)
 {
   close();
 }
@@ -285,21 +285,21 @@ class MyDialog : public finalcut::FDialog
     virtual void onClose (finalcut::FCloseEvent*);
 
     // Callback methods
-    void cb_noFunctionMsg (finalcut::FWidget*, data_ptr);
-    void cb_about (finalcut::FWidget*, data_ptr);
-    void cb_terminfo (finalcut::FWidget*, data_ptr);
-    void cb_drives (finalcut::FWidget*, data_ptr);
-    void cb_cutClipboard (finalcut::FWidget*, data_ptr);
-    void cb_copyClipboard (finalcut::FWidget*, data_ptr);
-    void cb_pasteClipboard (finalcut::FWidget*, data_ptr);
-    void cb_clearInput (finalcut::FWidget*, data_ptr);
-    void cb_input2buttonText (finalcut::FWidget*, data_ptr);
-    void cb_setTitlebar (finalcut::FWidget*, data_ptr);
-    void cb_ProgressBar (finalcut::FWidget*, data_ptr);
-    void cb_updateNumber (finalcut::FWidget*, data_ptr);
-    void cb_activateButton (finalcut::FWidget*, data_ptr);
-    void cb_view (finalcut::FWidget*, data_ptr);
-    void cb_setInput (finalcut::FWidget*, data_ptr);
+    void cb_noFunctionMsg (finalcut::FWidget*, FDataPtr);
+    void cb_about (finalcut::FWidget*, FDataPtr);
+    void cb_terminfo (finalcut::FWidget*, FDataPtr);
+    void cb_drives (finalcut::FWidget*, FDataPtr);
+    void cb_cutClipboard (finalcut::FWidget*, FDataPtr);
+    void cb_copyClipboard (finalcut::FWidget*, FDataPtr);
+    void cb_pasteClipboard (finalcut::FWidget*, FDataPtr);
+    void cb_clearInput (finalcut::FWidget*, FDataPtr);
+    void cb_input2buttonText (finalcut::FWidget*, FDataPtr);
+    void cb_setTitlebar (finalcut::FWidget*, FDataPtr);
+    void cb_ProgressBar (finalcut::FWidget*, FDataPtr);
+    void cb_updateNumber (finalcut::FWidget*, FDataPtr);
+    void cb_activateButton (finalcut::FWidget*, FDataPtr);
+    void cb_view (finalcut::FWidget*, FDataPtr);
+    void cb_setInput (finalcut::FWidget*, FDataPtr);
 
     // Data Members
     bool                      initialized{false};
@@ -442,21 +442,21 @@ void MyDialog::initFileMenuCallbacks()
   (
     "clicked",
     F_METHOD_CALLBACK (this, &MyDialog::cb_view),
-    static_cast<finalcut::FWidget::data_ptr>(&File1)
+    static_cast<FDataPtr>(&File1)
   );
 
   File2.addCallback
   (
     "clicked",
     F_METHOD_CALLBACK (this, &MyDialog::cb_view),
-    static_cast<finalcut::FWidget::data_ptr>(&File2)
+    static_cast<FDataPtr>(&File2)
   );
 
   File3.addCallback
   (
     "clicked",
     F_METHOD_CALLBACK (this, &MyDialog::cb_view),
-    static_cast<finalcut::FWidget::data_ptr>(&File3)
+    static_cast<FDataPtr>(&File3)
   );
 }
 
@@ -666,7 +666,7 @@ void MyDialog::initButtons()
   (
     "clicked",
     F_METHOD_CALLBACK (this, &MyDialog::cb_input2buttonText),
-    static_cast<finalcut::FWidget::data_ptr>(&myLineEdit)
+    static_cast<FDataPtr>(&myLineEdit)
   );
 
   MyButton5.addCallback
@@ -718,21 +718,21 @@ void MyDialog::initWidgetsCallbacks()
   (
     "toggled",
     F_METHOD_CALLBACK (this, &MyDialog::cb_activateButton),
-    static_cast<finalcut::FWidget::data_ptr>(&MyButton5)
+    static_cast<FDataPtr>(&MyButton5)
   );
 
   myList.addCallback
   (
     "clicked",
     F_METHOD_CALLBACK (this, &MyDialog::cb_setInput),
-    static_cast<finalcut::FWidget::data_ptr>(&myLineEdit)
+    static_cast<FDataPtr>(&myLineEdit)
   );
 
   myList.addCallback
   (
     "row-selected",
     F_METHOD_CALLBACK (this, &MyDialog::cb_updateNumber),
-    static_cast<finalcut::FWidget::data_ptr>(&tagged_count)
+    static_cast<FDataPtr>(&tagged_count)
   );
 }
 
@@ -761,7 +761,7 @@ void MyDialog::onClose (finalcut::FCloseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_noFunctionMsg (finalcut::FWidget* widget, data_ptr)
+void MyDialog::cb_noFunctionMsg (finalcut::FWidget* widget, FDataPtr)
 {
   auto& button = *(static_cast<finalcut::FButton*>(widget));
   auto text = button.getText();
@@ -772,7 +772,7 @@ void MyDialog::cb_noFunctionMsg (finalcut::FWidget* widget, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_about (finalcut::FWidget*, data_ptr)
+void MyDialog::cb_about (finalcut::FWidget*, FDataPtr)
 {
   constexpr char libver[] = F_VERSION;
   const finalcut::FString line(2, finalcut::fc::BoxDrawingsHorizontal);
@@ -787,7 +787,7 @@ void MyDialog::cb_about (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_terminfo (finalcut::FWidget*, data_ptr)
+void MyDialog::cb_terminfo (finalcut::FWidget*, FDataPtr)
 {
   auto x = getDesktopWidth();
   auto y = getDesktopHeight();
@@ -808,7 +808,7 @@ void MyDialog::cb_terminfo (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_drives (finalcut::FWidget*, data_ptr)
+void MyDialog::cb_drives (finalcut::FWidget*, FDataPtr)
 {
   finalcut::FMessageBox info2 \
   (
@@ -859,7 +859,7 @@ void MyDialog::cb_drives (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_cutClipboard (finalcut::FWidget*, data_ptr)
+void MyDialog::cb_cutClipboard (finalcut::FWidget*, FDataPtr)
 {
   clipboard = myLineEdit.getText();
   myLineEdit.clear();
@@ -867,20 +867,20 @@ void MyDialog::cb_cutClipboard (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_copyClipboard (finalcut::FWidget*, data_ptr)
+void MyDialog::cb_copyClipboard (finalcut::FWidget*, FDataPtr)
 {
   clipboard = myLineEdit.getText();
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_pasteClipboard (finalcut::FWidget*, data_ptr)
+void MyDialog::cb_pasteClipboard (finalcut::FWidget*, FDataPtr)
 {
   myLineEdit = clipboard;
   myLineEdit.redraw();
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_clearInput (finalcut::FWidget*, data_ptr)
+void MyDialog::cb_clearInput (finalcut::FWidget*, FDataPtr)
 {
   clipboard.clear();
   myLineEdit.clear();
@@ -888,7 +888,7 @@ void MyDialog::cb_clearInput (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_input2buttonText (finalcut::FWidget* widget, data_ptr data)
+void MyDialog::cb_input2buttonText (finalcut::FWidget* widget, FDataPtr data)
 {
   auto& button = *(static_cast<finalcut::FButton*>(widget));
   const auto& lineedit = *(static_cast<finalcut::FLineEdit*>(data));
@@ -897,7 +897,7 @@ void MyDialog::cb_input2buttonText (finalcut::FWidget* widget, data_ptr data)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_setTitlebar (finalcut::FWidget* widget, data_ptr)
+void MyDialog::cb_setTitlebar (finalcut::FWidget* widget, FDataPtr)
 {
   auto& lineedit = *(static_cast<finalcut::FLineEdit*>(widget));
   finalcut::FString title;
@@ -908,14 +908,14 @@ void MyDialog::cb_setTitlebar (finalcut::FWidget* widget, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_ProgressBar (finalcut::FWidget*, data_ptr)
+void MyDialog::cb_ProgressBar (finalcut::FWidget*, FDataPtr)
 {
   auto p_dgl = new ProgressDialog(this);
   p_dgl->show();
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_updateNumber (finalcut::FWidget* widget, data_ptr data)
+void MyDialog::cb_updateNumber (finalcut::FWidget* widget, FDataPtr data)
 {
   auto& list = *(static_cast<finalcut::FListBox*>(widget));
   auto& num = *(static_cast<finalcut::FLabel*>(data));
@@ -932,7 +932,7 @@ void MyDialog::cb_updateNumber (finalcut::FWidget* widget, data_ptr data)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_activateButton (finalcut::FWidget* widget, data_ptr data)
+void MyDialog::cb_activateButton (finalcut::FWidget* widget, FDataPtr data)
 {
   auto& rb = *(static_cast<finalcut::FRadioButton*>(widget));
   auto& button = *(static_cast<finalcut::FButton*>(data));
@@ -946,7 +946,7 @@ void MyDialog::cb_activateButton (finalcut::FWidget* widget, data_ptr data)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_view (finalcut::FWidget*, data_ptr data)
+void MyDialog::cb_view (finalcut::FWidget*, FDataPtr data)
 {
   finalcut::FString file;
   auto item = static_cast<finalcut::FMenuItem*>(data);
@@ -984,7 +984,7 @@ void MyDialog::cb_view (finalcut::FWidget*, data_ptr data)
 }
 
 //----------------------------------------------------------------------
-void MyDialog::cb_setInput (finalcut::FWidget* widget, data_ptr data)
+void MyDialog::cb_setInput (finalcut::FWidget* widget, FDataPtr data)
 {
   auto& ListBox = *(static_cast<finalcut::FListBox*>(widget));
   auto& lineedit = *(static_cast<finalcut::FLineEdit*>(data));
diff --git a/examples/watch.cpp b/examples/watch.cpp
index e5c13d40..f65aeb1c 100644
--- a/examples/watch.cpp
+++ b/examples/watch.cpp
@@ -54,8 +54,8 @@ class Watch : public finalcut::FDialog
     virtual void onClose (finalcut::FCloseEvent*);
 
     // Callback methods
-    void cb_clock (finalcut::FWidget*, data_ptr);
-    void cb_seconds (finalcut::FWidget*, data_ptr);
+    void cb_clock (finalcut::FWidget*, FDataPtr);
+    void cb_seconds (finalcut::FWidget*, FDataPtr);
 
   protected:
     // Method
@@ -153,7 +153,7 @@ void Watch::onClose (finalcut::FCloseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void Watch::cb_clock (finalcut::FWidget*, data_ptr)
+void Watch::cb_clock (finalcut::FWidget*, FDataPtr)
 {
   if ( clock_sw.isChecked() )
   {
@@ -169,7 +169,7 @@ void Watch::cb_clock (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void Watch::cb_seconds (finalcut::FWidget*, data_ptr)
+void Watch::cb_seconds (finalcut::FWidget*, FDataPtr)
 {
   if ( seconds_sw.isChecked() )
     sec = true;
diff --git a/examples/windows.cpp b/examples/windows.cpp
index 534f0ce2..526bd649 100644
--- a/examples/windows.cpp
+++ b/examples/windows.cpp
@@ -179,8 +179,8 @@ class Window : public finalcut::FDialog
 
   private:
     // Typedefs
-    typedef void (Window::*WindowCallback)(finalcut::FWidget*, data_ptr);
-    typedef void (finalcut::FApplication::*FAppCallback)(finalcut::FWidget*, data_ptr);
+    typedef void (Window::*WindowCallback)(finalcut::FWidget*, FDataPtr);
+    typedef void (finalcut::FApplication::*FAppCallback)(finalcut::FWidget*, FDataPtr);
 
     struct win_data
     {
@@ -210,11 +210,11 @@ class Window : public finalcut::FDialog
     virtual void onClose (finalcut::FCloseEvent*);
 
     // Callback methods
-    void cb_createWindows (finalcut::FWidget*, data_ptr);
-    void cb_closeWindows (finalcut::FWidget*, data_ptr);
-    void cb_next (finalcut::FWidget*, data_ptr);
-    void cb_previous (finalcut::FWidget*, data_ptr);
-    void cb_destroyWindow (finalcut::FWidget*, data_ptr);
+    void cb_createWindows (finalcut::FWidget*, FDataPtr);
+    void cb_closeWindows (finalcut::FWidget*, FDataPtr);
+    void cb_next (finalcut::FWidget*, FDataPtr);
+    void cb_previous (finalcut::FWidget*, FDataPtr);
+    void cb_destroyWindow (finalcut::FWidget*, FDataPtr);
 
     // Data Members
     std::vector<win_data*>    windows{};
@@ -405,7 +405,7 @@ void Window::onClose (finalcut::FCloseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void Window::cb_createWindows (finalcut::FWidget*, data_ptr)
+void Window::cb_createWindows (finalcut::FWidget*, FDataPtr)
 {
   auto first = windows.begin();
   auto iter = first;
@@ -435,7 +435,7 @@ void Window::cb_createWindows (finalcut::FWidget*, data_ptr)
       (
         "destroy",
         F_METHOD_CALLBACK (this, &Window::cb_destroyWindow),
-        static_cast<finalcut::FWidget::data_ptr>(win_dat)
+        static_cast<FDataPtr>(win_dat)
       );
     }
 
@@ -446,7 +446,7 @@ void Window::cb_createWindows (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void Window::cb_closeWindows (finalcut::FWidget*, data_ptr)
+void Window::cb_closeWindows (finalcut::FWidget*, FDataPtr)
 {
   if ( ! dialog_list || dialog_list->empty() )
     return;
@@ -466,7 +466,7 @@ void Window::cb_closeWindows (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void Window::cb_next (finalcut::FWidget*, data_ptr)
+void Window::cb_next (finalcut::FWidget*, FDataPtr)
 {
   if ( ! dialog_list || dialog_list->empty() )
     return;
@@ -502,7 +502,7 @@ void Window::cb_next (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void Window::cb_previous (finalcut::FWidget*, data_ptr)
+void Window::cb_previous (finalcut::FWidget*, FDataPtr)
 {
   if ( ! dialog_list || dialog_list->empty() )
     return;
@@ -539,7 +539,7 @@ void Window::cb_previous (finalcut::FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void Window::cb_destroyWindow (finalcut::FWidget*, data_ptr data)
+void Window::cb_destroyWindow (finalcut::FWidget*, FDataPtr data)
 {
   auto win_dat = static_cast<win_data*>(data);
 
diff --git a/src/fbuttongroup.cpp b/src/fbuttongroup.cpp
index bd878b22..0d08b8d1 100644
--- a/src/fbuttongroup.cpp
+++ b/src/fbuttongroup.cpp
@@ -381,7 +381,7 @@ void FButtonGroup::onFocusIn (FFocusEvent* in_ev)
 }
 
 //----------------------------------------------------------------------
-void FButtonGroup::cb_buttonToggled (FWidget* widget, data_ptr)
+void FButtonGroup::cb_buttonToggled (FWidget* widget, FDataPtr)
 {
   auto button = static_cast<FToggleButton*>(widget);
 
diff --git a/src/fdialog.cpp b/src/fdialog.cpp
index 6be9436f..7d7b1c55 100644
--- a/src/fdialog.cpp
+++ b/src/fdialog.cpp
@@ -1646,7 +1646,7 @@ void FDialog::delDialog (FWidget* obj)
 }
 
 //----------------------------------------------------------------------
-void FDialog::cb_move (FWidget*, data_ptr)
+void FDialog::cb_move (FWidget*, FDataPtr)
 {
   if ( isZoomed() )
     return;
@@ -1697,7 +1697,7 @@ void FDialog::cb_move (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FDialog::cb_zoom (FWidget*, data_ptr)
+void FDialog::cb_zoom (FWidget*, FDataPtr)
 {
   dialog_menu->unselectItem();
   dialog_menu->hide();
@@ -1708,7 +1708,7 @@ void FDialog::cb_zoom (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FDialog::cb_close (FWidget*, data_ptr)
+void FDialog::cb_close (FWidget*, FDataPtr)
 {
   dialog_menu->unselectItem();
   dialog_menu->hide();
diff --git a/src/fevent.cpp b/src/fevent.cpp
index 21d36d83..e9edd8a0 100644
--- a/src/fevent.cpp
+++ b/src/fevent.cpp
@@ -369,11 +369,11 @@ int FUserEvent::getUserId() const
 { return uid; }
 
 //----------------------------------------------------------------------
-FUserEvent::data_ptr FUserEvent::getData() const
+FDataPtr FUserEvent::getData() const
 { return data_pointer; }
 
 //----------------------------------------------------------------------
-void FUserEvent::setData (data_ptr data)
+void FUserEvent::setData (FDataPtr data)
 { data_pointer = data; }
 
 }  // namespace finalcut
diff --git a/src/ffiledialog.cpp b/src/ffiledialog.cpp
index 48c5d55c..b111923c 100644
--- a/src/ffiledialog.cpp
+++ b/src/ffiledialog.cpp
@@ -748,7 +748,7 @@ const FString FFileDialog::getHomeDir()
 }
 
 //----------------------------------------------------------------------
-void FFileDialog::cb_processActivate (FWidget*, data_ptr)
+void FFileDialog::cb_processActivate (FWidget*, FDataPtr)
 {
   if ( filename.getText().includes('*')
     || filename.getText().includes('?') )
@@ -796,7 +796,7 @@ void FFileDialog::cb_processActivate (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FFileDialog::cb_processRowChanged (FWidget*, data_ptr)
+void FFileDialog::cb_processRowChanged (FWidget*, FDataPtr)
 {
   const std::size_t n = filebrowser.currentItem();
 
@@ -814,7 +814,7 @@ void FFileDialog::cb_processRowChanged (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FFileDialog::cb_processClicked (FWidget*, data_ptr)
+void FFileDialog::cb_processClicked (FWidget*, FDataPtr)
 {
   const uLong n = uLong(filebrowser.currentItem() - 1);
 
@@ -825,19 +825,19 @@ void FFileDialog::cb_processClicked (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FFileDialog::cb_processCancel (FWidget*, data_ptr)
+void FFileDialog::cb_processCancel (FWidget*, FDataPtr)
 {
   done (FDialog::Reject);
 }
 
 //----------------------------------------------------------------------
-void FFileDialog::cb_processOpen (FWidget*, data_ptr)
+void FFileDialog::cb_processOpen (FWidget*, FDataPtr)
 {
   done (FDialog::Accept);
 }
 
 //----------------------------------------------------------------------
-void FFileDialog::cb_processShowHidden (FWidget*, data_ptr)
+void FFileDialog::cb_processShowHidden (FWidget*, FDataPtr)
 {
   setShowHiddenFiles(! show_hidden);
 }
diff --git a/src/flabel.cpp b/src/flabel.cpp
index 6c19272f..e9e48471 100644
--- a/src/flabel.cpp
+++ b/src/flabel.cpp
@@ -342,7 +342,7 @@ void FLabel::onAccel (FAccelEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void FLabel::cb_accel_widget_destroyed (FWidget*, data_ptr)
+void FLabel::cb_accel_widget_destroyed (FWidget*, FDataPtr)
 {
   accel_widget = nullptr;
   delAccelerator();
diff --git a/src/flistbox.cpp b/src/flistbox.cpp
index 34778dac..a9ca484b 100644
--- a/src/flistbox.cpp
+++ b/src/flistbox.cpp
@@ -48,7 +48,7 @@ FListBoxItem::FListBoxItem (const FListBoxItem& item)
 { }
 
 //----------------------------------------------------------------------
-FListBoxItem::FListBoxItem (const FString& txt, FWidget::data_ptr data)
+FListBoxItem::FListBoxItem (const FString& txt, FDataPtr data)
   : text(txt)
   , data_pointer(data)
 { }
@@ -264,7 +264,7 @@ void FListBox::insert (FListBoxItem listItem)
 void FListBox::insert ( const FString& item
                       , fc::brackets_type b
                       , bool s
-                      , data_ptr d )
+                      , FDataPtr d )
 {
   FListBoxItem listItem (item, d);
   listItem.brackets = b;
@@ -276,7 +276,7 @@ void FListBox::insert ( const FString& item
 void FListBox::insert ( long item
                       , fc::brackets_type b
                       , bool s
-                      , data_ptr d )
+                      , FDataPtr d )
 {
   insert (FString() << item, b, s, d);
 }
@@ -1846,7 +1846,7 @@ void FListBox::lazyConvert(listBoxItems::iterator iter, int y)
 }
 
 //----------------------------------------------------------------------
-void FListBox::cb_VBarChange (FWidget*, data_ptr)
+void FListBox::cb_VBarChange (FWidget*, FDataPtr)
 {
   FScrollbar::sType scrollType;
   std::size_t current_before = current;
@@ -1913,7 +1913,7 @@ void FListBox::cb_VBarChange (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FListBox::cb_HBarChange (FWidget*, data_ptr)
+void FListBox::cb_HBarChange (FWidget*, FDataPtr)
 {
   static constexpr int padding_space = 2;  // 1 leading space + 1 trailing space
   FScrollbar::sType scrollType;
diff --git a/src/flistview.cpp b/src/flistview.cpp
index 9678f5ce..c092ed41 100644
--- a/src/flistview.cpp
+++ b/src/flistview.cpp
@@ -186,7 +186,7 @@ FListViewItem::FListViewItem (FObjectIterator parent_iter)
 
 //----------------------------------------------------------------------
 FListViewItem::FListViewItem ( const FStringList& cols
-                             , FWidget::data_ptr data
+                             , FDataPtr data
                              , FObjectIterator parent_iter )
   : FObject(0)
   , column_list(cols)
@@ -788,7 +788,7 @@ FObject::FObjectIterator FListView::insert ( FListViewItem* item
 
 //----------------------------------------------------------------------
 FObject::FObjectIterator FListView::insert ( const FStringList& cols
-                                           , data_ptr d
+                                           , FDataPtr d
                                            , FObjectIterator parent_iter )
 {
   FListViewItem* item;
@@ -815,7 +815,7 @@ FObject::FObjectIterator FListView::insert ( const FStringList& cols
 
 //----------------------------------------------------------------------
 FObject::FObjectIterator FListView::insert ( const std::vector<long>& cols
-                                           , data_ptr d
+                                           , FDataPtr d
                                            , FObjectIterator parent_iter )
 {
   FStringList str_cols;
@@ -2504,7 +2504,7 @@ void FListView::scrollBy (int dx, int dy)
 }
 
 //----------------------------------------------------------------------
-void FListView::cb_VBarChange (FWidget*, data_ptr)
+void FListView::cb_VBarChange (FWidget*, FDataPtr)
 {
   FScrollbar::sType scrollType = vbar->getScrollType();
   int distance = 1
@@ -2564,7 +2564,7 @@ void FListView::cb_VBarChange (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FListView::cb_HBarChange (FWidget*, data_ptr)
+void FListView::cb_HBarChange (FWidget*, FDataPtr)
 {
   FScrollbar::sType scrollType = hbar->getScrollType();
   int distance = 1
diff --git a/src/fmenu.cpp b/src/fmenu.cpp
index 95411f58..a6b8dea3 100644
--- a/src/fmenu.cpp
+++ b/src/fmenu.cpp
@@ -312,7 +312,7 @@ void FMenu::onMouseMove (FMouseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void FMenu::cb_menuitem_toggled (FWidget* widget, data_ptr)
+void FMenu::cb_menuitem_toggled (FWidget* widget, FDataPtr)
 {
   auto menuitem = static_cast<FMenuItem*>(widget);
 
diff --git a/src/fmenubar.cpp b/src/fmenubar.cpp
index 6b7fd56a..a6718fde 100644
--- a/src/fmenubar.cpp
+++ b/src/fmenubar.cpp
@@ -215,7 +215,7 @@ void FMenuBar::onAccel (FAccelEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void FMenuBar::cb_item_deactivated (FWidget* widget, data_ptr)
+void FMenuBar::cb_item_deactivated (FWidget* widget, FDataPtr)
 {
   auto menuitem = static_cast<FMenuItem*>(widget);
 
diff --git a/src/fmenuitem.cpp b/src/fmenuitem.cpp
index 5486d1ac..559b1bb7 100644
--- a/src/fmenuitem.cpp
+++ b/src/fmenuitem.cpp
@@ -653,7 +653,7 @@ void FMenuItem::createDialogList (FMenu* winmenu)
         (
           "clicked",
           F_METHOD_CALLBACK (win_item, &FMenuItem::cb_switchToDialog),
-          static_cast<FWidget::data_ptr>(win)
+          static_cast<FDataPtr>(win)
         );
 
         win->addCallback
@@ -716,7 +716,7 @@ void FMenuItem::passMouseEvent ( T widget, FMouseEvent* ev
 }
 
 //----------------------------------------------------------------------
-void FMenuItem::cb_switchToDialog (FWidget*, data_ptr data)
+void FMenuItem::cb_switchToDialog (FWidget*, FDataPtr data)
 {
   auto win = static_cast<FDialog*>(data);
 
@@ -729,7 +729,7 @@ void FMenuItem::cb_switchToDialog (FWidget*, data_ptr data)
 }
 
 //----------------------------------------------------------------------
-void FMenuItem::cb_destroyDialog (FWidget* widget, data_ptr)
+void FMenuItem::cb_destroyDialog (FWidget* widget, FDataPtr)
 {
   auto win = static_cast<FDialog*>(widget);
   auto fapp = FApplication::getApplicationObject();
diff --git a/src/fmessagebox.cpp b/src/fmessagebox.cpp
index 7aa96dcc..131f8055 100644
--- a/src/fmessagebox.cpp
+++ b/src/fmessagebox.cpp
@@ -189,7 +189,7 @@ void FMessageBox::adjustSize()
 }
 
 //----------------------------------------------------------------------
-void FMessageBox::cb_processClick (FWidget*, data_ptr data)
+void FMessageBox::cb_processClick (FWidget*, FDataPtr data)
 {
   int reply = *(static_cast<int*>(data));
   done (reply);
@@ -281,7 +281,7 @@ inline void FMessageBox::initCallbacks()
     (
       "clicked",
       F_METHOD_CALLBACK (this, &FMessageBox::cb_processClick),
-      static_cast<FWidget::data_ptr>(&button_digit[0])
+      static_cast<FDataPtr>(&button_digit[0])
     );
   }
 
@@ -291,7 +291,7 @@ inline void FMessageBox::initCallbacks()
     (
       "clicked",
       F_METHOD_CALLBACK (this, &FMessageBox::cb_processClick),
-      static_cast<FWidget::data_ptr>(&button_digit[1])
+      static_cast<FDataPtr>(&button_digit[1])
     );
   }
 
@@ -301,7 +301,7 @@ inline void FMessageBox::initCallbacks()
     (
       "clicked",
       F_METHOD_CALLBACK (this, &FMessageBox::cb_processClick),
-      static_cast<FWidget::data_ptr>(&button_digit[2])
+      static_cast<FDataPtr>(&button_digit[2])
     );
   }
 }
diff --git a/src/fscrollview.cpp b/src/fscrollview.cpp
index ada1ed2b..2a011dd1 100644
--- a/src/fscrollview.cpp
+++ b/src/fscrollview.cpp
@@ -876,7 +876,7 @@ void FScrollView::setViewportCursor()
 }
 
 //----------------------------------------------------------------------
-void FScrollView::cb_VBarChange (FWidget*, data_ptr)
+void FScrollView::cb_VBarChange (FWidget*, FDataPtr)
 {
   FScrollbar::sType scrollType = vbar->getScrollType();
   int distance = 1;
@@ -928,7 +928,7 @@ void FScrollView::cb_VBarChange (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FScrollView::cb_HBarChange (FWidget*, data_ptr)
+void FScrollView::cb_HBarChange (FWidget*, FDataPtr)
 {
   FScrollbar::sType scrollType = hbar->getScrollType();
   int distance = 1;
diff --git a/src/fstatusbar.cpp b/src/fstatusbar.cpp
index 993d5758..17e5056b 100644
--- a/src/fstatusbar.cpp
+++ b/src/fstatusbar.cpp
@@ -479,7 +479,7 @@ void FStatusBar::onMouseMove (FMouseEvent* ev)
 }
 
 //----------------------------------------------------------------------
-void FStatusBar::cb_statuskey_activated (FWidget* widget, data_ptr)
+void FStatusBar::cb_statuskey_activated (FWidget* widget, FDataPtr)
 {
   if ( ! key_list.empty() )
   {
diff --git a/src/ftextview.cpp b/src/ftextview.cpp
index 3194f957..e369c3c5 100644
--- a/src/ftextview.cpp
+++ b/src/ftextview.cpp
@@ -781,7 +781,7 @@ inline void FTextView::drawVBar()
 }
 
 //----------------------------------------------------------------------
-void FTextView::cb_VBarChange (FWidget*, data_ptr)
+void FTextView::cb_VBarChange (FWidget*, FDataPtr)
 {
   FScrollbar::sType scrollType = vbar->getScrollType();
   int distance = 1;
@@ -837,7 +837,7 @@ void FTextView::cb_VBarChange (FWidget*, data_ptr)
 }
 
 //----------------------------------------------------------------------
-void FTextView::cb_HBarChange (FWidget*, data_ptr)
+void FTextView::cb_HBarChange (FWidget*, FDataPtr)
 {
   FScrollbar::sType scrollType = hbar->getScrollType();
   int distance = 1;
diff --git a/src/fwidget.cpp b/src/fwidget.cpp
index a04c3663..f51505f9 100644
--- a/src/fwidget.cpp
+++ b/src/fwidget.cpp
@@ -826,7 +826,7 @@ bool FWidget::close()
 //----------------------------------------------------------------------
 void FWidget::addCallback ( const FString& cb_signal
                           , FCallback cb_handler
-                          , data_ptr data )
+                          , FDataPtr data )
 {
   // add a (normal) function pointer as callback
   callback_data obj = { cb_signal, cb_handler, data };
@@ -837,7 +837,7 @@ void FWidget::addCallback ( const FString& cb_signal
 void FWidget::addCallback ( const FString& cb_signal
                           , FWidget* cb_instance
                           , FMemberCallback cb_handler
-                          , data_ptr data )
+                          , FDataPtr data )
 {
   // add a member function pointer as callback
   member_callback_data obj = { cb_signal, cb_instance, cb_handler, data };
diff --git a/src/include/final/fapplication.h b/src/include/final/fapplication.h
index 62e955ea..99febf82 100644
--- a/src/include/final/fapplication.h
+++ b/src/include/final/fapplication.h
@@ -124,7 +124,7 @@ class FApplication : public FWidget
     static void           closeConfirmationDialog (FWidget*, FCloseEvent*);
 
     // Callback method
-    void cb_exitApp (FWidget*, FWidget::data_ptr);
+    void cb_exitApp (FWidget*, FDataPtr);
 
   private:
     // Typedefs and Enumerations
@@ -206,7 +206,7 @@ inline char** FApplication::getArgv() const
 { return app_argv; }
 
 //----------------------------------------------------------------------
-inline void FApplication::cb_exitApp (FWidget*, FWidget::data_ptr)
+inline void FApplication::cb_exitApp (FWidget*, FDataPtr)
 { close(); }
 
 }  // namespace finalcut
diff --git a/src/include/final/fbuttongroup.h b/src/include/final/fbuttongroup.h
index 95b1f0c5..2b054bbb 100644
--- a/src/include/final/fbuttongroup.h
+++ b/src/include/final/fbuttongroup.h
@@ -117,7 +117,7 @@ class FButtonGroup : public FScrollView
     virtual void   onFocusIn (FFocusEvent*);
 
     // Callback method
-    void           cb_buttonToggled (FWidget*, data_ptr);
+    void           cb_buttonToggled (FWidget*, FDataPtr);
 
   protected:
     // Accessor
diff --git a/src/include/final/fdialog.h b/src/include/final/fdialog.h
index 8190c61d..37f2abc3 100644
--- a/src/include/final/fdialog.h
+++ b/src/include/final/fdialog.h
@@ -217,9 +217,9 @@ class FDialog : public FWindow
     static void         delDialog (FWidget*);
 
     // Callback methods
-    void                cb_move (FWidget*, data_ptr);
-    void                cb_zoom (FWidget*, data_ptr);
-    void                cb_close (FWidget*, data_ptr);
+    void                cb_move (FWidget*, FDataPtr);
+    void                cb_zoom (FWidget*, FDataPtr);
+    void                cb_close (FWidget*, FDataPtr);
 
     // Data Members
     FString             tb_text{};  // title bar text
diff --git a/src/include/final/fevent.h b/src/include/final/fevent.h
index d77b4428..fb754679 100644
--- a/src/include/final/fevent.h
+++ b/src/include/final/fevent.h
@@ -78,6 +78,7 @@
 
 #include "final/fc.h"
 #include "final/fpoint.h"
+#include "final/ftypes.h"
 
 namespace finalcut
 {
@@ -352,20 +353,17 @@ class FTimerEvent : public FEvent  // timer event
 class FUserEvent : public FEvent  // timer event
 {
   public:
-    // Typedef
-    typedef void* data_ptr;
-
     FUserEvent() = default;
     FUserEvent (fc::events, int);
     ~FUserEvent();
 
     int getUserId() const;
-    data_ptr getData() const;
-    void setData (data_ptr);
+    FDataPtr getData() const;
+    void setData (FDataPtr);
 
   protected:
     int uid;
-    data_ptr data_pointer{nullptr};
+    FDataPtr data_pointer{nullptr};
 };
 
 #pragma pack(pop)
diff --git a/src/include/final/ffiledialog.h b/src/include/final/ffiledialog.h
index 847b8c6b..94a1ead4 100644
--- a/src/include/final/ffiledialog.h
+++ b/src/include/final/ffiledialog.h
@@ -180,12 +180,12 @@ class FFileDialog : public FDialog
     static const FString getHomeDir();
 
     // Callback methods
-    void          cb_processActivate (FWidget*, data_ptr);
-    void          cb_processRowChanged (FWidget*, data_ptr);
-    void          cb_processClicked (FWidget*, data_ptr);
-    void          cb_processCancel (FWidget*, data_ptr);
-    void          cb_processOpen (FWidget*, data_ptr);
-    void          cb_processShowHidden (FWidget*, data_ptr);
+    void          cb_processActivate (FWidget*, FDataPtr);
+    void          cb_processRowChanged (FWidget*, FDataPtr);
+    void          cb_processClicked (FWidget*, FDataPtr);
+    void          cb_processCancel (FWidget*, FDataPtr);
+    void          cb_processOpen (FWidget*, FDataPtr);
+    void          cb_processShowHidden (FWidget*, FDataPtr);
 
     // Data Members
     DIR*          directory_stream{nullptr};
diff --git a/src/include/final/flabel.h b/src/include/final/flabel.h
index 0be75abc..89afe013 100644
--- a/src/include/final/flabel.h
+++ b/src/include/final/flabel.h
@@ -135,7 +135,7 @@ class FLabel : public FWidget
     virtual void       onAccel (FAccelEvent*);
 
     // Callback method
-    void               cb_accel_widget_destroyed (FWidget*, data_ptr);
+    void               cb_accel_widget_destroyed (FWidget*, FDataPtr);
 
   private:
     // Constants
diff --git a/src/include/final/flistbox.h b/src/include/final/flistbox.h
index 470cb1d7..148fa219 100644
--- a/src/include/final/flistbox.h
+++ b/src/include/final/flistbox.h
@@ -75,7 +75,7 @@ class FListBoxItem
     // Constructors
     FListBoxItem ();
     FListBoxItem (const FListBoxItem&);  // copy constructor
-    explicit FListBoxItem (const FString&, FWidget::data_ptr = nullptr);
+    explicit FListBoxItem (const FString&, FDataPtr = nullptr);
 
     // Destructor
     virtual ~FListBoxItem();
@@ -85,11 +85,11 @@ class FListBoxItem
 
     // Accessors
     virtual FString& getText();
-    virtual FWidget::data_ptr getData() const;
+    virtual FDataPtr getData() const;
 
     // Mutators
     void setText (const FString&);
-    void setData (FWidget::data_ptr);
+    void setData (FDataPtr);
 
     // Methods
     void clear();
@@ -100,7 +100,7 @@ class FListBoxItem
 
     // Data Members
     FString           text{};
-    FWidget::data_ptr data_pointer{nullptr};
+    FDataPtr          data_pointer{nullptr};
     fc::brackets_type brackets{fc::NoBrackets};
     bool              selected{false};
 };
@@ -113,7 +113,7 @@ inline FString& FListBoxItem::getText()
 { return text; }
 
 //----------------------------------------------------------------------
-inline FWidget::data_ptr FListBoxItem::getData() const
+inline FDataPtr FListBoxItem::getData() const
 { return data_pointer; }
 
 //----------------------------------------------------------------------
@@ -121,7 +121,7 @@ inline void FListBoxItem::setText (const FString& txt)
 { text = txt; }
 
 //----------------------------------------------------------------------
-inline void FListBoxItem::setData (FWidget::data_ptr data)
+inline void FListBoxItem::setData (FDataPtr data)
 { data_pointer = data; }
 
 //----------------------------------------------------------------------
@@ -206,11 +206,11 @@ class FListBox : public FWidget
     void         insert ( const FString&
                         , fc::brackets_type = fc::NoBrackets
                         , bool = false
-                        , data_ptr = nullptr );
+                        , FDataPtr = nullptr );
     void         insert ( long
                         , fc::brackets_type = fc::NoBrackets
                         , bool = false
-                        , data_ptr = nullptr );
+                        , FDataPtr = nullptr );
     void         remove (std::size_t);
     void         clear();
 
@@ -296,17 +296,17 @@ class FListBox : public FWidget
     listBoxItems::iterator index2iterator (std::size_t);
 
     // Callback methods
-    void         cb_VBarChange (FWidget*, data_ptr);
-    void         cb_HBarChange (FWidget*, data_ptr);
+    void         cb_VBarChange (FWidget*, FDataPtr);
+    void         cb_HBarChange (FWidget*, FDataPtr);
 
     // Function Pointer
     void         (*convertToItem) ( FListBoxItem&
-                                  , FWidget::data_ptr
+                                  , FDataPtr
                                   , int index ){nullptr};
 
     // Data Members
     listBoxItems      itemlist{};
-    FWidget::data_ptr source_container{nullptr};
+    FDataPtr          source_container{nullptr};
     convert_type      conv_type{FListBox::no_convert};
     FScrollbarPtr     vbar{nullptr};
     FScrollbarPtr     hbar{nullptr};
diff --git a/src/include/final/flistview.h b/src/include/final/flistview.h
index 78ee2a5a..f020e615 100644
--- a/src/include/final/flistview.h
+++ b/src/include/final/flistview.h
@@ -81,7 +81,7 @@ class FListViewItem : public FObject
     FListViewItem (const FListViewItem&);  // copy constructor
     explicit FListViewItem (FObjectIterator);
     FListViewItem ( const FStringList&
-                  , FWidget::data_ptr
+                  , FDataPtr
                   , FObjectIterator );
 
     // Destructor
@@ -95,12 +95,12 @@ class FListViewItem : public FObject
     uInt              getColumnCount() const;
     int               getSortColumn() const;
     FString           getText (int) const;
-    FWidget::data_ptr getData() const;
+    FDataPtr          getData() const;
     uInt              getDepth() const;
 
     // Mutators
     void              setText (int, const FString&);
-    void              setData (FWidget::data_ptr);
+    void              setData (FDataPtr);
     void              setCheckable (bool);
     void              setChecked (bool);
 
@@ -129,7 +129,7 @@ class FListViewItem : public FObject
 
     // Data Members
     FStringList       column_list{};
-    FWidget::data_ptr data_pointer{nullptr};
+    FDataPtr          data_pointer{nullptr};
     FObjectIterator   root{};
     std::size_t       visible_lines{1};
     bool              expandable{false};
@@ -154,11 +154,11 @@ inline uInt FListViewItem::getColumnCount() const
 { return uInt(column_list.size()); }
 
 //----------------------------------------------------------------------
-inline FWidget::data_ptr FListViewItem::getData() const
+inline FDataPtr FListViewItem::getData() const
 { return data_pointer; }
 
 //----------------------------------------------------------------------
-inline void FListViewItem::setData (FWidget::data_ptr data)
+inline void FListViewItem::setData (FDataPtr data)
 { data_pointer = data; }
 
 //----------------------------------------------------------------------
@@ -317,18 +317,18 @@ class FListView : public FWidget
     FObjectIterator      insert (FListViewItem*);
     FObjectIterator      insert (FListViewItem*, FObjectIterator);
     FObjectIterator      insert ( const FStringList&
-                                , data_ptr = nullptr );
+                                , FDataPtr = nullptr );
     FObjectIterator      insert ( const FStringList&
                                 , FObjectIterator );
     FObjectIterator      insert ( const FStringList&
-                                , data_ptr
+                                , FDataPtr
                                 , FObjectIterator );
     FObjectIterator      insert ( const std::vector<long>&
-                                , data_ptr = nullptr );
+                                , FDataPtr = nullptr );
     FObjectIterator      insert ( const std::vector<long>&
                                 , FObjectIterator );
     FObjectIterator      insert ( const std::vector<long>&
-                                , data_ptr
+                                , FDataPtr
                                 , FObjectIterator );
     FObjectIterator      beginOfList();
     FObjectIterator      endOfList();
@@ -419,8 +419,8 @@ class FListView : public FWidget
     bool                 hasCheckableItems() const;
 
     // Callback methods
-    void                 cb_VBarChange (FWidget*, data_ptr);
-    void                 cb_HBarChange (FWidget*, data_ptr);
+    void                 cb_VBarChange (FWidget*, FDataPtr);
+    void                 cb_HBarChange (FWidget*, FDataPtr);
 
     // Data Members
     FObjectIterator      root{};
@@ -526,7 +526,7 @@ inline FObject::FObjectIterator FListView::insert (FListViewItem* item)
 
 //----------------------------------------------------------------------
 inline FObject::FObjectIterator
-    FListView::insert (const FStringList& cols, data_ptr d)
+    FListView::insert (const FStringList& cols, FDataPtr d)
 { return insert (cols, d, root); }
 
 //----------------------------------------------------------------------
@@ -537,7 +537,7 @@ inline FObject::FObjectIterator
 
 //----------------------------------------------------------------------
 inline FObject::FObjectIterator
-    FListView::insert (const std::vector<long>& cols, data_ptr d)
+    FListView::insert (const std::vector<long>& cols, FDataPtr d)
 { return insert (cols, d, root); }
 
 //----------------------------------------------------------------------
diff --git a/src/include/final/fmenu.h b/src/include/final/fmenu.h
index 01794232..8da190c0 100644
--- a/src/include/final/fmenu.h
+++ b/src/include/final/fmenu.h
@@ -127,7 +127,7 @@ class FMenu : public FWindow, public FMenuList
     virtual void        onAccel (FAccelEvent*);
 
     // Callback method
-    void                cb_menuitem_toggled (FWidget*, data_ptr);
+    void                cb_menuitem_toggled (FWidget*, FDataPtr);
 
   private:
     // Constants
diff --git a/src/include/final/fmenubar.h b/src/include/final/fmenubar.h
index 11466cd7..f8e6c17a 100644
--- a/src/include/final/fmenubar.h
+++ b/src/include/final/fmenubar.h
@@ -104,7 +104,7 @@ class FMenuBar : public FWindow, public FMenuList
     virtual void onAccel (FAccelEvent*);
 
     // Callback methods
-    void         cb_item_deactivated (FWidget*, data_ptr);
+    void         cb_item_deactivated (FWidget*, FDataPtr);
 
   private:
     // Constants
diff --git a/src/include/final/fmenuitem.h b/src/include/final/fmenuitem.h
index c96b9a34..f3d216de 100644
--- a/src/include/final/fmenuitem.h
+++ b/src/include/final/fmenuitem.h
@@ -179,8 +179,8 @@ class FMenuItem : public FWidget
     void         passMouseEvent (T, FMouseEvent*, fc::events);
 
     // Callback methods
-    void         cb_switchToDialog (FWidget*, data_ptr);
-    void         cb_destroyDialog (FWidget*, data_ptr);
+    void         cb_switchToDialog (FWidget*, FDataPtr);
+    void         cb_destroyDialog (FWidget*, FDataPtr);
 
     virtual void processClicked();
 
diff --git a/src/include/final/fmessagebox.h b/src/include/final/fmessagebox.h
index a87ad04f..a206ac25 100644
--- a/src/include/final/fmessagebox.h
+++ b/src/include/final/fmessagebox.h
@@ -140,7 +140,7 @@ class FMessageBox : public FDialog
     virtual void  adjustSize();
 
     // Callback method
-    void          cb_processClick (FWidget*, data_ptr);
+    void          cb_processClick (FWidget*, FDataPtr);
 
   private:
     // Methods
diff --git a/src/include/final/fscrollview.h b/src/include/final/fscrollview.h
index 9e375ba3..a33cb12a 100644
--- a/src/include/final/fscrollview.h
+++ b/src/include/final/fscrollview.h
@@ -175,8 +175,8 @@ class FScrollView : public FWidget
     void              drawVBar();
 
     // Callback methods
-    void              cb_VBarChange (FWidget*, data_ptr);
-    void              cb_HBarChange (FWidget*, data_ptr);
+    void              cb_VBarChange (FWidget*, FDataPtr);
+    void              cb_HBarChange (FWidget*, FDataPtr);
 
     // Data Members
     FRect             scroll_geometry{1, 1, 1, 1};
diff --git a/src/include/final/fstatusbar.h b/src/include/final/fstatusbar.h
index 6fa2d8b7..cdcff344 100644
--- a/src/include/final/fstatusbar.h
+++ b/src/include/final/fstatusbar.h
@@ -236,7 +236,7 @@ class FStatusBar : public FWindow
     virtual void        onMouseMove (FMouseEvent*);
 
     // Callback method
-    void                cb_statuskey_activated (FWidget*, data_ptr);
+    void                cb_statuskey_activated (FWidget*, FDataPtr);
 
   private:
     // Typedef
diff --git a/src/include/final/ftextview.h b/src/include/final/ftextview.h
index 015335b2..d6a568b6 100644
--- a/src/include/final/ftextview.h
+++ b/src/include/final/ftextview.h
@@ -145,8 +145,8 @@ class FTextView : public FWidget
     void               drawVBar();
 
     // Callback methods
-    void               cb_VBarChange (FWidget*, data_ptr);
-    void               cb_HBarChange (FWidget*, data_ptr);
+    void               cb_VBarChange (FWidget*, FDataPtr);
+    void               cb_HBarChange (FWidget*, FDataPtr);
 
     // Data Members
     FStringList        data{};
diff --git a/src/include/final/ftypes.h b/src/include/final/ftypes.h
index 045f4867..e680d308 100644
--- a/src/include/final/ftypes.h
+++ b/src/include/final/ftypes.h
@@ -58,6 +58,7 @@ typedef long double    lDouble;
 
 typedef uInt16         FColor;
 typedef uInt32         FKey;
+typedef void*          FDataPtr;
 
 }  // namespace
 
diff --git a/src/include/final/fwidget.h b/src/include/final/fwidget.h
index a509878d..28f623be 100644
--- a/src/include/final/fwidget.h
+++ b/src/include/final/fwidget.h
@@ -138,10 +138,9 @@ class FWidget : public FVTerm, public FObject
 
     // Typedefs
     typedef std::vector<FWidget*> widgetList;
-    typedef void* data_ptr;
-    typedef void (*FCallback)(FWidget*, data_ptr);
-    typedef void (FWidget::*FMemberCallback)(FWidget*, data_ptr);
     typedef std::vector<accelerator> Accelerators;
+    typedef void (*FCallback)(FWidget*, FDataPtr);
+    typedef void (FWidget::*FMemberCallback)(FWidget*, FDataPtr);
 
     struct widget_flags  // Properties of a widget ⚑
     {
@@ -307,11 +306,11 @@ class FWidget : public FVTerm, public FObject
     void               clearStatusbarMessage();
     void               addCallback ( const FString&
                                    , FCallback
-                                   , data_ptr = nullptr );
+                                   , FDataPtr = nullptr );
     void               addCallback ( const FString&
                                    , FWidget*
                                    , FMemberCallback
-                                   , data_ptr = nullptr );
+                                   , FDataPtr = nullptr );
     void               delCallback (FCallback);
     void               delCallback (FWidget*);
     void               delCallbacks();
@@ -347,7 +346,7 @@ class FWidget : public FVTerm, public FObject
     {
       FString   cb_signal;
       FCallback cb_handler;
-      data_ptr  data;
+      FDataPtr  data;
     };
 
     struct member_callback_data
@@ -355,7 +354,7 @@ class FWidget : public FVTerm, public FObject
       FString         cb_signal;
       FWidget*        cb_instance;
       FMemberCallback cb_handler;
-      data_ptr        data;
+      FDataPtr        data;
     };
 
     // Typedefs