Window functions to retrieve more detailed window type

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3-porting@11358 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

FL/Fl_Double_Window.H

@@ -23,7 +23,6 @@
 #define Fl_Double_Window_H
 
 #include "Fl_Window.H"
-class Fl_Overlay_Window;
 
 /**
   The Fl_Double_Window provides a double-buffered window.
@@ -45,7 +44,6 @@ public:
   /**
     Return non-null if this is an Fl_Overlay_Window object.
   */
-  virtual Fl_Overlay_Window *as_overlay_window() {return NULL; }
   virtual Fl_Double_Window *as_double_window() {return this; }
   void show();
   void show(int a, char **b) {Fl_Window::show(a,b);}

FL/Fl_Widget.H

@@ -1010,8 +1010,8 @@ public:
       \see Fl_Widget::as_group(), Fl_Widget::as_window()
    */
   virtual class Fl_Gl_Window* as_gl_window() {return 0;}
-  
-  /** Returns non zero if MAC_USE_ACCENTS_MENU flag is set, 0 otherwise. 
+
+  /** Returns non zero if MAC_USE_ACCENTS_MENU flag is set, 0 otherwise.
    */
   int use_accents_menu() { return flags() & MAC_USE_ACCENTS_MENU; }
   

FL/Fl_Window.H

@@ -544,9 +544,6 @@ public:
   */
   void make_current();
 
-  // Note: Doxygen docs in Fl_Widget.H to avoid redundancy.
-  virtual Fl_Window* as_window() { return this; }
-
   /**
     Changes the cursor for this window.  This always calls the system, if
     you are changing the cursor a lot you may want to keep track of how
@@ -581,10 +578,19 @@ public:
 
   Fl_Window_Driver *driver() { return pWindowDriver; }
 
+  // Note: Doxygen docs in Fl_Widget.H to avoid redundancy.
+  virtual Fl_Window* as_window() { return this; }
+
+  /**
+   Return non-null if this is an Fl_Overlay_Window object.
+   */
+  virtual class Fl_Overlay_Window *as_overlay_window() {return 0L; }
+
   /**
    Return non-null if this is an Fl_Double_Window object.
    */
-  virtual Fl_Double_Window *as_double_window() {return NULL;}
+  virtual class Fl_Double_Window *as_double_window() {return 0L;}
+  
   void shape(const Fl_Image* img);
   void shape(const Fl_Image& b) ;
   int is_shaped();