Fix and update alignment #346 (#701)

* interactive layout alignment rewritten
* interface for new alignment rules
* new alignment dialog box
* user defined layout rules added
* layout rules can be stored in projects, settings, and external files
* Valgrind verification

FL/Fl_Gl_Window.H

@@ -207,7 +207,8 @@ public:
   void make_overlay_current();
 
   // Note: Doxygen docs in Fl_Widget.H to avoid redundancy.
-  Fl_Gl_Window* as_gl_window() FL_OVERRIDE {return this;}
+  Fl_Gl_Window* as_gl_window() FL_OVERRIDE { return this; }
+  Fl_Gl_Window const* as_gl_window() const FL_OVERRIDE { return this; }
 
   float pixels_per_unit();
   /** Gives the window width in OpenGL pixels.

FL/Fl_Group.H

@@ -228,6 +228,7 @@ public:
 
   // Note: Doxygen docs in Fl_Widget.H to avoid redundancy.
   Fl_Group* as_group() FL_OVERRIDE { return this; }
+  Fl_Group const* as_group() const FL_OVERRIDE { return this; }
 
   // back compatibility functions:
 

FL/Fl_Menu_Item.H

@@ -317,6 +317,10 @@ struct FL_EXPORT Fl_Menu_Item {
         before FLTK 1.4.0.
   */
   int value() const {return (flags & FL_MENU_VALUE) ? 1 : 0;}
+
+  /** Sets the current value of the check or radio item. */
+  void value(int v) { v ? set() : clear(); }
+
   /**
     Turns the check or radio item "on" for the menu item. Note that this
     does not turn off any adjacent radio items like setonly() does.
@@ -326,7 +330,7 @@ struct FL_EXPORT Fl_Menu_Item {
   /** Turns the check or radio item "off" for the menu item. */
   void clear() {flags &= ~FL_MENU_VALUE;}
 
-  void setonly();
+  void setonly(Fl_Menu_Item const* first = NULL);
 
   /** Gets the visibility of an item. */
   int visible() const {return !(flags&FL_MENU_INVISIBLE);}

FL/Fl_Widget.H

@@ -1091,7 +1091,8 @@ public:
       \note This method is provided to avoid dynamic_cast.
       \see Fl_Widget::as_window(), Fl_Widget::as_gl_window()
    */
-  virtual Fl_Group* as_group() {return 0;}
+  virtual Fl_Group* as_group() { return NULL; }
+  virtual Fl_Group const* as_group() const { return NULL; }
 
   /** Returns an Fl_Window pointer if this widget is an Fl_Window.
 
@@ -1105,7 +1106,8 @@ public:
       \note This method is provided to avoid dynamic_cast.
       \see Fl_Widget::as_group(), Fl_Widget::as_gl_window()
    */
-  virtual Fl_Window* as_window() {return 0;}
+  virtual Fl_Window* as_window() { return 0; }
+  virtual Fl_Window const* as_window() const { return NULL; }
 
   /** Returns an Fl_Gl_Window pointer if this widget is an Fl_Gl_Window.
 
@@ -1117,7 +1119,8 @@ public:
       \note This method is provided to avoid dynamic_cast.
       \see Fl_Widget::as_group(), Fl_Widget::as_window()
    */
-  virtual class Fl_Gl_Window* as_gl_window() {return 0;}
+  virtual class Fl_Gl_Window* as_gl_window() { return NULL; }
+  virtual class Fl_Gl_Window const* as_gl_window() const { return NULL; }
 
   /** Returns non zero if MAC_USE_ACCENTS_MENU flag is set, 0 otherwise.
    */

FL/Fl_Window.H

@@ -560,6 +560,7 @@ public:
 
   // Note: Doxygen docs in Fl_Widget.H to avoid redundancy.
   Fl_Window* as_window() FL_OVERRIDE { return this; }
+  Fl_Window const* as_window() const FL_OVERRIDE { return this; }
 
   /**
    Return non-null if this is an Fl_Overlay_Window object.