Dynamically update list of tabs in arenas screen, to better handle when addons arenas are first installed

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@10142 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/states_screens/arenas_screen.cpp

@@ -49,6 +49,13 @@ ArenasScreen::ArenasScreen() : Screen("arenas.stkgui")
 
 void ArenasScreen::loadedFromFile()
 {
+}
+
+// ------------------------------------------------------------------------------------------------------
+
+void ArenasScreen::beforeAddingWidget()
+{
+    
     // Dynamically add tabs
     RibbonWidget* tabs = this->getWidget<RibbonWidget>("trackgroups");
     assert( tabs != NULL );
@@ -90,8 +97,7 @@ void ArenasScreen::loadedFromFile()
     DynamicRibbonWidget* tracks_widget = this->getWidget<DynamicRibbonWidget>("tracks");
     assert( tracks_widget != NULL );
     tracks_widget->setItemCountHint(num_of_arenas); //set the item hint to that number to prevent weird formatting
-    
-}   // ArenasScreen
+}
 
 // ------------------------------------------------------------------------------------------------------
 

src/states_screens/arenas_screen.hpp

@@ -36,6 +36,9 @@ class ArenasScreen : public GUIEngine::Screen, public GUIEngine::ScreenSingleton
 
 public:
     
+    /** \brief implement callback from parent class GUIEngine::Screen */
+    virtual void beforeAddingWidget();
+    
     /** \brief implement callback from parent class GUIEngine::Screen */
     virtual void loadedFromFile();