Assign the PageDisplay on initialization

apps/openmw/mwgui/bookpage.cpp

@@ -1252,72 +1252,65 @@ class BookPageImpl : public BookPage
 MYGUI_RTTI_DERIVED(BookPage)
 public:
 
+    BookPageImpl()
+        : mPageDisplay(NULL)
+    {
+    }
+
     void showPage (TypesetBook::Ptr book, size_t page)
     {
-        if (PageDisplay* pd = dynamic_cast <PageDisplay*> (getSubWidgetText ()))
-            pd->showPage (book, page);
-        else
-            throw std::runtime_error ("The main sub-widget for a BookPage must be a PageDisplay.");
+        mPageDisplay->showPage (book, page);
     }
 
     void adviseLinkClicked (boost::function <void (InteractiveId)> linkClicked)
     {
-        if (PageDisplay* pd = dynamic_cast <PageDisplay*> (getSubWidgetText ()))
-        {
-            pd->mLinkClicked = linkClicked;
-        }
+        mPageDisplay->mLinkClicked = linkClicked;
     }
 
     void unadviseLinkClicked ()
     {
-        if (PageDisplay* pd = dynamic_cast <PageDisplay*> (getSubWidgetText ()))
+        mPageDisplay->mLinkClicked = boost::function <void (InteractiveId)> ();
+    }
+
+protected:
+
+    virtual void initialiseOverride()
+    {
+        Base::initialiseOverride();
+
+        if (getSubWidgetText())
+        {
+            mPageDisplay = getSubWidgetText()->castType<PageDisplay>();
+        }
+        else
         {
-            pd->mLinkClicked = boost::function <void (InteractiveId)> ();
+            throw std::runtime_error("BookPage unable to find page display sub widget");
         }
     }
 
-protected:
     void onMouseLostFocus(Widget* _new)
     {
         // NOTE: MyGUI also fires eventMouseLostFocus for widgets that are about to be destroyed (if they had focus).
         // Child widgets may already be destroyed! So be careful.
-        if (PageDisplay* pd = dynamic_cast <PageDisplay*> (getSubWidgetText ()))
-        {
-            pd->onMouseLostFocus ();
-        }
-        else
-            Widget::onMouseLostFocus (_new);
+        mPageDisplay->onMouseLostFocus ();
     }
 
     void onMouseMove(int left, int top)
     {
-        if (PageDisplay* pd = dynamic_cast <PageDisplay*> (getSubWidgetText ()))
-        {
-            pd->onMouseMove (left, top);
-        }
-        else
-            Widget::onMouseMove (left, top);
+        mPageDisplay->onMouseMove (left, top);
     }
 
     void onMouseButtonPressed (int left, int top, MyGUI::MouseButton id)
     {
-        if (PageDisplay* pd = dynamic_cast <PageDisplay*> (getSubWidgetText ()))
-        {
-            pd->onMouseButtonPressed (left, top, id);
-        }
-        else
-            Widget::onMouseButtonPressed (left, top, id);
+        mPageDisplay->onMouseButtonPressed (left, top, id);
     }
 
     void onMouseButtonReleased(int left, int top, MyGUI::MouseButton id)
     {
-        if (PageDisplay* pd = dynamic_cast <PageDisplay*> (getSubWidgetText ()))
-        {
-            pd->onMouseButtonReleased (left, top, id);
-        }
-        else
-            Widget::onMouseButtonReleased (left, top, id);
+        mPageDisplay->onMouseButtonReleased (left, top, id);
     }
+
+    PageDisplay* mPageDisplay;
 };
 
 void BookPage::registerMyGUIComponents ()