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[wxWidgets.git] / docs / latex / wx / truntime.tex

diff --git a/docs/latex/wx/truntime.tex b/docs/latex/wx/truntime.tex
index b6c9e8e746d9f46341b33a6ee3171edb05b745ce..04ee1e02a7a5ed06bcbf99d2c6608b5c3e89a6eb 100644 (file)
--- a/docs/latex/wx/truntime.tex
+++ b/docs/latex/wx/truntime.tex
@@ -1,22 +1,34 @@
-\section{Run time class information overview}\label{runtimeclassoverview}
+\section{Runtime class information (aka RTTI) overview}\label{runtimeclassoverview}
 
 Classes: \helpref{wxObject}{wxobject}, \helpref{wxClassInfo}{wxclassinfo}.
 
-One of the failings of C++ is that no run-time information is provided
+One of the failings of C++ used to be that no run-time information was provided
 about a class and its position in the inheritance hierarchy.
-Another is that instances of a class cannot be created just by knowing the name of a class,
-which makes facilities such as persistent storage hard to implement.
+Another, which still persists, is that instances of a class cannot be created
+just by knowing the name of a class, which makes facilities such as persistent
+storage hard to implement.
 
 Most C++ GUI frameworks overcome these limitations by means of a set of
-macros and functions and wxWindows is no exception.
-Each class that you wish to be known the type system should have
+macros and functions and wxWidgets is no exception. As it originated before the
+addition of RTTI to the C++ standard and as support for it is still missing from
+some (albeit old) compilers, wxWidgets doesn't (yet) use it, but provides its
+own macro-based RTTI system.
+
+In the future, the standard C++ RTTI will be used though and you're encouraged
+to use whenever possible the \helpref{wxDynamicCast()}{wxdynamiccast} macro which,
+for the implementations that support it, is defined just as dynamic\_cast<> and
+uses wxWidgets RTTI for all the others. This macro is limited to wxWidgets
+classes only and only works with pointers (unlike the real dynamic\_cast<> which
+also accepts references).
+
+Each class that you wish to be known to the type system should have
 a macro such as DECLARE\_DYNAMIC\_CLASS just inside the class declaration.
 The macro IMPLEMENT\_DYNAMIC\_CLASS should be in the implementation file.
 Note that these are entirely optional; use them if you wish to check object
 types, or create instances of classes using the class name. However,
 it is good to get into the habit of adding these macros for all classes.
 
-Variations on these \helpref{macros}{macros} are used for multiple inheritance, and abstract
+Variations on these \helpref{macros}{rttimacros} are used for multiple inheritance, and abstract
 classes that cannot be instantiated dynamically or otherwise.
 
 DECLARE\_DYNAMIC\_CLASS inserts a static wxClassInfo declaration into the
@@ -31,18 +43,18 @@ dynamic object of the class in question. A pointer to this function is
 stored in wxClassInfo, and is used when an object should be created
 dynamically.
 
-wxObject::IsKindOf uses the linked list of wxClassInfo. It takes
-a wxClassInfo argument, so use CLASSINFO(className) to return an
-appropriate wxClassInfo pointer to use in this function.
+\helpref{wxObject::IsKindOf}{wxobjectiskindof} uses the linked list of
+wxClassInfo. It takes a wxClassInfo argument, so use CLASSINFO(className)
+to return an appropriate wxClassInfo pointer to use in this function.
 
 The function \helpref{wxCreateDynamicObject}{wxcreatedynamicobject} can be used
 to construct a new object of a given type, by supplying a string name.
 If you have a pointer to the wxClassInfo object instead, then you
-can simply call wxClassInfo::CreateObject.
+can simply call \helpref{wxClassInfo::CreateObject}{wxclassinfocreateobject}.
 
 \subsection{wxClassInfo}\label{wxclassinfooverview}
 
-\overview{Run time class information overview}{runtimeclassoverview}
+\overview{Runtime class information (aka RTTI) overview}{runtimeclassoverview}
 
 Class: \helpref{wxClassInfo}{wxclassinfo}
 
@@ -66,28 +78,29 @@ You can get the wxClassInfo for an object using wxObject::GetClassInfo.
 
 See also \helpref{wxObject}{wxobject} and \helpref{wxCreateDynamicObject}{wxcreatedynamicobject}.
 
-\subsection{Example}
+\subsection{Example}\label{runtimeclassinformationexample}
 
-In a header file wx\_frame.h:
+In a header file frame.h:
 
 \begin{verbatim}
-class wxFrame: public wxWindow
+class wxFrame : public wxWindow
 {
-  DECLARE_DYNAMIC_CLASS(wxFrame)
+DECLARE_DYNAMIC_CLASS(wxFrame)
 
- private:
-  char *frameTitle;
- public:
-  ...
+private:
+    wxString m_title;
+
+public:
+    ...
 };
 \end{verbatim}
 
-In a C++ file wx\_frame.cc:
+In a C++ file frame.cpp:
 
 \begin{verbatim}
 IMPLEMENT_DYNAMIC_CLASS(wxFrame, wxWindow)
 
-wxFrame::wxFrame(void)
+wxFrame::wxFrame()
 {
 ...
 }