Update and reorganize XRC overview to make it more useful.

[wxWidgets.git] / docs / doxygen / overviews / refcount.h

diff --git a/docs/doxygen/overviews/refcount.h b/docs/doxygen/overviews/refcount.h
index be24a53e5ececdd9b5d07ddaa6a82121dd4336b9..081cad74ebef3d64fec954702cef5970357b9198 100644 (file)
--- a/docs/doxygen/overviews/refcount.h
+++ b/docs/doxygen/overviews/refcount.h
@@ -3,10 +3,10 @@
 // Purpose:     topic overview
 // Author:      wxWidgets team
 // RCS-ID:      $Id$
-// Licence:     wxWindows license
+// Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-/*!
+/**
 
 @page overview_refcount Reference Counting
 
@@ -41,9 +41,10 @@ operation on it is the same.
 
 @section overview_refcount_equality Object Comparison
 
-The == and != operators of the reference counted classes always do a @c deep
-comparison. This means that the equality operator will return @true if two
-objects are identical and not only if they share the same data.
+The == and != operators of @ref overview_refcount_list "the reference counted classes"
+always do a <em>deep comparison</em>. This means that the equality operator
+will return @true if two objects are identical and not only if they share the
+same data.
 
 Note that wxWidgets follows the <em>STL philosophy</em>: when a comparison
 operator can not be implemented efficiently (like for e.g. wxImage's ==
@@ -53,7 +54,7 @@ provide comparison operators.
 
 Also note that if you only need to do a @c shallow comparison between two
 wxObject derived classes, you should not use the == and != operators but
-rather the wxObject::IsSameAs function.
+rather the wxObject::IsSameAs() function.
 
 
 @section overview_refcount_destruct Object Destruction
@@ -77,6 +78,12 @@ operators and copy constructors since they are reference-counted:
 @li wxBrush
 @li wxCursor
 @li wxFont
+@li wxGraphicsBrush
+@li wxGraphicsContext
+@li wxGraphicsFont
+@li wxGraphicsMatrix
+@li wxGraphicsPath
+@li wxGraphicsPen
 @li wxIcon
 @li wxImage
 @li wxMetafile
@@ -90,14 +97,20 @@ operators and copy constructors since they are reference-counted:
 Note that the list above reports the objects which are reference counted in all
 ports of wxWidgets; some ports may use this technique also for other classes.
 
+All the objects implement a function @b IsOk() to test if they are referencing valid
+data; when the objects are in uninitialized state, you can only use the @b IsOk() getter;
+trying to call any other getter, e.g. wxBrush::GetStyle() on the ::wxNullBrush object,
+will result in an assert failure in debug builds.
+
 
 @section overview_refcount_object Making Your Own Reference Counted Class
 
-Reference counting can be implemented easily using wxObject and wxObjectRefData
-classes. Alternatively, you can also use the wxObjectDataPtr<T> template.
+Reference counting can be implemented easily using wxObject or using
+the intermediate wxRefCounter class directly. 
+Alternatively, you can also use the wxObjectDataPtr<T> template.
 
-First, derive a new class from wxObjectRefData and put there the
-memory-consuming data.
+First, derive a new class from wxRefCounter (or wxObjectRefData when
+using a wxObject derived class) and put the memory-consuming data in it.
 
 Then derive a new class from wxObject and implement there the public interface
 which will be seen by the user of your class. You'll probably want to add a
@@ -115,7 +128,7 @@ In fact, any time you need to read the data from your wxObject-derived class,
 you will need to call this function.
 
 @note Any time you need to actually modify the data placed inside your wxObject
-derived class, you must first call the wxObject::UnShare function to ensure
+derived class, you must first call the wxObject::UnShare() function to ensure
 that the modifications won't affect other instances which are eventually
 sharing your object's data.