docs/doxygen/overviews/changes_since28.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        changes_since28.h
   3 // Purpose:     topic overview
   4 // Author:      Vadim Zeitlin
   5 // Created:     2008-05-08
   6 // RCS-ID:      $Id$
   7 // Licence:     wxWindows license
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 /**
  11
  12 @page overview_changes_since28 Changes Since wxWidgets 2.8
  13
  14 This topic describes backwards-incompatible changes in wxWidgets 3.0 compared
  15 to the last stable release.
  16
  17 The incompatible changes can be grouped into the following categories:
  18
  19 @li @ref overview_changes_unicode
  20 @li @ref overview_changes_other
  21
  22
  23 <hr>
  24
  25 @section overview_changes_unicode Unicode-related Changes
  26
  27 If you used Unicode build of wxWidgets 2.8 or previous version, please read
  28 @ref overview_unicode for the details about how the API changed in 3.0 as a lot
  29 of the information which was correct before doesn't apply any longer.
  30
  31 For example, the notorious (due to the confusion they created) macros @c wxT()
  32 and @c _T() are not needed at all any longer. Basically, you can remove them
  33 from any code which used them. On the other hand, there is no particular harm
  34 in leaving them neither as the code will still compile and work correctly --
  35 you only need to remove them if you think that your code looks tidier without
  36 them. You also don't need to use @c wxChar any longer but can directly use the
  37 standard @c wchar_t type even if, again, @c wxChar continues to work.
  38
  39 The most serious backwards-incompatible change is related to the change of
  40 return type of wxString::c_str() method: it returns a special proxy object
  41 instead of a simple @c char* or @c wchar_t* now. Because of this, you cannot
  42 pass its result to any standard vararg functions such as @c printf() any more
  43 as described in @ref overview_unicode_compilation_errors. All wxWidgets
  44 functions, such as wxPrintf(), wxLogMessage() &c still work with it, but
  45 passing it to @c printf() will now result in a crash. It is strongly advised to
  46 recompile your code with a compiler warning about passing non-POD objects to
  47 vararg functions, such as g++.
  48
  49 The other class of incompatible changes is due to modifying some virtual
  50 methods to use @c wxString parameters instead of @c const @c wxChar* ones to
  51 make them accept both narrow and wide strings. This is not a problem if you
  52 simply call these functions but you need to change the signature of the derived
  53 class versions if you override them as otherwise they wouldn't be called any
  54 more. Again, the best way to ensure that this problem doesn't arise is to
  55 rebuild your code using a compiler which warns about function signature
  56 mismatch (you can use @c -Woverloaded-virtual g++ option).
  57
  58 Finally, a few structure fields, notable @c wxCmdLineEntryDesc::shortName,
  59 @c longName and @c description fields have been changed to be of type @c const
  60 @c char* instead of @c const @c wxChar* so you will need to remove @c wxT() or
  61 @c _T() if you used it with their initializers.
  62
  63 @section overview_changes_other Miscellaneous Other Changes
  64
  65 Please see @c docs/changes.txt for details of the other changes until they are
  66 described in more details here.
  67
  68 */
  69