Use UTF16 for text data object on Mac. Fixes #10902
[wxWidgets.git] / docs / doxygen / overviews / changes_since28.h
CommitLineData
cc506697
VZ
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
14This topic describes backwards-incompatible changes in wxWidgets 3.0 compared
15to the last stable release.
16
17The 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
27If 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
29of the information which was correct before doesn't apply any longer.
30
31For example, the notorious (due to the confusion they created) macros @c wxT()
32and @c _T() are not needed at all any longer. Basically, you can remove them
33from any code which used them. On the other hand, there is no particular harm
34in leaving them neither as the code will still compile and work correctly --
35you only need to remove them if you think that your code looks tidier without
36them. You also don't need to use @c wxChar any longer but can directly use the
37standard @c wchar_t type even if, again, @c wxChar continues to work.
38
39The most serious backwards-incompatible change is related to the change of
40return type of wxString::c_str() method: it returns a special proxy object
41instead of a simple @c char* or @c wchar_t* now. Because of this, you cannot
42pass its result to any standard vararg functions such as @c printf() any more
43as described in @ref overview_unicode_compilation_errors. All wxWidgets
44functions, such as wxPrintf(), wxLogMessage() &c still work with it, but
45passing it to @c printf() will now result in a crash. It is strongly advised to
46recompile your code with a compiler warning about passing non-POD objects to
47vararg functions, such as g++.
48
73ba5ab9
VZ
49The change of the type of wxString::c_str() can also result in compilation
50errors when passing its result to a function overloaded to take both narrow and
51wide strings and in this case you must select the version which you really want
52to use, e.g.:
53@code
54 void OpenLogFile(const char *filename);
55 void OpenLogFile(const wchar_t *filename);
56
57 wxString s;
58 OpenLogFile(s); // ERROR: ambiguity
59 OpenLogFile(s.c_str()); // ERROR: ambiguity
60 OpenLogFile(s.wx_str()); // OK: function called depends on the build
61 OpenLogFile(s.mb_str()); // OK: always calls narrow string overload
62 OpenLogFile(s.wc_str()); // OK: always calls wide string overload
63@endcode
64
cc506697
VZ
65The other class of incompatible changes is due to modifying some virtual
66methods to use @c wxString parameters instead of @c const @c wxChar* ones to
67make them accept both narrow and wide strings. This is not a problem if you
68simply call these functions but you need to change the signature of the derived
69class versions if you override them as otherwise they wouldn't be called any
70more. Again, the best way to ensure that this problem doesn't arise is to
71rebuild your code using a compiler which warns about function signature
72mismatch (you can use @c -Woverloaded-virtual g++ option).
73
74Finally, a few structure fields, notable @c wxCmdLineEntryDesc::shortName,
75@c longName and @c description fields have been changed to be of type @c const
76@c char* instead of @c const @c wxChar* so you will need to remove @c wxT() or
77@c _T() if you used it with their initializers.
78
79@section overview_changes_other Miscellaneous Other Changes
80
9c8116f8
VZ
81- Default location of wxFileConfig files has changed under Windows, you will
82 need to update your code if you access these files directly.
83
84- wxWindow::IsEnabled() now returns false if a window parent (and not
85 necessarily the window itself) is disabled, new function IsThisEnabled()
86 with the same behaviour as old IsEnabled() was added.
87
88- Generating wxNavigationKeyEvent events doesn't work any more under wxGTK (and
89 other platforms in the future), use wxWindow::Navigate() or NavigateIn()
90 instead.
91
92- Sizers distribute only the extra space between the stretchable items
93 according to their proportions and not all available space. We believe the
94 new behaviour corresponds better to user expectations but if you did rely
95 on the old behaviour you will have to update your code to set the minimal
96 sizes of the sizer items to be in the same proportion as the items
97 proportions to return to the old behaviour.
98
99- wxWindow::Freeze/Thaw() are not virtual any more, if you overrode them in
100 your code you need to override DoFreeze/Thaw() instead now.
101
102- wxCalendarCtrl has native implementation in wxGTK, but it has less features
103 than the generic one. The native implementation is used by default, but you
104 can still use wxGenericCalendarCtrl instead of wxCalendarCtrl in your code if
105 you need the extra features.
106
107- wxDocument::FileHistoryLoad() and wxFileHistory::Load() now take const
108 reference to wxConfigBase argument and not just a reference, please update
109 your code if you overrode these functions and change the functions in the
110 derived classes to use const reference as well.
cc506697 111
500b128d
VZ
112- Calling wxConfig::Write() with an enum value will fail to compile because
113 wxConfig now tries to convert all unknown types to wxString automatically
114 using wxToString() function.
115
116 The simplest solution is to cast the enum value to int, e.g.
117 @code
118 enum Colour { Red, Green, Blue };
119
120 wxConfig conf;
121 conf.Write("MyFavouriteColour", Red); // ERROR: no match
122 conf.Write("MyFavouriteColour", int(Red)); // OK
123 @endcode
124
125 Another possibility which exists now is to provide an overload of
126 wxToString() (and wxFromString()) for your own type, e.g.
127
128 @code
129 wxString wxToString(Colour col)
130 {
131 return col == Red ? "R" : col == Green ? "G" : "B";
132 }
133
134 bool wxFromString(const wxString& s, Colour* col)
135 {
136 if ( s.length() != 1 )
137 return false;
138
139 switch ( s[0].GetValue() )
140 {
141 case 'R': *col = Red; return true;
142 case 'G': *col = Green; return true;
143 case 'B': *col = Blue; return true;
144 }
145
146 return false;
147 }
148 @endcode
149
150 Of course, this will change the format of the wxConfig output which may be
151 undesirable.
053ac76f
VZ
152
153- wxTE_AUTO_SCROLL style is deprecated as it's always on by default anyhow in
154 the ports which support it so you should simply remove any mentions of it
155 from your code.
1d7b600d
VZ
156
157- If you use wxScrolled<T>::SetTargetWindow() you must override
158 wxScrolled<T>::GetSizeAvailableForScrollTarget() method to compute the size
159 available for the scroll target as function of the main window size, please
160 see the documentation of this method for more details.
cc506697
VZ
161*/
162