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  16 <b>wxWidgets FAQ: General</b>
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  22 <P>
  23
  24 See also <a href="faq.htm">top-level FAQ page</a>.
  25 <hr>
  26 <h3>List of questions in this category</h3>
  27 <ul>
  28 <li><a href="#whatis">What is wxWidgets?</a></li>
  29 <li><a href="#licence">Can I use wxWidgets for both proprietary projects, and GPL&#39;ed projects?</a></li>
  30 <li><a href="#support">Is there support?</a></li>
  31 <li><a href="#users">Who uses wxWidgets?</a></li>
  32 <li><a href="#platforms">What platforms are supported by wxWidgets?</a></li>
  33 <li><a href="#specific">How does wxWidgets support platform-specific features?</a></li>
  34 <li><a href="#stl">Does wxWidgets use STL? or the standard string class?</a></li>
  35 <li><a href="#richedit">Is there a rich edit/markup widget for wxWidgets?</a></ li>
  36 <li><a href="#exceptions">How to use C++ exceptions with wxWidgets?</a></ li>
  37 <li><a href="#dev">How is wxWidgets being developed?</a></li>
  38 <li><a href="#distrib">How is wxWidgets distributed?</a></li>
  39 <!--
  40 <li><a href="#future">What are the plans for the future?</a></li>
  41 -->
  42 <li><a href="#base">What is wxBase?</a></li>
  43 <li><a href="#univ">What is wxUniversal?</a></li>
  44 <li><a href="#jave">What about Java?</a></li>
  45 <li><a href="#dotnet">What about .NET/Mono?</a></li>
  46 <li><a href="#help">How can I help the project?</a></li>
  47 <li><a href="#newport">How do I start a new port?</a></li>
  48 </ul>
  49 <hr>
  50
  51 <H3><a name="whatis">What is wxWidgets?</a></H3>
  52
  53 wxWidgets is a class library that allows you to compile graphical C++ programs on a range of
  54 different platforms. wxWidgets defines a common API across platforms, but uses the native graphical user interface (GUI) on each platform,
  55 so your program will take on the native &#39;look and feel&#39; that users are familiar with.<P>
  56
  57 Although GUI applications are mostly built programmatically, there are several dialog editors to help
  58 build attractive dialogs and panels. Robert Roebling&#39;s <a href="http://www.roebling.com">wxDesigner</a>
  59 and Anthemion Software&#39;s <a href="http://www.anthemion.co.uk/dialogblocks/" target=_new>DialogBlocks</a>
  60 are two commercial examples, but there are others: see the <a href="lnk_tool.htm">Useful Tools</a> page.<P>
  61
  62 You don&#39;t have to use C++ to use wxWidgets: there is a <a href="http://wxpython.org">Python interface</a> for wxWidgets,
  63 and also a <a href="http://wxperl.sourceforge.net" target=_top>Perl interface</a>.
  64 <P>
  65
  66 <h3><a name="licence">Can I use wxWidgets for both proprietary (commercial) projects, and GPL&#39;ed projects?</a></h3>
  67
  68 Yes. Please see the <a href="newlicen.htm">licence</a> for details, but basically
  69 you can distribute proprietary binaries without distributing any source code, and neither will wxWidgets
  70 conflict with GPL code you may be using or developing with it.
  71 <P>
  72 The conditions for using wxWidgets are the same whether you are a personal, academic
  73 or commercial developer.
  74 <P>
  75
  76 <h3><a name="support">Is there support?</a></h3>
  77
  78 No official support, but the mailing list is very helpful and some people say that
  79 wxWidgets support is better than for much commercial software. The developers are
  80 keen to fix bugs as soon as possible, though obviously there are no guarantees.
  81 <P>
  82
  83 <H3><a name="users">Who uses wxWidgets?</a></H3>
  84
  85 Many organisations - commercial, government, and academic - across the
  86 world. It&#39;s impossible to estimate the true number of users, since
  87 wxWidgets is obtained by many different means, and we cannot monitor
  88 distribution. The mailing list contains around 300-400 entries which is
  89 quite large for a list of this type.<P>
  90
  91 See <a href="users.htm">Users</a> for a list of some users and their applications, and
  92 also <A href="feedback.htm">Feedback</a> for comments.<P>
  93 Our highest-profile user yet is industry veteran and Lotus Corp. founder Mitch Kapor
  94 and his <a href="http://www.osafoundation.org" target=_new>Open Source Applications Foundation</a>.
  95 <P>
  96
  97 <H3><a name="platforms">What platforms are supported by wxWidgets?</a></H3>
  98
  99 <ul>
 100 <li>Windows 3.1, Windows 95/98, Windows NT, Windows 2000, Windows ME.
 101 <li>Linux and other Unix platforms with GTK+.
 102 <li>Unix with Motif or the free Motif clone Lesstif.
 103 <li>Mac OS.
 104 <li>Embedded platforms are being investigated. See the <a href="wxuniv.htm">wxUniversal</a> project.
 105 <li>An OS/2 port is in progress, and you can also compile wxWidgets for GTK+ or Motif
 106 on OS/2.
 107 </ul>
 108 <P>
 109
 110 <H3><a name="specific">How does wxWidgets support platform-specific
 111 features?</a></H3>
 112
 113 This is a hotly-debated topic amongst the developers. My own philosophy
 114 is to make wxWidgets as platform-independent as possible, but allow in a
 115 few classes (functions, window styles) that are platform-specific.
 116 For example, Windows metafiles and Windows 95 taskbar icons have
 117 their own classes on Windows, but nowhere else. Because these classes
 118 are provided and are wxWidgets-compatible, it doesn&#39;t take much
 119 coding effort for an application programmer to add support for
 120 some functionality that the user on a particular platform might otherwise
 121 miss. Also, some classes that started off as platform-specific, such
 122 as the MDI classes, have been emulated on other platforms. I can imagine
 123 that even wxTaskBarIcon may be implemented for Unix desktops one day.
 124 <P>
 125
 126 In other words, wxWidgets is not a &#39;lowest common denominator&#39; approach,
 127 but it will still be possible to write portable programs using the
 128 core API. Forbidding some platform-specific classes would be a stupid
 129 approach that would alienate many potential users, and encourage
 130 the perception that toolkits such as wxWidgets are not up to the demands
 131 of today&#39;s sophisticated applications.<P>
 132
 133 Currently resources such as bitmaps and icons are handled in a platform-specific
 134 way, but it is hoped to reduce this dependence in due course.<P>
 135
 136 Another reason why wxWidgets is not a &#39;lowest common denominator&#39; toolkit is that
 137 some functionality missing on some platform has been provided using generic,
 138 platform-independent code, such as the wxTreeCtrl and wxListCtrl classes.<P>
 139
 140 <H3><a name="stl">Does wxWidgets use STL? or the standard string class?</a></H3>
 141
 142 No. This is a much-discussed topic that has (many times) ended with the conclusion that it is in
 143 wxWidgets&#39; best interests to avoid use of templates. Not all compilers can handle
 144 templates adequately so it would dramatically reduce the number of compilers
 145 and platforms that could be supported. It would also be undesirable to make
 146 wxWidgets dependent on another large library that may have to be downloaded and installed.
 147 In addition, use of templates can lead to executable bloat, which is something
 148 wxWidgets is strenuously trying to avoid.<P>
 149
 150 The standard C++ string class is not used, again because it is not available to all compilers,
 151 and it is not necessarily a very efficient implementation. Also, we retain more flexibility
 152 by being able to modify our own string class. Some compatibility with the string class
 153 has been built into wxString.<P>
 154
 155 There is nothing to stop an application using templates or the string class for its own
 156 purposes. With wxWidgets debugging options on, you may find you get errors when including
 157 STL headers. You can work around it either by switching off memory checking,
 158 or by adding this to a header before you include any STL files:<P>
 159
 160 <PRE>
 161 &#35;ifdef new
 162 &#35;undef new
 163 &#35;endif
 164 </PRE>
 165
 166 <P>
 167
 168
 169 <H3><a name="richedit">Is there a rich edit/markup widget for wxWidgets?</a></H3>
 170
 171 These are the possibilities so far:<P>
 172
 173 <ul>
 174 <li>See <a href="http://www.scintilla.org" target=_top>www.scintilla.org</a> for
 175 a very nice syntax-highlighting editor widget. Robin Dunn has written a wxWidgets wrapper
 176 for this widget, available in the wxWidgets distribution under contrib/src/stc.
 177 <li>If you only need to display marked-up information, rather than edit it,
 178 then wxHTML will suit your needs. wxHTML is built into wxWidgets - please see the reference
 179 manual for details, and samples/html.
 180 <li>There are rich edit widgets in both WIN32 and GTK+, but there is currently
 181 no wxWidgets wrapper for these (but text attribute functions are being added in the wxWidgets 2.3.x series).
 182 </ul>
 183
 184 <P>
 185
 186 <h3><a name="exceptions">How to use C++ exceptions with wxWidgets?</a></h3>
 187
 188 wxWidgets library itself is unfortunately <i>not</i> exception-safe (as its
 189 initial version predates, by far, the addition of the exceptions to the C++
 190 language). However you can still use the exceptions in your own code and use
 191 the other libraries using the exceptions for the error reporting together with
 192 wxWidgets.
 193
 194 <p>
 195 There are a few issues to keep in mind, though:
 196 <ul>
 197     <li>You shouldn&#39;t let the exceptions propagate through wxWidgets code,
 198         in particular you should always catch the exceptions thrown by the
 199         functions called from an event handler in the handler itself and not
 200         let them propagate upwards to wxWidgets.
 201
 202     <li>You may need to ensure that the compiler support for the exceptions is
 203         enabled as, considering that wxWidgets itself doesn&#39;t use the
 204         exceptions and turning their support on results in the library size
 205         augmentation of 10% to 20%, it is turned off by default for a few
 206         compilers. Moreover, for gcc (or at least its mingw version) you must
 207         also turn on the RTTI support to be able to use the exceptions, so you
 208         should use <tt>--disable-no_rtti --disable-no_exceptions</tt> options
 209         when configuring the library (attention to the double negation).
 210 </ul>
 211
 212 <p>
 213
 214 <H3><a name="dev">How is wxWidgets being developed?</a></H3>
 215
 216 We are using the <a href="cvs.htm">CVS</a> system to develop and maintain wxWidgets. This allows
 217 us to make alterations and upload them instantly to the server, from
 218 which others can update their source.<P>
 219
 220 To build source from CVS, see the file BuildCVS.txt in the top-level wxWidgets distribution
 221 directory.<P>
 222
 223 <H3><a name="distrib">How is wxWidgets distributed?</a></H3>
 224
 225 By ftp, and via the <a href="cdrom2.htm">wxWidgets CD-ROM</a>.
 226 <P>
 227 If you are feeling adventurous, you may also check out the sources directly
 228 from <a href="cvs.htm">cvs</a>.
 229 <p>
 230
 231 <!--
 232 <H3><a name="future">What are the plans for the future?</a></H3>
 233
 234 TODO
 235
 236 <p>
 237
 238 -->
 239
 240 <h3><a name="base">What is wxBase?</a></h3>
 241
 242 wxBase is a subset of wxWidgets comprised by the non-GUI classes. It includes
 243 wxWidgets container and primitive data type classes (including wxString,
 244 wxDateTime and so on) and also useful wrappers for the operating system objects
 245 such as files, processes, threads, sockets and so on. With very minor
 246 exceptions wxBase may be used in exactly the same way as wxWidgets but it
 247 doesn&#39;t require a GUI to run and so is ideal for creating console mode
 248 utilities or server programs. It is also possible to create a program which can
 249 be compiled either as a console application (using wxBase) or a GUI one (using
 250 a full featured wxWidgets port).
 251
 252 <H3><a name="univ">What is wxUniversal?</a></H3>
 253
 254 The main difference between wxUniversal-based ports (such as wxX11, wxMGL) and other ports (such as wxMSW, wxGTK+, wxMac)
 255 is that wxUniversal implements all controls (or widgets) in
 256 wxWidgets itself thus allowing to have much more flexibility (for example, support for
 257 themes even under MS Windows). It also means that it is now much easier to
 258 port wxWidgets to a new platform as only the low-level classes must be ported
 259 which make for a small part of the library.
 260 <p>
 261 You may find more about wxUniversal <a href=wxuniv.htm>here</a>.
 262
 263 <H3><a name="jave">What about Java?</a></H3>
 264
 265 The Java honeymoon period is over :-) and people are realising that it cannot
 266 meet all their cross-platform development needs. We don&#39;t anticipate a major threat
 267 from Java, and the level of interest in wxWidgets is as high as ever.<P>
 268
 269 <H3><a name="dotnet">What about .NET/Mono?</a></H3>
 270
 271 Microsoft is spending a lot on promoting the .NET initiative, which
 272 is a set of languages, APIs and web service components for Windows.
 273 Ximian has started an open source version of .NET, mostly for Linux.
 274 C&#35; is Microsoft&#39;s alternative to Java, supporting &#39;managed code&#39;,
 275 garbage collection and various other Java-like language features.<P>
 276
 277 Although this may be attractive to some developers, there
 278 is a variety of reasons why the .NET/Mono combination is unlikely
 279 to make wxWidgets redundant. Please note that the following comments
 280 are Julian Smart&#39;s opinions.<P>
 281
 282 <ol>
 283 <li>Not everyone wants or needs net services.
 284 <li>C++ will be used for a long time to come; compared with C++, C&#35; is a recent development and its future is not certain.
 285 <li>Mono Forms may only target Winelib (at least to begin with), so the end result is not as native as
 286 wxWidgets (I&#39;m aware there is GTK&#35; for use with the C&#35; language).
 287 <li>C&#35; is usually byte-compiled and therefore slower. Plus, .NET adds a layer of overhead to the client computer
 288 that wxWidgets does not require.
 289 <li>Mono hasn&#39;t proven its long-term viability yet (it&#39;s a complex system of components); wxWidgets is ready now.
 290 <li>You may not wish to buy into Microsoft marketing spin and APIs.
 291 <li>Microsoft may at some point sue developers of non-Microsoft .NET implementations. After all,
 292 platform-independence is not in Microsoft&#39;s interest.
 293 <li>.NET might never be implemented on some platforms, especially Mac and embedded variants of Linux.
 294 <li>wxPython and other language variants provide further reasons for wxWidgets to continue.
 295 <li>The same issue exists for Qt: if Qt sales remain strong, it&#39;s a good indication that
 296 the market for a C++-based approach is still there. (Either that, or everyone&#39;s turning to wxWidgets!)
 297 </ol>
 298
 299 There is nothing to stop folk from developing a C&#35; version of the wxWidgets API;
 300 we already have bindings to Python, Perl, JavaScript, Lua, Basic, and Eiffel.
 301 Update: a <a href="http://wxnet.sourceforge.net/" target=_new>wx.NET</a> project is now in progress.
 302
 303 <P>
 304
 305 <H3><a name="help">How can I help the project?</a></H3>
 306
 307 Please check out the <a href="http://www.wxwidgets.org/develop2.htm">Community</a> pages,
 308 in particular the <a href="projects.htm">suggested projects</a>, and
 309 mail the developers&#39; mailing list with your own suggestions.<P>
 310
 311 <H3><a name="newport">How do I start a new port?</a></H3>
 312
 313 Please subscribe to the wx-dev <a href="maillst2.htm">developers&#39; mailing list</a> and
 314 ask if anyone else is interested in helping with the port, or
 315 has specific suggestions. Also please read the <a href="standard.htm">coding standards</a>.
 316
 317 <P>
 318 Each port consists of a platform-specific part (e.g. src/msw, include/wx/msw),
 319 a generic set of widgets and dialogs for when the port doesn&#39;t support
 320 them natively (src/generic, include/wx/generic) and the common code
 321 that all ports use (src/common, include/wx). By browsing the source
 322 you should get a good idea of the general pattern.<P>
 323
 324 Take a port that most closely matches your port, and strip out
 325 the implementation so you have a skeleton port that compiles. Ask on wx-dev
 326 first for the wxStubs port - however, any such predefined skeleton
 327 port may be out of date, so make a judgement on whether to use it.
 328 Perhaps it will still save you time to clean up wxStubs, and
 329 others may benefit from this too.<P>
 330
 331 You will need to define a symbol for the new port, e.g. __WXXBOX__.
 332 Look at files such as wx/defs.h, wx/wxchar.h for areas where you&#39;ll
 333 need to add to existing conditionals to set up wide character
 334 support and other issues. If the GUI runs on a Unix variant,
 335 define the __UNIX__ variable in your makefile.<P>
 336
 337 Then you can start implementing the port, starting with
 338 wxWindow, wxTopLevelWindow, wxFrame, wxDialog so you
 339 can get the minimal sample running as soon as possible.<P>
 340
 341 If GDI objects (wxPen, wxBrush, etc.) are not concepts in your
 342 native GUI, you may wish to use very generic versions of
 343 some of these - see the wxX11 port.<P>
 344
 345 Consider using the wxUniversal widget set as a quick way
 346 to implement wxWidgets on your platform. You only need
 347 to define some basic classes such as device contexts,
 348 wxWindow, wxTopLevelWindow, GDI objects etc. and
 349 the actual widgets will be drawn for you. See wxX11,
 350 wxMGL, and wxMSW/Univ for sample wxUniversal ports.<P>
 351
 352 To begin with, you can use whatever makefiles or project
 353 files work for you. Look at existing makefiles to see what
 354 generic/common/Unix files need to be included. Later, you&#39;ll want to integrate support
 355 for your port into configure (Unix-like systems and gcc under Windows),
 356 and bakefile (for other makefiles on Windows).<P>
 357
 358 Submit your port as patches via SourceForge; you might
 359 wish to separate it into one patch that touches common headers
 360 and source files, and another containing the port-specific code, to make
 361 it much easier for us to review and apply the patches.<P>
 362
 363 Good luck!
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