1 2<HTML> 3 4<HEAD> 5<TITLE>wxWidgets FAQ: General</TITLE> 6</HEAD> 7 8<BODY BGCOLOR=#FFFFFF TEXT=#000000 VLINK="#00376A" LINK="#00529C" ALINK="#313063"> 9 10<font face="Arial, Lucida Sans, Helvetica"> 11 12<table width=100% border=0 cellpadding=3 cellspacing=0> 13<tr> 14<td bgcolor="#004080" align=left height=24 background="images/bluetitlegradient.gif"> 15<font size=+1 face="Arial, Lucida Sans, Helvetica" color="#FFFFFF"> 16<b>wxWidgets FAQ: General</b> 17</font> 18</td> 19</tr> 20</table> 21 22<P> 23 24See 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'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 53wxWidgets is a class library that allows you to compile graphical C++ programs on a range of 54different platforms. wxWidgets defines a common API across platforms, but uses the native graphical user interface (GUI) on each platform, 55so your program will take on the native 'look and feel' that users are familiar with.<P> 56 57Although GUI applications are mostly built programmatically, there are several dialog editors to help 58build attractive dialogs and panels. Robert Roebling's <a href="http://www.roebling.com">wxDesigner</a> 59and Anthemion Software's <a href="http://www.anthemion.co.uk/dialogblocks/" target=_new>DialogBlocks</a> 60are two commercial examples, but there are others: see the <a href="lnk_tool.htm">Useful Tools</a> page.<P> 61 62You don't have to use C++ to use wxWidgets: there is a <a href="http://wxpython.org">Python interface</a> for wxWidgets, 63and 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'ed projects?</a></h3> 67 68Yes. Please see the <a href="newlicen.htm">licence</a> for details, but basically 69you can distribute proprietary binaries without distributing any source code, and neither will wxWidgets 70conflict with GPL code you may be using or developing with it. 71<P> 72The conditions for using wxWidgets are the same whether you are a personal, academic 73or commercial developer. 74<P> 75 76<h3><a name="support">Is there support?</a></h3> 77 78No official support, but the mailing list is very helpful and some people say that 79wxWidgets support is better than for much commercial software. The developers are 80keen 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 85Many organisations - commercial, government, and academic - across the 86world. It's impossible to estimate the true number of users, since 87wxWidgets is obtained by many different means, and we cannot monitor 88distribution. The mailing list contains around 300-400 entries which is 89quite large for a list of this type.<P> 90 91See <a href="users.htm">Users</a> for a list of some users and their applications, and 92also <A href="feedback.htm">Feedback</a> for comments.<P> 93Our highest-profile user yet is industry veteran and Lotus Corp. founder Mitch Kapor 94and 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 106on OS/2. 107</ul> 108<P> 109 110<H3><a name="specific">How does wxWidgets support platform-specific 111features?</a></H3> 112 113This is a hotly-debated topic amongst the developers. My own philosophy 114is to make wxWidgets as platform-independent as possible, but allow in a 115few classes (functions, window styles) that are platform-specific. 116For example, Windows metafiles and Windows 95 taskbar icons have 117their own classes on Windows, but nowhere else. Because these classes 118are provided and are wxWidgets-compatible, it doesn't take much 119coding effort for an application programmer to add support for 120some functionality that the user on a particular platform might otherwise 121miss. Also, some classes that started off as platform-specific, such 122as the MDI classes, have been emulated on other platforms. I can imagine 123that even wxTaskBarIcon may be implemented for Unix desktops one day. 124<P> 125 126In other words, wxWidgets is not a 'lowest common denominator' approach, 127but it will still be possible to write portable programs using the 128core API. Forbidding some platform-specific classes would be a stupid 129approach that would alienate many potential users, and encourage 130the perception that toolkits such as wxWidgets are not up to the demands 131of today's sophisticated applications.<P> 132 133Currently resources such as bitmaps and icons are handled in a platform-specific 134way, but it is hoped to reduce this dependence in due course.<P> 135 136Another reason why wxWidgets is not a 'lowest common denominator' toolkit is that 137some functionality missing on some platform has been provided using generic, 138platform-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 142No. This is a much-discussed topic that has (many times) ended with the conclusion that it is in 143wxWidgets' best interests to avoid use of templates. Not all compilers can handle 144templates adequately so it would dramatically reduce the number of compilers 145and platforms that could be supported. It would also be undesirable to make 146wxWidgets dependent on another large library that may have to be downloaded and installed. 147In addition, use of templates can lead to executable bloat, which is something 148wxWidgets is strenuously trying to avoid.<P> 149 150The standard C++ string class is not used, again because it is not available to all compilers, 151and it is not necessarily a very efficient implementation. Also, we retain more flexibility 152by being able to modify our own string class. Some compatibility with the string class 153has been built into wxString.<P> 154 155There is nothing to stop an application using templates or the string class for its own 156purposes. With wxWidgets debugging options on, you may find you get errors when including 157STL headers. You can work around it either by switching off memory checking, 158or by adding this to a header before you include any STL files:<P> 159 160<PRE> 161#ifdef new 162#undef new 163#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 171These 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 175a very nice syntax-highlighting editor widget. Robin Dunn has written a wxWidgets wrapper 176for 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, 178then wxHTML will suit your needs. wxHTML is built into wxWidgets - please see the reference 179manual for details, and samples/html. 180<li>There are rich edit widgets in both WIN32 and GTK+, but there is currently 181no 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 188wxWidgets library itself is unfortunately <i>not</i> exception-safe (as its 189initial version predates, by far, the addition of the exceptions to the C++ 190language). However you can still use the exceptions in your own code and use 191the other libraries using the exceptions for the error reporting together with 192wxWidgets. 193 194<p> 195There are a few issues to keep in mind, though: 196<ul> 197 <li>You shouldn'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'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 216We are using the <a href="cvs.htm">CVS</a> system to develop and maintain wxWidgets. This allows 217us to make alterations and upload them instantly to the server, from 218which others can update their source.<P> 219 220To build source from CVS, see the file BuildCVS.txt in the top-level wxWidgets distribution 221directory.<P> 222 223<H3><a name="distrib">How is wxWidgets distributed?</a></H3> 224 225By ftp, and via the <a href="cdrom2.htm">wxWidgets CD-ROM</a>. 226<P> 227If you are feeling adventurous, you may also check out the sources directly 228from <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 234TODO 235 236<p> 237 238--> 239 240<h3><a name="base">What is wxBase?</a></h3> 241 242wxBase is a subset of wxWidgets comprised by the non-GUI classes. It includes 243wxWidgets container and primitive data type classes (including wxString, 244wxDateTime and so on) and also useful wrappers for the operating system objects 245such as files, processes, threads, sockets and so on. With very minor 246exceptions wxBase may be used in exactly the same way as wxWidgets but it 247doesn't require a GUI to run and so is ideal for creating console mode 248utilities or server programs. It is also possible to create a program which can 249be compiled either as a console application (using wxBase) or a GUI one (using 250a full featured wxWidgets port). 251 252<H3><a name="univ">What is wxUniversal?</a></H3> 253 254The main difference between wxUniversal-based ports (such as wxX11, wxMGL) and other ports (such as wxMSW, wxGTK+, wxMac) 255is that wxUniversal implements all controls (or widgets) in 256wxWidgets itself thus allowing to have much more flexibility (for example, support for 257themes even under MS Windows). It also means that it is now much easier to 258port wxWidgets to a new platform as only the low-level classes must be ported 259which make for a small part of the library. 260<p> 261You may find more about wxUniversal <a href=wxuniv.htm>here</a>. 262 263<H3><a name="jave">What about Java?</a></H3> 264 265The Java honeymoon period is over :-) and people are realising that it cannot 266meet all their cross-platform development needs. We don't anticipate a major threat 267from 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 271Microsoft is spending a lot on promoting the .NET initiative, which 272is a set of languages, APIs and web service components for Windows. 273Ximian has started an open source version of .NET, mostly for Linux. 274C# is Microsoft's alternative to Java, supporting 'managed code', 275garbage collection and various other Java-like language features.<P> 276 277Although this may be attractive to some developers, there 278is a variety of reasons why the .NET/Mono combination is unlikely 279to make wxWidgets redundant. Please note that the following comments 280are Julian Smart'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# 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 286wxWidgets (I'm aware there is GTK# for use with the C# language). 287<li>C# is usually byte-compiled and therefore slower. Plus, .NET adds a layer of overhead to the client computer 288that wxWidgets does not require. 289<li>Mono hasn't proven its long-term viability yet (it'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, 292platform-independence is not in Microsoft'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's a good indication that 296the market for a C++-based approach is still there. (Either that, or everyone's turning to wxWidgets!) 297</ol> 298 299There is nothing to stop folk from developing a C# version of the wxWidgets API; 300we already have bindings to Python, Perl, JavaScript, Lua, Basic, and Eiffel. 301Update: 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 307Please check out the <a href="http://www.wxwidgets.org/develop2.htm">Community</a> pages, 308in particular the <a href="projects.htm">suggested projects</a>, and 309mail the developers' mailing list with your own suggestions.<P> 310 311<H3><a name="newport">How do I start a new port?</a></H3> 312 313Please subscribe to the wx-dev <a href="maillst2.htm">developers' mailing list</a> and 314ask if anyone else is interested in helping with the port, or 315has specific suggestions. Also please read the <a href="standard.htm">coding standards</a>. 316 317<P> 318Each port consists of a platform-specific part (e.g. src/msw, include/wx/msw), 319a generic set of widgets and dialogs for when the port doesn't support 320them natively (src/generic, include/wx/generic) and the common code 321that all ports use (src/common, include/wx). By browsing the source 322you should get a good idea of the general pattern.<P> 323 324Take a port that most closely matches your port, and strip out 325the implementation so you have a skeleton port that compiles. Ask on wx-dev 326first for the wxStubs port - however, any such predefined skeleton 327port may be out of date, so make a judgement on whether to use it. 328Perhaps it will still save you time to clean up wxStubs, and 329others may benefit from this too.<P> 330 331You will need to define a symbol for the new port, e.g. __WXXBOX__. 332Look at files such as wx/defs.h, wx/wxchar.h for areas where you'll 333need to add to existing conditionals to set up wide character 334support and other issues. If the GUI runs on a Unix variant, 335define the __UNIX__ variable in your makefile.<P> 336 337Then you can start implementing the port, starting with 338wxWindow, wxTopLevelWindow, wxFrame, wxDialog so you 339can get the minimal sample running as soon as possible.<P> 340 341If GDI objects (wxPen, wxBrush, etc.) are not concepts in your 342native GUI, you may wish to use very generic versions of 343some of these - see the wxX11 port.<P> 344 345Consider using the wxUniversal widget set as a quick way 346to implement wxWidgets on your platform. You only need 347to define some basic classes such as device contexts, 348wxWindow, wxTopLevelWindow, GDI objects etc. and 349the actual widgets will be drawn for you. See wxX11, 350wxMGL, and wxMSW/Univ for sample wxUniversal ports.<P> 351 352To begin with, you can use whatever makefiles or project 353files work for you. Look at existing makefiles to see what 354generic/common/Unix files need to be included. Later, you'll want to integrate support 355for your port into configure (Unix-like systems and gcc under Windows), 356and bakefile (for other makefiles on Windows).<P> 357 358Submit your port as patches via SourceForge; you might 359wish to separate it into one patch that touches common headers 360and source files, and another containing the port-specific code, to make 361it much easier for us to review and apply the patches.<P> 362 363Good luck! 364 365</font> 366 367</BODY> 368 369</HTML> 370