wxWidgets/docs/html/faqgen.htm
2003-05-19 07:36:47 +00:00

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<TITLE>wxWindows 2 FAQ: General</TITLE>
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<b>wxWindows 2 FAQ: General</b>
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<P>
See also <a href="faq.htm">top-level FAQ page</a>.
<hr>
<h3>List of questions in this category</h3>
<ul>
<li><a href="#whatis">What is wxWindows?</a></li>
<li><a href="#licence">Can I use wxWindows 2 for both proprietary projects, and GPL&#39;ed projects?</a></li>
<li><a href="#support">Is there support?</a></li>
<li><a href="#users">Who uses wxWindows?</a></li>
<li><a href="#platforms">What platforms are supported by wxWindows?</a></li>
<li><a href="#specific">How does wxWindows support platform-specific features?</a></li>
<li><a href="#stl">Does wxWindows use STL? or the standard string class?</a></li>
<li><a href="#richedit">Is there a rich edit/markup widget for wxWindows?</a></ li>
<li><a href="#exceptions">How to use C++ exceptions with wxWindows?</a></ li>
<li><a href="#dev">How is wxWindows being developed?</a></li>
<li><a href="#distrib">How is wxWindows distributed?</a></li>
<li><a href="#future">What are the plans for the future?</a></li>
<li><a href="#base">What is wxBase?</a></li>
<li><a href="#univ">What is wxUniversal?</a></li>
<li><a href="#jave">What about Java?</a></li>
<li><a href="#dotnet">What about .NET/Mono?</a></li>
<li><a href="#help">How can I help the project?</a></li>
</ul>
<hr>
<H3><a name="whatis">What is wxWindows?</a></H3>
wxWindows is a class library that allows you to compile graphical C++ programs on a range of
different platforms. wxWindows defines a common API across platforms, but uses the native graphical user interface (GUI) on each platform,
so your program will take on the native &#39;look and feel&#39; that users are familiar with.<P>
Although GUI applications are mostly built programmatically, there is a dialog editor to help
build attractive dialogs and panels. Robert Roebling&#39;s <a href="http://www.roebling.com">wxDesigner</a>
makes light work of resizable, portable dialogs.<P>
You don&#39;t have to use C++ to use wxWindows: there is a <a href="http://wxpython.org">Python interface</a> for wxWindows 2,
and also a <a href="http://wxperl.sourceforge.net" target=_top>Perl interface</a>.
<P>
<h3><a name="licence">Can I use wxWindows 2 for both proprietary (commercial) projects, and GPL&#39;ed projects?</a></h3>
Yes. Please see the <a href="newlicen.htm">licence</a> for details, but basically
you can distribute proprietary binaries without distributing any source code, and neither will wxWindows
conflict with GPL code you may be using or developing with it.
<P>
The conditions for using wxWindows 2 are the same whether you are a personal, academic
or commercial developer.
<P>
<h3><a name="support">Is there support?</a></h3>
No official support, but the mailing list is very helpful and some people say that
wxWindows support is better than for much commercial software. The developers are
keen to fix bugs as soon as possible, though obviously there are no guarantees.
<P>
<H3><a name="users">Who uses wxWindows?</a></H3>
Many organisations - commercial, government, and academic - across the
world. It&#39;s impossible to estimate the true number of users, since
wxWindows is obtained by many different means, and we cannot monitor
distribution. The mailing list contains around 300-400 entries which is
quite large for a list of this type.<P>
See <a href="users.htm">Users</a> for a list of some users and their applications, and
also <A href="feedback.htm">Feedback</a> for comments.<P>
Our highest-profile user yet is industry veteran and Lotus Corp. founder Mitch Kapor
and his <a href="http://www.osafoundation.org" target=_new>Open Source Applications Foundation</a>.
<P>
<H3><a name="platforms">What platforms are supported by wxWindows 2?</a></H3>
<ul>
<li>Windows 3.1, Windows 95/98, Windows NT, Windows 2000, Windows ME.
<li>Linux and other Unix platforms with GTK+.
<li>Unix with Motif or the free Motif clone Lesstif.
<li>Mac OS.
<li>Embedded platforms are being investigated. See the <a href="wxuniv.htm">wxUniversal</a> project.
<li>An OS/2 port is in progress, and you can also compile wxWindows for GTK+ or Motif
on OS/2.
</ul>
<P>
<H3><a name="specific">How does wxWindows 2 support platform-specific
features?</a></H3>
This is a hotly-debated topic amongst the developers. My own philosophy
is to make wxWindows as platform-independent as possible, but allow in a
few classes (functions, window styles) that are platform-specific.
For example, Windows metafiles and Windows 95 taskbar icons have
their own classes on Windows, but nowhere else. Because these classes
are provided and are wxWindows-compatible, it doesn&#39;t take much
coding effort for an application programmer to add support for
some functionality that the user on a particular platform might otherwise
miss. Also, some classes that started off as platform-specific, such
as the MDI classes, have been emulated on other platforms. I can imagine
that even wxTaskBarIcon may be implemented for Unix desktops one day.
<P>
In other words, wxWindows is not a &#39;lowest common denominator&#39; approach,
but it will still be possible to write portable programs using the
core API. Forbidding some platform-specific classes would be a stupid
approach that would alienate many potential users, and encourage
the perception that toolkits such as wxWindows are not up to the demands
of today&#39;s sophisticated applications.<P>
Currently resources such as bitmaps and icons are handled in a platform-specific
way, but it is hoped to reduce this dependence in due course.<P>
Another reason why wxWindows 2 is not a &#39;lowest common denominator&#39; toolkit is that
some functionality missing on some platform has been provided using generic,
platform-independent code, such as the wxTreeCtrl and wxListCtrl classes.<P>
<H3><a name="stl">Does wxWindows use STL? or the standard string class?</a></H3>
No. This is a much-discussed topic that has (many times) ended with the conclusion that it is in
wxWindows&#39; best interests to avoid use of templates. Not all compilers can handle
templates adequately so it would dramatically reduce the number of compilers
and platforms that could be supported. It would also be undersirable to make
wxWindows dependent on another large library that may have to be downloaded and installed.
In addition, use of templates can lead to executable bloat, which is something
wxWindows 2 is strenously trying to avoid.<P>
The standard C++ string class is not used, again because it is not available to all compilers,
and it is not necessarily a very efficient implementation. Also, we retain more flexibility
by being able to modify our own string class. Some compatibility with the string class
has been built into wxString.<P>
There is nothing to stop an application using templates or the string class for its own
purposes. With wxWindows debugging options on, you may find you get errors when including
STL headers. You can work around it either by switching off memory checking,
or by adding this to a header before you include any STL files:<P>
<PRE>
&#35;ifdef new
&#35;undef new
&#35;endif
</PRE>
<P>
<H3><a name="richedit">Is there a rich edit/markup widget for wxWindows 2?</a></H3>
These are the possibilities so far:<P>
<ul>
<li>See <a href="http://www.scintilla.org" target=_top>www.scintilla.org</a> for
a very nice syntax-highlighting editor widget. Robin Dunn has written a wxWindows wrapper
for this widget, available in the wxWindows distribution under contrib/src/stc.
<li>If you only need to display marked-up information, rather than edit it,
then wxHTML will suit your needs. wxHTML is built into wxWindows - please see the reference
manual for details, and samples/html.
<li>There are rich edit widgets in both WIN32 and GTK+, but there is currently
no wxWindows wrapper for these (but text attribute functions are being added in the wxWindows 2.3.x series).
</ul>
<P>
<h3><a name="exceptions">How to use C++ exceptions with wxWindows?</a></h3>
wxWindows library itself is unfortunately <i>not</i> exception-safe (as its
initial version predates, by far, the addition of the exceptions to the C++
language). However you can still use the exceptions in your own code and use
the other libraries using the exceptions for the error reporting together with
wxWindows.
<p>
There are a few issues to keep in mind, though:
<ul>
<li>You shouldn&#39;t let the exceptions propagate through wxWindows code,
in particular you should always catch the exceptions thrown by the
functions called from an event handler in the handler itself and not
let them propagate upwards to wxWindows.
<li>You may need to ensure that the compiler support for the exceptions is
enabled as, considering that wxWindows itself doesn&#39;t use the
exceptions and turning their support on results in the library size
augmentation of 10% to 20%, it is turned off by default for a few
compilers. Moreover, for gcc (or at least its mingw version) you must
also turn on the RTTI support to be able to use the exceptions, so you
should use <tt>--disable-no_rtti --disable-no_exceptions</tt> options
when configuring the library (attention to the double negation).
</ul>
<p>
<H3><a name="dev">How is wxWindows being developed?</a></H3>
We are using the <a href="cvs.htm">CVS</a> system to develop and maintain wxWindows. This allows
us to make alterations and upload them instantly to the server, from
which others can update their source.<P>
To build source from CVS, see the file BuildCVS.txt in the top-level wxWindows distribution
directory.<P>
<H3><a name="distrib">How is wxWindows distributed?</a></H3>
By ftp, and via the <a href="cdrom2.htm">wxWindows CD-ROM</a>.
<P>
If you are feeling adventurous, you may also check out the sources directly
from <a href="cvs.htm">cvs</a>.
<p>
<H3><a name="future">What are the plans for the future?</a></H3>
Currently we&#39;re working too hard on getting wxWindows finished (are GUI toolkits ever
finished?) to think very far ahead. However, we know we want to make wxWindows as robust
and well-publicised as possible. We also want to aim for better platform-independence of
resources such as icons and bitmaps, standardising on PNG and XPM for all platforms.<P>
Other possibilities include: DCOM/CORBA compatibility; a wxWindows book;
<a href="http://wxworkshop.sourceforge.net/">wxWorkshop</a>, an IDE;
other platforms, especially embedded systems; other interface abilities such as speech output.<P>
We will investigate the possibility of compiler or operating system vendors bundling wxWindows with
their product.<P>
The high-level goal of wxWindows is to be thought of as the number one C++ framework,
for virtually any platform. Move over, MFC!<P>
<h3><a name="base">What is wxBase?</a></h3>
wxBase is a subset of wxWindows comprised by the non-GUI classes. It includes
wxWindows container and primitive data type classes (including wxString,
wxDateTime and so on) and also useful wrappers for the operating system objects
such as files, processes, threads, sockets and so on. With very minor
exceptions wxBase may be used in exactly the same way as wxWindows but it
doesn&#39;t require a GUI to run and so is ideal for creating console mode
utilities or server programs. It is also possible to create a program which can
be compiled either as a console application (using wxBase) or a GUI one (using
a full featured wxWindows port).
<H3><a name="univ">What is wxUniversal?</a></H3>
The main difference between wxUniversal-based ports (such as wxX11, wxMGL) and other ports (such as wxMSW, wxGTK+, wxMac)
is that wxUniversal implements all controls (or widgets) in
wxWindows itself thus allowing to have much more flexibility (for example, support for
themes even under MS Windows). It also means that it is now much easier to
port wxWindows to a new platform as only the low-level classes must be ported
which make for a small part of the library.
<p>
You may find more about wxUniversal <a href=wxuniv.htm>here</a>.
<H3><a name="jave">What about Java?</a></H3>
The Java honeymoon period is over :-) and people are realising that it cannot
meet all their cross-platform development needs. We don&#39;t anticipate a major threat
from Java, and the level of interest in wxWindows is as high as ever.<P>
<H3><a name="dotnet">What about .NET/Mono?</a></H3>
Microsoft is spending a lot on promoting the .NET initiative, which
is a set of languages, APIs and web service components for Windows.
Ximian has started an open source version of .NET, mostly for Linux.
C&#35; is Microsoft's alternative to Java, supporting 'managed code',
garbage collection and various other Java-like language features.<P>
Although this may be attractive to some developers, there
is a variety of reasons why the .NET/Mono combination is unlikely
to make wxWindows redundant. Please note that the following comments
are Julian Smart's opinions.<P>
<ol>
<li>Not everyone wants or needs net services.
<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.
<li>Mono Forms may only target Winelib (at least to begin with), so the end result is not as native as
wxWindows (I'm aware there is GTK&#35; for use with the C&#35; language).
<li>C&#35; is usually byte-compiled and therefore slower. Plus, .NET adds a layer of overhead to the client computer
that wxWindows does not require.
<li>Mono hasn't proven its long-term viability yet (it's a complex system of components); wxWindows is ready now.
<li>You may not wish to buy into Microsoft marketing spin and APIs.
<li>.NET might never be implemented on some platforms, especially Mac and embedded variants of Linux.
<li>wxPython and other language variants provide further reasons for wxWindows to continue.
<li>The same issue exists for Qt: if Qt sales remain strong, it's a good indication that
the market for a C++-based approach is still there. (Either that, or everyone's turning to wxWindows!)
</ol>
There is nothing to stop folk from developing a C&#35; version of the wxWindows API;
we already have bindings to Python, Perl, JavaScript, Lua, Basic, and Eiffel.
Update: a <a href="http://wxnet.sourceforge.net/" target=_new>wx.NET</a> project is now in progress.
<P>
<H3><a name="help">How can I help the project?</a></H3>
Please check out the <a href="http://www.wxwindows.org/develop2.htm">Community</a> pages,
in particular the <a href="projects.htm">suggested projects</a>, and
mail the developers&#39; mailing list with your own suggestions.<P>
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