-|
+ |
-wxWindows 2 FAQ: General
+wxWidgets FAQ: General
|
@@ -22,45 +23,345 @@ wxWindows 2 FAQ: General
See also top-level FAQ page.
+List of questions in this category
+
+
-
+
-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 'look and feel' that users are familiar with.
+wxWidgets is a class library that allows you to compile graphical C++ programs on a range of
+different platforms. wxWidgets 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 'look and feel' that users are familiar with.
-Although GUI applications are mostly built programmatically, there is a dialog editor to help
-build attractive dialogs and panels.
+Although GUI applications are mostly built programmatically, there are several dialog editors to help
+build attractive dialogs and panels. Robert Roebling's wxDesigner
+and Anthemion Software's DialogBlocks
+are two commercial examples, but there are others: see the Useful Tools page.
-You don't have to use C++ to use wxWindows: wxWindows 1 has been interfaced to several interpreted languages,
-such as CLIPS, Python, Scheme, XLisp and Perl, and there is a Python interface for wxWindows 2.
+You don't have to use C++ to use wxWidgets: there is a Python interface for wxWidgets,
+and also a Perl interface.
-
Can I use wxWindows 2 for both proprietary (commercial) projects, and GPL'ed projects?
+
Yes. Please see the licence for details, but basically
-you can distribute proprietary binaries without distributing any source code, and neither will wxWindows
+you can distribute proprietary binaries without distributing any source code, and neither will wxWidgets
conflict with GPL code you may be using or developing with it.
-The conditions for using wxWindows 2 are the same whether you are a personal, academic
+The conditions for using wxWidgets are the same whether you are a personal, academic
or commercial developer.
-
Is there support?
+
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
+wxWidgets 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.
-
+
Many organisations - commercial, government, and academic - across the
-world. It's impossible to estimate the true number of users, since
-wxWindows is obtained by many different means, and we cannot monitor
+world. It's impossible to estimate the true number of users, since
+wxWidgets 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.
+See Users for a list of some users and their applications, and
+also Feedback for comments.
+Our highest-profile user yet is industry veteran and Lotus Corp. founder Mitch Kapor
+and his Open Source Applications Foundation.
+
+
+
+
+
+- Windows 3.1, Windows 95/98, Windows NT, Windows 2000, Windows ME.
+
- Linux and other Unix platforms with GTK+.
+
- Unix with Motif or the free Motif clone Lesstif.
+
- Mac OS.
+
- Embedded platforms are being investigated. See the wxUniversal project.
+
- An OS/2 port is in progress, and you can also compile wxWidgets for GTK+ or Motif
+on OS/2.
+
+
+
+
+
+This is a hotly-debated topic amongst the developers. My own philosophy
+is to make wxWidgets 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 wxWidgets-compatible, it doesn'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.
+
+
+In other words, wxWidgets is not a 'lowest common denominator' 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 wxWidgets are not up to the demands
+of today's sophisticated applications.
+
+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.
+
+Another reason why wxWidgets is not a 'lowest common denominator' toolkit is that
+some functionality missing on some platform has been provided using generic,
+platform-independent code, such as the wxTreeCtrl and wxListCtrl classes.
+
+
+
+No. This is a much-discussed topic that has (many times) ended with the conclusion that it is in
+wxWidgets' 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 undesirable to make
+wxWidgets 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
+wxWidgets is strenuously trying to avoid.
+
+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.
+
+There is nothing to stop an application using templates or the string class for its own
+purposes. With wxWidgets 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:
+
+
+#ifdef new
+#undef new
+#endif
+
+
+
+
+
+
+
+These are the possibilities so far:
+
+
+- See www.scintilla.org for
+a very nice syntax-highlighting editor widget. Robin Dunn has written a wxWidgets wrapper
+for this widget, available in the wxWidgets distribution under contrib/src/stc.
+
- If you only need to display marked-up information, rather than edit it,
+then wxHTML will suit your needs. wxHTML is built into wxWidgets - please see the reference
+manual for details, and samples/html.
+
- There are rich edit widgets in both WIN32 and GTK+, but there is currently
+no wxWidgets wrapper for these (but text attribute functions are being added in the wxWidgets 2.3.x series).
+
+
+
+
+
+
+wxWidgets library itself is unfortunately not 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
+wxWidgets.
+
+
+There are a few issues to keep in mind, though:
+
+ - You shouldn't let the exceptions propagate through wxWidgets 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 wxWidgets.
+
+
- You may need to ensure that the compiler support for the exceptions is
+ enabled as, considering that wxWidgets itself doesn'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 --disable-no_rtti --disable-no_exceptions options
+ when configuring the library (attention to the double negation).
+
+
+
+
+
+
+We are using the CVS system to develop and maintain wxWidgets. This allows
+us to make alterations and upload them instantly to the server, from
+which others can update their source.
+
+To build source from CVS, see the file BuildCVS.txt in the top-level wxWidgets distribution
+directory.
+
+
+
+By ftp, and via the wxWidgets CD-ROM.
+
+If you are feeling adventurous, you may also check out the sources directly
+from cvs.
+
+
+
+
+
+
+wxBase is a subset of wxWidgets comprised by the non-GUI classes. It includes
+wxWidgets 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 wxWidgets but it
+doesn'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 wxWidgets port).
+
+
+
+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
+wxWidgets 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 wxWidgets to a new platform as only the low-level classes must be ported
+which make for a small part of the library.
+
+You may find more about wxUniversal here.
+
+
+
+The Java honeymoon period is over :-) and people are realising that it cannot
+meet all their cross-platform development needs. We don't anticipate a major threat
+from Java, and the level of interest in wxWidgets is as high as ever.
+
+
+
+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# is Microsoft's alternative to Java, supporting 'managed code',
+garbage collection and various other Java-like language features.
+
+Although this may be attractive to some developers, there
+is a variety of reasons why the .NET/Mono combination is unlikely
+to make wxWidgets redundant. Please note that the following comments
+are Julian Smart's opinions.
+
+
+- Not everyone wants or needs net services.
+
- C++ will be used for a long time to come; compared with C++, C# is a recent development and its future is not certain.
+
- Mono Forms may only target Winelib (at least to begin with), so the end result is not as native as
+wxWidgets (I'm aware there is GTK# for use with the C# language).
+
- C# is usually byte-compiled and therefore slower. Plus, .NET adds a layer of overhead to the client computer
+that wxWidgets does not require.
+
- Mono hasn't proven its long-term viability yet (it's a complex system of components); wxWidgets is ready now.
+
- You may not wish to buy into Microsoft marketing spin and APIs.
+
- Microsoft may at some point sue developers of non-Microsoft .NET implementations. After all,
+platform-independence is not in Microsoft's interest.
+
- .NET might never be implemented on some platforms, especially Mac and embedded variants of Linux.
+
- wxPython and other language variants provide further reasons for wxWidgets to continue.
+
- 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 wxWidgets!)
+
+
+There is nothing to stop folk from developing a C# version of the wxWidgets API;
+we already have bindings to Python, Perl, JavaScript, Lua, Basic, and Eiffel.
+Update: a wx.NET project is now in progress.
+
+
+
+
+
+Please check out the Community pages,
+in particular the suggested projects, and
+mail the developers' mailing list with your own suggestions.
+
+
+
+Please subscribe to the wx-dev developers' mailing list and
+ask if anyone else is interested in helping with the port, or
+has specific suggestions. Also please read the coding standards.
+
+
+Each port consists of a platform-specific part (e.g. src/msw, include/wx/msw),
+a generic set of widgets and dialogs for when the port doesn't support
+them natively (src/generic, include/wx/generic) and the common code
+that all ports use (src/common, include/wx). By browsing the source
+you should get a good idea of the general pattern.
+
+Take a port that most closely matches your port, and strip out
+the implementation so you have a skeleton port that compiles. Ask on wx-dev
+first for the wxStubs port - however, any such predefined skeleton
+port may be out of date, so make a judgement on whether to use it.
+Perhaps it will still save you time to clean up wxStubs, and
+others may benefit from this too.
+
+You will need to define a symbol for the new port, e.g. __WXXBOX__.
+Look at files such as wx/defs.h, wx/wxchar.h for areas where you'll
+need to add to existing conditionals to set up wide character
+support and other issues. If the GUI runs on a Unix variant,
+define the __UNIX__ variable in your makefile.
+
+Then you can start implementing the port, starting with
+wxWindow, wxTopLevelWindow, wxFrame, wxDialog so you
+can get the minimal sample running as soon as possible.
+
+If GDI objects (wxPen, wxBrush, etc.) are not concepts in your
+native GUI, you may wish to use very generic versions of
+some of these - see the wxX11 port.
+
+Consider using the wxUniversal widget set as a quick way
+to implement wxWidgets on your platform. You only need
+to define some basic classes such as device contexts,
+wxWindow, wxTopLevelWindow, GDI objects etc. and
+the actual widgets will be drawn for you. See wxX11,
+wxMGL, and wxMSW/Univ for sample wxUniversal ports.
+
+To begin with, you can use whatever makefiles or project
+files work for you. Look at existing makefiles to see what
+generic/common/Unix files need to be included. Later, you'll want to integrate support
+for your port into configure (Unix-like systems and gcc under Windows),
+and bakefile (for other makefiles on Windows).
+
+Submit your port as patches via SourceForge; you might
+wish to separate it into one patch that touches common headers
+and source files, and another containing the port-specific code, to make
+it much easier for us to review and apply the patches.
+
+Good luck!
+