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  16 <b>wxWidgets 2 for GTK FAQ</b>
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  22 <P>
  23
  24 See also <a href="faq.htm">top-level FAQ page</a>
  25 and <a href="faqunx.htm">Unix FAQ page</a>.
  26 <hr>
  27 <h3>List of questions in this category</h3>
  28
  29 <ul>
  30 <li><a href="#wxgtk">What is wxWidgets 2 for GTK+?</a></li>
  31 <li><a href="#locale">Why doesn&#39;t reading floating point numbers work when using wxWidgets?</a></li>
  32 <li><a href="#gnome">Does wxGTK have GNOME support?</a></li>
  33 <li><a href="#redhat">Warning about GTK libraries supplied with RedHat</a></li>
  34 <li><a href="#bincompat">What range of Intel Linux platforms will a given application binary be usable on?</a></li>
  35 <li><a href="#static">Can I statically link the GTK+ library?</a></li>
  36 <li><a href="#charinframe">Why does my simple program using <tt>EVT_CHAR</tt> not work?</a></li>
  37 <li><a href="#debugging">How do I trace the cause of an X11 error such as BadMatch?</a></li>
  38 </ul>
  39
  40 <hr>
  41
  42 <h3><a name="wxgtk">What is wxWidgets 2 for GTK?</a></h3>
  43
  44 wxWidgets 2 for GTK is a port of wxWidgets to the <a href="http://www.gimp.org/gtk" target=_top>GTK+ toolkit</a>,
  45 which is freely available for most flavours of Unix with X. wxWidgets 2 for GTK is
  46 often abbreviated to wxGTK. wxGTK has a separate home page <a href="http://www.freiburg.linux.de/~wxxt" target=_top>here</a>.
  47 <P>
  48
  49 <h3><a name="locale">Why doesn&#39;t reading floating point numbers work when using wxWidgets?</a></h3>
  50
  51 If your program reads the floating point numbers in the format <tt>123.45</tt>
  52 from a file, it may suddenly start returning just <tt>123</tt> instead of the
  53 correct value on some systems -- which is all the more mysterious as the same
  54 code in a standalone program works just fine.
  55
  56 <p>
  57 The explanation is that GTK+ changes the current locale on program startup. If
  58 the decimal point character in the current locale is not the period (for
  59 example, it is comma in the French locale), all the standard C functions won&#39;t
  60 recognize the numbers such as above as floating point ones any more.
  61
  62 <p>
  63 The solution is to either use your own function for reading the floating point
  64 numbers (probably the best one) or to call <tt>setlocale(LC_NUMERIC, "C")</tt>
  65 before reading from file and restore the old locale back afterwards if needed.
  66
  67 <h3><a name="gnome">Does wxGTK have GNOME support?</a></h3>
  68
  69 Currently wxGTK does not have any features that would involve dependence on any desktop
  70 environment&#39;s libraries, so it can work on GNOME, KDE and with other window managers
  71 without installation hassles. Some GNOME and KDE integration features are file based, and
  72 so may be added without dependence on libraries. Other features may be supported in the
  73 future, probably as a separate library.
  74 <P>
  75
  76 <h3><a name="redhat">Warning about GTK+ libraries supplied with RedHat</a></h3>
  77
  78 It seems that some versions of RedHat include a badly patched version of GTK+ (not wxGTK)
  79 which causes some trouble with wxWidgets&#39; socket code. Common symptoms are that when
  80 a client tries to establish a connection to an existing server which refuses the request,
  81 the client will get notified twice, first getting a LOST event and then a CONNECT event.
  82 This problem can be solved by updating GTK with an official distribution of the library.
  83 <P>
  84
  85 <h3><a name="bincompat">What range of Intel Linux platforms will a given application binary be usable on?</h3>
  86
  87 Robert Roebling replies:<P>
  88
  89 "The important thing is the libc version that your app
  90 is linked against. The most recent version is 2.2.5
  91 and programs linked against it will not run with version
  92 2.1.X so that you will fare best if you compile your app
  93 on a 2.1.X system. It will then run on practically all
  94 Linux distros (if you link you app statically against
  95 the image libraries and std C++ lib)."
  96 <P>
  97
  98 <h3><a name="#static">Can I statically link the GTK+ library?</a></h3>
  99
 100 No, this is not possible. It leads to crashes in GTK+.
 101 <P>
 102
 103 <h3><a name="#charinframe">Why does my simple program using
 104 <tt>EVT_CHAR</tt> not work?</a></h3>
 105
 106 In wxGTK, the frames never get focus and so can never receive <tt>CHAR</tt>
 107 nor <tt>KEY</tt> events so an <tt>EVT_CHAR</tt> handler for a frame will be
 108 never called. To receive these events, you should create a <tt>wxPanel</tt>
 109 inside the frame and register the key event handlers for the panel, not the
 110 frame.
 111
 112 <p>
 113
 114 <h3><a name="#debugging">How do I trace the cause of an X11 error such as BadMatch?</h3>
 115
 116 When a fatal X11 error occurs, the application quits with no stack trace.
 117 To find out where the problem is, put a breakpoint on g_log (<tt>b g_log</tt>
 118 in gdb).
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