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