1 2<HTML> 3 4<HEAD> 5<TITLE>wxWidgets for GTK FAQ</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 for GTK FAQ</b> 17</font> 18</td> 19</tr> 20</table> 21 22<P> 23 24See also <a href="faq.htm">top-level FAQ page</a> 25and <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 for GTK+?</a></li> 31<li><a href="#locale">Why doesn'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 for GTK?</a></h3> 43 44wxWidgets for GTK is a port of wxWidgets to the <a href="http://www.gimp.org/gtk" target=_top>GTK+ toolkit</a>, 45which is freely available for most flavours of Unix with X. wxWidgets for GTK is 46often 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't reading floating point numbers work when using wxWidgets?</a></h3> 50 51If your program reads the floating point numbers in the format <tt>123.45</tt> 52from a file, it may suddenly start returning just <tt>123</tt> instead of the 53correct value on some systems -- which is all the more mysterious as the same 54code in a standalone program works just fine. 55 56<p> 57The explanation is that GTK+ changes the current locale on program startup. If 58the decimal point character in the current locale is not the period (for 59example, it is comma in the French locale), all the standard C functions won't 60recognize the numbers such as above as floating point ones any more. 61 62<p> 63The solution is to either use your own function for reading the floating point 64numbers (probably the best one) or to call <tt>setlocale(LC_NUMERIC, "C")</tt> 65before 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 69Currently wxGTK does not have any features that would involve dependence on any desktop 70environment's libraries, so it can work on GNOME, KDE and with other window managers 71without installation hassles. Some GNOME and KDE integration features are file based, and 72so may be added without dependence on libraries. Other features may be supported in the 73future, probably as a separate library. 74<P> 75 76<h3><a name="redhat">Warning about GTK+ libraries supplied with RedHat</a></h3> 77 78It seems that some versions of RedHat include a badly patched version of GTK+ (not wxGTK) 79which causes some trouble with wxWidgets' socket code. Common symptoms are that when 80a client tries to establish a connection to an existing server which refuses the request, 81the client will get notified twice, first getting a LOST event and then a CONNECT event. 82This 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 87Robert Roebling replies:<P> 88 89"The important thing is the libc version that your app 90is linked against. The most recent version is 2.2.5 91and programs linked against it will not run with version 922.1.X so that you will fare best if you compile your app 93on a 2.1.X system. It will then run on practically all 94Linux distros (if you link you app statically against 95the image libraries and std C++ lib)." 96<P> 97 98<h3><a name="#static">Can I statically link the GTK+ library?</a></h3> 99 100No, 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 106In wxGTK, the frames never get focus and so can never receive <tt>CHAR</tt> 107nor <tt>KEY</tt> events so an <tt>EVT_CHAR</tt> handler for a frame will be 108never called. To receive these events, you should create a <tt>wxPanel</tt> 109inside the frame and register the key event handlers for the panel, not the 110frame. 111 112<p> 113 114<h3><a name="#debugging">How do I trace the cause of an X11 error such as BadMatch?</h3> 115 116When a fatal X11 error occurs, the application quits with no stack trace. 117To find out where the problem is, put a breakpoint on g_log (<tt>b g_log</tt> 118in gdb). 119 120<p> 121 122</font> 123 124</BODY> 125 126</HTML> 127
