Mercurial > sdl-ios-xcode
view docs/html/sdlseteventfilter.html @ 855:aa4ac9e65d92
I noticed MacOSX SDL sets up working directory to parent of executable.
On BeOS is should setup it the same way, but it only does when Tracker
wasn't restarted.
I checked code and it looks like a hack to me :(
It looks for env variable and than comapres it to default when OpenTracker
was started after boot, and wasn't restarted. That's probably ok, for that
exact case. Unfortunetly that variable isn't always like that. For
example, after Tracker crashes and is restarted, env variable most
probably is different (depends on how Tracker was restarted, by what
application, etc... for example: i have launcher application from which i
can restart Tracker, and after that nev variable points to that
application's directory, not Tracker's).
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 24 Feb 2004 18:58:40 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >SDL_SetEventFilter</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Event Functions." HREF="eventfunctions.html"><LINK REL="PREVIOUS" TITLE="SDL_PushEvent" HREF="sdlpushevent.html"><LINK REL="NEXT" TITLE="SDL_GetEventFilter" HREF="sdlgeteventfilter.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdlpushevent.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlgeteventfilter.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSETEVENTFILTER" ></A >SDL_SetEventFilter</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN5575" ></A ><H2 >Name</H2 >SDL_SetEventFilter -- Sets up a filter to process all events before they are posted to the event queue.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN5578" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN5579" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >void <B CLASS="FSFUNC" >SDL_SetEventFilter</B ></CODE >(SDL_EventFilter filter);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN5585" ></A ><H2 >Description</H2 ><P >This function sets up a filter to process all events before they are posted to the event queue. This is a very powerful and flexible feature. The filter is prototyped as: <PRE CLASS="PROGRAMLISTING" >typedef int (*SDL_EventFilter)(const SDL_Event *event);</PRE > If the filter returns <SPAN CLASS="RETURNVALUE" >1</SPAN >, then the event will be added to the internal queue. If it returns <SPAN CLASS="RETURNVALUE" >0</SPAN >, then the event will be dropped from the queue. This allows selective filtering of dynamically.</P ><P >There is one caveat when dealing with the <TT CLASS="LITERAL" >SDL_QUITEVENT</TT > event type. The event filter is only called when the window manager desires to close the application window. If the event filter returns 1, then the window will be closed, otherwise the window will remain open if possible. If the quit event is generated by an interrupt signal, it will bypass the internal queue and be delivered to the application at the next event poll.</P ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >Events pushed onto the queue with <A HREF="sdlpushevent.html" ><TT CLASS="FUNCTION" >SDL_PushEvent</TT ></A > or <A HREF="sdlpeepevents.html" ><TT CLASS="FUNCTION" >SDL_PeepEvents</TT ></A > do not get passed through the event filter.</P ></BLOCKQUOTE ></DIV ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B ><SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >Be Careful!</I ></SPAN > The event filter function may run in a different thread so be careful what you do within it.</P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN5602" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A >, <A HREF="sdlgeteventfilter.html" ><TT CLASS="FUNCTION" >SDL_GetEventFilter</TT ></A >, <A HREF="sdlpushevent.html" ><TT CLASS="FUNCTION" >SDL_PushEvent</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlpushevent.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlgeteventfilter.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_PushEvent</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="eventfunctions.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_GetEventFilter</TD ></TR ></TABLE ></DIV ></BODY ></HTML >