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view docs/html/sdlpollevent.html @ 615:7ec821f3cbd0
Date: Thu, 17 Apr 2003 23:27:34 -0400
From: Darrell Walisser
Subject: Yet another OS X cursor bug
The synopsis:
1. Call SDL_ShowCursor(0);
2. Call SDL_SetVideoMode();
3. Call SDL_GetEvent();
3. Call SDL_ShowCursor(1);
The result: Sometimes the cursor doesn't come back! Ack! Oddly enough,
it does come back when mousing over the dock or clicking in the menu
bar. But that's besides the point.
The reason why this is happening is a flaw in the handling of
activation/deactivation events. The short explanation is that the
HideCursor() and ShowCursor() calls must be balanced, but if the cursor
was initially hidden, HideCursor() was called again on the activate
event - so now the next ShowCursor() fails (as does the next, and the
next, for some reason).
So, here's the patch. All it does is keep track of the
HideCursor()/ShowCursor() calls so that they will always be balanced.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 20 Apr 2003 05:41:16 +0000 |
parents | e5bc29de3f0a |
children | 355632dca928 |
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<HTML ><HEAD ><TITLE >SDL_PollEvent</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.64 "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Event Functions." HREF="eventfunctions.html"><LINK REL="PREVIOUS" TITLE="SDL_PeepEvents" HREF="sdlpeepevents.html"><LINK REL="NEXT" TITLE="SDL_WaitEvent" HREF="sdlwaitevent.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><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="sdlpeepevents.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlwaitevent.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLPOLLEVENT" >SDL_PollEvent</A ></H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN5084" ></A ><H2 >Name</H2 >SDL_PollEvent -- Polls for currently pending events.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN5087" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN5088" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_PollEvent</B ></CODE >(SDL_Event *event);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN5094" ></A ><H2 >Description</H2 ><P >Polls for currently pending events, and returns <SPAN CLASS="RETURNVALUE" >1</SPAN > if there are any pending events, or <SPAN CLASS="RETURNVALUE" >0</SPAN > if there are none available. </P ><P >If <TT CLASS="PARAMETER" ><I >event</I ></TT > is not <TT CLASS="LITERAL" >NULL</TT >, the next event is removed from the queue and stored in that area.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN5102" ></A ><H2 >Examples</H2 ><P ><PRE CLASS="PROGRAMLISTING" >SDL_Event event; /* Event structure */ . . . /* Check for events */ while(SDL_PollEvent(&event)){ /* Loop until there are no events left on the queue */ switch(event.type){ /* Process the appropiate event type */ case SDL_KEYDOWN: /* Handle a KEYDOWN event */ printf("Oh! Key press\n"); break; case SDL_MOUSEMOTION: . . . default: /* Report an unhandled event */ printf("I don't know what this event is!\n"); } }</PRE ></P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN5106" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A >, <A HREF="sdlwaitevent.html" ><TT CLASS="FUNCTION" >SDL_WaitEvent</TT ></A >, <A HREF="sdlpeepevents.html" ><TT CLASS="FUNCTION" >SDL_PeepEvents</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlpeepevents.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlwaitevent.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_PeepEvents</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="eventfunctions.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_WaitEvent</TD ></TR ></TABLE ></DIV ></BODY ></HTML >