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Date: Fri, 13 Feb 2004 17:03:16 +0100
From: Max Horn
Subject: Modifier key fix
The internal modifier state can get out of sync with reality. To
trigger this, do for example this:
1) Launch an SDL app
2) Alt-click on the desktop (this will hide the SDL app).
3) Bring the SDL app back to the front
4) SDL will still think alt is pressed (and as such will treat left
clicks like middle clicks). If you press and release alt, it'll be fine
again.
The attached patch cures this by rechecking the modifier state whenever
we process an event.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 13 Feb 2004 17:57:16 +0000 |
parents | 355632dca928 |
children |
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<HTML ><HEAD ><TITLE >Events</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="SDL Reference" HREF="reference.html"><LINK REL="PREVIOUS" TITLE="SDL_WM_GrabInput" HREF="sdlwmgrabinput.html"><LINK REL="NEXT" TITLE="SDL Event Structures." HREF="eventstructures.html"><META NAME="KEYWORD" CONTENT="events"><META NAME="KEYWORD" CONTENT="function"></HEAD ><BODY CLASS="CHAPTER" 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="sdlwmgrabinput.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="eventstructures.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="EVENT" ></A >Chapter 8. Events</H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT ><A HREF="event.html#AEN3691" >Introduction</A ></DT ><DT ><A HREF="eventstructures.html" >SDL Event Structures.</A ></DT ><DT ><A HREF="eventfunctions.html" >Event Functions.</A ></DT ></DL ></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="AEN3691" ></A >Introduction</H1 ><P >Event handling allows your application to receive input from the user. Event handling is initalised (along with video) with a call to: <PRE CLASS="PROGRAMLISTING" >SDL_Init(SDL_INIT_VIDEO);</PRE > Internally, SDL stores all the events waiting to be handled in an event queue. Using functions like <A HREF="sdlpollevent.html" ><TT CLASS="FUNCTION" >SDL_PollEvent</TT ></A > and <A HREF="sdlpeepevents.html" ><TT CLASS="FUNCTION" >SDL_PeepEvents</TT ></A > you can observe and handle waiting input events.</P ><P >The key to event handling in SDL is the <A HREF="sdlevent.html" ><SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN ></A > union. The event queue itself is composed of a series of <SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN > unions, one for each waiting event. <SPAN CLASS="STRUCTNAME" >SDL_Event</SPAN > unions are read from the queue with the <TT CLASS="FUNCTION" >SDL_PollEvent</TT > function and it is then up to the application to process the information stored with them.</P ></DIV ></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="sdlwmgrabinput.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="eventstructures.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_WM_GrabInput</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="reference.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL Event Structures.</TD ></TR ></TABLE ></DIV ></BODY ></HTML >