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Date: Thu, 19 Jan 2006 20:02:29 +0200 From: Vassilis Virvilis <vasvir@iit.demokritos.gr> Subject: [SDL] Request: Please reconsider adding tag in SDL_Event Hi, Patch in question: --- include/SDL_events.h 20 Aug 2004 18:57:01 -0000 1.11 +++ include/SDL_events.h 19 Jan 2006 17:35:09 -0000 @@ -214,7 +214,7 @@ } SDL_SysWMEvent; /* General event structure */ -typedef union { +typedef union SDL_Event { Uint8 type; SDL_ActiveEvent active; SDL_KeyboardEvent key; Reasoning: ---------- 1) Allows forward declaration of the SDL_Event union in C++. Please note that in plain C it is possible to forward declare it. 2) Forward declaration is good because it allows encapsulation. It hides the specific implementation and does not necessarily exposes SDL staff to my appication's namespace 3) It can't harm plain C because tags are living in a different namespace than typenames 4) It is already done like this in other places in SDL. Check for example SDL_KeySym, and SDL_.*Event structures. 5) Right now I have to include SDL/event.h from a C++ header file. See 2)
author Sam Lantinga <slouken@libsdl.org>
date Fri, 20 Jan 2006 13:07:25 +0000
parents 355632dca928
children
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<HTML
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>SDL_SetEventFilter</TITLE
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><H1
><A
NAME="SDLSETEVENTFILTER"
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>SDL_SetEventFilter</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN5575"
></A
><H2
>Name</H2
>SDL_SetEventFilter&nbsp;--&nbsp;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
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><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
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><BLOCKQUOTE
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><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
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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
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><A
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></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
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><TT
CLASS="FUNCTION"
>SDL_PushEvent</TT
></A
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