view docs/html/sdlseteventfilter.html @ 1585:980d2a0dc2a3

Date: Tue, 4 Mar 2003 15:05:31 -0800 From: "Jim" Subject: [SDL] Frame Buffer patches... Okay I'm new at patch generation - so please tell me if there's a better way I could have done this. Attached are two patch files generated with 'cvs diff -u' SDL-fb-open-lock.patch applies to SDL_fbvideo.c Modifies the open loop to check /dev/fb/0 found on devfs... Modifies the lock code to return failure if the current virtual terminal is not the one opened for frame buffer writing... Lock would hang forever if switched away (ctrl-alt-F1) ... SDL-fb-mousedrv-screensave.patch applies to SDL_fbevents.c Switches default mouse mode based on SDL_MOUSEDRV - currently only accepts PS2 - otherwise default is MS Mouse. When the screen is switched - exisiting code (wrapped in ifdef SAVE_SCREEN_COTENTS) would save the wrong bit of the screen.... ( I run frame buffer 1600x1200, the size I requested was 800x600 - the save would save the top 800 lines (non biased) and restore them... Adding screen->offset fixed that ) However, if that option is not set, then a call to SDL_UpdateRect (full screen) is made. (which may have had it's contents changed since the screen is not entirely locked because of lock-failure patch) Jim [patches slightly tweaked for SDL 1.2.10]
author Sam Lantinga <slouken@libsdl.org>
date Wed, 22 Mar 2006 07:48:22 +0000
parents 355632dca928
children
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>SDL_SetEventFilter</TITLE
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><H1
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>SDL_SetEventFilter</H1
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><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
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>Synopsis</H2
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><P
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><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
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><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
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><B
>Note: </B
>Events pushed onto the queue with <A
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><TT
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>SDL_PushEvent</TT
></A
> or <A
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><TT
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>SDL_PeepEvents</TT
></A
> do not get passed through the event filter.</P
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><B
>Note: </B
><SPAN
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><I
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>Be Careful!</I
></SPAN
> The event filter function may run in a different thread so be careful what you do within it.</P
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>See Also</H2
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>SDL_Event</SPAN
></A
>,
<A
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><TT
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>SDL_GetEventFilter</TT
></A
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>SDL_PushEvent</TT
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