view src/SDL_fatal.c @ 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 f6ffac90895c
children b8d311d90021
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

/* General fatal signal handling code for SDL */

#ifdef NO_SIGNAL_H

/* No signals on this platform, nothing to do.. */

void SDL_InstallParachute(void)
{
	return;
}

void SDL_UninstallParachute(void)
{
	return;
}

#else

#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <string.h>

#include "SDL.h"
#include "SDL_fatal.h"

#ifdef __CYGWIN__
#define DISABLE_STDIO
#endif

/* This installs some signal handlers for the more common fatal signals,
   so that if the programmer is lazy, the app doesn't die so horribly if
   the program crashes.
*/

static void print_msg(const char *text)
{
#ifndef DISABLE_STDIO
	fprintf(stderr, "%s", text);
#endif
}

static void SDL_Parachute(int sig)
{
	signal(sig, SIG_DFL);
	print_msg("Fatal signal: ");
	switch (sig) {
		case SIGSEGV:
			print_msg("Segmentation Fault");
			break;
#ifdef SIGBUS
#if SIGBUS != SIGSEGV
		case SIGBUS:
			print_msg("Bus Error");
			break;
#endif
#endif /* SIGBUS */
#ifdef SIGFPE
		case SIGFPE:
			print_msg("Floating Point Exception");
			break;
#endif /* SIGFPE */
#ifdef SIGQUIT
		case SIGQUIT:
			print_msg("Keyboard Quit");
			break;
#endif /* SIGQUIT */
#ifdef SIGPIPE
		case SIGPIPE:
			print_msg("Broken Pipe");
			break;
#endif /* SIGPIPE */
		default:
#ifndef DISABLE_STDIO
			fprintf(stderr, "# %d", sig);
#endif
			break;
	}
	print_msg(" (SDL Parachute Deployed)\n");
	SDL_Quit();
	exit(-sig);
}

static int SDL_fatal_signals[] = {
	SIGSEGV,
#ifdef SIGBUS
	SIGBUS,
#endif
#ifdef SIGFPE
	SIGFPE,
#endif
#ifdef SIGQUIT
	SIGQUIT,
#endif
#ifdef SIGPIPE
	SIGPIPE,
#endif
	0
};

void SDL_InstallParachute(void)
{
	int i;
	void (*ohandler)(int);

	/* Set a handler for any fatal signal not already handled */
	for ( i=0; SDL_fatal_signals[i]; ++i ) {
		ohandler = signal(SDL_fatal_signals[i], SDL_Parachute);
		if ( ohandler != SIG_DFL ) {
			signal(SDL_fatal_signals[i], ohandler);
		}
	}
#ifdef SIGALRM
	/* Set SIGALRM to be ignored -- necessary on Solaris */
	{
		struct sigaction action, oaction;

		/* Set SIG_IGN action */
		memset(&action, 0, (sizeof action));
		action.sa_handler = SIG_IGN;
		sigaction(SIGALRM, &action, &oaction);

		/* Reset original action if it was already being handled */
		if ( oaction.sa_handler != SIG_DFL ) {
			sigaction(SIGALRM, &oaction, NULL);
		}
	}
#endif
	return;
}

void SDL_UninstallParachute(void)
{
	int i;
	void (*ohandler)(int);

	/* Remove a handler for any fatal signal handled */
	for ( i=0; SDL_fatal_signals[i]; ++i ) {
		ohandler = signal(SDL_fatal_signals[i], SIG_DFL);
		if ( ohandler != SDL_Parachute ) {
			signal(SDL_fatal_signals[i], ohandler);
		}
	}
}

#endif /* NO_SIGNAL_H */