Let app set SDL_VIDEO_ALLOW_SCREENSAVER environment variable to override SDL's

attempt to disable screen savers. Works for Quartz (Mac OS X) and X11.

Need a formal API for this in 1.3, still.

  Fixes Bugzilla #415.

--HG--
branch : SDL-1.2
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/branches/SDL-1.2%402305

src/video/quartz/SDL_QuartzEvents.m

@@ -734,11 +734,13 @@ void QZ_PumpEvents (_THIS)
         return;  /* don't do anything if there's no screen surface. */
 
     /* Update activity every five seconds to prevent screensaver. --ryan. */
-    nowTicks = SDL_GetTicks();
-    if ((nowTicks - screensaverTicks) > 5000)
-    {
-        UpdateSystemActivity(UsrActivity);
-        screensaverTicks = nowTicks;
+    if (!allow_screensaver) {
+        nowTicks = SDL_GetTicks();
+        if ((nowTicks - screensaverTicks) > 5000)
+        {
+            UpdateSystemActivity(UsrActivity);
+            screensaverTicks = nowTicks;
+        }
     }
 
     pool = [ [ NSAutoreleasePool alloc ] init ];

src/video/quartz/SDL_QuartzVideo.h

@@ -80,6 +80,7 @@
 /* Main driver structure to store required state information */
 typedef struct SDL_PrivateVideoData {
 
+    BOOL               allow_screensaver;  /* 0 == disable screensaver */
     CGDirectDisplayID  display;            /* 0 == main display (only support single display) */
     CFDictionaryRef    mode;               /* current mode of the display */
     CFDictionaryRef    save_mode;          /* original mode of the display */
@@ -127,6 +128,7 @@ typedef struct SDL_PrivateVideoData {
 #define display_id (this->hidden->display)
 #define mode (this->hidden->mode)
 #define save_mode (this->hidden->save_mode)
+#define allow_screensaver (this->hidden->allow_screensaver)
 #define mode_list (this->hidden->mode_list)
 #define palette (this->hidden->palette)
 #define gl_context (this->hidden->gl_context)

src/video/quartz/SDL_QuartzVideo.m

@@ -169,12 +169,17 @@ static void QZ_DeleteDevice (SDL_VideoDevice *device) {
 
 static int QZ_VideoInit (_THIS, SDL_PixelFormat *video_format) {
 
+    const char *env = NULL;
+
     /* Initialize the video settings; this data persists between mode switches */
     display_id = kCGDirectMainDisplay;
     save_mode  = CGDisplayCurrentMode    (display_id);
     mode_list  = CGDisplayAvailableModes (display_id);
     palette    = CGPaletteCreateDefaultColorPalette ();
 
+    env = SDL_getenv("SDL_VIDEO_ALLOW_SCREENSAVER");
+    allow_screensaver = ( env && SDL_atoi(env) ) ? YES : NO;
+
     /* Gather some information that is useful to know about the display */
     CFNumberGetValue (CFDictionaryGetValue (save_mode, kCGDisplayBitsPerPixel),
                       kCFNumberSInt32Type, &device_bpp);

src/video/x11/SDL_x11events.c

@@ -1136,9 +1136,14 @@ void X11_SaveScreenSaver(Display *display, int *saved_timeout, BOOL *dpms)
 #endif /* SDL_VIDEO_DRIVER_X11_DPMS */
 }
 
-void X11_DisableScreenSaver(Display *display)
+void X11_DisableScreenSaver(_THIS, Display *display)
 {
 	int timeout, interval, prefer_blank, allow_exp;
+
+	if (this->hidden->allow_screensaver) {
+		return;
+	}
+
 	XGetScreenSaver(display, &timeout, &interval, &prefer_blank, &allow_exp);
 	timeout = 0;
 	XSetScreenSaver(display, timeout, interval, prefer_blank, allow_exp);
@@ -1153,9 +1158,14 @@ void X11_DisableScreenSaver(Display *display)
 #endif /* SDL_VIDEO_DRIVER_X11_DPMS */
 }
 
-void X11_RestoreScreenSaver(Display *display, int saved_timeout, BOOL dpms)
+void X11_RestoreScreenSaver(_THIS, Display *display, int saved_timeout, BOOL dpms)
 {
 	int timeout, interval, prefer_blank, allow_exp;
+
+	if (this->hidden->allow_screensaver) {
+		return;
+	}
+
 	XGetScreenSaver(display, &timeout, &interval, &prefer_blank, &allow_exp);
 	timeout = saved_timeout;
 	XSetScreenSaver(display, timeout, interval, prefer_blank, allow_exp);

src/video/x11/SDL_x11events_c.h

@@ -29,5 +29,5 @@ extern void X11_PumpEvents(_THIS);
 extern void X11_SetKeyboardState(Display *display, const char *key_vec);
 
 extern void X11_SaveScreenSaver(Display *display, int *saved_timeout, BOOL *dpms);
-extern void X11_DisableScreenSaver(Display *display);
-extern void X11_RestoreScreenSaver(Display *display, int saved_timeout, BOOL dpms);
+extern void X11_DisableScreenSaver(_THIS, Display *display);
+extern void X11_RestoreScreenSaver(_THIS, Display *display, int saved_timeout, BOOL dpms);

src/video/x11/SDL_x11video.c

@@ -441,6 +441,7 @@ static void create_aux_windows(_THIS)
 
 static int X11_VideoInit(_THIS, SDL_PixelFormat *vformat)
 {
+	const char *env = NULL;
 	char *display;
 	int i;
 
@@ -546,7 +547,7 @@ static int X11_VideoInit(_THIS, SDL_PixelFormat *vformat)
 
 	/* Save DPMS and screensaver settings */
 	X11_SaveScreenSaver(SDL_Display, &screensaver_timeout, &dpms_enabled);
-	X11_DisableScreenSaver(SDL_Display);
+	X11_DisableScreenSaver(this, SDL_Display);
 
 	/* See if we have been passed a window to use */
 	SDL_windowid = SDL_getenv("SDL_WINDOWID");
@@ -562,6 +563,10 @@ static int X11_VideoInit(_THIS, SDL_PixelFormat *vformat)
 	/* Fill in some window manager capabilities */
 	this->info.wm_available = 1;
 
+	/* Allow environment override of screensaver disable. */
+	env = SDL_getenv("SDL_VIDEO_ALLOW_SCREENSAVER");
+	this->hidden->allow_screensaver = ( (env && SDL_atoi(env)) ? 1 : 0 );
+
 	/* We're done! */
 	XFlush(SDL_Display);
 	return(0);
@@ -1375,7 +1380,7 @@ void X11_VideoQuit(_THIS)
 		}
 
 		/* Restore DPMS and screensaver settings */
-		X11_RestoreScreenSaver(SDL_Display, screensaver_timeout, dpms_enabled);
+		X11_RestoreScreenSaver(this, SDL_Display, screensaver_timeout, dpms_enabled);
 
 		/* Free that blank cursor */
 		if ( SDL_BlankCursor != NULL ) {

src/video/x11/SDL_x11video.h

@@ -139,6 +139,8 @@ struct SDL_PrivateVideoData {
     int use_xme;
     int currently_fullscreen;
 
+    int allow_screensaver;
+
     /* Automatic mode switching support (entering/leaving fullscreen) */
     Uint32 switch_waiting;
     Uint32 switch_time;