X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=driver%2Fdpms.c;h=d88737eefd98340fe9412a6ce4f03f4c2179aec8;hb=1d7308dd9032b39a92fda86e8c2db04218b45fbf;hp=b45f4d2f2e130bb60174753cd945457eb37cb7c6;hpb=3f438031d610c7e15fd33876a879b97e290e05fb;p=xscreensaver

diff --git a/driver/dpms.c b/driver/dpms.c
index b45f4d2f..d88737ee 100644
--- a/driver/dpms.c
+++ b/driver/dpms.c
@@ -1,5 +1,5 @@
 /* dpms.c --- syncing the X Display Power Management values
- * xscreensaver, Copyright (c) 2001, 2005 Jamie Zawinski <jwz@jwz.org>
+ * xscreensaver, Copyright (c) 2001-2011 Jamie Zawinski <jwz@jwz.org>
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
  * documentation for any purpose is hereby granted without fee, provided that
@@ -55,7 +55,7 @@
 
 # include <X11/Xproto.h>
 # include <X11/extensions/dpms.h>
-# include <X11/extensions/dpmsstr.h>
+/*# include <X11/extensions/dpmsstr.h>*/
 
   /* Why this crap is not in a header file somewhere, I have no idea.  Losers!
    */
@@ -86,6 +86,16 @@
 
 #ifdef HAVE_DPMS_EXTENSION
 
+static Bool error_handler_hit_p = False;
+
+static int
+ignore_all_errors_ehandler (Display *dpy, XErrorEvent *error)
+{
+  error_handler_hit_p = True;
+  return 0;
+}
+
+
 void
 sync_server_dpms_settings (Display *dpy, Bool enabled_p,
                            int standby_secs, int suspend_secs, int off_secs,
@@ -217,16 +227,46 @@ monitor_powered_on_p (saver_info *si)
 }
 
 void
-monitor_power_on (saver_info *si)
+monitor_power_on (saver_info *si, Bool on_p)
 {
-  if (!monitor_powered_on_p (si))
+  if ((!!on_p) != monitor_powered_on_p (si))
     {
-      DPMSForceLevel(si->dpy, DPMSModeOn);
-      XSync(si->dpy, False);
-      if (!monitor_powered_on_p (si))
+      XErrorHandler old_handler;
+      int event_number, error_number;
+      if (!DPMSQueryExtension(si->dpy, &event_number, &error_number) ||
+          !DPMSCapable(si->dpy))
+        {
+          if (si->prefs.verbose_p)
+            fprintf (stderr,
+                     "%s: unable to power %s monitor: no DPMS extension.\n",
+                     blurb(), (on_p ? "on" : "off"));
+          return;
+        }
+
+      /* The manual for DPMSForceLevel() says that it throws BadMatch if
+         "DPMS is disabled on the specified display."
+
+         The manual for DPMSCapable() says that it "returns True if the X
+         server is capable of DPMS."
+
+         Apparently they consider "capable of DPMS" and "DPMS is enabled"
+         to be different things, and so even if DPMSCapable() returns
+         True, DPMSForceLevel() *might* throw an X Error.  Isn't that
+         just fucking special.
+       */
+      XSync (si->dpy, False);
+      error_handler_hit_p = False;
+      old_handler = XSetErrorHandler (ignore_all_errors_ehandler);
+      XSync (si->dpy, False);
+      DPMSForceLevel(si->dpy, (on_p ? DPMSModeOn : DPMSModeOff));
+      XSync (si->dpy, False);
+      /* Ignore error_handler_hit_p, just probe monitor instead */
+
+      if ((!!on_p) != monitor_powered_on_p (si))  /* double-check */
 	fprintf (stderr,
-       "%s: DPMSForceLevel(dpy, DPMSModeOn) did not power the monitor on?\n",
-		 blurb());
+       "%s: DPMSForceLevel(dpy, %s) did not change monitor power state.\n",
+		 blurb(),
+                 (on_p ? "DPMSModeOn" : "DPMSModeOff"));
     }
 }
 
@@ -248,7 +288,7 @@ monitor_powered_on_p (saver_info *si)
 }
 
 void
-monitor_power_on (saver_info *si)
+monitor_power_on (saver_info *si, Bool on_p)
 {
   return; 
 }