[gnome-settings-daemon] power: Switch off backlight before suspend

[Bastien Nocera <hadess src gnome org>]

commit 168d3ee1a08be38051e0cc054659ad7946b1c14d
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Jan 14 11:10:26 2013 +0100

    power: Switch off backlight before suspend
    
    When suspending, switch off the backlight and turn it back on when
    resuming.
    
    Note that we need to capture the current backlight before DPMS Off,
    otherwise xbacklight will return zero.
    
    Note that this only has an effect on machines where the lowest backlight
    level turns the screen off, such as MacBooks.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=691702

 plugins/power/gsd-power-manager.c |   23 +++++++++++++++++++++++
 1 files changed, 23 insertions(+), 0 deletions(-)
---
diff --git a/plugins/power/gsd-power-manager.c b/plugins/power/gsd-power-manager.c
index 5637cdc..7295df5 100644
--- a/plugins/power/gsd-power-manager.c
+++ b/plugins/power/gsd-power-manager.c
@@ -183,6 +183,7 @@ struct GsdPowerManagerPrivate
         guint                    low_percentage;
         guint                    low_time;
         gint                     pre_dim_brightness; /* level, not percentage */
+        gint                     pre_dpms_brightness;
         UpDevice                *device_composite;
         NotifyNotification      *notification_discharging;
         NotifyNotification      *notification_low;
@@ -224,6 +225,11 @@ static void      do_power_action_type (GsdPowerManager *manager, GsdPowerActionT
 static void      do_lid_closed_action (GsdPowerManager *manager);
 static void      uninhibit_lid_switch (GsdPowerManager *manager);
 static gboolean  external_monitor_is_connected (GnomeRRScreen *screen);
+static gint      backlight_set_abs (GsdPowerManager *manager,
+                                    guint value,
+                                    gboolean emit_changed,
+                                    GError **error);
+static gint      backlight_get_abs (GsdPowerManager *manager, GError **error);
 
 G_DEFINE_TYPE (GsdPowerManager, gsd_power_manager, G_TYPE_OBJECT)
 
@@ -3883,6 +3889,18 @@ screen_lock_done_cb (gpointer data)
 static void
 handle_suspend_actions (GsdPowerManager *manager)
 {
+        GnomeRRDpmsMode mode;
+
+        /* Save the backlight, as DPMS isn't on yet, so we can capture it */
+        if (!gnome_rr_screen_get_dpms_mode (manager->priv->x11_screen, &mode, NULL) ||
+            mode != GNOME_RR_DPMS_ON) {
+                manager->priv->pre_dpms_brightness = -1;
+        } else {
+                manager->priv->pre_dpms_brightness = backlight_get_abs (manager, NULL);
+        }
+        if (manager->priv->pre_dpms_brightness != -1)
+                backlight_set_abs (manager, backlight_get_min (manager), FALSE, NULL);
+
         lock_screensaver (manager, screen_lock_done_cb);
 }
 
@@ -3907,6 +3925,11 @@ handle_resume_actions (GsdPowerManager *manager)
                 g_error_free (error);
         }
 
+        if (manager->priv->pre_dpms_brightness != -1) {
+                backlight_set_abs (manager, manager->priv->pre_dpms_brightness, FALSE, &error);
+                manager->priv->pre_dpms_brightness = -1;
+        }
+
         /* set up the delay again */
         inhibit_suspend (manager);
 }