[gpm] [patch] fixing backlight control

[Andy Wingo <wingo pobox com>]

Hello,

Please find attached a patch to implement the algorithm I discussed last
week.

Thanks,

Andy
-- 
http://wingolog.org/

--- gnome-power-manager-2.21.1.orig/src/gpm-brightness-lcd.c
+++ gnome-power-manager-2.21.1/src/gpm-brightness-lcd.c
@@ -322,7 +322,7 @@
  * If possible, put the brightness of the LCD up one unit.
  **/
 gboolean
-gpm_brightness_lcd_up (GpmBrightnessLcd *brightness)
+gpm_brightness_lcd_up (GpmBrightnessLcd *brightness, guint *new_percentage)
 {
 	gint step;
 	gint percentage;
@@ -349,6 +349,7 @@
 
 	percentage = gpm_discrete_to_percent (brightness->priv->last_set_hw,
 					      brightness->priv->levels);
+	*new_percentage = percentage;
 	gpm_debug ("emitting brightness-changed (%i)", percentage);
 	g_signal_emit (brightness, signals [BRIGHTNESS_CHANGED], 0, percentage);
 
@@ -362,7 +363,7 @@
  * If possible, put the brightness of the LCD down one unit.
  **/
 gboolean
-gpm_brightness_lcd_down (GpmBrightnessLcd *brightness)
+gpm_brightness_lcd_down (GpmBrightnessLcd *brightness, guint *new_percentage)
 {
 	gint step;
 	gint percentage;
@@ -389,6 +390,7 @@
 
 	percentage = gpm_discrete_to_percent (brightness->priv->last_set_hw,
 					      brightness->priv->levels);
+	*new_percentage = percentage;
 	gpm_debug ("emitting brightness-changed (%i)", percentage);
 	g_signal_emit (brightness, signals [BRIGHTNESS_CHANGED], 0, percentage);
 
--- gnome-power-manager-2.21.1.orig/src/gpm-brightness-lcd.h
+++ gnome-power-manager-2.21.1/src/gpm-brightness-lcd.h
@@ -53,8 +53,10 @@
 GpmBrightnessLcd *gpm_brightness_lcd_new	(void);
 gboolean	  gpm_brightness_lcd_has_hw	(void);
 
-gboolean	 gpm_brightness_lcd_up		(GpmBrightnessLcd	*brightness);
-gboolean	 gpm_brightness_lcd_down	(GpmBrightnessLcd	*brightness);
+gboolean	 gpm_brightness_lcd_up		(GpmBrightnessLcd	*brightness,
+						 guint			*new_percentage);
+gboolean	 gpm_brightness_lcd_down	(GpmBrightnessLcd	*brightness,
+						 guint			*new_percentage);
 gboolean	 gpm_brightness_lcd_get		(GpmBrightnessLcd	*brightness,
 						 guint			*brightness_level);
 gboolean	 gpm_brightness_lcd_set_std	(GpmBrightnessLcd	*brightness,
--- gnome-power-manager-2.21.1.orig/src/gpm-backlight.c
+++ gnome-power-manager-2.21.1/src/gpm-backlight.c
@@ -500,6 +490,49 @@
 	gpm_backlight_brightness_evaluate_and_set (backlight, TRUE);
 }
 
+static void
+adjust_brightness (GpmBacklight *backlight,
+		   gboolean (*do_adjust_brightness)(GpmBrightnessLcd*, guint*))
+{
+	guint brightness, brightness_ac;
+	gboolean success, battery_reduce;
+
+	if (!backlight->priv->can_dim)
+		return;
+	
+	success = do_adjust_brightness (backlight->priv->brightness,
+					&brightness);
+	if (!success)
+		return;
+	
+	if (!gpm_ac_adapter_is_present (backlight->priv->ac_adapter)
+	    && gpm_conf_get_uint (backlight->priv->conf,
+				  GPM_CONF_BACKLIGHT_BRIGHTNESS_AC,
+				  &brightness_ac)
+	    && gpm_conf_get_bool (backlight->priv->conf,
+				  GPM_CONF_BACKLIGHT_BATTERY_REDUCE,
+				  &battery_reduce)
+	    && battery_reduce) {
+		if (brightness >= brightness_ac) {
+			gpm_conf_set_uint (backlight->priv->conf,
+					   GPM_CONF_BACKLIGHT_BRIGHTNESS_AC,
+					   brightness);	
+			gpm_conf_set_uint (backlight->priv->conf,
+					   GPM_CONF_BACKLIGHT_BRIGHTNESS_BATT,
+					   0);
+		} else {
+			gpm_conf_set_uint (backlight->priv->conf,
+					   GPM_CONF_BACKLIGHT_BRIGHTNESS_BATT,
+					   (brightness_ac - brightness) * 100 / brightness_ac);
+		}
+	} else {
+		gpm_conf_set_uint (backlight->priv->conf,
+				   GPM_CONF_BACKLIGHT_BRIGHTNESS_AC,
+				   brightness);	
+	}
+}
+
+
 /**
  * button_pressed_cb:
  * @power: The power class instance
@@ -516,16 +549,10 @@
 
 	if (strcmp (type, GPM_BUTTON_BRIGHT_UP) == 0) {
 
-		if (backlight->priv->can_dim == TRUE) {
-			gpm_brightness_lcd_up (backlight->priv->brightness);
-		}
-
+		adjust_brightness (backlight, gpm_brightness_lcd_up);
 	} else if (strcmp (type, GPM_BUTTON_BRIGHT_DOWN) == 0) {
 
-		if (backlight->priv->can_dim == TRUE) {
-			gpm_brightness_lcd_down (backlight->priv->brightness);
-		}
-
+		adjust_brightness (backlight, gpm_brightness_lcd_down);
 	} else if (strcmp (type, GPM_BUTTON_LID_OPEN) == 0) {
 
 		/* make sure we undim when we lift the lid */