[gnome-settings-daemon] wacom: write to status_led{0,1}_select only

[Olivier Fourdan <ofourdan src gnome org>]

commit a50edff1532257a87068bc1414a0f33724ff36f2
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Mon Oct 1 16:14:23 2012 +0200

    wacom: write to status_led{0,1}_select only
    
    if a device has only one ring/strip, use status_led0_select;
    otherwise the left ring/strip is controlled by status_led1_select
    and the right ring/strip by status_led0_select.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=676558

 plugins/wacom/gsd-wacom-device.c  |   36 ++++++++++++++++++++++++
 plugins/wacom/gsd-wacom-device.h  |    2 +
 plugins/wacom/gsd-wacom-manager.c |   55 ++++++++++++++++++++++++++++++++++++-
 3 files changed, 92 insertions(+), 1 deletions(-)
---
diff --git a/plugins/wacom/gsd-wacom-device.c b/plugins/wacom/gsd-wacom-device.c
index c1de506..2f52d2a 100644
--- a/plugins/wacom/gsd-wacom-device.c
+++ b/plugins/wacom/gsd-wacom-device.c
@@ -335,6 +335,8 @@ struct GsdWacomDevicePrivate
 	GList *styli;
 	GsdWacomStylus *last_stylus;
 	GList *buttons;
+	gint num_rings;
+	gint num_strips;
 	GHashTable *modes; /* key = int (group), value = int (index) */
 	GHashTable *num_modes; /* key = int (group), value = int (index) */
 	GSettings *wacom_settings;
@@ -1173,6 +1175,21 @@ gsd_wacom_device_add_buttons (GsdWacomDevice *device,
 }
 
 static void
+gsd_wacom_device_get_modeswitches (WacomDevice      *wacom_device,
+				   gint             *num_rings,
+				   gint             *num_strips)
+{
+	*num_strips = libwacom_get_num_strips (wacom_device);
+
+	if (libwacom_has_ring2 (wacom_device))
+		*num_rings = 2;
+	else if  (libwacom_has_ring (wacom_device))
+		*num_rings = 1;
+	else
+		*num_rings = 0;
+}
+
+static void
 gsd_wacom_device_add_modes (GsdWacomDevice *device,
 			    WacomDevice    *wacom_device)
 {
@@ -1230,6 +1247,9 @@ gsd_wacom_device_update_from_db (GsdWacomDevice *device,
 	}
 
 	if (device->priv->type == WACOM_TYPE_PAD) {
+		gsd_wacom_device_get_modeswitches (wacom_device,
+						   &device->priv->num_rings,
+						   &device->priv->num_strips);
 		gsd_wacom_device_add_buttons (device, wacom_device, settings_path);
 		gsd_wacom_device_add_modes (device, wacom_device);
 	}
@@ -1558,6 +1578,22 @@ gsd_wacom_device_is_fallback (GsdWacomDevice *device)
 	return device->priv->is_fallback;
 }
 
+gint
+gsd_wacom_device_get_num_strips (GsdWacomDevice *device)
+{
+	g_return_val_if_fail (GSD_IS_WACOM_DEVICE (device), 0);
+
+	return device->priv->num_strips;
+}
+
+gint
+gsd_wacom_device_get_num_rings (GsdWacomDevice *device)
+{
+	g_return_val_if_fail (GSD_IS_WACOM_DEVICE (device), 0);
+
+	return device->priv->num_rings;
+}
+
 GSettings *
 gsd_wacom_device_get_settings (GsdWacomDevice *device)
 {
diff --git a/plugins/wacom/gsd-wacom-device.h b/plugins/wacom/gsd-wacom-device.h
index 8604ee4..24e6e06 100644
--- a/plugins/wacom/gsd-wacom-device.h
+++ b/plugins/wacom/gsd-wacom-device.h
@@ -143,6 +143,8 @@ const char     * gsd_wacom_device_get_tool_name    (GsdWacomDevice *device);
 gboolean         gsd_wacom_device_reversible       (GsdWacomDevice *device);
 gboolean         gsd_wacom_device_is_screen_tablet (GsdWacomDevice *device);
 gboolean         gsd_wacom_device_is_fallback      (GsdWacomDevice *device);
+gint             gsd_wacom_device_get_num_strips   (GsdWacomDevice *device);
+gint             gsd_wacom_device_get_num_rings    (GsdWacomDevice *device);
 GSettings      * gsd_wacom_device_get_settings     (GsdWacomDevice *device);
 void             gsd_wacom_device_set_current_stylus (GsdWacomDevice *device,
 						      int             stylus_id);
diff --git a/plugins/wacom/gsd-wacom-manager.c b/plugins/wacom/gsd-wacom-manager.c
index d178afb..8890988 100644
--- a/plugins/wacom/gsd-wacom-manager.c
+++ b/plugins/wacom/gsd-wacom-manager.c
@@ -540,6 +540,52 @@ apply_stylus_settings (GsdWacomDevice *device)
 	set_pressurethreshold (device, threshold);
 }
 
+/*
+ * The rule to determine the status LED to use is as follow:
+ *
+ * "[...] if a device has only one ring/strip, use status_led0_select;
+ *  otherwise the left ring/strip is controlled by status_led1_select and
+ *  the right ring/strip by status_led0_select."
+ *
+ * http://sourceforge.net/mailarchive/message.php?msg_id=29898591
+ */
+static int
+get_led_group_id(GsdWacomDevice *device,
+		 int             group_id)
+{
+	gint num_rings;
+	gint num_strips;
+
+	num_rings = gsd_wacom_device_get_num_rings (device);
+	num_strips = gsd_wacom_device_get_num_strips (device);
+
+	/* Given group_id is in {1..4} as follow
+	 * WACOM_BUTTON_RING_MODESWITCH        => group_id == 1
+	 * WACOM_BUTTON_RING2_MODESWITCH       => group_id == 2
+	 * WACOM_BUTTON_TOUCHSTRIP_MODESWITCH  => group_id == 3
+	 * WACOM_BUTTON_TOUCHSTRIP2_MODESWITCH => group_id == 4
+	 *
+	 * see function flags_to_group() in gsd-wacom-device.c
+	 */
+
+	if ((num_rings == 1) && (group_id == 1))
+		return 0;
+
+	if ((num_strips == 1) && (group_id == 3))
+		return 0;
+
+	if ((num_rings == 2) && (group_id == 1 ||  group_id == 2))
+		return (group_id & 1);
+
+	if ((num_strips == 2) && (group_id == 3 ||  group_id == 4))
+		return (group_id & 1);
+
+	g_debug ("Unhandled number of rings/strips setup (%d ring(s), %d strip(s), mode=%d",
+		 num_rings, num_strips, group_id);
+
+	return -1;
+}
+
 static void
 set_led (GsdWacomDevice *device,
 	 int             group_id,
@@ -548,6 +594,7 @@ set_led (GsdWacomDevice *device,
 	GError *error = NULL;
 	const char *path;
 	char *command;
+	gint status_led;
 	gboolean ret;
 
 #ifndef HAVE_GUDEV
@@ -557,11 +604,17 @@ set_led (GsdWacomDevice *device,
 	g_return_if_fail (index >= 1);
 
 	path = gsd_wacom_device_get_path (device);
+	status_led = get_led_group_id (device, group_id);
 
+	if (status_led < 0) {
+		g_debug ("Ignoring unhandled group ID %d for device %s",
+		         group_id, gsd_wacom_device_get_name (device));
+		return;
+	}
 	g_debug ("Switching group ID %d to index %d for device %s", group_id, index, path);
 
 	command = g_strdup_printf ("pkexec " LIBEXECDIR "/gsd-wacom-led-helper --path %s --group %d --led %d",
-				   path, group_id - 1, index - 1);
+				   path, status_led, index - 1);
 	ret = g_spawn_command_line_sync (command,
 					 NULL,
 					 NULL,