[gnome-color-manager] When devices are connected and disconnected, do not remove then add them, just change the state

[Richard Hughes <rhughes src gnome org>]

commit f1929c56715b23eb6a987737da1545d313ea4b5c
Author: Richard Hughes <richard hughsie com>
Date:   Wed Mar 24 12:59:31 2010 +0000

    When devices are connected and disconnected, do not remove then add them, just change the state
    
    This allows us to follow the state of SANE scanners as they are hotplugged.

 rules/95-gcm-devices.rules |   13 +++-
 src/gcm-client.c           |  149 ++++++++++++++++++++++++++++++++------------
 2 files changed, 120 insertions(+), 42 deletions(-)
---
diff --git a/rules/95-gcm-devices.rules b/rules/95-gcm-devices.rules
index 857fbf5..4356d92 100644
--- a/rules/95-gcm-devices.rules
+++ b/rules/95-gcm-devices.rules
@@ -8,11 +8,12 @@
 # the Free Software Foundation; either version 2 of the License, or
 # (at your option) any later version.
 #
-# Colorimeter devices used for profiling
+# Devices that may have profiles.
 #
 # These are properties defining the behavior:
-#  GCM_DEVICE		(Can be assinged a profile)
-#  GCM_TYPE		(The type of device)
+#  GCM_DEVICE		Can be assinged a profile
+#  GCM_TYPE		The type of device
+#  GCM_RESCAN		If we should rescan a particualr device class
 
 # Cameras with gphoto drivers
 SUBSYSTEM=="usb", ENV{ID_GPHOTO2}!="", ENV{GCM_DEVICE}="1", ENV{GCM_TYPE}="camera"
@@ -20,3 +21,9 @@ SUBSYSTEM=="usb", ENV{ID_GPHOTO2}!="", ENV{GCM_DEVICE}="1", ENV{GCM_TYPE}="camer
 # video cameras
 SUBSYSTEM=="video4linux", ENV{ID_V4L_PRODUCT}!="", ENV{GCM_DEVICE}="1", ENV{GCM_TYPE}="camera"
 
+# USB SANE scanners
+SUBSYSTEM=="usb", ENV{libsane_matched}!="", ENV{GCM_RESCAN}="scanner"
+
+# HP Printers
+SUBSYSTEM=="usb", ENV{ID_HPLIP}!="", ENV{GCM_RESCAN}="printer"
+
diff --git a/src/gcm-client.c b/src/gcm-client.c
index e7a366a..2875869 100644
--- a/src/gcm-client.c
+++ b/src/gcm-client.c
@@ -52,6 +52,8 @@ static void     gcm_client_finalize	(GObject     *object);
 #define GCM_CLIENT_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GCM_TYPE_CLIENT, GcmClientPrivate))
 
 static void gcm_client_xrandr_add (GcmClient *client, GnomeRROutput *output);
+static gboolean gcm_client_add_connected_devices_sane (GcmClient *client, GError **error);
+static gpointer gcm_client_add_connected_devices_sane_thrd (GcmClient *client);
 
 /**
  * GcmClientPrivate:
@@ -89,6 +91,8 @@ static guint signals[SIGNAL_LAST] = { 0 };
 
 G_DEFINE_TYPE (GcmClient, gcm_client, G_TYPE_OBJECT)
 
+#define	GCM_CLIENT_SANE_REMOVED_TIMEOUT		200	/* ms */
+
 /**
  * gcm_client_set_use_threads:
  **/
@@ -209,47 +213,44 @@ gcm_client_get_id_for_udev_device (GUdevDevice *udev_device)
 /**
  * gcm_client_gudev_remove:
  **/
-static void
+static gboolean
 gcm_client_gudev_remove (GcmClient *client, GUdevDevice *udev_device)
 {
 	GcmDevice *device;
 	gchar *id;
-	gboolean ret;
-	GcmClientPrivate *priv = client->priv;
+	gboolean ret = FALSE;
 
 	/* generate id */
 	id = gcm_client_get_id_for_udev_device (udev_device);
 
 	/* do we have a device that matches */
 	device = gcm_client_get_device_by_id (client, id);
-	if (device == NULL)
-		goto out;
-
-	/* remove device first as we hold a reference to it */
-	ret = g_ptr_array_remove (priv->array, device);
-	if (!ret) {
-		egg_warning ("failed to remove %s", id);
+	if (device == NULL) {
+		egg_debug ("no match for %s", id);
 		goto out;
 	}
 
-	/* emit a signal */
-	egg_debug ("emit removed: %s", id);
-	g_signal_emit (client, signals[SIGNAL_REMOVED], 0, device);
+	/* set disconnected */
+	gcm_device_set_connected (device, FALSE);
+
+	/* success */
+	ret = TRUE;
 out:
 	if (device != NULL)
 		g_object_unref (device);
 	g_free (id);
+	return ret;
 }
 
 /**
  * gcm_client_gudev_add:
  **/
-static void
+static gboolean
 gcm_client_gudev_add (GcmClient *client, GUdevDevice *udev_device)
 {
 	GcmDevice *device = NULL;
 	GcmDevice *device_tmp = NULL;
-	gboolean ret;
+	gboolean ret = FALSE;
 	const gchar *value;
 	GError *error = NULL;
 	GcmClientPrivate *priv = client->priv;
@@ -271,13 +272,10 @@ gcm_client_gudev_add (GcmClient *client, GUdevDevice *udev_device)
 	/* we might have a previous saved device with this ID, in which case nuke it */
 	device_tmp = gcm_client_get_device_by_id (client, gcm_device_get_id (device));
 	if (device_tmp != NULL) {
-
-		/* remove from the array */
-		g_ptr_array_remove (client->priv->array, device_tmp);
-
-		/* emit a signal */
-		egg_debug ("emit removed: %s", gcm_device_get_id (device));
-		g_signal_emit (client, signals[SIGNAL_REMOVED], 0, device_tmp);
+		/* already disconnected device now connected */
+		g_object_unref (device);
+		device = g_object_ref (device_tmp);
+		gcm_device_set_connected (device, TRUE);
 	}
 
 	/* load the device */
@@ -302,6 +300,42 @@ out:
 		g_object_unref (device);
 	if (device_tmp != NULL)
 		g_object_unref (device_tmp);
+	return ret;
+}
+
+/**
+ * gcm_client_sane_refresh_cb:
+ **/
+static gboolean
+gcm_client_sane_refresh_cb (GcmClient *client)
+{
+	gboolean ret;
+	GError *error = NULL;
+	GThread *thread;
+
+	/* inform UI if we are loading devices still */
+	client->priv->loading_refcount = 1;
+	gcm_client_set_loading (client, TRUE);
+
+	/* rescan */
+	egg_debug ("rescanning sane");
+	if (client->priv->use_threads) {
+		thread = g_thread_create ((GThreadFunc) gcm_client_add_connected_devices_sane_thrd, client, FALSE, &error);
+		if (thread == NULL) {
+			egg_debug ("failed to rescan sane devices: %s", error->message);
+			g_error_free (error);
+			goto out;
+		}
+	} else {
+		ret = gcm_client_add_connected_devices_sane (client, &error);
+		if (!ret) {
+			egg_debug ("failed to rescan sane devices: %s", error->message);
+			g_error_free (error);
+			goto out;
+		}
+	}
+out:
+	return FALSE;
 }
 
 /**
@@ -310,10 +344,42 @@ out:
 static void
 gcm_client_uevent_cb (GUdevClient *gudev_client, const gchar *action, GUdevDevice *udev_device, GcmClient *client)
 {
-	if (g_strcmp0 (action, "remove") == 0)
-		gcm_client_gudev_remove (client, udev_device);
-	else if (g_strcmp0 (action, "add") == 0)
-		gcm_client_gudev_add (client, udev_device);
+	gboolean ret;
+	const gchar *value;
+	GcmDevice *device_tmp;
+	guint i;
+	GcmClientPrivate *priv = client->priv;
+
+	if (g_strcmp0 (action, "remove") == 0) {
+		ret = gcm_client_gudev_remove (client, udev_device);
+		if (ret)
+			egg_debug ("removed %s", g_udev_device_get_sysfs_path (udev_device));
+
+		/* we need to remove scanner devices */
+		value = g_udev_device_get_property (udev_device, "GCM_RESCAN");
+		if (g_strcmp0 (value, "scanner") == 0) {
+
+			/* set all scanners as disconnected */
+			for (i=0; i<priv->array->len; i++) {
+				device_tmp = g_ptr_array_index (priv->array, i);
+				if (gcm_device_get_kind (device_tmp) == GCM_DEVICE_TYPE_ENUM_SCANNER)
+					gcm_device_set_connected (device_tmp, FALSE);
+			}
+
+			/* find any others that might still be connected */
+			g_timeout_add (GCM_CLIENT_SANE_REMOVED_TIMEOUT, (GSourceFunc) gcm_client_sane_refresh_cb, client);
+		}
+
+	} else if (g_strcmp0 (action, "add") == 0) {
+		ret = gcm_client_gudev_add (client, udev_device);
+		if (ret)
+			egg_debug ("added %s", g_udev_device_get_sysfs_path (udev_device));
+
+		/* we need to rescan scanner devices */
+		value = g_udev_device_get_property (udev_device, "GCM_RESCAN");
+		if (g_strcmp0 (value, "scanner") == 0)
+			g_timeout_add (GCM_CLIENT_SANE_REMOVED_TIMEOUT, (GSourceFunc) gcm_client_sane_refresh_cb, client);
+	}
 }
 
 /**
@@ -346,6 +412,7 @@ gcm_client_add_connected_devices_udev (GcmClient *client, GError **error)
 
 	/* inform the UI */
 	gcm_client_done_loading (client);
+
 	return TRUE;
 }
 
@@ -509,27 +576,20 @@ gcm_client_xrandr_add (GcmClient *client, GnomeRROutput *output)
 		goto out;
 	}
 
-	/* we might have a previous saved device with this ID, in which case nuke it */
+	/* we might have a previous saved device with this ID, in which use that instead */
 	device_tmp = gcm_client_get_device_by_id (client, gcm_device_get_id (device));
 	if (device_tmp != NULL) {
 
-		/* old device not connected */
-		g_object_get (device_tmp,
-			      "connected", &connected,
-			      NULL);
-
 		/* this is just a dupe */
+		connected = gcm_device_get_connected (device_tmp);
 		if (connected) {
 			egg_debug ("ignoring dupe");
 			goto out;
 		}
 
-		/* remove from the array */
-		g_ptr_array_remove (client->priv->array, device_tmp);
-
-		/* emit a signal */
-		egg_debug ("emit removed: %s (unconnected device that has just been connected)", gcm_device_get_id (device_tmp));
-		g_signal_emit (client, signals[SIGNAL_REMOVED], 0, device_tmp);
+		/* use original device */
+		g_object_unref (device);
+		device = g_object_ref (device_tmp);
 	}
 
 	/* load the device */
@@ -659,6 +719,7 @@ gcm_client_sane_add (GcmClient *client, const SANE_Device *sane_device)
 	gboolean ret;
 	GError *error = NULL;
 	GcmDevice *device = NULL;
+	GcmDevice *device_tmp = NULL;
 	GcmClientPrivate *priv = client->priv;
 
 	/* create new device */
@@ -670,6 +731,14 @@ gcm_client_sane_add (GcmClient *client, const SANE_Device *sane_device)
 		goto out;
 	}
 
+	/* we might have a previous saved device with this ID, in which use that instead */
+	device_tmp = gcm_client_get_device_by_id (client, gcm_device_get_id (device));
+	if (device_tmp != NULL) {
+		gcm_device_set_connected (device_tmp, TRUE);
+		g_object_unref (device);
+		device = g_object_ref (device_tmp);
+	}
+
 	/* load the device */
 	ret = gcm_device_load (device, &error);
 	if (!ret) {
@@ -690,6 +759,8 @@ gcm_client_sane_add (GcmClient *client, const SANE_Device *sane_device)
 out:
 	if (device != NULL)
 		g_object_unref (device);
+	if (device_tmp != NULL)
+		g_object_unref (device_tmp);
 }
 
 /**
@@ -894,7 +965,7 @@ gcm_client_add_connected (GcmClient *client, GError **error)
 	if (!ret)
 		goto out;
 
-	/* inform UI if we are loading devces still */
+	/* inform UI if we are loading devices still */
 	client->priv->loading_refcount = 3;
 	gcm_client_set_loading (client, TRUE);