[aravis] gv_device: add a "control-lost" signal.

[Emmanuel Pacaud <emmanuel src gnome org>]

commit 3b35a2915dd1421e07f7e183121280c7a10b0a9e
Author: Emmanuel Pacaud <emmanuel gnome org>
Date:   Wed Jul 6 11:35:55 2011 +0200

    gv_device: add a "control-lost" signal.
    
    This signal is emited when control of a device is lost.

 src/arvgvdevice.c     |   33 ++++++++++++++++++++++++++++++++-
 src/arvgvdevice.h     |    3 +++
 src/arvstream.h       |    1 +
 tests/arvcameratest.c |   12 ++++++++++++
 4 files changed, 48 insertions(+), 1 deletions(-)
---
diff --git a/src/arvgvdevice.c b/src/arvgvdevice.c
index 748987f..e74325f 100644
--- a/src/arvgvdevice.c
+++ b/src/arvgvdevice.c
@@ -34,6 +34,13 @@
 #include <string.h>
 #include <stdlib.h>
 
+enum {
+	ARV_GV_DEVICE_SIGNAL_CONTROL_LOST,
+	ARV_GV_DEVICE_SIGNAL_LAST
+} ArvGvDeviceSignals;
+
+static guint arv_gv_device_signals[ARV_GV_DEVICE_SIGNAL_LAST] = {0};
+
 static GObjectClass *parent_class = NULL;
 static GRegex *arv_gv_device_url_regex = NULL;
 
@@ -324,6 +331,7 @@ _write_register (ArvGvDeviceIOData *io_data, guint32 address, guint32 value)
 /* Heartbeat thread */
 
 typedef struct {
+	ArvGvDevice *gv_device;
 	ArvGvDeviceIOData *io_data;
 	int period_us;
 	gboolean cancel;
@@ -351,6 +359,10 @@ arv_gv_device_heartbeat_thread (void *data)
 			if ((value & (ARV_GVBS_CONTROL_CHANNEL_PRIVILEGE_CONTROL |
 				      ARV_GVBS_CONTROL_CHANNEL_PRIVILEGE_EXCLUSIVE)) == 0) {
 				arv_warning_device ("[GvDevice::Heartbeat] Control access lost");
+
+				g_signal_emit (thread_data->gv_device,
+					       arv_gv_device_signals[ARV_GV_DEVICE_SIGNAL_CONTROL_LOST], 0);
+
 				io_data->is_controller = FALSE;
 			}
 		}
@@ -383,9 +395,10 @@ arv_gv_device_leave_control (ArvGvDevice *gv_device)
 {
 	gboolean success;
 
+	gv_device->priv->io_data->is_controller = FALSE;
+
 	success = arv_device_write_register (ARV_DEVICE (gv_device),
 					    ARV_GVBS_CONTROL_CHANNEL_PRIVILEGE_OFFSET, 0);
-	gv_device->priv->io_data->is_controller = FALSE;
 
 	return success;
 }
@@ -711,6 +724,7 @@ arv_gv_device_new (GInetAddress *interface_address, GInetAddress *device_address
 	arv_gv_device_take_control (gv_device);
 
 	heartbeat_data = g_new (ArvGvDeviceHeartbeatData, 1);
+	heartbeat_data->gv_device = gv_device;
 	heartbeat_data->io_data = io_data;
 	heartbeat_data->period_us = 1000000;
 	heartbeat_data->cancel = FALSE;
@@ -792,6 +806,23 @@ arv_gv_device_class_init (ArvGvDeviceClass *gv_device_class)
 	device_class->read_register = arv_gv_device_read_register;
 	device_class->write_register = arv_gv_device_write_register;
 
+	/**
+	 * ArvGvDevice::control-lost:
+	 * @gv_device:a #ArvGvDevice
+	 *
+	 * Signal that the control of the device is lost.
+	 *
+	 * This signal is emited from the heartbeat thread, so please take care to shared data access.
+	 */
+
+	arv_gv_device_signals[ARV_GV_DEVICE_SIGNAL_CONTROL_LOST] =
+		g_signal_new ("control-lost",
+			      G_TYPE_FROM_CLASS (gv_device_class),
+			      G_SIGNAL_RUN_LAST,
+			      G_STRUCT_OFFSET (ArvGvDeviceClass, control_lost),
+			      NULL, NULL,
+			      g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
+
 	arv_gv_device_url_regex = g_regex_new ("^(local:|file:|http:)(.+\\.[^;]+);?([0-9:a-f]*)?;?([0-9:a-f]*)?$",
 					       G_REGEX_CASELESS, 0, NULL);
 }
diff --git a/src/arvgvdevice.h b/src/arvgvdevice.h
index 9281f67..190af79 100644
--- a/src/arvgvdevice.h
+++ b/src/arvgvdevice.h
@@ -54,6 +54,9 @@ struct _ArvGvDevice {
 
 struct _ArvGvDeviceClass {
 	ArvDeviceClass parent_class;
+
+	/* signals */
+	void		(*control_lost)		(ArvGvDevice *gv_device);
 };
 
 GType arv_gv_device_get_type (void);
diff --git a/src/arvstream.h b/src/arvstream.h
index e1c2d2f..d1f539f 100644
--- a/src/arvstream.h
+++ b/src/arvstream.h
@@ -68,6 +68,7 @@ struct _ArvStreamClass {
 	void		(*get_statistics)	(ArvStream *stream, guint64 *n_completed_buffers,
 						 guint64 *n_failures, guint64 *n_underruns);
 
+	/* signals */
 	void        	(*new_buffer)   	(ArvStream *stream);
 };
 
diff --git a/tests/arvcameratest.c b/tests/arvcameratest.c
index 45db418..4e4dafa 100644
--- a/tests/arvcameratest.c
+++ b/tests/arvcameratest.c
@@ -141,6 +141,14 @@ emit_software_trigger (void *abstract_data)
 	return TRUE;
 }
 
+static void
+control_lost_cb (ArvGvDevice *gv_device)
+{
+	g_printf ("Control lost\n");
+
+	cancel = TRUE;
+}
+
 int
 main (int argc, char **argv)
 {
@@ -251,6 +259,10 @@ main (int argc, char **argv)
 			g_signal_connect (stream, "new-buffer", G_CALLBACK (new_buffer_cb), &data);
 			arv_stream_set_emit_signals (stream, TRUE);
 
+			if (ARV_IS_GV_DEVICE (arv_camera_get_device (camera)))
+			    g_signal_connect (arv_camera_get_device (camera), "control-lost",
+					      G_CALLBACK (control_lost_cb), NULL);
+
 			g_timeout_add_seconds (1, periodic_task_cb, &data);
 
 			data.main_loop = g_main_loop_new (NULL, FALSE);