Use property notification instead of signal

Up to this point we used a custom signal to notify about starting and stopping
recording of data. However, such signals come (almost) for free for each
property. This way, you can query "is-recording" but also be notified when
"is-recording" was changed by the camera itself.

3 files changed, 68 insertions, 39 deletions

diff --git a/src/uca-camera.c b/src/uca-camera.c
index 7079279..35e15b7 100644
--- a/src/uca-camera.c
+++ b/src/uca-camera.c
@@ -33,9 +33,6 @@ GQuark uca_camera_error_quark()
 }
 
 enum {
-    RECORDING_STARTED,
-    RECORDING_STOPPED,
-    PROPERTY_CHANGED,
     LAST_SIGNAL
 };
 
@@ -50,6 +47,7 @@ enum {
     PROP_SENSOR_VERTICAL_BINNINGS,
     PROP_HAS_STREAMING,
     PROP_HAS_CAMRAM_RECORDING,
+    PROP_IS_RECORDING,
     N_PROPERTIES
 };
 
@@ -59,7 +57,7 @@ struct _UcaCameraPrivate {
 
 static GParamSpec *camera_properties[N_PROPERTIES] = { NULL, };
 
-static guint camera_signals[LAST_SIGNAL] = { 0 };
+/* static guint camera_signals[LAST_SIGNAL] = { 0 }; */
 
 static void uca_camera_set_property(GObject *object, guint property_id, const GValue *value, GParamSpec *pspec)
 {
@@ -68,7 +66,16 @@ static void uca_camera_set_property(GObject *object, guint property_id, const GV
 
 static void uca_camera_get_property(GObject *object, guint property_id, GValue *value, GParamSpec *pspec)
 {
-    G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec);
+    UcaCameraPrivate *priv = UCA_CAMERA_GET_PRIVATE(object);
+
+    switch (property_id) {
+        case PROP_IS_RECORDING:
+            g_value_set_boolean(value, priv->recording);
+            break;
+
+        default:
+            G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec);
+    }
 }
 
 static void uca_camera_class_init(UcaCameraClass *klass)
@@ -150,27 +157,15 @@ static void uca_camera_class_init(UcaCameraClass *klass)
             "Is the camera able to record the data in-camera",
             FALSE, G_PARAM_READABLE);
 
+    camera_properties[PROP_IS_RECORDING] = 
+        g_param_spec_boolean("is-recording",
+            "Is camera recording",
+            "Is the camera currently recording",
+            FALSE, G_PARAM_READABLE);
+
     for (guint id = PROP_0 + 1; id < N_PROPERTIES; id++)
         g_object_class_install_property(gobject_class, id, camera_properties[id]);
 
-    camera_signals[RECORDING_STARTED] = 
-        g_signal_new("recording-started",
-                G_OBJECT_CLASS_TYPE(gobject_class),
-                G_SIGNAL_RUN_FIRST,
-                G_STRUCT_OFFSET(UcaCameraClass, recording_started),
-                NULL, NULL,
-                g_cclosure_marshal_VOID__VOID,
-                G_TYPE_NONE, 0, NULL);
-
-    camera_signals[RECORDING_STOPPED] = 
-        g_signal_new("recording-stopped",
-                G_OBJECT_CLASS_TYPE(gobject_class),
-                G_SIGNAL_RUN_FIRST,
-                G_STRUCT_OFFSET(UcaCameraClass, recording_stopped),
-                NULL, NULL,
-                g_cclosure_marshal_VOID__VOID,
-                G_TYPE_NONE, 0, NULL);
-
     g_type_class_add_private(klass, sizeof(UcaCameraPrivate));
 }
 
@@ -197,7 +192,7 @@ void uca_camera_start_recording(UcaCamera *camera, GError **error)
 
     camera->priv->recording = TRUE;
     (*klass->start_recording)(camera, error);
-    g_signal_emit_by_name(G_OBJECT(camera), "recording-started");
+    g_object_notify_by_pspec(G_OBJECT(camera), camera_properties[PROP_IS_RECORDING]);
 }
 
 void uca_camera_stop_recording(UcaCamera *camera, GError **error)
@@ -217,7 +212,7 @@ void uca_camera_stop_recording(UcaCamera *camera, GError **error)
 
     camera->priv->recording = FALSE;
     (*klass->stop_recording)(camera, error);
-    g_signal_emit_by_name(G_OBJECT(camera), "recording-stopped");
+    g_object_notify_by_pspec(G_OBJECT(camera), camera_properties[PROP_IS_RECORDING]);
 }
 
 void uca_camera_set_grab_func(UcaCamera *camera, UcaCameraGrabFunc func)
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index b853cb5..4ee097b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -51,9 +51,9 @@ target_link_libraries(test-gobject
     ${GOBJECT2_LIBRARIES}
     )
 
-#add_executable(test-mock test-mock.c)
-#target_link_libraries(test-mock
-#    uca-gobject 
-#    ${GLIB2_LIBRARIES}
-#    ${GOBJECT2_LIBRARIES}
-#    )
+add_executable(test-mock test-mock.c)
+target_link_libraries(test-mock
+    uca-gobject 
+    ${GLIB2_LIBRARIES}
+    ${GOBJECT2_LIBRARIES}
+    )
diff --git a/test/test-mock.c b/test/test-mock.c
index 2b298a9..ceb4b20 100644
--- a/test/test-mock.c
+++ b/test/test-mock.c
@@ -20,6 +20,12 @@ static void fixture_teardown(Fixture *fixture, gconstpointer data)
     g_object_unref(fixture->camera);
 }
 
+static void on_property_change(gpointer instance, GParamSpec *pspec, gpointer user_data)
+{
+    gboolean *success = (gboolean *) user_data;
+    *success = TRUE;
+}
+
 static void test_recording(Fixture *fixture, gconstpointer data)
 {
     GError *error = NULL;
@@ -35,6 +41,39 @@ static void test_recording(Fixture *fixture, gconstpointer data)
     g_assert(error == NULL);
 }
 
+static void test_recording_signal(Fixture *fixture, gconstpointer data)
+{
+    UcaCamera *camera = UCA_CAMERA(fixture->camera);
+    gboolean success = FALSE;
+    g_signal_connect(G_OBJECT(camera), "notify::is-recording", 
+            (GCallback) on_property_change, &success);
+
+    uca_camera_start_recording(camera, NULL);
+    g_assert(success == TRUE);
+
+    success = FALSE;
+    uca_camera_stop_recording(camera, NULL);
+    g_assert(success == TRUE);
+}
+
+static void test_recording_property(Fixture *fixture, gconstpointer data)
+{
+    UcaCamera *camera = UCA_CAMERA(fixture->camera);
+
+    gboolean is_recording = FALSE;
+    uca_camera_start_recording(camera, NULL);
+    g_object_get(G_OBJECT(camera),
+            "is-recording", &is_recording,
+            NULL);
+    g_assert(is_recording == TRUE);
+
+    uca_camera_stop_recording(camera, NULL);
+    g_object_get(G_OBJECT(camera),
+            "is-recording", &is_recording,
+            NULL);
+    g_assert(is_recording == FALSE);
+}
+
 static void test_base_properties(Fixture *fixture, gconstpointer data)
 {
     UcaCamera *camera = UCA_CAMERA(fixture->camera);
@@ -65,18 +104,11 @@ static void test_binnings_properties(Fixture *fixture, gconstpointer data)
     g_assert(g_value_get_uint(value) == 1);
 }
 
-static void signal_handler(gpointer instance, const gchar *name, gpointer user_data)
-{
-    g_print("name: %s\n", name);
-    gboolean *success = (gboolean *) user_data;
-    *success = TRUE;
-}
-
 static void test_signal(Fixture *fixture, gconstpointer data)
 {
     UcaCamera *camera = UCA_CAMERA(fixture->camera);
     gboolean success = FALSE;
-    g_signal_connect(camera, "property-changed", (GCallback) signal_handler, &success);
+    g_signal_connect(camera, "notify::framerate", (GCallback) on_property_change, &success);
     g_object_set(G_OBJECT(camera),
             "framerate", 30,
             NULL);
@@ -90,7 +122,9 @@ int main(int argc, char *argv[])
     g_test_bug_base("http://ufo.kit.edu/ufo/ticket");
 
     g_test_add("/recording", Fixture, NULL, fixture_setup, test_recording, fixture_teardown);
+    g_test_add("/recording/signal", Fixture, NULL, fixture_setup, test_recording_signal, fixture_teardown);
     g_test_add("/properties/base", Fixture, NULL, fixture_setup, test_base_properties, fixture_teardown);
+    g_test_add("/properties/recording", Fixture, NULL, fixture_setup, test_recording_property, fixture_teardown);
     g_test_add("/properties/binnings", Fixture, NULL, fixture_setup, test_binnings_properties, fixture_teardown);
     g_test_add("/signal", Fixture, NULL, fixture_setup, test_signal, fixture_teardown);