gobject: Add install_properties()

Since we added g_object_notify_by_pspec(), an efficient way to install
and notify properties relies on storing the GParamSpec pointers inside
a static arrays, like we do for signal identifiers.

Instead of multiple calls to g_object_class_install_property(), we
should have a single function to take the static array of GParamSpecs
and iterate it.

https://bugzilla.gnome.org/show_bug.cgi?id=626919

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>

gobject/tests/properties.c

@@ -0,0 +1,222 @@
+#include <stdlib.h>
+#include <gstdio.h>
+#include <glib-object.h>
+
+typedef struct _TestObject {
+  GObject parent_instance;
+  gint foo;
+  gboolean bar;
+  gchar *baz;
+} TestObject;
+
+typedef struct _TestObjectClass {
+  GObjectClass parent_class;
+} TestObjectClass;
+
+enum { PROP_0, PROP_FOO, PROP_BAR, PROP_BAZ, N_PROPERTIES };
+
+static GParamSpec *properties[N_PROPERTIES] = { NULL, };
+
+G_DEFINE_TYPE (TestObject, test_object, G_TYPE_OBJECT);
+
+static void
+test_object_set_foo (TestObject *obj,
+                     gint        foo)
+{
+  if (obj->foo != foo)
+    {
+      obj->foo = foo;
+
+      g_assert (properties[PROP_FOO] != NULL);
+      g_object_notify_by_pspec (G_OBJECT (obj), properties[PROP_FOO]);
+    }
+}
+
+static void
+test_object_set_bar (TestObject *obj,
+                     gboolean    bar)
+{
+  bar = !!bar;
+
+  if (obj->bar != bar)
+    {
+      obj->bar = bar;
+
+      g_assert (properties[PROP_BAR] != NULL);
+      g_object_notify_by_pspec (G_OBJECT (obj), properties[PROP_BAR]);
+    }
+}
+
+static void
+test_object_set_baz (TestObject  *obj,
+                     const gchar *baz)
+{
+  if (g_strcmp0 (obj->baz, baz) != 0)
+    {
+      g_free (obj->baz);
+      obj->baz = g_strdup (baz);
+
+      g_assert (properties[PROP_BAZ] != NULL);
+      g_object_notify_by_pspec (G_OBJECT (obj), properties[PROP_BAZ]);
+    }
+}
+
+static void
+test_object_finalize (GObject *gobject)
+{
+  g_free (((TestObject *) gobject)->baz);
+
+  G_OBJECT_CLASS (test_object_parent_class)->finalize (gobject);
+}
+
+static void
+test_object_set_property (GObject *gobject,
+                          guint prop_id,
+                          const GValue *value,
+                          GParamSpec *pspec)
+{
+  TestObject *tobj = (TestObject *) gobject;
+
+  g_assert_cmpint (prop_id, !=, 0);
+  g_assert_cmpint (prop_id, !=, N_PROPERTIES);
+  g_assert (pspec == properties[prop_id]);
+
+  switch (prop_id)
+    {
+    case PROP_FOO:
+      test_object_set_foo (tobj, g_value_get_int (value));
+      break;
+
+    case PROP_BAR:
+      test_object_set_bar (tobj, g_value_get_boolean (value));
+      break;
+
+    case PROP_BAZ:
+      test_object_set_baz (tobj, g_value_get_string (value));
+      break;
+
+    default:
+      g_assert_not_reached ();
+    }
+}
+
+static void
+test_object_get_property (GObject *gobject,
+                          guint prop_id,
+                          GValue *value,
+                          GParamSpec *pspec)
+{
+  TestObject *tobj = (TestObject *) gobject;
+
+  g_assert_cmpint (prop_id, !=, 0);
+  g_assert_cmpint (prop_id, !=, N_PROPERTIES);
+  g_assert (pspec == properties[prop_id]);
+
+  switch (prop_id)
+    {
+    case PROP_FOO:
+      g_value_set_int (value, tobj->foo);
+      break;
+
+    case PROP_BAR:
+      g_value_set_boolean (value, tobj->bar);
+      break;
+
+    case PROP_BAZ:
+      g_value_set_string (value, tobj->baz);
+      break;
+
+    default:
+      g_assert_not_reached ();
+    }
+}
+
+static void
+test_object_class_init (TestObjectClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+  properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "Foo",
+                                           -1, G_MAXINT,
+                                           0,
+                                           G_PARAM_READWRITE);
+  properties[PROP_BAR] = g_param_spec_boolean ("bar", "Bar", "Bar",
+                                               FALSE,
+                                               G_PARAM_READWRITE);
+  properties[PROP_BAZ] = g_param_spec_string ("baz", "Baz", "Baz",
+                                              NULL,
+                                              G_PARAM_READWRITE);
+
+  gobject_class->set_property = test_object_set_property;
+  gobject_class->get_property = test_object_get_property;
+  gobject_class->finalize = test_object_finalize;
+
+  g_object_class_install_properties (gobject_class, N_PROPERTIES, properties);
+}
+
+static void
+test_object_init (TestObject *self)
+{
+  self->foo = 42;
+  self->bar = TRUE;
+  self->baz = g_strdup ("Hello");
+}
+
+static void
+properties_install (void)
+{
+  TestObject *obj = g_object_new (test_object_get_type (), NULL);
+  GParamSpec *pspec;
+
+  g_assert (properties[PROP_FOO] != NULL);
+
+  pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (obj), "foo");
+  g_assert (properties[PROP_FOO] == pspec);
+
+  g_object_unref (obj);
+}
+
+typedef struct {
+  const gchar *name;
+  GParamSpec *pspec;
+} TestNotifyClosure;
+
+static void
+on_notify (GObject           *gobject,
+           GParamSpec        *pspec,
+           TestNotifyClosure *clos)
+{
+  g_assert (clos->pspec == pspec);
+  g_assert_cmpstr (clos->name, ==, pspec->name);
+}
+
+static void
+properties_notify (void)
+{
+  TestObject *obj = g_object_new (test_object_get_type (), NULL);
+  TestNotifyClosure clos;
+
+  g_assert (properties[PROP_FOO] != NULL);
+
+  clos.name = "foo";
+  clos.pspec = properties[PROP_FOO];
+
+  g_signal_connect (obj, "notify", G_CALLBACK (on_notify), &clos);
+  g_object_set (obj, "foo", 47, NULL);
+
+  g_object_unref (obj);
+}
+
+int
+main (int argc, char *argv[])
+{
+  g_type_init ();
+  g_test_init (&argc, &argv, NULL);
+
+  g_test_bug_base ("http://bugzilla.gnome.org/");
+
+  g_test_add_func ("/properties/install", properties_install);
+  g_test_add_func ("/properties/notify", properties_notify);
+
+  return g_test_run ();
+}