GtkThemingEngine: Add ::name construct only property

This property is to be set by theming engines, the name set will be favored
over the object type name when registering custom properties, making possible
something like:

-Clearlooks-border: blah;

gtk/gtkthemingengine.c

@@ -26,6 +26,7 @@
 #include <gtk/gtkstylecontext.h>
 #include <gtk/gtkintl.h>
 
+#include "gtkprivate.h"
 #include "gtk9slice.h"
 #include "gtkpango.h"
 
@@ -56,13 +57,29 @@ enum {
   SIDE_ALL    = 0xF
 };
 
+enum {
+  PROP_0,
+  PROP_NAME
+};
+
 struct GtkThemingEnginePrivate
 {
   GtkStyleContext *context;
+  gchar *name;
 };
 
 #define GTK_THEMING_ENGINE_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GTK_TYPE_THEMING_ENGINE, GtkThemingEnginePrivate))
 
+static void gtk_theming_engine_finalize          (GObject      *object);
+static void gtk_theming_engine_impl_set_property (GObject      *object,
+                                                  guint         prop_id,
+                                                  const GValue *value,
+                                                  GParamSpec   *pspec);
+static void gtk_theming_engine_impl_get_property (GObject      *object,
+                                                  guint         prop_id,
+                                                  GValue       *value,
+                                                  GParamSpec   *pspec);
+
 static void gtk_theming_engine_render_check (GtkThemingEngine *engine,
                                              cairo_t          *cr,
                                              gdouble           x,
@@ -179,6 +196,10 @@ gtk_theming_engine_class_init (GtkThemingEngineClass *klass)
 {
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
+  object_class->finalize = gtk_theming_engine_finalize;
+  object_class->set_property = gtk_theming_engine_impl_set_property;
+  object_class->get_property = gtk_theming_engine_impl_get_property;
+
   klass->render_check = gtk_theming_engine_render_check;
   klass->render_option = gtk_theming_engine_render_option;
   klass->render_arrow = gtk_theming_engine_render_arrow;
@@ -193,6 +214,27 @@ gtk_theming_engine_class_init (GtkThemingEngineClass *klass)
   klass->render_extension = gtk_theming_engine_render_extension;
   klass->render_handle = gtk_theming_engine_render_handle;
 
+  /**
+   * GtkThemingEngine:name:
+   *
+   * The theming engine name, this name will be used when registering
+   * custom properties, for a theming engine named "Clearlooks" registering
+   * a "glossy" custom property, it could be referenced in the CSS file as
+   *
+   * <programlisting>
+   * -Clearlooks-glossy: true;
+   * </programlisting>
+   *
+   * Since: 3.0
+   */
+  g_object_class_install_property (object_class,
+				   PROP_NAME,
+				   g_param_spec_string ("name",
+                                                        P_("Name"),
+                                                        P_("Theming engine name"),
+                                                        NULL,
+                                                        G_PARAM_CONSTRUCT_ONLY | GTK_PARAM_READWRITE));
+
   g_type_class_add_private (object_class, sizeof (GtkThemingEnginePrivate));
 }
 
@@ -202,6 +244,62 @@ gtk_theming_engine_init (GtkThemingEngine *engine)
   engine->priv = GTK_THEMING_ENGINE_GET_PRIVATE (engine);
 }
 
+static void
+gtk_theming_engine_finalize (GObject *object)
+{
+  GtkThemingEnginePrivate *priv;
+
+  priv = GTK_THEMING_ENGINE (object)->priv;
+  g_free (priv->name);
+
+  G_OBJECT_GET_CLASS (gtk_theming_engine_parent_class)->finalize (object);
+}
+
+static void
+gtk_theming_engine_impl_set_property (GObject      *object,
+                                      guint         prop_id,
+                                      const GValue *value,
+                                      GParamSpec   *pspec)
+{
+  GtkThemingEnginePrivate *priv;
+
+  priv = GTK_THEMING_ENGINE (object)->priv;
+
+  switch (prop_id)
+    {
+    case PROP_NAME:
+      if (priv->name)
+        g_free (priv->name);
+
+      priv->name = g_value_dup_string (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_theming_engine_impl_get_property (GObject    *object,
+                                      guint       prop_id,
+                                      GValue     *value,
+                                      GParamSpec *pspec)
+{
+  GtkThemingEnginePrivate *priv;
+
+  priv = GTK_THEMING_ENGINE (object)->priv;
+
+  switch (prop_id)
+    {
+    case PROP_NAME:
+      g_value_set_string (value, priv->name);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
 void
 _gtk_theming_engine_set_context (GtkThemingEngine *engine,
                                  GtkStyleContext  *context)
@@ -226,8 +324,8 @@ _gtk_theming_engine_set_context (GtkThemingEngine *engine,
  * Registers a property so it can be used in the CSS file format,
  * on the CSS file the property will look like
  * "-${engine-object-name}-${@property_name}". being
- * ${engine-object-name} the same than G_OBJECT_TYPE_NAME(engine)
- * would return.
+ * ${engine-object-name} either the GtkThemingEngine:name property
+ * or G_OBJECT_TYPE_NAME(engine).
  *
  * For any type a @parse_func may be provided, being this function
  * used for turning any property value (between ':' and ';') in
@@ -261,14 +359,22 @@ gtk_theming_engine_register_property (GtkThemingEngine       *engine,
                                       const GValue           *default_value,
                                       GtkStylePropertyParser  parse_func)
 {
-  gchar *name;
+  GtkThemingEnginePrivate *priv;
+  gchar *engine_name, *name;
 
   g_return_if_fail (GTK_IS_THEMING_ENGINE (engine));
   g_return_if_fail (property_name != NULL);
   g_return_if_fail (type != G_TYPE_INVALID);
   g_return_if_fail (default_value != NULL && G_IS_VALUE (default_value));
 
-  name = g_strdup_printf ("-%s-%s", G_OBJECT_TYPE_NAME (engine), property_name);
+  priv = engine->priv;
+
+  if (priv->name)
+    engine_name = priv->name;
+  else
+    engine_name = G_OBJECT_TYPE_NAME (engine);
+
+  name = g_strdup_printf ("-%s-%s", engine_name, property_name);
   gtk_style_set_register_property (name, type, default_value, parse_func);
   g_free (name);
 }