GtkBuilder: Add private _gtk_builder_extend_with_template()

This adds the definition of the <template> tag with some documentation
on the variant of the format.

_gtk_builder_extend_with_template() is to be used while GtkContainer
builds from composite templates. A couple of error codes are also added
to handle a few new possible failure cases.

DTD Files gtkbuilder.rnc and gtkbuilder.rng have been updated to include
the new <template> tag and it's attributes.

6 files changed, 297 insertions, 20 deletions

diff --git a/gtk/gtkbuilder.c b/gtk/gtkbuilder.c
index 9e2f29466e..7e0880240d 100644
--- a/gtk/gtkbuilder.c
+++ b/gtk/gtkbuilder.c
@@ -275,6 +275,7 @@ struct _GtkBuilderPrivate
   GSList *signals;
   gchar *filename;
   gchar *resource_prefix;
+  GType template_type;
 };
 
 G_DEFINE_TYPE (GtkBuilder, gtk_builder, G_TYPE_OBJECT)
@@ -459,8 +460,9 @@ gtk_builder_get_parameters (GtkBuilder  *builder,
                             GType        object_type,
                             const gchar *object_name,
                             GSList      *properties,
+			    GParamFlags  filter_flags,
                             GArray      **parameters,
-                            GArray      **construct_parameters)
+                            GArray      **filtered_parameters)
 {
   GSList *l;
   GParamSpec *pspec;
@@ -471,8 +473,10 @@ gtk_builder_get_parameters (GtkBuilder  *builder,
   oclass = g_type_class_ref (object_type);
   g_assert (oclass != NULL);
 
-  *parameters = g_array_new (FALSE, FALSE, sizeof (GParameter));
-  *construct_parameters = g_array_new (FALSE, FALSE, sizeof (GParameter));
+  if (parameters)
+    *parameters = g_array_new (FALSE, FALSE, sizeof (GParameter));
+  if (filtered_parameters)
+    *filtered_parameters = g_array_new (FALSE, FALSE, sizeof (GParameter));
 
   for (l = properties; l; l = l->next)
     {
@@ -530,10 +534,16 @@ gtk_builder_get_parameters (GtkBuilder  *builder,
           continue;
         }
 
-      if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
-        g_array_append_val (*construct_parameters, parameter);
+      if (pspec->flags & filter_flags)
+	{
+	  if (filtered_parameters)
+	    g_array_append_val (*filtered_parameters, parameter);
+	}
       else
-        g_array_append_val (*parameters, parameter);
+	{
+	  if (parameters)
+	    g_array_append_val (*parameters, parameter);
+	}
     }
 
   g_type_class_unref (oclass);
@@ -619,10 +629,22 @@ _gtk_builder_construct (GtkBuilder *builder,
 		   info->class_name);
       return NULL;
     }
+  else if (builder->priv->template_type != 0 &&
+	   g_type_is_a (object_type, builder->priv->template_type))
+    {
+      g_set_error (error,
+		   GTK_BUILDER_ERROR,
+		   GTK_BUILDER_ERROR_OBJECT_TYPE_REFUSED,
+		   "Refused to build object of type `%s' because it "
+		   "conforms to the template type `%s', avoiding infinite recursion.",
+		   info->class_name, g_type_name (builder->priv->template_type));
+      return NULL;
+    }
 
   gtk_builder_get_parameters (builder, object_type,
                               info->id,
                               info->properties,
+			      (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY),
                               &parameters,
                               &construct_parameters);
 
@@ -735,6 +757,61 @@ _gtk_builder_construct (GtkBuilder *builder,
 }
 
 void
+_gtk_builder_apply_properties (GtkBuilder *builder,
+			       ObjectInfo *info,
+			       GError **error)
+{
+  GArray *parameters;
+  GType object_type;
+  GtkBuildableIface *iface;
+  GtkBuildable *buildable;
+  gboolean custom_set_property;
+  gint i;
+
+  g_assert (info->object != NULL);
+  g_assert (info->class_name != NULL);
+  object_type = gtk_builder_get_type_from_name (builder, info->class_name);
+
+  /* Fetch all properties that are not construct-only */
+  gtk_builder_get_parameters (builder, object_type,
+                              info->id,
+                              info->properties,
+			      G_PARAM_CONSTRUCT_ONLY,
+                              &parameters, NULL);
+
+  custom_set_property = FALSE;
+  buildable = NULL;
+  iface = NULL;
+  if (GTK_IS_BUILDABLE (info->object))
+    {
+      buildable = GTK_BUILDABLE (info->object);
+      iface = GTK_BUILDABLE_GET_IFACE (info->object);
+      if (iface->set_buildable_property)
+        custom_set_property = TRUE;
+    }
+
+  for (i = 0; i < parameters->len; i++)
+    {
+      GParameter *param = &g_array_index (parameters, GParameter, i);
+      if (custom_set_property)
+        iface->set_buildable_property (buildable, builder, param->name, &param->value);
+      else
+        g_object_set_property (info->object, param->name, &param->value);
+
+#if G_ENABLE_DEBUG
+      if (gtk_get_debug_flags () & GTK_DEBUG_BUILDER)
+        {
+          gchar *str = g_strdup_value_contents ((const GValue*)&param->value);
+          g_print ("set %s: %s = %s\n", info->id, param->name, str);
+          g_free (str);
+        }
+#endif      
+      g_value_unset (&param->value);
+    }
+  g_array_free (parameters, TRUE);
+}
+
+void
 _gtk_builder_add (GtkBuilder *builder,
                   ChildInfo  *child_info)
 {
@@ -987,6 +1064,48 @@ gtk_builder_add_objects_from_file (GtkBuilder   *builder,
   return 1;
 }
 
+/* Main private entry point for building composite container
+ * components from template XML
+ */
+guint
+_gtk_builder_extend_with_template (GtkBuilder    *builder,
+				   GtkWidget     *widget,
+				   GType          template_type,
+				   const gchar   *buffer,
+				   gsize          length,
+				   GError       **error)
+{
+  GError *tmp_error;
+
+  g_return_val_if_fail (GTK_IS_BUILDER (builder), 0);
+  g_return_val_if_fail (GTK_IS_WIDGET (widget), 0);
+  g_return_val_if_fail (g_type_name (template_type) != NULL, 0);
+  g_return_val_if_fail (g_type_is_a (G_OBJECT_TYPE (widget), template_type), 0);
+  g_return_val_if_fail (buffer && buffer[0], 0);
+
+  tmp_error = NULL;
+
+  g_free (builder->priv->filename);
+  g_free (builder->priv->resource_prefix);
+  builder->priv->filename = g_strdup (".");
+  builder->priv->resource_prefix = NULL;
+  builder->priv->template_type = template_type;
+
+  gtk_builder_expose_object (builder, g_type_name (template_type), G_OBJECT (widget));
+  _gtk_builder_parser_parse_buffer (builder, "<input>",
+                                    buffer, length,
+                                    NULL,
+                                    &tmp_error);
+
+  if (tmp_error != NULL)
+    {
+      g_propagate_error (error, tmp_error);
+      return 0;
+    }
+
+  return 1;
+}
+
 /**
  * gtk_builder_add_from_resource:
  * @builder: a #GtkBuilder
@@ -2141,6 +2260,12 @@ _gtk_builder_get_absolute_filename (GtkBuilder *builder, const gchar *string)
   return filename;
 }
 
+GType
+_gtk_builder_get_template_type (GtkBuilder *builder)
+{
+  return builder->priv->template_type;
+}
+
 /**
  * gtk_builder_add_callback_symbol:
  * @builder: a #GtkBuilder
diff --git a/gtk/gtkbuilder.h b/gtk/gtkbuilder.h
index 5b22eb13cb..f002353d36 100644
--- a/gtk/gtkbuilder.h
+++ b/gtk/gtkbuilder.h
@@ -59,6 +59,9 @@ typedef struct _GtkBuilderPrivate GtkBuilderPrivate;
  * @GTK_BUILDER_ERROR_VERSION_MISMATCH: The input file requires a newer version
  *  of GTK+.
  * @GTK_BUILDER_ERROR_DUPLICATE_ID: An object id occurred twice.
+ * @GTK_BUILDER_ERROR_OBJECT_TYPE_REFUSED: A specified object type is of the same type or
+ *  derived from the type of the composite class being extended with builder XML.
+ * @GTK_BUILDER_ERROR_TEMPLATE_MISMATCH: The wrong type was specified in a composite class's template XML
  *
  * Error codes that identify various errors that can occur while using
  * #GtkBuilder.
@@ -73,7 +76,9 @@ typedef enum
   GTK_BUILDER_ERROR_MISSING_PROPERTY_VALUE,
   GTK_BUILDER_ERROR_INVALID_VALUE,
   GTK_BUILDER_ERROR_VERSION_MISMATCH,
-  GTK_BUILDER_ERROR_DUPLICATE_ID
+  GTK_BUILDER_ERROR_DUPLICATE_ID,
+  GTK_BUILDER_ERROR_OBJECT_TYPE_REFUSED,
+  GTK_BUILDER_ERROR_TEMPLATE_MISMATCH
 } GtkBuilderError;
 
 GQuark gtk_builder_error_quark (void);
diff --git a/gtk/gtkbuilder.rnc b/gtk/gtkbuilder.rnc
index a2b40320b9..635fd4f289 100644
--- a/gtk/gtkbuilder.rnc
+++ b/gtk/gtkbuilder.rnc
@@ -1,6 +1,6 @@
 start = element interface {
   attribute domain { text } ?,
-  ( requires | object | menu ) *
+  ( requires | object | template | menu ) *
 }
 
 requires = element requires {
@@ -16,6 +16,12 @@ object = element object {
   (property | signal | child | ANY) *
 }
 
+template = element template {
+  attribute class { text },
+  attribute parent { text },
+  (property | signal | child | ANY) *
+}
+
 property = element property {
   attribute name { text },
   attribute translatable { "yes" | "no" } ?,
@@ -76,7 +82,7 @@ section = element section {
   (attribute_ | item | submenu | section) *
 }
 
-ANY = element * - (interface | requires | object | property | signal | child | menu | item | attribute | link | submenu | section) {
+ANY = element * - (interface | requires | object | template | property | signal | child | menu | item | attribute | link | submenu | section) {
   attribute * { text } *,
   (ALL * & text ?)
 }
diff --git a/gtk/gtkbuilder.rng b/gtk/gtkbuilder.rng
index e36d05194a..eee698a607 100644
--- a/gtk/gtkbuilder.rng
+++ b/gtk/gtkbuilder.rng
@@ -11,6 +11,7 @@
         <choice>
           <ref name="requires"/>
           <ref name="object"/>
+          <ref name="template"/>
           <ref name="menu"/>
         </choice>
       </zeroOrMore>
@@ -54,6 +55,24 @@
       </zeroOrMore>
     </element>
   </define>
+  <define name="template">
+    <element name="template">
+      <attribute name="class">
+        <text/>
+      </attribute>
+      <attribute name="parent">
+        <text/>
+      </attribute>
+      <zeroOrMore>
+        <choice>
+          <ref name="property"/>
+          <ref name="signal"/>
+          <ref name="child"/>
+          <ref name="ANY"/>
+        </choice>
+      </zeroOrMore>
+    </element>
+  </define>
   <define name="property">
     <element name="property">
       <attribute name="name">
diff --git a/gtk/gtkbuilderparser.c b/gtk/gtkbuilderparser.c
index 6344258905..9a4b4062e2 100644
--- a/gtk/gtkbuilderparser.c
+++ b/gtk/gtkbuilderparser.c
@@ -187,14 +187,27 @@ builder_construct (ParserData  *data,
 
   g_assert (object_info != NULL);
 
-  if (object_info->object)
+  if (object_info->object && object_info->applied_properties)
     return object_info->object;
 
   object_info->properties = g_slist_reverse (object_info->properties);
 
-  object = _gtk_builder_construct (data->builder, object_info, error);
-  if (!object)
-    return NULL;
+  if (object_info->object == NULL)
+    {
+      object = _gtk_builder_construct (data->builder, object_info, error);
+      if (!object)
+	return NULL;
+    }
+  else
+    {
+      /* We're building a template, the object is already set and
+       * we just want to resolve the properties at the right time
+       */
+      object = object_info->object;
+      _gtk_builder_apply_properties (data->builder, object_info, error);
+    }
+
+  object_info->applied_properties = TRUE;
 
   g_assert (G_IS_OBJECT (object));
 
@@ -412,6 +425,92 @@ parse_object (GMarkupParseContext  *context,
 }
 
 static void
+parse_template (GMarkupParseContext  *context,
+		ParserData           *data,
+		const gchar          *element_name,
+		const gchar         **names,
+		const gchar         **values,
+		GError              **error)
+{
+  ObjectInfo *object_info;
+  int i;
+  gchar *object_class = NULL;
+  gint line, line2;
+  GType template_type = _gtk_builder_get_template_type (data->builder);
+  GType parsed_type;
+
+  if (template_type == 0)
+    {
+      g_set_error (error,
+		   GTK_BUILDER_ERROR,
+		   GTK_BUILDER_ERROR_UNHANDLED_TAG,
+		   "Encountered template definition but not parsing a template.");
+      return;
+    }
+  else if (state_peek (data) != NULL)
+    {
+      g_set_error (error,
+		   GTK_BUILDER_ERROR,
+		   GTK_BUILDER_ERROR_UNHANDLED_TAG,
+		   "Encountered template definition that is not at the top level.");
+      return;
+    }
+
+  for (i = 0; names[i] != NULL; i++)
+    {
+      if (strcmp (names[i], "class") == 0)
+        object_class = g_strdup (values[i]);
+      else if (strcmp (names[i], "parent") == 0)
+        /* Ignore 'parent' attribute, however it's needed by Glade */;
+      else
+	{
+	  error_invalid_attribute (data, element_name, names[i], error);
+	  return;
+	}
+    }
+
+  if (!object_class)
+    {
+      error_missing_attribute (data, element_name, "class", error);
+      return;
+    }
+
+  parsed_type = g_type_from_name (object_class);
+  if (template_type != parsed_type)
+    {
+      g_set_error (error,
+		   GTK_BUILDER_ERROR,
+		   GTK_BUILDER_ERROR_TEMPLATE_MISMATCH,
+		   "Parsed template definition for type `%s', expected type `%s'.",
+		   object_class, g_type_name (template_type));
+      return;
+    }
+
+  ++data->cur_object_level;
+
+  object_info = g_slice_new0 (ObjectInfo);
+  object_info->class_name = object_class;
+  object_info->id = g_strdup (object_class);
+  object_info->object = gtk_builder_get_object (data->builder, object_class);
+  state_push (data, object_info);
+  object_info->tag.name = element_name;
+
+  g_markup_parse_context_get_position (context, &line, NULL);
+  line2 = GPOINTER_TO_INT (g_hash_table_lookup (data->object_ids, object_class));
+  if (line2 != 0)
+    {
+      g_set_error (error, GTK_BUILDER_ERROR,
+                   GTK_BUILDER_ERROR_DUPLICATE_ID,
+                   _("Duplicate object ID '%s' on line %d (previously on line %d)"),
+                   object_class, line, line2);
+      return;
+    }
+
+  g_hash_table_insert (data->object_ids, g_strdup (object_class), GINT_TO_POINTER (line));
+}
+
+
+static void
 free_object_info (ObjectInfo *info)
 {
   /* Do not free the signal items, which GtkBuilder takes ownership of */
@@ -446,7 +545,9 @@ parse_child (ParserData   *data,
   guint i;
 
   object_info = state_peek_info (data, ObjectInfo);
-  if (!object_info || strcmp (object_info->tag.name, "object") != 0)
+  if (!object_info ||
+      !(strcmp (object_info->tag.name, "object") == 0 ||
+	strcmp (object_info->tag.name, "template") == 0))
     {
       error_invalid_tag (data, element_name, NULL, error);
       return;
@@ -493,7 +594,9 @@ parse_property (ParserData   *data,
   int i;
 
   object_info = state_peek_info (data, ObjectInfo);
-  if (!object_info || strcmp (object_info->tag.name, "object") != 0)
+  if (!object_info || 
+      !(strcmp (object_info->tag.name, "object") == 0 ||
+	strcmp (object_info->tag.name, "template") == 0))
     {
       error_invalid_tag (data, element_name, NULL, error);
       return;
@@ -566,7 +669,9 @@ parse_signal (ParserData   *data,
   int i;
 
   object_info = state_peek_info (data, ObjectInfo);
-  if (!object_info || strcmp (object_info->tag.name, "object") != 0)
+  if (!object_info ||
+      !(strcmp (object_info->tag.name, "object") == 0 ||
+	strcmp (object_info->tag.name, "template") == 0))
     {
       error_invalid_tag (data, element_name, NULL, error);
       return;
@@ -784,7 +889,8 @@ parse_custom (GMarkupParseContext *context,
   if (!parent_info)
     return FALSE;
 
-  if (strcmp (parent_info->tag.name, "object") == 0)
+  if (strcmp (parent_info->tag.name, "object") == 0 ||
+      strcmp (parent_info->tag.name, "template") == 0)
     {
       ObjectInfo* object_info = (ObjectInfo*)parent_info;
       if (!object_info->object)
@@ -877,6 +983,8 @@ start_element (GMarkupParseContext *context,
     parse_requires (data, element_name, names, values, error);
   else if (strcmp (element_name, "object") == 0)
     parse_object (context, data, element_name, names, values, error);
+  else if (strcmp (element_name, "template") == 0)
+    parse_template (context, data, element_name, names, values, error);
   else if (data->requested_objects && !data->inside_requested_object)
     {
       /* If outside a requested object, simply ignore this tag */
@@ -972,7 +1080,8 @@ end_element (GMarkupParseContext *context,
     {
       _gtk_builder_menu_end (data);
     }
-  else if (strcmp (element_name, "object") == 0)
+  else if (strcmp (element_name, "object") == 0 ||
+	   strcmp (element_name, "template") == 0)
     {
       ObjectInfo *object_info = state_pop_info (data, ObjectInfo);
       ChildInfo* child_info = state_peek_info (data, ChildInfo);
@@ -1012,7 +1121,8 @@ end_element (GMarkupParseContext *context,
       CommonInfo *info = state_peek_info (data, CommonInfo);
 
       /* Normal properties */
-      if (strcmp (info->tag.name, "object") == 0)
+      if (strcmp (info->tag.name, "object") == 0 ||
+	  strcmp (info->tag.name, "template") == 0)
         {
           ObjectInfo *object_info = (ObjectInfo*)info;
 
@@ -1101,7 +1211,8 @@ text (GMarkupParseContext *context,
 static void
 free_info (CommonInfo *info)
 {
-  if (strcmp (info->tag.name, "object") == 0)
+  if (strcmp (info->tag.name, "object") == 0 ||
+      strcmp (info->tag.name, "template") == 0)
     free_object_info ((ObjectInfo *)info);
   else if (strcmp (info->tag.name, "child") == 0)
     free_child_info ((ChildInfo *)info);
diff --git a/gtk/gtkbuilderprivate.h b/gtk/gtkbuilderprivate.h
index 3667ed52d0..9af96d9865 100644
--- a/gtk/gtkbuilderprivate.h
+++ b/gtk/gtkbuilderprivate.h
@@ -38,6 +38,7 @@ typedef struct {
   GSList *signals;
   GObject *object;
   CommonInfo *parent;
+  gboolean applied_properties;
 } ObjectInfo;
 
 typedef struct {
@@ -121,6 +122,9 @@ void _gtk_builder_parser_parse_buffer (GtkBuilder *builder,
 GObject * _gtk_builder_construct (GtkBuilder *builder,
                                   ObjectInfo *info,
 				  GError    **error);
+void      _gtk_builder_apply_properties (GtkBuilder *builder,
+					 ObjectInfo *info,
+					 GError **error);
 void      _gtk_builder_add_object (GtkBuilder  *builder,
                                    const gchar *id,
                                    GObject     *object);
@@ -159,5 +163,12 @@ void      _gtk_builder_menu_start (ParserData   *parser_data,
                                    GError      **error);
 void      _gtk_builder_menu_end   (ParserData  *parser_data);
 
+GType     _gtk_builder_get_template_type (GtkBuilder *builder);
+guint     _gtk_builder_extend_with_template (GtkBuilder    *builder,
+					     GtkWidget     *widget,
+					     GType          template_type,
+					     const gchar   *buffer,
+					     gsize          length,
+					     GError       **error);
 
 #endif /* __GTK_BUILDER_PRIVATE_H__ */