[evolution-data-server] Add e_source_registry_check_enabled().

[Matthew Barnes <mbarnes src gnome org>]

commit 7e21729caf6dd4c2f3a92935c0e38d6d27b589f0
Author: Matthew Barnes <mbarnes redhat com>
Date:   Thu Oct 25 10:38:43 2012 -0400

    Add e_source_registry_check_enabled().
    
    Checks the enabled state of a given #ESource and of its ancestors to
    determine if the #ESource should be displayed or acted on.
    
    This is somewhat similar to widget sensitivity in GTK+.
    cf. gtk_widget_get_sensitive() versus gtk_widget_is_sensitive()

 .../libedataserver/libedataserver-sections.txt     |    1 +
 libedataserver/e-source-registry.c                 |   52 ++++++++++++++++++++
 libedataserver/e-source-registry.h                 |    2 +
 libedataserver/e-source.c                          |    8 +++
 4 files changed, 63 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/libedataserver/libedataserver-sections.txt b/docs/reference/libedataserver/libedataserver-sections.txt
index 52b9b57..fd2df4c 100644
--- a/docs/reference/libedataserver/libedataserver-sections.txt
+++ b/docs/reference/libedataserver/libedataserver-sections.txt
@@ -823,6 +823,7 @@ e_source_registry_create_sources_finish
 e_source_registry_ref_source
 e_source_registry_list_sources
 e_source_registry_find_extension
+e_source_registry_check_enabled
 e_source_registry_build_display_tree
 e_source_registry_free_display_tree
 e_source_registry_debug_dump
diff --git a/libedataserver/e-source-registry.c b/libedataserver/e-source-registry.c
index 3933712..d37a84f 100644
--- a/libedataserver/e-source-registry.c
+++ b/libedataserver/e-source-registry.c
@@ -2236,6 +2236,58 @@ e_source_registry_list_sources (ESourceRegistry *registry,
 }
 
 /**
+ * e_source_registry_check_enabled:
+ * @registry: an #ESourceRegistry
+ * @source: an #ESource
+ *
+ * Determines whether @source is "effectively" enabled by examining its
+ * own #ESource:enabled property as well as those of its ancestors in the
+ * #ESource hierarchy.  If all examined #ESource:enabled properties are
+ * %TRUE, then the function returns %TRUE.  If any are %FALSE, then the
+ * function returns %FALSE.
+ *
+ * Use this function instead of e_source_get_enabled() to determine
+ * things like whether to display an #ESource in a user interface or
+ * whether to act on the data set described by the #ESource.
+ *
+ * Returns: whether @source is "effectively" enabled
+ *
+ * Since: 3.8
+ **/
+gboolean
+e_source_registry_check_enabled (ESourceRegistry *registry,
+                                 ESource *source)
+{
+	gboolean enabled;
+	gchar *parent_uid;
+
+	g_return_val_if_fail (E_IS_SOURCE_REGISTRY (registry), FALSE);
+	g_return_val_if_fail (E_IS_SOURCE (source), FALSE);
+
+	enabled = e_source_get_enabled (source);
+	parent_uid = e_source_dup_parent (source);
+
+	while (enabled && parent_uid != NULL) {
+		ESource *parent;
+
+		parent = e_source_registry_ref_source (registry, parent_uid);
+
+		g_free (parent_uid);
+		parent_uid = NULL;
+
+		if (parent != NULL) {
+			enabled = e_source_get_enabled (parent);
+			parent_uid = e_source_dup_parent (parent);
+			g_object_unref (parent);
+		}
+	}
+
+	g_free (parent_uid);
+
+	return enabled;
+}
+
+/**
  * e_source_registry_find_extension:
  * @registry: an #ESourceRegistry
  * @source: an #ESource
diff --git a/libedataserver/e-source-registry.h b/libedataserver/e-source-registry.h
index 8ee290f..5a2a6fe 100644
--- a/libedataserver/e-source-registry.h
+++ b/libedataserver/e-source-registry.h
@@ -143,6 +143,8 @@ ESource *	e_source_registry_find_extension
 						(ESourceRegistry *registry,
 						 ESource *source,
 						 const gchar *extension_name);
+gboolean	e_source_registry_check_enabled	(ESourceRegistry *registry,
+						 ESource *source);
 GNode *		e_source_registry_build_display_tree
 						(ESourceRegistry *registry,
 						 const gchar *extension_name);
diff --git a/libedataserver/e-source.c b/libedataserver/e-source.c
index 29318cd..1c27c18 100644
--- a/libedataserver/e-source.c
+++ b/libedataserver/e-source.c
@@ -1879,6 +1879,14 @@ e_source_set_parent (ESource *source,
  * even if it does not provide a way to change the setting through its
  * user interface.  Disabled data sources should generally be hidden.
  *
+ * <note><para>
+ *   This function does not take into account @source's ancestors in the
+ *   #ESource hierarchy, each of which have their own enabled state.  If
+ *   any of @source's ancestors are disabled, then @source itself should
+ *   be treated as disabled.  Use e_source_registry_check_enabled() to
+ *   easily check for this.
+ * </para></note>
+ *
  * Returns: whether @source is enabled
  *
  * Since: 3.6