X-Git-Url: https://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2Fsvgtiny_css.c;h=01b566f93c876ef5f86111b62aa089f614734930;hb=1c82bd4791dc03bca184c5517f6ff4b5bb592788;hp=8abaa03de863e308de1c09e3ea0d60ba3682326e;hpb=8a193eb5807addc9e89b5804360d1cdc72cb1889;p=libsvgtiny.git

diff --git a/src/svgtiny_css.c b/src/svgtiny_css.c
index 8abaa03..01b566f 100644
--- a/src/svgtiny_css.c
+++ b/src/svgtiny_css.c
@@ -7,6 +7,8 @@ static css_error node_name(void *pw, void *node, css_qname *qname);
 static css_error node_classes(void *pw, void *node,
 		lwc_string ***classes, uint32_t *n_classes);
 static css_error node_id(void *pw, void *node, lwc_string **id);
+static css_error named_parent_node(void *pw, void *node,
+		const css_qname *qname, void **parent);
 
 
 /**
@@ -180,3 +182,49 @@ css_error node_id(void *pw, void *node, lwc_string **id)
 	dom_string_unref(attr);
 	return CSS_OK;
 }
+
+
+
+/**
+ * Find the first parent of the given element having the given name
+ *
+ * \param pw      Pointer to the current SVG parser state
+ * \param node    Libdom SVG node
+ * \param qname   Name of the parent node to search for
+ * \param parent  Address at which to store the parent node pointer
+ *
+ * \return Always returns CSS_OK
+ *
+ * \post If a suitable element is found, a pointer to it will be
+ *       stored at the address pointed to by \a parent; otherwise,
+ *       NULL will be stored at the address pointed to by \a parent
+ */
+css_error named_parent_node(void *pw, void *node,
+		const css_qname *qname, void **parent)
+{
+	UNUSED(pw);
+	/* dom_element_named_parent_node() was invented to implement
+	 * this select handler so there isn't much for us to do except
+	 * call it. It's OK if node isn't an element, libdom checks
+	 * for it. */
+	dom_element_named_parent_node((dom_element *)node,
+				qname->name,
+				(struct dom_element **)parent);
+
+	/* Implementation detail: dom_element_named_parent_node()
+	 * increments the reference count of the parent element before
+	 * returning it to us. According to docs/RefCnt in the libdom
+	 * repository, this will prevent the parent element from being
+	 * destroyed if it is pruned from the DOM. That sounds good,
+	 * since we don't want to be using a pointer to an object that
+	 * has been destroyed... but we also have no way of later
+	 * decrementing the reference count ourselves, and don't want
+	 * to make the returned node eternal. Decrementing the
+	 * reference counter now allows it to be destroyed when the
+	 * DOM no longer needs it, and so long as no other parts of
+	 * libsvgtiny are messing with the DOM during parsing, that
+	 * shouldn't (ha ha) cause any problems. */
+	dom_node_unref(*parent);
+
+	return CSS_OK;
+}