From: Michael Orlitzky <michael@orlitzky.com>
Date: Sat, 14 Oct 2023 15:39:20 +0000 (-0400)
Subject: src/svgtiny_css.c: implement node_is_empty() select handler
X-Git-Url: http://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=092d632d8f8e3a05e51ed536d01f8598d847ac00;p=libsvgtiny.git

src/svgtiny_css.c: implement node_is_empty() select handler
---

diff --git a/src/svgtiny_css.c b/src/svgtiny_css.c
index ffc9c3e..ebf432d 100644
--- a/src/svgtiny_css.c
+++ b/src/svgtiny_css.c
@@ -45,6 +45,7 @@ static css_error node_has_attribute_substring(void *pw, void *node,
 static css_error node_is_root(void *pw, void *node, bool *match);
 static css_error node_count_siblings(void *pw, void *node,
 		bool same_name, bool after, int32_t *count);
+static css_error node_is_empty(void *pw, void *node, bool *is_empty);
 
 
 /**
@@ -1363,3 +1364,65 @@ css_error node_count_siblings(void *pw, void *node,
 
 	return CSS_OK;
 }
+
+
+/**
+ * Determine whether or not the given element is empty
+ *
+ * An element is "nonempty" if it has a child that is either an
+ * element node or a text node.
+ *
+ * \param pw          Pointer to the current SVG parser state
+ * \param node        Libdom SVG node to check for emptiness
+ * \param is_empty    Pointer to the return value
+ *
+ * \return CSS_OK on success, or CSS_NOMEM if anything goes wrong
+ */
+css_error node_is_empty(void *pw, void *node, bool *is_empty)
+{
+	UNUSED(pw);
+	dom_node *child; /* current child node pointer */
+	dom_node *next;  /* next child node pointer */
+	dom_node_type type; /* what type of node is "child" */
+	dom_exception err;
+
+	/* Assume that it's empty by default */
+	*is_empty = true;
+
+	/* Get the given node's first child. Implementation detail:
+	 * this increments the reference counter on the child node. */
+	err = dom_node_get_first_child((dom_node *)node, &child);
+	if (err != DOM_NO_ERR) {
+		return CSS_NOMEM;
+	}
+
+	/* And now loop through all children looking for a
+	 * text/element node. If we find one, the original
+	 * node is "nonempty" */
+	while (child != NULL) {
+		err = dom_node_get_node_type(child, &type);
+		if (err != DOM_NO_ERR) {
+			dom_node_unref(child);
+			return CSS_NOMEM;
+		}
+
+		if (type == DOM_ELEMENT_NODE || type == DOM_TEXT_NODE) {
+			*is_empty = false;
+			dom_node_unref(child);
+			return CSS_OK;
+		}
+
+		err = dom_node_get_next_sibling(child, &next);
+		if (err != DOM_NO_ERR) {
+			dom_node_unref(child);
+			return CSS_NOMEM;
+		}
+
+		/* If we're moving to the next node, we can release
+		 * the reference to the current one */
+		dom_node_unref(child);
+		child = next;
+	}
+
+	return CSS_OK;
+}