X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2Fsvgtiny_css.c;h=97d6307d69c015ad8cf30ef58d1579c772ec9087;hb=1494831bf29ad3bcbc2c02cb50e0c95795a88005;hp=de82a835071e602853810ad0f5e6c38554891fdc;hpb=ed265576e5a9c4daf8e938548f3d18b106bd07fe;p=libsvgtiny.git

diff --git a/src/svgtiny_css.c b/src/svgtiny_css.c
index de82a83..97d6307 100644
--- a/src/svgtiny_css.c
+++ b/src/svgtiny_css.c
@@ -8,6 +8,8 @@ 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_ancestor_node(void *pw, void *node,
+		const css_qname *qname, void **ancestor);
 static css_error named_parent_node(void *pw, void *node,
 		const css_qname *qname, void **parent);
 static css_error named_sibling_node(void *pw, void *node,
@@ -47,6 +49,7 @@ 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);
 static css_error node_is_link(void *pw, void *node, bool *is_link);
+static css_error node_is_visited(void *pw, void *node, bool *is_visited);
 static css_error node_is_hover(void *pw, void *node, bool *is_hover);
 static css_error node_is_active(void *pw, void *node, bool *is_active);
 static css_error node_is_focus(void *pw, void *node, bool *is_focus);
@@ -54,6 +57,16 @@ static css_error node_is_enabled(void *pw, void *node, bool *is_enabled);
 static css_error node_is_disabled(void *pw, void *node, bool *is_disabled);
 static css_error node_is_checked(void *pw, void *node, bool *is_checked);
 static css_error node_is_target(void *pw, void *node, bool *is_target);
+static css_error node_is_lang(void *pw, void *node,
+		lwc_string *lang, bool *is_lang);
+static css_error node_presentational_hint(void *pw, void *node,
+		uint32_t *nhints, css_hint **hints);
+static css_error ua_default_for_property(void *pw, uint32_t property,
+	css_hint *hint);
+static css_error set_libcss_node_data(void *pw, void *node,
+		void *libcss_node_data);
+static css_error get_libcss_node_data(void *pw, void *node,
+		void **libcss_node_data);
 
 
 /**
@@ -229,6 +242,40 @@ css_error node_id(void *pw, void *node, lwc_string **id)
 }
 
 
+/**
+ * Find the first ancestor of the given element having the given name
+ *
+ * This function thinly wraps dom_element_named_ancestor_node(), which
+ * performs exactly the search we want.
+ *
+ * \param pw        Pointer to the current SVG parser state
+ * \param node      Libdom SVG node whose ancestor we want
+ * \param qname     Name of the ancestor node to search for
+ * \param ancestor  Address at which to store the ancestor 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 ancestor; otherwise,
+ *       NULL will be stored at the address pointed to by \a ancestor
+ */
+css_error named_ancestor_node(void *pw, void *node,
+		const css_qname *qname, void **ancestor)
+{
+	UNUSED(pw);
+
+	/* It's OK if node isn't an element, libdom checks for it. */
+	dom_element_named_ancestor_node((dom_element *)node,
+			qname->name,
+			(struct dom_element **)ancestor);
+
+	/* A comment in named_parent_node() explains why we unref
+	 * this here. */
+	dom_node_unref(*ancestor);
+
+	return CSS_OK;
+}
+
 
 /**
  * Find the first parent of the given element having the given name
@@ -1510,6 +1557,26 @@ css_error node_is_link(void *pw, void *node, bool *is_link)
 	return CSS_OK;
 }
 
+/**
+ * Check if the given node is a link that has been visited already
+ *
+ * This check always fails because the SVG DOM does not have the
+ * necessary information (it's a UI property).
+ *
+ * \param pw           Pointer to the current SVG parser state; unused
+ * \param node         Libdom SVG node to check; unused
+ * \param is_visited   Pointer to the boolean return value
+ *
+ * \return Always returns CSS_OK
+ */
+css_error node_is_visited(void *pw, void *node, bool *is_visited)
+{
+	UNUSED(pw);
+	UNUSED(node);
+	*is_visited = false;
+	return CSS_OK;
+}
+
 
 /**
  * Check if the given node is being "hovered" over
@@ -1657,3 +1724,199 @@ css_error node_is_target(void *pw, void *node, bool *is_target)
 	*is_target = false;
 	return CSS_OK;
 }
+
+
+/**
+ * Check if the given node is the given language
+ *
+ * This test is corresponds to the CSS :lang() selector and is not
+ * fully implemented yet: it looks only for "lang" attributes on the
+ * given element and its parents, and performs a simple substring
+ * check. This results in a partial implementation of CSS Level 3 for
+ * SVG 2.0. In particular, it ignores all "xml:lang" attributes in
+ * favor of the "lang" attribute that is defined only in SVG 2.0.
+ *
+ * \param pw            Pointer to the current SVG parser state; unused
+ * \param node          Libdom SVG node to check
+ * \param lang          The language to match
+ * \param is_lang       Pointer to the boolean return value
+ *
+ * \return CSS_OK on success, or CSS_NOMEM if anything goes wrong
+ */
+static css_error node_is_lang(void *pw, void *node,
+		lwc_string *lang, bool *is_lang)
+{
+	UNUSED(pw);
+	/* SVG2 elements support both "lang" and "xml:lang"
+	 * attributes; earlier versions have only the XML
+	 * attribute. It would not be too hard to add support for
+	 * xml:lang" here. The main difficulty standing in the way of
+	 * a full Level 4 implementation is the complexity of the
+	 * :lang() selector:
+	 *
+	 *   https://www.w3.org/TR/selectors-4/#the-lang-pseudo
+	 *
+	 */
+
+	css_error c_err;
+	dom_exception d_err;
+	dom_node *n; /* current node */
+	dom_node *p; /* parent node */
+	bool match;  /* retval from node_has_attribute_substring() */
+
+	/* Define the attribute name "lang" that we're looking for.
+	 * We only use a css_qname here because that's what the
+	 * node_has_attribute_substring() takes; the namespace
+	 * portion of it is irrelevant. */
+	css_qname attr;
+	attr.ns = NULL;
+
+	if (lwc_intern_string("lang", 4, &attr.name) != lwc_error_ok) {
+		return CSS_NOMEM;
+	}
+
+	*is_lang = false; /* default to no match */
+	n = (dom_node *)node;
+
+	/* Loop through all parents of the given node looking for a
+	 * substring match */
+	while (n != NULL) {
+		c_err = _node_has_attribute_substring(pw, (void *)n, &attr,
+						lang, &match, true);
+		if (c_err != CSS_OK) {
+			lwc_string_destroy(attr.name);
+			return c_err;
+		}
+		if (match) {
+			/* matched this element; we're done */
+			lwc_string_destroy(attr.name);
+			*is_lang = true;
+			return CSS_OK;
+		}
+
+		/* no match on this element, try its parent */
+		d_err = dom_node_get_parent_node(n, &p);
+		if (d_err != DOM_NO_ERR) {
+			lwc_string_destroy(attr.name);
+			return CSS_NOMEM;
+		}
+		n = p;
+	}
+
+	/* If we never find a match we may wind up here */
+	lwc_string_destroy(attr.name);
+	return CSS_OK;
+}
+
+
+/**
+ * Return presentational hints for the given node
+ *
+ * Unless an SVG is being rendered from within an HTML document,
+ * there are no presentational hints. We always return an empty
+ * array (no hints).
+ *
+ * \param pw        Pointer to the current SVG parser state; unused
+ * \param node      Libdom SVG node whose hints we want; unused
+ * \param nhints    How many hints are returned (return by reference)
+ * \param hints     Array of css_hint structures (return by reference)
+ *
+ * \return Always returns CSS_OK
+ */
+css_error node_presentational_hint(void *pw, void *node,
+		uint32_t *nhints, css_hint **hints)
+{
+	UNUSED(pw);
+	UNUSED(node);
+	*nhints = 0;
+	*hints = NULL;
+	return CSS_OK;
+}
+
+
+/**
+ * User-agent defaults for CSS properties
+ *
+ * For the moment, we provide no defaults, because libsvgtiny does not
+ * yet support any CSS properties that might need them.
+ *
+ * \param pw            Pointer to the current SVG parser state; unused
+ * \param property      LibCSS property identifier; unused
+ * \param hint          Pointer to hint object (a return value); unused
+ *
+ * \return Always returns CSS_INVALID
+ */
+css_error ua_default_for_property(void *pw, uint32_t property,
+	css_hint *hint)
+{
+	UNUSED(pw);
+	UNUSED(property);
+	UNUSED(hint);
+	return CSS_INVALID;
+}
+
+
+/**
+ * Store libcss data on a node
+ *
+ * This is part of the libcss select handler API that we need to
+ * implement. It is essentially a thin dom_node_set_user_data()
+ * wrapper.
+ *
+ * \param pw                 Pointer to the current SVG parser state
+ * \param node               Libdom SVG node on which to store the data
+ * \param libcss_node_data   Pointer to the data to store
+ *
+ * \return Always returns CSS_OK
+ */
+css_error set_libcss_node_data(void *pw, void *node,
+		void *libcss_node_data)
+{
+	struct svgtiny_parse_state *state;
+	void *old_data;
+
+	/* A unique "userdata key" (a string) is used to identify this
+	 * data. The fourth parameter (NULL) is a "user handler
+	 * function." We will eventually have one, but for now we set
+	 * it to NULL to avoid a circular reference mess that would
+	 * break the build temporarily. */
+	state = (struct svgtiny_parse_state *)pw;
+	dom_node_set_user_data((dom_node *)node,
+				state->interned_userdata_key,
+				libcss_node_data,
+				NULL,
+				&old_data);
+
+	/* dom_node_set_user_data() always returns DOM_NO_ERR */
+	return CSS_OK;
+}
+
+
+/**
+ * Retrieve libcss data from a node
+ *
+ * This is part of the libcss select handler API that we need to
+ * implement. It is essentially a thin dom_node_get_user_data()
+ * wrapper.
+ *
+ * \param pw                 Pointer to the current SVG parser state
+ * \param node               Libdom SVG node from which to get the data
+ * \param libcss_node_data   Address at which to store a pointer to the data
+ *
+ * \return Always returns CSS_OK
+ */
+css_error get_libcss_node_data(void *pw, void *node,
+		void **libcss_node_data)
+{
+	struct svgtiny_parse_state *state;
+
+	/* A unique "userdata key" (a string) is used to identify this
+	 * data. */
+	state = (struct svgtiny_parse_state *)pw;
+	dom_node_get_user_data((dom_node *)node,
+				state->interned_userdata_key,
+				libcss_node_data);
+
+	/* dom_node_get_user_data() always returns DOM_NO_ERR */
+	return CSS_OK;
+}