static css_error node_has_attribute_substring(void *pw, void *node,
const css_qname *qname, lwc_string *substring,
bool *match);
+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);
+static css_error node_is_link(void *pw, void *node, bool *is_link);
/**
return CSS_OK;
}
+
+
+/**
+ * Test whether or not the given node is the document's root element
+ * This corresponds to the CSS :root pseudo-selector.
+ *
+ * \param pw Pointer to the current SVG parser state
+ * \param node Libdom SVG node to test
+ * \param match Pointer to the test result
+ *
+ * \return CSS_OK on success, or CSS_NOMEM if anything goes wrong
+ */
+css_error node_is_root(void *pw, void *node, bool *match)
+{
+ UNUSED(pw);
+ dom_node *parent;
+ dom_node_type type;
+ dom_exception err;
+
+ err = dom_node_get_parent_node((dom_node *)node, &parent);
+ if (err != DOM_NO_ERR) {
+ return CSS_NOMEM;
+ }
+
+ /* It's the root element if it doesn't have a parent element */
+ if (parent != NULL) {
+ err = dom_node_get_node_type(parent, &type);
+ dom_node_unref(parent);
+ if (err != DOM_NO_ERR) {
+ return CSS_NOMEM;
+ }
+ if (type != DOM_DOCUMENT_NODE) {
+ /* DOM_DOCUMENT_NODE is the only allowable
+ * type of parent node for the root element */
+ *match = false;
+ return CSS_OK;
+ }
+ }
+
+ *match = true;
+ return CSS_OK;
+}
+
+
+/**
+ * Used internally in node_count_siblings() to "count" the given
+ * sibling node. It factors out the node type and name checks.
+ */
+static int node_count_siblings_check(dom_node *dnode,
+ bool check_name,
+ dom_string *name)
+{
+ int ret;
+ dom_node_type type;
+ dom_exception exc;
+ dom_string *dnode_name;
+
+ /* We flip this to 1 if/when we count this node */
+ ret = 0;
+
+ if (dnode == NULL) {
+ return ret;
+ }
+
+ exc = dom_node_get_node_type(dnode, &type);
+ if ((exc != DOM_NO_ERR) || (type != DOM_ELEMENT_NODE)) {
+ /* We only count element siblings */
+ return ret;
+ }
+
+ /* ... with the right name */
+ if (check_name) {
+ dnode_name = NULL;
+ exc = dom_node_get_node_name(dnode, &dnode_name);
+
+ if ((exc == DOM_NO_ERR) && (dnode_name != NULL)) {
+ if (dom_string_isequal(name,
+ dnode_name)) {
+ ret = 1;
+ }
+ dom_string_unref(dnode_name);
+ }
+ }
+ else {
+ ret = 1;
+ }
+
+ return ret;
+}
+
+/**
+ * Count the given node's sibling elements
+ *
+ * This counts the given node's sibling elements in one direction,
+ * either forwards or backwards, in the DOM. Keep in mind that the
+ * libdom tree is upside-down compared to the CSS one; so "next" and
+ * "previous" are actually reversed; the default is to count preceding
+ * libdom siblings which correspond to subsequent CSS siblings.
+ *
+ * This operation is central to the CSS :first-child, :nth-child, and
+ * :last-child (et cetera) pseudo-selectors.
+ *
+ * If same_name is true, then only nodes having the same
+ * (case-sensitive) name as the given node are counted.
+ *
+ * \param pw Pointer to the current SVG parser state
+ * \param node Libdom SVG node whose siblings we're counting
+ * \param same_name Whether or not to count only siblings having
+ * the same name as the given node
+ * \param after Count subsequent siblings rather than precedent
+ * ones (the default)
+ * \param count Pointer to the return value, the number of sibling
+ * elements
+ *
+ * \return CSS_OK on success, or CSS_NOMEM if anything goes wrong
+ */
+css_error node_count_siblings(void *pw, void *node,
+ bool same_name, bool after, int32_t *count)
+{
+ UNUSED(pw);
+ dom_exception exc;
+ dom_node *dnode; /* node, but with the right type */
+ dom_string *dnode_name;
+ dom_node *next; /* "next" sibling (depends on direction) */
+
+ /* Pointer to the "next sibling" function */
+ dom_exception (*next_func)(dom_node *, dom_node **);
+
+ *count = 0;
+
+ dnode_name = NULL;
+ dnode = (dom_node *)node;
+ if (same_name) {
+ exc = dom_node_get_node_name(dnode, &dnode_name);
+ if ((exc != DOM_NO_ERR) || (dnode_name == NULL)) {
+ return CSS_NOMEM;
+ }
+ }
+
+ /* Increment the reference counter for dnode for as long as
+ * we retain a reference to it. */
+ dnode = dom_node_ref(dnode);
+
+ next_func = dom_node_get_previous_sibling;
+ if (after) {
+ next_func = dom_node_get_next_sibling;
+ }
+
+ do {
+ exc = next_func(dnode, &next);
+ if (exc != DOM_NO_ERR) {
+ break;
+ }
+
+ /* If next_func worked, we're about to swap "next"
+ * with "dnode" meaning that we will no longer retain
+ * a reference to the current dnode. */
+ dom_node_unref(dnode);
+ dnode = next;
+
+ *count += node_count_siblings_check(dnode,
+ same_name,
+ dnode_name);
+ } while (dnode != NULL);
+
+ if (dnode_name != NULL) {
+ dom_string_unref(dnode_name);
+ }
+
+ 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;
+}
+
+
+/**
+ * Determine whether or not the given node is a link
+ *
+ * A node is a link if it is an element node whose name is "a" and if
+ * it has an "href" attribute (case-sensitive). This selector
+ * corresponds to node:link pseudo-class in CSS.
+ *
+ * This pseudo-class is a bit awkward because the two standards (HTML5
+ * and CSS) disagree on what it means, and because libsvgtiny does not
+ * have enough information to determine if a link has been "visited"
+ * yet -- that's a UI property. CSS says that :link is for unvisited
+ * links, which we can't determine. HTML5 says that each link must
+ * be either a :link or :visited. Since we can't decide either way,
+ * It seems less wrong to declare that all links are unvisited; i.e.
+ * that they match :link.
+ *
+ * \param pw Pointer to the current SVG parser state
+ * \param node Libdom SVG node to check
+ * \param is_link Pointer to the boolean return value
+ *
+ * \return CSS_OK on success, or CSS_NOMEM if anything goes wrong
+ */
+css_error node_is_link(void *pw, void *node, bool *is_link)
+{
+ dom_exception exc;
+ dom_node *dnode; /* node, but with the right type */
+ dom_string *dnode_name;
+ bool has_href;
+ struct svgtiny_parse_state* state;
+
+ dnode = (dom_node *)node;
+ dnode_name = NULL;
+ has_href = false; /* assume no href attribute */
+ *is_link = false; /* assume that it's not a link */
+
+ exc = dom_node_get_node_name(dnode, &dnode_name);
+ if ((exc != DOM_NO_ERR) || (dnode_name == NULL)) {
+ return CSS_NOMEM;
+ }
+
+ state = (struct svgtiny_parse_state *)pw;
+ if (dom_string_isequal(dnode_name, state->interned_a)) {
+ exc = dom_element_has_attribute(node,
+ state->interned_href,
+ &has_href);
+ if (exc == DOM_NO_ERR && has_href) {
+ *is_link = true;
+ }
+ }
+
+ dom_string_unref(dnode_name);
+ return CSS_OK;
+}
projects / libsvgtiny.git / blobdiff