1 files changed, 103 insertions, 0 deletions
diff --git a/src/xml/node-fns.cpp b/src/xml/node-fns.cpp
new file mode 100644
index 000000000..16947e66e
--- /dev/null
+++ b/src/xml/node-fns.cpp
@@ -0,0 +1,103 @@
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <map>
+
+#include "xml/node-iterators.h"
+#include "algorithms/find-if-before.h"
+
+namespace Inkscape {
+namespace XML {
+
+/* the id_permitted stuff is a temporary-ish hack */
+
+namespace {
+
+bool id_permitted_internal(GQuark qname) {
+    char const *qname_s=g_quark_to_string(qname);
+    return !strncmp("svg:", qname_s, 4) || !strncmp("sodipodi:", qname_s, 9) ||
+           !strncmp("inkscape:", qname_s, 9);
+}
+
+
+bool id_permitted_internal_memoized(GQuark qname) {
+    typedef std::map<GQuark, bool> IdPermittedMap;
+    IdPermittedMap id_permitted_names;
+
+    IdPermittedMap::iterator found;
+    found = id_permitted_names.find(qname);
+    if ( found != id_permitted_names.end() ) {
+        return found->second;
+    } else {
+        bool permitted=id_permitted_internal(qname);
+        id_permitted_names[qname] = permitted;
+        return permitted;
+    }
+}
+
+}
+
+bool id_permitted(Node const *node) {
+    g_return_val_if_fail(node != NULL, false);
+
+    if ( node->type() != ELEMENT_NODE ) {
+        return false;
+    }
+
+    return id_permitted_internal_memoized((GQuark)node->code());
+}
+
+struct node_matches {
+    node_matches(Node const &n) : node(n) {}
+    bool operator()(Node const &other) { return &other == &node; }
+    Node const &node;
+};
+
+/** Returns the sibling before \a node in \a node's parent's children,
+ *  or NULL if \a node is the first of those children (or if child is
+ *  NULL or has no parent).
+ *
+ *  Useful in combination with Node::addChild, when you want to insert
+ *  a new child _before_ a given existing child.
+ *
+ *  Note: Involves a linear search (unlike next_node).
+ *
+ * \pre Links are correct, i.e. \a node isin its parent's children.
+ *
+ * \post (ret == NULL
+ *        ? node == NULL || node->parent() == NULL || node->parent()->firstChild() == node
+ *        : ret->next() == node).
+ */
+Node *previous_node(Node *node) {
+    using Inkscape::Algorithms::find_if_before;
+
+    if ( !node || !node->parent() ) {
+        return NULL;
+    }
+
+    Node *previous=find_if_before<NodeSiblingIterator>(
+        node->parent()->firstChild(), NULL, node_matches(*node)
+    );
+
+    g_assert(previous == NULL
+             ? node->parent()->firstChild() == node
+             : previous->next() == node);
+
+    return previous;
+}
+
+}
+}
+
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :