1 files changed, 138 insertions, 0 deletions
diff --git a/src/uri-references.h b/src/uri-references.h
new file mode 100644
index 000000000..8d4bf7098
--- /dev/null
+++ b/src/uri-references.h
@@ -0,0 +1,138 @@
+#ifndef __SP_URI_REFERENCES_H__
+#define __SP_URI_REFERENCES_H__
+
+/*
+ * Helper methods for resolving URI References
+ *
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *
+ * Copyright (C) 2001-2002 Lauris Kaplinski
+ * Copyright (C) 2001 Ximian, Inc.
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include <sigc++/connection.h>
+#include <sigc++/trackable.h>
+
+#include "bad-uri-exception.h"
+#include "forward.h"
+
+namespace Inkscape {
+
+/**
+ * A class encapsulating a reference to a particular URI; observers can
+ * be notified when the URI comes to reference a different SPObject.
+ *
+ * The URIReference increments and decrements the SPObject's hrefcount
+ * automatically.
+ *
+ * @see SPObject
+ * @see sp_object_href
+ * @see sp_object_hunref
+ */
+class URIReference : public sigc::trackable {
+public:
+	/**
+	 * Constructor.
+	 *
+	 * @param owner The object on whose behalf this URIReference
+	 *              is holding a reference to the target object.
+	 */
+	URIReference(SPObject *owner);
+
+	/**
+	 * Destructor.  Calls shutdown() if the reference has not been
+	 * shut down yet.
+	 */
+	virtual ~URIReference();
+
+	/**
+	 * Attaches to a URI, relative to the specified document.
+	 *
+	 * Throws a BadURIException if the URI is unsupported,
+	 * or the fragment identifier is xpointer and malformed.
+	 *
+	 * @param rel_document document for relative URIs
+	 * @param uri the URI to watch
+	 */
+	void attach(const URI &uri) throw(BadURIException);
+
+	/**
+	 * Detaches from the currently attached URI target, if any;
+	 * the current referrent is signaled as NULL.
+	 */
+	void detach();
+
+	/**
+	 * @brief Returns a pointer to the current referrent of the
+	 * attached URI, or NULL.
+	 *
+	 * @return a pointer to the referenced SPObject or NULL
+	 */
+	SPObject *getObject() const { return _obj; }
+
+	/**
+	 * @brief Returns a pointer to the URIReference's owner
+	 *
+	 * @return a pointer to the URIReference's owner
+	 */
+	SPObject *getOwner() const { return _owner; }
+
+	/**
+	 * Accessor for the referrent change notification signal;
+	 * this signal is emitted whenever the URIReference's
+	 * referrent changes.
+	 *
+	 * Signal handlers take two parameters: the old and new
+	 * referrents.
+	 *
+	 * @returns a signal
+	 */
+	sigc::signal<void, SPObject *, SPObject *> changedSignal() {
+		return _changed_signal;
+	}
+
+	/**
+	 * Returns a pointer to a URI containing the currently attached
+	 * URI, or NULL if no URI is currently attached.
+	 *
+	 * @returns the currently attached URI, or NULL
+	 */
+	const URI *getURI() const {
+		return _uri;
+	}
+
+	/**
+	 * Returns true if there is currently an attached URI
+	 *
+	 * @returns true if there is an attached URI
+	 */
+	bool isAttached() const {
+		return (bool)_uri;
+	}
+
+protected:
+	virtual bool _acceptObject(SPObject *obj) const { return true; }
+
+private:
+	SPObject *_owner;
+	sigc::connection _connection;
+	SPObject *_obj;
+	URI *_uri;
+
+	sigc::signal<void, SPObject *, SPObject *> _changed_signal;
+
+	void _setObject(SPObject *object);
+	static void _release(SPObject *object, URIReference *reference);
+
+	void operator=(const URIReference &ref);
+	/* Private and definition-less to prevent accidental use. */
+};
+
+}
+
+SPObject *sp_uri_reference_resolve (SPDocument *document, const gchar *uri);
+
+#endif