1 files changed, 80 insertions, 0 deletions
diff --git a/src/object/sp-tref-reference.h b/src/object/sp-tref-reference.h
new file mode 100644
index 0000000..f4c1c0f
--- /dev/null
+++ b/src/object/sp-tref-reference.h
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_SP_TREF_REFERENCE_H
+#define SEEN_SP_TREF_REFERENCE_H
+
+/*
+ * The reference corresponding to href of <tref> element.
+ *
+ * This file was created based on sp-use-reference.h
+ *
+ * Copyright (C) 2007 Gail Banaszkiewicz
+ *   Abhishek Sharma
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cstddef>
+#include <sigc++/sigc++.h>
+
+#include "sp-item.h"
+#include "uri-references.h"
+
+#include "util/share.h"
+#include "xml/node-observer.h"
+#include "xml/subtree.h"
+
+typedef unsigned int GQuark;
+
+class SPTRefReference : public Inkscape::URIReference,
+                        public Inkscape::XML::NodeObserver {
+public:
+    SPTRefReference(SPObject *owner) : URIReference(owner), subtreeObserved(nullptr) {
+        updateObserver();
+    }
+    
+    ~SPTRefReference() override {
+        if (subtreeObserved) {
+            subtreeObserved->removeObserver(*this);
+            delete subtreeObserved;
+        }   
+    }
+
+    SPItem *getObject() const {
+        return static_cast<SPItem *>(URIReference::getObject());
+    }
+   
+    void updateObserver();
+    
+    /////////////////////////////////////////////////////////////////////
+    // Node Observer Functions
+    // -----------------------
+    void notifyChildAdded(Inkscape::XML::Node &node, Inkscape::XML::Node &child, Inkscape::XML::Node *prev) override;
+    void notifyChildRemoved(Inkscape::XML::Node &node, Inkscape::XML::Node &child, Inkscape::XML::Node *prev) override;
+    void notifyChildOrderChanged(Inkscape::XML::Node &node, Inkscape::XML::Node &child,
+                                         Inkscape::XML::Node *old_prev, Inkscape::XML::Node *new_prev) override;
+    void notifyContentChanged(Inkscape::XML::Node &node,
+                                      Inkscape::Util::ptr_shared old_content,
+                                      Inkscape::Util::ptr_shared new_content) override;
+    void notifyAttributeChanged(Inkscape::XML::Node &node, GQuark name,
+                                        Inkscape::Util::ptr_shared old_value,
+                                        Inkscape::Util::ptr_shared new_value) override;
+    /////////////////////////////////////////////////////////////////////
+
+protected:
+    bool _acceptObject(SPObject * obj) const override; 
+    
+    Inkscape::XML::Subtree *subtreeObserved; 
+};
+
+#endif /* !SEEN_SP_TREF_REFERENCE_H */
+
+/*
+  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 :