1 files changed, 169 insertions, 0 deletions
diff --git a/src/object/uri-references.h b/src/object/uri-references.h
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--- /dev/null
+++ b/src/object/uri-references.h
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_SP_URI_REFERENCES_H
+#define SEEN_SP_URI_REFERENCES_H
+
+/*
+ * Helper methods for resolving URI References
+ *
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   Abhishek Sharma
+ *
+ * Copyright (C) 2001-2002 Lauris Kaplinski
+ * Copyright (C) 2001 Ximian, Inc.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cstddef>
+#include <vector>
+#include <set>
+#include <sigc++/connection.h>
+#include <sigc++/trackable.h>
+
+class SPObject;
+class SPDocument;
+
+namespace Inkscape {
+
+class URI;
+
+/**
+ * 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
+ */
+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);
+    URIReference(SPDocument *owner_document);
+
+    /* Definition-less to prevent accidental use. */
+    void operator=(URIReference const& ref) = delete;
+
+    /**
+     * 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 uri the URI to watch
+     */
+    void attach(URI const& uri);
+
+    /**
+     * Try to attach to a URI. Return false if URL is malformed and detach any
+     * previous attachment.
+     */
+    bool try_attach(char const *uri);
+
+    /**
+     * 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
+     */
+    URI const* 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;
+    }
+
+    SPDocument *getOwnerDocument() { return _owner_document; }
+    SPObject   *getOwnerObject()   { return _owner; }
+
+protected:
+    virtual bool _acceptObject(SPObject *obj) const;
+private:
+    SPObject *_owner;
+    SPDocument *_owner_document;
+    sigc::connection _connection;
+    sigc::connection _release_connection;
+    SPObject *_obj;
+    URI *_uri;
+
+    sigc::signal<void, SPObject *, SPObject *> _changed_signal;
+
+    void _setObject(SPObject *object);
+    void _release(SPObject *object);
+};
+
+}
+
+/**
+ * Resolves an item referenced by a URI in CSS form contained in "url(...)"
+ */
+SPObject* sp_css_uri_reference_resolve( SPDocument *document, const char *uri );
+
+SPObject *sp_uri_reference_resolve (SPDocument *document, const char *uri);
+
+#endif // SEEN_SP_URI_REFERENCES_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:fileencoding=utf-8 :