moving trunk for module inkscape

(bzr r1)

1 files changed, 712 insertions, 0 deletions

diff --git a/src/sp-use.cpp b/src/sp-use.cpp
new file mode 100644
index 000000000..3a55331a0
--- /dev/null
+++ b/src/sp-use.cpp
@@ -0,0 +1,712 @@
+#define __SP_USE_C__
+
+/*
+ * SVG <use> implementation
+ *
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   bulia byak <buliabyak@users.sf.net>
+ *
+ * Copyright (C) 1999-2005 authors
+ * Copyright (C) 2000-2001 Ximian, Inc.
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <libnr/nr-matrix-ops.h>
+#include <libnr/nr-matrix-fns.h>
+#include "libnr/nr-matrix-translate-ops.h"
+#include <glibmm/i18n.h>
+#include "display/nr-arena-group.h"
+#include "attributes.h"
+#include "document.h"
+#include "sp-object-repr.h"
+#include "sp-flowregion.h"
+#include "uri.h"
+#include "xml/repr.h"
+#include "prefs-utils.h"
+#include "style.h"
+#include "sp-symbol.h"
+#include "sp-use.h"
+#include "sp-use-reference.h"
+
+/* fixme: */
+
+static void sp_use_class_init(SPUseClass *classname);
+static void sp_use_init(SPUse *use);
+static void sp_use_finalize(GObject *obj);
+
+static void sp_use_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr);
+static void sp_use_release(SPObject *object);
+static void sp_use_set(SPObject *object, unsigned key, gchar const *value);
+static Inkscape::XML::Node *sp_use_write(SPObject *object, Inkscape::XML::Node *repr, guint flags);
+static void sp_use_update(SPObject *object, SPCtx *ctx, guint flags);
+static void sp_use_modified(SPObject *object, guint flags);
+
+static void sp_use_bbox(SPItem const *item, NRRect *bbox, NR::Matrix const &transform, unsigned const flags);
+static void sp_use_print(SPItem *item, SPPrintContext *ctx);
+static gchar *sp_use_description(SPItem *item);
+static NRArenaItem *sp_use_show(SPItem *item, NRArena *arena, unsigned key, unsigned flags);
+static void sp_use_hide(SPItem *item, unsigned key);
+
+static void sp_use_href_changed(SPObject *old_ref, SPObject *ref, SPUse *use);
+
+static void sp_use_delete_self(SPObject *deleted, SPUse *self);
+
+static SPItemClass *parent_class;
+
+//void m_print(gchar *say, NR::Matrix m)
+//{ g_print("%s %g %g %g %g %g %g\n", say, m[0], m[1], m[2], m[3], m[4], m[5]); }
+
+GType
+sp_use_get_type(void)
+{
+    static GType use_type = 0;
+    if (!use_type) {
+        GTypeInfo use_info = {
+            sizeof(SPUseClass),
+            NULL,   /* base_init */
+            NULL,   /* base_finalize */
+            (GClassInitFunc) sp_use_class_init,
+            NULL,   /* class_finalize */
+            NULL,   /* class_data */
+            sizeof(SPUse),
+            16,     /* n_preallocs */
+            (GInstanceInitFunc) sp_use_init,
+            NULL,   /* value_table */
+        };
+        use_type = g_type_register_static(SP_TYPE_ITEM, "SPUse", &use_info, (GTypeFlags)0);
+    }
+    return use_type;
+}
+
+static void
+sp_use_class_init(SPUseClass *classname)
+{
+    GObjectClass *gobject_class = (GObjectClass *) classname;
+    SPObjectClass *sp_object_class = (SPObjectClass *) classname;
+    SPItemClass *item_class = (SPItemClass *) classname;
+
+    parent_class = (SPItemClass*) g_type_class_ref(SP_TYPE_ITEM);
+
+    gobject_class->finalize = sp_use_finalize;
+
+    sp_object_class->build = sp_use_build;
+    sp_object_class->release = sp_use_release;
+    sp_object_class->set = sp_use_set;
+    sp_object_class->write = sp_use_write;
+    sp_object_class->update = sp_use_update;
+    sp_object_class->modified = sp_use_modified;
+
+    item_class->bbox = sp_use_bbox;
+    item_class->description = sp_use_description;
+    item_class->print = sp_use_print;
+    item_class->show = sp_use_show;
+    item_class->hide = sp_use_hide;
+}
+
+static void
+sp_use_init(SPUse *use)
+{
+    use->x.unset();
+    use->y.unset();
+    use->width.unset(SVGLength::PERCENT, 1.0, 1.0);
+    use->height.unset(SVGLength::PERCENT, 1.0, 1.0);
+    use->href = NULL;
+
+    new (&use->_delete_connection) sigc::connection();
+    new (&use->_changed_connection) sigc::connection();
+
+    new (&use->_transformed_connection) sigc::connection();
+
+    use->ref = new SPUseReference(SP_OBJECT(use));
+
+    use->_changed_connection = use->ref->changedSignal().connect(sigc::bind(sigc::ptr_fun(sp_use_href_changed), use));
+}
+
+static void
+sp_use_finalize(GObject *obj)
+{
+    SPUse *use = (SPUse *) obj;
+
+    delete use->ref;
+
+    use->_delete_connection.~connection();
+    use->_changed_connection.~connection();
+
+    use->_transformed_connection.~connection();
+}
+
+static void
+sp_use_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr)
+{
+    if (((SPObjectClass *) parent_class)->build) {
+        (* ((SPObjectClass *) parent_class)->build)(object, document, repr);
+    }
+
+    sp_object_read_attr(object, "x");
+    sp_object_read_attr(object, "y");
+    sp_object_read_attr(object, "width");
+    sp_object_read_attr(object, "height");
+    sp_object_read_attr(object, "xlink:href");
+
+    // We don't need to create child here:
+    // reading xlink:href will attach ref, and that will cause the changed signal to be emitted,
+    // which will call sp_use_href_changed, and that will take care of the child
+}
+
+static void
+sp_use_release(SPObject *object)
+{
+    SPUse *use = SP_USE(object);
+
+    use->child = NULL;
+
+    use->_delete_connection.disconnect();
+    use->_changed_connection.disconnect();
+    use->_transformed_connection.disconnect();
+
+    g_free(use->href);
+    use->href = NULL;
+
+    use->ref->detach();
+
+    if (((SPObjectClass *) parent_class)->release) {
+        ((SPObjectClass *) parent_class)->release(object);
+    }
+}
+
+static void
+sp_use_set(SPObject *object, unsigned key, gchar const *value)
+{
+    SPUse *use = SP_USE(object);
+
+    switch (key) {
+        case SP_ATTR_X:
+            use->x.readOrUnset(value);
+            object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
+            break;
+        case SP_ATTR_Y:
+            use->y.readOrUnset(value);
+            object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
+            break;
+        case SP_ATTR_WIDTH:
+            use->width.readOrUnset(value, SVGLength::PERCENT, 1.0, 1.0);
+            object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
+            break;
+        case SP_ATTR_HEIGHT:
+            use->height.readOrUnset(value, SVGLength::PERCENT, 1.0, 1.0);
+            object->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
+            break;
+
+        case SP_ATTR_XLINK_HREF: {
+            if ( value && use->href && ( strcmp(value, use->href) == 0 ) ) {
+                /* No change, do nothing. */
+            } else {
+                g_free(use->href);
+                use->href = NULL;
+                if (value) {
+                    // First, set the href field, because sp_use_href_changed will need it.
+                    use->href = g_strdup(value);
+
+                    // Now do the attaching, which emits the changed signal.
+                    try {
+                        use->ref->attach(Inkscape::URI(value));
+                    } catch (Inkscape::BadURIException &e) {
+                        g_warning("%s", e.what());
+                        use->ref->detach();
+                    }
+                } else {
+                    use->ref->detach();
+                }
+            }
+            break;
+        }
+
+        default:
+            if (((SPObjectClass *) parent_class)->set) {
+                ((SPObjectClass *) parent_class)->set(object, key, value);
+            }
+            break;
+    }
+}
+
+static Inkscape::XML::Node *
+sp_use_write(SPObject *object, Inkscape::XML::Node *repr, guint flags)
+{
+    SPUse *use = SP_USE(object);
+
+    if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) {
+        repr = sp_repr_new("svg:use");
+    }
+
+    if (((SPObjectClass *) (parent_class))->write) {
+        ((SPObjectClass *) (parent_class))->write(object, repr, flags);
+    }
+
+    sp_repr_set_svg_double(repr, "x", use->x.computed);
+    sp_repr_set_svg_double(repr, "y", use->y.computed);
+    sp_repr_set_svg_double(repr, "width", use->width.computed);
+    sp_repr_set_svg_double(repr, "height", use->height.computed);
+
+    if (use->ref->getURI()) {
+        gchar *uri_string = use->ref->getURI()->toString();
+        repr->setAttribute("xlink:href", uri_string);
+        g_free(uri_string);
+    }
+
+    return repr;
+}
+
+static void
+sp_use_bbox(SPItem const *item, NRRect *bbox, NR::Matrix const &transform, unsigned const flags)
+{
+    SPUse const *use = SP_USE(item);
+
+    if (use->child && SP_IS_ITEM(use->child)) {
+        SPItem *child = SP_ITEM(use->child);
+        NR::Matrix const ct( child->transform
+                             * NR::translate(use->x.computed,
+                                             use->y.computed)
+                             * transform );
+        sp_item_invoke_bbox_full(child, bbox, ct, flags, FALSE);
+    }
+}
+
+static void
+sp_use_print(SPItem *item, SPPrintContext *ctx)
+{
+    SPUse *use = SP_USE(item);
+
+    if (use->child && SP_IS_ITEM(use->child)) {
+        sp_item_invoke_print(SP_ITEM(use->child), ctx);
+    }
+}
+
+static gchar *
+sp_use_description(SPItem *item)
+{
+    SPUse *use = SP_USE(item);
+
+    char *ret;
+    if (use->child) {
+        static unsigned recursion_depth = 0;
+        if (recursion_depth >= 2) {
+            /* TRANSLATORS: Used for statusbar description for long <use> chains:
+             * "Clone of: Clone of: ... in Layer 1". */
+            return g_strdup(_("..."));
+            /* We could do better, e.g. chasing the href chain until we reach something other than
+             * a <use>, and giving its description. */
+        }
+        ++recursion_depth;
+        char *child_desc = sp_item_description(SP_ITEM(use->child));
+        --recursion_depth;
+
+        ret = g_strdup_printf(_("<b>Clone</b> of: %s"), child_desc);
+        g_free(child_desc);
+        return ret;
+    } else {
+        return g_strdup(_("<b>Orphaned clone</b>"));
+    }
+}
+
+static NRArenaItem *
+sp_use_show(SPItem *item, NRArena *arena, unsigned key, unsigned flags)
+{
+    SPUse *use = SP_USE(item);
+
+    NRArenaItem *ai = NRArenaGroup::create(arena);
+    nr_arena_group_set_transparent(NR_ARENA_GROUP(ai), FALSE);
+
+    if (use->child) {
+        NRArenaItem *ac = sp_item_invoke_show(SP_ITEM(use->child), arena, key, flags);
+        if (ac) {
+            nr_arena_item_add_child(ai, ac, NULL);
+            nr_arena_item_unref(ac);
+        }
+        NR::translate t(use->x.computed,
+                        use->y.computed);
+        nr_arena_group_set_child_transform(NR_ARENA_GROUP(ai), NR::Matrix(t));
+    }
+
+    return ai;
+}
+
+static void
+sp_use_hide(SPItem *item, unsigned key)
+{
+    SPUse *use = SP_USE(item);
+
+    if (use->child) {
+        sp_item_invoke_hide(SP_ITEM(use->child), key);
+    }
+
+    if (((SPItemClass *) parent_class)->hide) {
+        ((SPItemClass *) parent_class)->hide(item, key);
+    }
+}
+
+/**
+ * Returns the ultimate original of a SPUse (i.e. the first object in the chain of its originals
+ * which is not an SPUse).
+ *
+ * Note that the returned is the clone object, i.e. the child of an SPUse (of the argument one for
+ * the trivial case) and not the "true original".
+ */
+SPItem *
+sp_use_root(SPUse *use)
+{
+    SPObject *orig = use->child;
+    while (SP_IS_USE(orig)) {
+        orig = SP_USE(orig)->child;
+    }
+    g_assert(SP_IS_ITEM(orig));
+    return SP_ITEM(orig);
+}
+
+/**
+ * Returns the effective transform that goes from the ultimate original to given SPUse, both ends
+ * included.
+ */
+NR::Matrix
+sp_use_get_root_transform(SPUse *use)
+{
+    //track the ultimate source of a chain of uses
+    SPObject *orig = use->child;
+    GSList *chain = NULL;
+    chain = g_slist_prepend(chain, use);
+    while (SP_IS_USE(orig)) {
+        chain = g_slist_prepend(chain, orig);
+        orig = SP_USE(orig)->child;
+    }
+    chain = g_slist_prepend(chain, orig);
+
+
+    //calculate the accummulated transform, starting from the original
+    NR::Matrix t(NR::identity());
+    for (GSList *i = chain; i != NULL; i = i->next) {
+        SPItem *i_tem = SP_ITEM(i->data);
+
+        // "An additional transformation translate(x,y) is appended to the end (i.e.,
+        // right-side) of the transform attribute on the generated 'g', where x and y
+        // represent the values of the x and y attributes on the 'use' element." - http://www.w3.org/TR/SVG11/struct.html#UseElement
+        if (SP_IS_USE(i_tem)) {
+            SPUse *i_use = SP_USE(i_tem);
+            if ((i_use->x._set && i_use->x.computed != 0) || (i_use->y._set && i_use->y.computed != 0)) {
+                t = t * NR::translate(i_use->x._set ? i_use->x.computed : 0, i_use->y._set ? i_use->y.computed : 0);
+            }
+        }
+
+        t *= i_tem->transform;
+    }
+
+    g_slist_free(chain);
+    return t;
+}
+
+/**
+ * Returns the transform that leads to the use from its immediate original.
+ * Does not inlcude the original's transform if any.
+ */
+NR::Matrix
+sp_use_get_parent_transform(SPUse *use)
+{
+    NR::Matrix t(NR::identity());
+    if ((use->x._set && use->x.computed != 0) || (use->y._set && use->y.computed != 0)) {
+        t *= NR::translate(use->x._set ? use->x.computed : 0,
+                           use->y._set ? use->y.computed : 0);
+    }
+
+    t *= SP_ITEM(use)->transform;
+    return t;
+}
+
+/**
+ * Sensing a movement of the original, this function attempts to compensate for it in such a way
+ * that the clone stays unmoved or moves in parallel (depending on user setting) regardless of the
+ * clone's transform.
+ */
+static void
+sp_use_move_compensate(NR::Matrix const *mp, SPItem *original, SPUse *self)
+{
+    // the clone is orphaned; or this is not a real use, but a clone of another use;
+    // we skip it, otherwise duplicate compensation will occur
+    if (SP_OBJECT_IS_CLONED(self)) {
+        return;
+    }
+
+    // never compensate uses which are used in flowtext
+    if (SP_OBJECT_PARENT(self) && SP_IS_FLOWREGION(SP_OBJECT_PARENT(self))) {
+        return;
+    }
+
+    guint mode = prefs_get_int_attribute("options.clonecompensation", "value", SP_CLONE_COMPENSATION_PARALLEL);
+    // user wants no compensation
+    if (mode == SP_CLONE_COMPENSATION_NONE)
+        return;
+
+    NR::Matrix m(*mp);
+
+    // this is not a simple move, do not try to compensate
+    if (!(m.is_translation()))
+        return;
+
+    // restore item->transform field from the repr, in case it was changed by seltrans
+    sp_object_read_attr (SP_OBJECT (self), "transform");
+
+    NR::Matrix t = sp_use_get_parent_transform(self);
+    NR::Matrix clone_move = t.inverse() * m * t;
+
+    // calculate the compensation matrix and the advertized movement matrix
+    NR::Matrix advertized_move;
+    if (mode == SP_CLONE_COMPENSATION_PARALLEL) {
+        clone_move = clone_move.inverse() * m;
+        advertized_move = m;
+    } else if (mode == SP_CLONE_COMPENSATION_UNMOVED) {
+        clone_move = clone_move.inverse();
+        advertized_move.set_identity();
+    } else {
+        g_assert_not_reached();
+    }
+
+    // commit the compensation
+    SPItem *item = SP_ITEM(self);
+    item->transform *= clone_move;
+    sp_item_write_transform(item, SP_OBJECT_REPR(item), item->transform, &advertized_move);
+    SP_OBJECT(item)->requestDisplayUpdate(SP_OBJECT_MODIFIED_FLAG);
+}
+
+static void
+sp_use_href_changed(SPObject *old_ref, SPObject *ref, SPUse *use)
+{
+    SPItem *item = SP_ITEM(use);
+
+    use->_delete_connection.disconnect();
+    use->_transformed_connection.disconnect();
+
+    if (use->child) {
+        sp_object_detach(SP_OBJECT(use), use->child);
+        use->child = NULL;
+    }
+
+    if (use->href) {
+        SPItem *refobj = use->ref->getObject();
+        if (refobj) {
+            Inkscape::XML::Node *childrepr = SP_OBJECT_REPR(refobj);
+            GType type = sp_repr_type_lookup(childrepr);
+            g_return_if_fail(type > G_TYPE_NONE);
+            if (g_type_is_a(type, SP_TYPE_ITEM)) {
+                use->child = (SPObject*) g_object_new(type, 0);
+                sp_object_attach(SP_OBJECT(use), use->child, use->lastChild());
+                sp_object_unref(use->child, SP_OBJECT(use));
+                sp_object_invoke_build(use->child, SP_OBJECT(use)->document, childrepr, TRUE);
+
+                for (SPItemView *v = item->display; v != NULL; v = v->next) {
+                    NRArenaItem *ai;
+                    ai = sp_item_invoke_show(SP_ITEM(use->child), NR_ARENA_ITEM_ARENA(v->arenaitem), v->key, v->flags);
+                    if (ai) {
+                        nr_arena_item_add_child(v->arenaitem, ai, NULL);
+                        nr_arena_item_unref(ai);
+                    }
+                }
+
+            }
+            use->_delete_connection = SP_OBJECT(refobj)->connectDelete(sigc::bind(sigc::ptr_fun(&sp_use_delete_self), use));
+            use->_transformed_connection = SP_ITEM(refobj)->connectTransformed(sigc::bind(sigc::ptr_fun(&sp_use_move_compensate), use));
+        }
+    }
+}
+
+static void
+sp_use_delete_self(SPObject *deleted, SPUse *self)
+{
+    // always delete uses which are used in flowtext
+    if (SP_OBJECT_PARENT(self) && SP_IS_FLOWREGION(SP_OBJECT_PARENT(self))) {
+        SP_OBJECT(self)->deleteObject();
+        return;
+    }
+
+    guint const mode = prefs_get_int_attribute("options.cloneorphans", "value",
+                                               SP_CLONE_ORPHANS_UNLINK);
+
+    if (mode == SP_CLONE_ORPHANS_UNLINK) {
+        sp_use_unlink(self);
+    } else if (mode == SP_CLONE_ORPHANS_DELETE) {
+        SP_OBJECT(self)->deleteObject();
+    }
+}
+
+static void
+sp_use_update(SPObject *object, SPCtx *ctx, unsigned flags)
+{
+    SPItem *item = SP_ITEM(object);
+    SPUse *use = SP_USE(object);
+    SPItemCtx *ictx = (SPItemCtx *) ctx;
+    SPItemCtx cctx = *ictx;
+
+    if (((SPObjectClass *) (parent_class))->update)
+        ((SPObjectClass *) (parent_class))->update(object, ctx, flags);
+
+    if (flags & SP_OBJECT_MODIFIED_FLAG) flags |= SP_OBJECT_PARENT_MODIFIED_FLAG;
+    flags &= SP_OBJECT_MODIFIED_CASCADE;
+
+    /* Set up child viewport */
+    if (use->x.unit == SVGLength::PERCENT) {
+        use->x.computed = use->x.value * (ictx->vp.x1 - ictx->vp.x0);
+    }
+    if (use->y.unit == SVGLength::PERCENT) {
+        use->y.computed = use->y.value * (ictx->vp.y1 - ictx->vp.y0);
+    }
+    if (use->width.unit == SVGLength::PERCENT) {
+        use->width.computed = use->width.value * (ictx->vp.x1 - ictx->vp.x0);
+    }
+    if (use->height.unit == SVGLength::PERCENT) {
+        use->height.computed = use->height.value * (ictx->vp.y1 - ictx->vp.y0);
+    }
+    cctx.vp.x0 = 0.0;
+    cctx.vp.y0 = 0.0;
+    cctx.vp.x1 = use->width.computed;
+    cctx.vp.y1 = use->height.computed;
+    cctx.i2vp = NR::identity();
+    flags&=~SP_OBJECT_USER_MODIFIED_FLAG_B;
+
+    if (use->child) {
+        g_object_ref(G_OBJECT(use->child));
+        if (flags || (use->child->uflags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_CHILD_MODIFIED_FLAG))) {
+            if (SP_IS_ITEM(use->child)) {
+                SPItem const &chi = *SP_ITEM(use->child);
+                cctx.i2doc = chi.transform * ictx->i2doc;
+                cctx.i2vp = chi.transform * ictx->i2vp;
+                use->child->updateDisplay((SPCtx *)&cctx, flags);
+            } else {
+                use->child->updateDisplay(ctx, flags);
+            }
+        }
+        g_object_unref(G_OBJECT(use->child));
+    }
+
+    /* As last step set additional transform of arena group */
+    for (SPItemView *v = item->display; v != NULL; v = v->next) {
+        NRMatrix t;
+        nr_matrix_set_translate(&t, use->x.computed, use->y.computed);
+        nr_arena_group_set_child_transform(NR_ARENA_GROUP(v->arenaitem), &t);
+    }
+}
+
+static void
+sp_use_modified(SPObject *object, guint flags)
+{
+    SPUse *use_obj = SP_USE(object);
+
+    if (flags & SP_OBJECT_MODIFIED_FLAG) {
+        flags |= SP_OBJECT_PARENT_MODIFIED_FLAG;
+    }
+    flags &= SP_OBJECT_MODIFIED_CASCADE;
+
+    SPObject *child = use_obj->child;
+    if (child) {
+        g_object_ref(G_OBJECT(child));
+        if (flags || (child->mflags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_CHILD_MODIFIED_FLAG))) {
+            child->emitModified(flags);
+        }
+        g_object_unref(G_OBJECT(child));
+    }
+}
+
+SPItem *
+sp_use_unlink(SPUse *use)
+{
+    if (!use) return NULL;
+
+    Inkscape::XML::Node *repr = SP_OBJECT_REPR(use);
+    if (!repr) return NULL;
+
+    Inkscape::XML::Node *parent = sp_repr_parent(repr);
+    SPDocument *document = SP_OBJECT(use)->document;
+
+    // Track the ultimate source of a chain of uses.
+    SPItem *orig = sp_use_root(use);
+
+    // Calculate the accumulated transform, starting from the original.
+    NR::Matrix t = sp_use_get_root_transform(use);
+
+    Inkscape::XML::Node *copy = NULL;
+    if (SP_IS_SYMBOL(orig)) { // make a group, copy children
+        copy = sp_repr_new("svg:g");
+        for (Inkscape::XML::Node *child = SP_OBJECT_REPR(orig)->firstChild() ; child != NULL; child = child->next()) {
+                Inkscape::XML::Node *newchild = child->duplicate();
+                copy->appendChild(newchild);
+        }
+    } else { // just copy
+        copy = SP_OBJECT_REPR(orig)->duplicate();
+    }
+
+    // Add the duplicate repr just after the existing one.
+    parent->addChild(copy, repr);
+
+    // Retrieve the SPItem of the resulting repr.
+    SPObject *unlinked = document->getObjectByRepr(copy);
+
+    // Merge style from the use.
+    SPStyle *unli_sty = SP_OBJECT_STYLE(unlinked);
+    SPStyle const *use_sty = SP_OBJECT_STYLE(use);
+    sp_style_merge_from_dying_parent(unli_sty, use_sty);
+    sp_style_merge_from_parent(unli_sty, unlinked->parent->style);
+
+    SP_OBJECT(unlinked)->updateRepr();
+
+    // Hold onto our SPObject and repr for now.
+    sp_object_ref(SP_OBJECT(use), NULL);
+    Inkscape::GC::anchor(repr);
+
+    // Remove ourselves, not propagating delete events to avoid a
+    // chain-reaction with other elements that might reference us.
+    SP_OBJECT(use)->deleteObject(false);
+
+    // Give the copy our old id and let go of our old repr.
+    copy->setAttribute("id", repr->attribute("id"));
+    Inkscape::GC::release(repr);
+
+    // Remove tiled clone attrs.
+    copy->setAttribute("inkscape:tiled-clone-of", NULL);
+    copy->setAttribute("inkscape:tile-w", NULL);
+    copy->setAttribute("inkscape:tile-h", NULL);
+    copy->setAttribute("inkscape:tile-cx", NULL);
+    copy->setAttribute("inkscape:tile-cy", NULL);
+
+    // Establish the succession and let go of our object.
+    SP_OBJECT(use)->setSuccessor(unlinked);
+    sp_object_unref(SP_OBJECT(use), NULL);
+
+    SPItem *item = SP_ITEM(unlinked);
+    // Set the accummulated transform.
+    {
+        NR::Matrix nomove(NR::identity());
+        NRMatrix ctrans = t.operator const NRMatrix&();
+        // Advertise ourselves as not moving.
+        sp_item_write_transform(item, SP_OBJECT_REPR(item), &ctrans, &nomove);
+    }
+    return item;
+}
+
+SPItem *
+sp_use_get_original(SPUse *use)
+{
+    SPItem *ref = use->ref->getObject();
+    return ref;
+}
+
+
+/*
+  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 :