1 files changed, 72 insertions, 0 deletions
diff --git a/src/manipulation/copy-resource.cpp b/src/manipulation/copy-resource.cpp
new file mode 100644
index 0000000..f30045c
--- /dev/null
+++ b/src/manipulation/copy-resource.cpp
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "copy-resource.h"
+#include "document.h"
+#include "object/sp-defs.h"
+#include "object/sp-object.h"
+#include "extract-uri.h"
+#include "style.h"
+#include "xml/repr.h"
+
+// Make a copy of referenced: fill and stroke styles, clip paths
+void copy_style_links(const SPObject* source, SPDocument* src_document, SPDocument* dest_document) {
+
+    SPCSSAttr* css = sp_css_attr_from_object(const_cast<SPObject*>(source), SP_STYLE_FLAG_ALWAYS);
+
+    const char* fill = sp_repr_css_property(css, "fill", "none");
+    if (auto link = try_extract_uri(fill)) {
+        sp_copy_resource(src_document->getObjectByHref(*link), dest_document);
+    }
+
+    const char* stroke = sp_repr_css_property(css, "stroke", "none");
+    if (auto link = try_extract_uri(stroke)) {
+        sp_copy_resource(src_document->getObjectByHref(*link), dest_document);
+    }
+
+    sp_repr_css_attr_unref(css);
+
+    if (auto clip = source->getAttribute("clip-path")) {
+        if (auto clip_path = try_extract_uri(clip)) {
+            sp_copy_resource(src_document->getObjectByHref(*clip_path), dest_document);
+        }
+    }
+
+    for (auto& child : source->children) {
+        copy_style_links(&child, src_document, dest_document);
+    }
+}
+
+
+SPObject* sp_copy_resource(const SPObject* source, SPDocument* dest_document) {
+    if (!source || !source->document || !dest_document) {
+        return nullptr;
+    }
+
+    // make a copy of the 'source' object
+    auto src_doc = source->document;
+    auto dest_defs = dest_document->getDefs();
+    Inkscape::XML::Document* xml_doc = dest_document->getReprDoc();
+    Inkscape::XML::Node* repr = source->getRepr()->duplicate(xml_doc);
+    dest_defs->getRepr()->addChild(repr, nullptr);
+    auto object = dest_document->getObjectByRepr(repr);
+    g_assert(object != nullptr);
+    Inkscape::GC::release(repr);
+
+    // if 'source' references another object, copy it too
+    auto xhref = object->getAttribute("xlink:href");
+    auto href = object->getAttribute("href");
+
+    if (href || xhref) {
+        if (!href) {
+            href = xhref;
+        }
+        if (!dest_document->getObjectByHref(href)) {
+            sp_copy_resource(src_doc->getObjectByHref(href), dest_document);
+        }
+    }
+
+    // check fill and stroke for references to other objects, like gradients, and copy them too
+    copy_style_links(object, src_doc, dest_document);
+
+    return object;
+}