1 files changed, 70 insertions, 0 deletions
diff --git a/src/extension/implementation/implementation.cpp b/src/extension/implementation/implementation.cpp
new file mode 100644
index 0000000..36cd299
--- /dev/null
+++ b/src/extension/implementation/implementation.cpp
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+    Author:  Ted Gould <ted@gould.cx>
+    Copyright (c) 2003-2005,2007
+
+    Released under GNU GPL v2+, read the file 'COPYING' for more information.
+
+    This file is the backend to the extensions system.  These are
+    the parts of the system that most users will never see, but are
+    important for implementing the extensions themselves.  This file
+    contains the base class for all of that.
+*/
+
+#include "implementation.h"
+
+#include <extension/output.h>
+#include <extension/input.h>
+#include <extension/effect.h>
+
+#include "selection.h"
+#include "desktop.h"
+
+
+namespace Inkscape {
+namespace Extension {
+namespace Implementation {
+
+Gtk::Widget *
+Implementation::prefs_input(Inkscape::Extension::Input *module, gchar const */*filename*/) {
+    return module->autogui(nullptr, nullptr);
+}
+
+Gtk::Widget *
+Implementation::prefs_output(Inkscape::Extension::Output *module) {
+    return module->autogui(nullptr, nullptr);
+}
+
+Gtk::Widget *Implementation::prefs_effect(Inkscape::Extension::Effect *module, Inkscape::UI::View::View * view, sigc::signal<void> * changeSignal, ImplementationDocumentCache * /*docCache*/)
+{
+    if (module->widget_visible_count() == 0) {
+        return nullptr;
+    }
+
+    SPDocument * current_document = view->doc();
+
+    auto selected = ((SPDesktop *) view)->getSelection()->items();
+    Inkscape::XML::Node const* first_select = nullptr;
+    if (!selected.empty()) {
+        const SPItem * item = selected.front();
+        first_select = item->getRepr();
+    }
+
+    // TODO deal with this broken const correctness:
+    return module->autogui(current_document, const_cast<Inkscape::XML::Node *>(first_select), changeSignal);
+} // Implementation::prefs_effect
+
+}  /* namespace Implementation */
+}  /* namespace Extension */
+}  /* namespace Inkscape */
+
+/*
+  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:textwidth=99 :