diff -r f77d2230e87c -r d384df40c8e7 src/model.cpp
--- a/src/model.cpp	Wed Sep 22 00:25:13 2021 +0300
+++ b/src/model.cpp	Wed Sep 22 00:25:31 2021 +0300
@@ -32,8 +32,26 @@
 	return static_cast<int>(this->body.size());
 }
 
+/**
+ * @brief Looks up the object ID at the specified index. If out of bounds, returns NULL_ID.
+ * @param index Index of object to look up
+ * @return object ID
+ */
+ldraw::id_t Model::at(int index) const
+{
+	if (index >= 0 and index < this->size())
+	{
+		return this->body[index]->id;
+	}
+	else
+	{
+		return ldraw::NULL_ID;
+	}
+}
+
 Model::EditContext Model::edit()
 {
+	this->editCounter += 1;
 	return {*this};
 }
 
@@ -118,6 +136,17 @@
 	object->getPolygons(polygons_out, context);
 }
 
+void Model::editFinished()
+{
+	this->editCounter -= 1;
+}
+
+void Model::objectModified(ldraw::id_t id)
+{
+	const QModelIndex index = this->lookup(id);
+	Q_EMIT this->dataChanged(index, index);
+}
+
 void Model::append(ModelObjectPointer&& object)
 {
 	const int position = static_cast<int>(this->body.size());