diff -r e628fc2e0c72 -r 03f8e6d42e13 src/modeleditcontext.cpp
--- a/src/modeleditcontext.cpp	Thu Mar 03 21:13:16 2022 +0200
+++ b/src/modeleditcontext.cpp	Fri Mar 04 11:37:50 2022 +0200
@@ -20,40 +20,42 @@
 #include "linetypes/triangle.h"
 #include "linetypes/quadrilateral.h"
 
-Model::EditContext::EditContext(Model& model) :
+ModelEditor::ModelEditor(Model& model) :
 	storedModel{model}
 {
 }
 
-Model::EditContext::~EditContext()
+ModelEditor::~ModelEditor()
 {
 	for (ldraw::id_t id : this->modifiedObjects)
 	{
-		this->model().objectModified(id);
+		const QModelIndex index = this->model().find(id);
+		if (index.isValid())
+		{
+			Q_EMIT this->objectModified(index.row());
+		}
 	}
-	this->model().editFinished();
 }
 
-ldraw::id_t Model::EditContext::append(std::unique_ptr<ldraw::Object>&& object)
+ldraw::id_t ModelEditor::append(std::unique_ptr<ldraw::Object>&& object)
 {
-	const ldraw::id_t id = object->id;
-	this->model().objectsById[id] = object.get();
-	this->model().append(std::move(object));
-	return id;
+	this->storedModel.append(std::move(object));
+	Q_EMIT this->objectAdded(this->model().size() - 1);
+	return object->id;
 }
 
-void Model::EditContext::remove(int position)
+void ModelEditor::remove(int position)
 {
-	this->model().remove(position);
+	this->storedModel.remove(position);
 }
 
-auto Model::EditContext::setObjectProperty(
+auto ModelEditor::setObjectProperty(
 	const ldraw::id_t id,
 	const ldraw::Property property,
 	const QVariant& value)
 	-> ldraw::Object::SetPropertyResult
 {
-	ldraw::Object* const object = this->model().findObjectById(id);
+	ldraw::Object* const object = this->storedModel.findObjectById(id);
 	if (object != nullptr)
 	{
 		const ldraw::Object::SetPropertyResult result = object->setProperty(ldraw::PropertyKeyValue{property, value});
@@ -66,9 +68,9 @@
 	}
 }
 
-void Model::EditContext::setObjectPoint(ldraw::id_t id, int pointId, const glm::vec3& value)
+void ModelEditor::setObjectPoint(ldraw::id_t id, int pointId, const glm::vec3& value)
 {
-	ldraw::Object* object = this->model().findObjectById(id);
+	ldraw::Object* object = this->storedModel.findObjectById(id);
 	if (object != nullptr)
 	{
 		object->setProperty(ldraw::PropertyKeyValue{ldraw::pointProperty(pointId), QVariant::fromValue(value)});
@@ -76,53 +78,8 @@
 	}
 }
 
-void Model::EditContext::invertObject(ldraw::id_t id)
-{
-	auto it = this->model().objectsById.find(id);
-	if (it != this->model().objectsById.end())
-	{
-		ldraw::Object* object = it->second;
-		object->invert();
-	}
-}
-
-Model& Model::EditContext::model()
+const Model &ModelEditor::model()
 {
 	return this->storedModel;
 }
 
-static std::array<geom::Triangle, 2> splitTriangles(ldraw::Diagonal diagonal, const std::array<glm::vec3, 4>& points)
-{
-	std::array<geom::Triangle, 2> result;
-	switch (diagonal)
-	{
-	case ldraw::Diagonal::Diagonal_13:
-		result = {geom::Triangle{points[0], points[1], points[2]}, {points[0], points[2], points[3]}};
-		break;
-	case ldraw::Diagonal::Diagonal_24:
-		result = {geom::Triangle{points[0], points[1], points[3]}, {points[1], points[2], points[3]}};
-		break;
-	}
-	return result;
-}
-
-auto ldraw::splitQuadrilateral(
-	Model::EditContext& editor,
-	ldraw::quadrilateralid_t quadrilateral_id,
-	ldraw::Diagonal splitType
-) -> std::optional<std::pair<ldraw::triangleid_t, ldraw::triangleid_t>>
-{
-	std::optional<std::pair<ldraw::triangleid_t, ldraw::triangleid_t>> result;
-	const auto resolved = editor.model().get2(quadrilateral_id);
-	if (resolved.object != nullptr)
-	{
-		const ldraw::Color color = resolved.object->colorIndex;
-		const std::array<geom::Triangle, 2> split = splitTriangles(splitType, resolved.object->points);
-		const int position = resolved.index.row();
-		editor.remove(position);
-		result = std::make_pair(
-			editor.insert<ldraw::Triangle>(position, split[0].points, color),
-			editor.insert<ldraw::Triangle>(position, split[1].points, color));
-	}
-	return result;
-}