diff -r ee5758ddb6d2 -r 8e1fe64ce4e3 src/documentmanager.cpp
--- a/src/documentmanager.cpp	Sat Jun 11 15:20:24 2022 +0300
+++ b/src/documentmanager.cpp	Sun Jun 12 20:47:04 2022 +0300
@@ -24,7 +24,8 @@
 #include "documentmanager.h"
 #include "parser.h"
 
-DocumentManager::DocumentManager()
+DocumentManager::DocumentManager(QObject *parent) :
+	QObject{parent}
 {
 }
 
@@ -35,8 +36,10 @@
 ModelId DocumentManager::newModel()
 {
 	const ModelId modelId{++this->modelIdCounter};
-	this->openModels[modelId].id = modelId;
-	this->openModels[modelId].opentype = OpenType::ManuallyOpened;
+	this->openModels.emplace(std::make_pair(modelId, ModelInfo{
+		.id = modelId,
+		.opentype = OpenType::ManuallyOpened,
+	}));
 	this->makePolygonCacheForModel(modelId);
 	return modelId;
 }
@@ -122,13 +125,13 @@
 	if (file.error() == QFile::NoError)
 	{
 		const ModelId modelId{++this->modelIdCounter};
-		this->openModels[modelId] = {
+		this->openModels.emplace(std::make_pair(modelId, ModelInfo{
 			.model = std::move(newModel),
 			.id = modelId,
 			.path = path,
 			.opentype = openType,
 			.polygonCache = {},
-		};
+		}));
 		this->makePolygonCacheForModel(modelId);
 		result = modelId;
 	}
@@ -241,11 +244,20 @@
 	}
 }
 
-const DocumentManager::ModelInfo *DocumentManager::infoForModel(ModelId modelId) const
+const DocumentManager::ModelInfo *DocumentManager::find(ModelId modelId) const
 {
 	return findInMap(this->openModels, modelId);
 }
 
+void DocumentManager::setModelPayload(ModelId modelId, QObject *object)
+{
+	ModelInfo* info = findInMap(this->openModels, modelId);
+	if (info != nullptr) {
+		info->payload = object;
+		object->setParent(this);
+	}
+}
+
 QString errorStringFromMissingDependencies(const DocumentManager::MissingDependencies& missing)
 {
 	QString missingString;