diff -r 128efb9d148b -r 02f142b399b1 src/ui/canvas.cpp
--- a/src/ui/canvas.cpp	Tue Jul 20 01:22:01 2021 +0300
+++ b/src/ui/canvas.cpp	Sat Jul 24 01:50:38 2021 +0300
@@ -91,17 +91,6 @@
 {
 	if (this->totalMouseMove < (2.0 / sqrt(2)) * 5.0)
 	{
-		if (this->highlighted == ldraw::NULL_ID)
-		{
-			this->selection = {};
-		}
-		else
-		{
-			this->selection = {this->highlighted};
-		}
-		this->compiler->setSelectedObjects(this->selection);
-		emit selectionChanged(this->selection);
-		this->update();
 		MouseClickInfo info;
 		info.worldPosition = this->worldPosition;
 		info.invoker = this;
@@ -297,3 +286,19 @@
 {
 	return previewLayers[static_cast<unsigned int>(name)];
 }
+
+void Canvas::clearSelection()
+{
+	this->selection.clear();
+	this->compiler->setSelectedObjects(this->selection);
+	emit selectionChanged(this->selection);
+	this->update();
+}
+
+void Canvas::addToSelection(ldraw::id_t id)
+{
+	this->selection.insert(id);
+	this->compiler->setSelectedObjects(this->selection);
+	emit selectionChanged(this->selection);
+	this->update();
+}