diff --git a/src/qteletextmaker/mainwidget.cpp b/src/qteletextmaker/mainwidget.cpp
index b304250..0d4eb6a 100644
--- a/src/qteletextmaker/mainwidget.cpp
+++ b/src/qteletextmaker/mainwidget.cpp
@@ -391,17 +391,24 @@ void TeletextWidget::toggleCharacterBit(unsigned char bitToToggle)
 	m_teletextDocument->undoStack()->push(new ToggleMosaicBitCommand(m_teletextDocument, bitToToggle));
 }
 
-void TeletextWidget::shiftMosaics(int key)
+QSet<QPair<int, int>> TeletextWidget::findMosaics()
 {
-	if (!m_teletextDocument->selectionActive())
-		return;
+	QSet<QPair<int, int>> result;
 
-	QSet<QPair<int, int>> mosaicList;
+	if (!m_teletextDocument->selectionActive())
+		return result;
 
 	for (int r=m_teletextDocument->selectionTopRow(); r<=m_teletextDocument->selectionBottomRow(); r++)
 		for (int c=m_teletextDocument->selectionLeftColumn(); c<=m_teletextDocument->selectionRightColumn(); c++)
 			if (m_pageDecode.level1MosaicChar(r, c))
-				mosaicList.insert(qMakePair(r, c));
+				result.insert(qMakePair(r, c));
+
+	return result;
+}
+
+void TeletextWidget::shiftMosaics(int key)
+{
+	const QSet<QPair<int, int>> mosaicList = findMosaics();
 
 	if (!mosaicList.isEmpty())
 		switch (key) {
diff --git a/src/qteletextmaker/mainwidget.h b/src/qteletextmaker/mainwidget.h
index 7538f33..a731642 100644
--- a/src/qteletextmaker/mainwidget.h
+++ b/src/qteletextmaker/mainwidget.h
@@ -102,6 +102,7 @@ private:
 	int m_flashTiming, m_flashPhase;
 
 	void timerEvent(QTimerEvent *event) override;
+	QSet<QPair<int, int>> findMosaics();
 	void shiftMosaics(int key);
 	void selectionToClipboard();