fix CTRL in songeditor by losing focus (#3796)

* fix CTRL in songeditor by losing focus

* init m_ctrlAction

include/SongEditor.h

@@ -165,6 +165,7 @@ protected slots:
 	void recordAccompany();
 	void stop();
 
+	void lostFocus();
 	void adjustUiAfterProjectLoad();
 
 signals:

include/SubWindow.h

@@ -65,7 +65,10 @@ protected:
 	virtual void resizeEvent( QResizeEvent * event );
 	virtual void paintEvent( QPaintEvent * pe );
 	virtual void changeEvent( QEvent * event );
-	
+
+signals:
+	void focusLost();
+
 private:
 	const QSize m_buttonSize;
 	const int m_titleBarHeight;
@@ -79,10 +82,14 @@ private:
 	QRect m_trackedNormalGeom;
 	QLabel * m_windowTitle;
 	QGraphicsDropShadowEffect * m_shadow;
+	bool m_hasFocus;
 
 	static void elideText( QLabel *label, QString text );
 	bool isMaximized();
 	void adjustTitleBar();
+
+private slots:
+	void focusChanged( QMdiSubWindow * subWindow );
 };
 
 #endif