Fix track handles dissapearing (#6338)

include/TrackContainerView.h

@@ -168,8 +168,6 @@ public slots:
 protected:
 	static const int DEFAULT_PIXELS_PER_BAR = 128;
 
-	void resizeEvent( QResizeEvent * ) override;
-
 	TimePos m_currentPosition;
 
 

src/gui/editors/TrackContainerView.cpp

@@ -89,18 +89,23 @@ TrackContainerView::TrackContainerView( TrackContainer * _tc ) :
 	m_tc->setHook( this );
 	//keeps the direction of the widget, undepended on the locale
 	setLayoutDirection( Qt::LeftToRight );
+
+	// The main layout - by default it only contains the scroll area,
+	// but SongEditor uses the layout to add a TimeLineWidget on top
 	auto layout = new QVBoxLayout(this);
 	layout->setContentsMargins(0, 0, 0, 0);
 	layout->setSpacing( 0 );
 	layout->addWidget( m_scrollArea );
 
+	// The widget that will contain all TrackViews
 	auto scrollContent = new QWidget;
 	m_scrollLayout = new QVBoxLayout( scrollContent );
 	m_scrollLayout->setContentsMargins(0, 0, 0, 0);
 	m_scrollLayout->setSpacing( 0 );
 	m_scrollLayout->setSizeConstraint( QLayout::SetMinAndMaxSize );
 
 	m_scrollArea->setWidget( scrollContent );
+	m_scrollArea->setWidgetResizable(true);
 
 	m_scrollArea->show();
 	m_rubberBand->hide();
@@ -254,10 +259,6 @@ void TrackContainerView::scrollToTrackView( TrackView * _tv )
 
 void TrackContainerView::realignTracks()
 {
-	m_scrollArea->widget()->setFixedWidth(width());
-	m_scrollArea->widget()->setFixedHeight(
-				m_scrollArea->widget()->minimumSizeHint().height());
-
 	for (const auto& trackView : m_trackViews)
 	{
 		trackView->show();
@@ -447,15 +448,6 @@ void TrackContainerView::dropEvent( QDropEvent * _de )
 
 
 
-void TrackContainerView::resizeEvent( QResizeEvent * _re )
-{
-	realignTracks();
-	QWidget::resizeEvent( _re );
-}
-
-
-
-
 RubberBand *TrackContainerView::rubberBand() const
 {
 	return m_rubberBand;