Default some empty destructors

Moving empty destructors out of the .cpp files and into headers
allows them to be devirtualized in certain cases.
(When the compiler can't "see" a function in a header, it must largely
assume it's some black box that the linker will resolve.)

While we're at it, use C++11's `= default` to define empty virtual
desturctors for us.

For some classes (e.g., Piano), nothing is derived from it, so we can
mark the class as final and remove any explicit virtual dtor.

There are many other places where this can be done, but this is a large
enough patch as-is.

src/core/AutomationPattern.cpp

@@ -98,16 +98,6 @@ AutomationPattern::AutomationPattern( const AutomationPattern & _pat_to_copy ) :
 	}
 }
 
-
-
-
-AutomationPattern::~AutomationPattern()
-{
-}
-
-
-
-
 bool AutomationPattern::addObject( AutomatableModel * _obj, bool _search_dup )
 {
 	if( _search_dup && m_objects.contains(_obj) )

src/core/Instrument.cpp

@@ -34,16 +34,6 @@ Instrument::Instrument( InstrumentTrack * _instrument_track,
 {
 }
 
-
-
-
-Instrument::~Instrument()
-{
-}
-
-
-
-
 void Instrument::play( sampleFrame * )
 {
 }

src/core/Piano.cpp

@@ -70,19 +70,6 @@ Piano::Piano( InstrumentTrack* track ) :
 
 }
 
-
-
-
-/*! \brief Destroy this new keyboard display
- *
- */
-Piano::~Piano()
-{
-}
-
-
-
-
 /*! \brief Turn a key on or off
  *
  *  \param key the key number to change

src/gui/AutomatableModelView.cpp

@@ -50,16 +50,6 @@ AutomatableModelView::AutomatableModelView( ::Model* model, QWidget* _this ) :
 	widget()->setCursor( QCursor( embed::getIconPixmap( "hand" ), 3, 3 ) );
 }
 
-
-
-
-AutomatableModelView::~AutomatableModelView()
-{
-}
-
-
-
-
 void AutomatableModelView::addDefaultActions( QMenu* menu )
 {
 	AutomatableModel* model = modelUntyped();

src/gui/FileBrowser.cpp

@@ -112,16 +112,6 @@ FileBrowser::FileBrowser(const QString & directories, const QString & filter,
 	show();
 }
 
-
-
-
-FileBrowser::~FileBrowser()
-{
-}
-
-
-
-
 bool FileBrowser::filterItems( const QString & filter, QTreeWidgetItem * item )
 {
 	// call with item=NULL to filter the entire tree
@@ -338,16 +328,6 @@ FileBrowserTreeWidget::FileBrowserTreeWidget(QWidget * parent ) :
 
 }
 
-
-
-
-FileBrowserTreeWidget::~FileBrowserTreeWidget()
-{
-}
-
-
-
-
 void FileBrowserTreeWidget::contextMenuEvent(QContextMenuEvent * e )
 {
 	FileItem * f = dynamic_cast<FileItem *>( itemAt( e->pos() ) );

src/gui/PianoView.cpp

@@ -130,19 +130,6 @@ PianoView::PianoView( QWidget * _parent ) :
 
 }
 
-
-
-
-/*! \brief Destroy this piano display view
- *
- */
-PianoView::~PianoView()
-{
-}
-
-
-
-
 /*! \brief Map a keyboard key being pressed to a note in our keyboard view
  *
  *  \param _k The keyboard scan code of the key being pressed.

src/gui/widgets/Fader.cpp

@@ -133,12 +133,6 @@ Fader::Fader( FloatModel * model, const QString & name, QWidget * parent, QPixma
 	init(model, name);
 }
 
-
-Fader::~Fader()
-{
-}
-
-
 void Fader::init(FloatModel * model, QString const & name)
 {
 	setWindowTitle( name );

src/gui/widgets/Graph.cpp

@@ -56,13 +56,6 @@ Graph::Graph( QWidget * _parent, graphStyle _style, int _width,
 			this, SLOT( updateGraph( ) ) );
 }
 
-
-Graph::~Graph()
-{
-}
-
-
-
 void Graph::setForeground( const QPixmap &_pixmap )
 {
 	m_foreground = _pixmap;
@@ -470,14 +463,6 @@ graphModel::graphModel( float _min, float _max, int _length,
 {
 }
 
-
-
-graphModel::~graphModel()
-{
-}
-
-
-
 void graphModel::setRange( float _min, float _max )
 {
 	if( _min != m_minValue || _max != m_maxValue )

src/gui/widgets/LcdSpinBox.cpp

@@ -58,14 +58,6 @@ LcdSpinBox::LcdSpinBox( int numDigits, const QString& style, QWidget* parent, co
 {
 }
 
-
-
-LcdSpinBox::~LcdSpinBox()
-{
-}
-
-
-
 void LcdSpinBox::update()
 {
 	setValue( model()->value() + m_displayOffset );

src/gui/widgets/SideBar.cpp

@@ -41,9 +41,8 @@ public:
 		m_orientation( _orientation )
 	{
 	}
-	virtual ~SideBarButton()
-	{
-	}
+
+	virtual ~SideBarButton() = default;
 
 	Qt::Orientation orientation() const
 	{

src/gui/widgets/TabBar.cpp

@@ -41,16 +41,6 @@ TabBar::TabBar( QWidget * _parent, QBoxLayout::Direction _dir ) :
 	setLayout( m_layout );
 }
 
-
-
-
-TabBar::~TabBar()
-{
-}
-
-
-
-
 TabButton * TabBar::addTab( QWidget * _w, const QString & _text, int _id,
 				bool _add_stretch, bool _text_is_tooltip )
 {

src/gui/widgets/TabWidget.cpp

@@ -61,12 +61,6 @@ TabWidget::TabWidget( const QString & caption, QWidget * parent, bool usePixmap
 
 }
 
-
-TabWidget::~TabWidget()
-{
-}
-
-
 void TabWidget::addTab( QWidget * w, const QString & name, const char *pixmap, int idx )
 {
 	setFont( pointSize<8>( font() ) );

src/gui/widgets/TimeDisplayWidget.cpp

@@ -58,17 +58,6 @@ TimeDisplayWidget::TimeDisplayWidget() :
 					this, SLOT( updateTime() ) );
 }
 
-
-
-
-TimeDisplayWidget::~TimeDisplayWidget()
-{
-}
-
-
-
-
-
 void TimeDisplayWidget::setDisplayMode( DisplayMode displayMode )
 {
 	m_displayMode = displayMode;

src/gui/widgets/ToolButton.cpp

@@ -41,10 +41,3 @@ ToolButton::ToolButton( const QPixmap & _pixmap, const QString & _tooltip,
 	ToolTip::add( this, _tooltip );
 	setIcon( _pixmap );
 }
-
-
-
-
-ToolButton::~ToolButton()
-{
-}

src/tracks/AutomationTrack.cpp

@@ -40,16 +40,6 @@ AutomationTrack::AutomationTrack( TrackContainer* tc, bool _hidden ) :
 	setName( tr( "Automation track" ) );
 }
 
-
-
-
-AutomationTrack::~AutomationTrack()
-{
-}
-
-
-
-
 bool AutomationTrack::play( const MidiTime & time_start, const fpp_t _frames,
 							const f_cnt_t _frame_base, int _tco_num )
 {
@@ -108,16 +98,6 @@ AutomationTrackView::AutomationTrackView( AutomationTrack * _at, TrackContainerV
 	setModel( _at );
 }
 
-
-
-
-AutomationTrackView::~AutomationTrackView()
-{
-}
-
-
-
-
 void AutomationTrackView::dragEnterEvent( QDragEnterEvent * _dee )
 {
 	StringPairDrag::processDragEnterEvent( _dee, "automatable_model" );

src/tracks/BBTrack.cpp

@@ -61,16 +61,6 @@ BBTCO::BBTCO( Track * _track ) :
 	setAutoResize( false );
 }
 
-
-
-
-BBTCO::~BBTCO()
-{
-}
-
-
-
-
 void BBTCO::saveSettings( QDomDocument & doc, QDomElement & element )
 {
 	element.setAttribute( "name", name() );
@@ -168,16 +158,6 @@ BBTCOView::BBTCOView( TrackContentObject * _tco, TrackView * _tv ) :
 	setStyle( QApplication::style() );
 }
 
-
-
-
-BBTCOView::~BBTCOView()
-{
-}
-
-
-
-
 void BBTCOView::constructContextMenu( QMenu * _cm )
 {
 	QAction * a = new QAction( embed::getIconPixmap( "bb_track" ),

src/tracks/Pattern.cpp

@@ -616,19 +616,6 @@ PatternView::PatternView( Pattern* pattern, TrackView* parent ) :
 	setStyle( QApplication::style() );
 }
 
-
-
-
-
-
-PatternView::~PatternView()
-{
-}
-
-
-
-
-
 void PatternView::update()
 {
 	ToolTip::add(this, m_pat->name());

src/tracks/SampleTrack.cpp

@@ -302,16 +302,6 @@ SampleTCOView::SampleTCOView( SampleTCO * _tco, TrackView * _tv ) :
 	setStyle( QApplication::style() );
 }
 
-
-
-
-SampleTCOView::~SampleTCOView()
-{
-}
-
-
-
-
 void SampleTCOView::updateSample()
 {
 	update();