Merge remote-tracking branch 'lukas/cleanup/qt4'

# Conflicts:
#	cmake/toolchains/common/MSYS.cmake

cmake/toolchains/common/MSYS.cmake

@@ -19,18 +19,4 @@ ENDIF()
 SET(CMAKE_C_USE_RESPONSE_FILE_FOR_INCLUDES   OFF)
 SET(CMAKE_CXX_USE_RESPONSE_FILE_FOR_INCLUDES OFF)
 
-# Variable to assist override Qt debug libraries with release versions
-SET(QT_OVERRIDE_LIBRARIES
-	optimized;${MINGW_PREFIX}/bin/QtGui4.dll;
-	optimized;${MINGW_PREFIX}/bin/QtCore4.dll;
-	optimized;${MINGW_PREFIX}/bin/QtXml4.dll;
-	debug;${MINGW_PREFIX}/bin/QtGui4.dll;
-	debug;${MINGW_PREFIX}/bin/QtCore4.dll;
-	debug;${MINGW_PREFIX}/bin/QtXml4.dll;
-)
-IF(LMMS_BUILD_MSYS AND CMAKE_BUILD_TYPE STREQUAL "Debug")
-	# Override Qt debug libraries with release versions
-	SET(QT_LIBRARIES "${QT_OVERRIDE_LIBRARIES}")
-ENDIF()
-
 SET(LMMS_BUILD_MSYS 1)

include/AutomatableButton.h

@@ -39,7 +39,7 @@ class LMMS_EXPORT AutomatableButton : public QPushButton, public BoolModelView
 	Q_OBJECT
 public:
 	AutomatableButton( QWidget * _parent, const QString & _name
-			= QString::null );
+			= QString() );
 	virtual ~AutomatableButton();
 
 	inline void setCheckable( bool _on )
@@ -84,7 +84,7 @@ class LMMS_EXPORT automatableButtonGroup : public QWidget, public IntModelView
 	Q_OBJECT
 public:
 	automatableButtonGroup( QWidget * _parent, const QString & _name
-			= QString::null );
+			= QString() );
 	virtual ~automatableButtonGroup();
 
 	void addButton( AutomatableButton * _btn );

include/AutomatableSlider.h

@@ -36,7 +36,7 @@ class AutomatableSlider : public QSlider, public IntModelView
 {
 	Q_OBJECT
 public:
-	AutomatableSlider( QWidget * _parent, const QString & _name = QString::null );
+	AutomatableSlider( QWidget * _parent, const QString & _name = QString() );
 	virtual ~AutomatableSlider();
 
 	bool showStatus()

include/FileBrowser.h

@@ -129,13 +129,13 @@ public:
 
 	void update( void );
 
-	inline QString fullName( QString path = QString::null )
+	inline QString fullName( QString path = QString() )
 	{
-		if( path == QString::null )
+		if( path == QString() )
 		{
 			path = m_directories[0];
 		}
-		if( path != QString::null )
+		if( path != QString() )
 		{
 			path += QDir::separator();
 		}

include/LcdSpinBox.h

@@ -34,9 +34,9 @@ class LMMS_EXPORT LcdSpinBox : public LcdWidget, public IntModelView
 {
 	Q_OBJECT
 public:
-	LcdSpinBox( int numDigits, QWidget* parent, const QString& name = QString::null );
+	LcdSpinBox( int numDigits, QWidget* parent, const QString& name = QString() );
 
-	LcdSpinBox( int numDigits, const QString& style, QWidget* parent, const QString& name = QString::null );
+	LcdSpinBox( int numDigits, const QString& style, QWidget* parent, const QString& name = QString() );
 
 	virtual ~LcdSpinBox() = default;
 

include/LcdWidget.h

@@ -40,9 +40,9 @@ class LMMS_EXPORT LcdWidget : public QWidget
 	Q_PROPERTY( QColor textShadowColor READ textShadowColor WRITE setTextShadowColor )
 	
 public:
-	LcdWidget( QWidget* parent, const QString& name = QString::null );
-	LcdWidget( int numDigits, QWidget* parent, const QString& name = QString::null );
-	LcdWidget( int numDigits, const QString& style, QWidget* parent, const QString& name = QString::null );
+	LcdWidget( QWidget* parent, const QString& name = QString() );
+	LcdWidget( int numDigits, QWidget* parent, const QString& name = QString() );
+	LcdWidget( int numDigits, const QString& style, QWidget* parent, const QString& name = QString() );
 
 	virtual ~LcdWidget();
 

include/LedCheckbox.h

@@ -45,10 +45,10 @@ public:
 	} ;
 
 	LedCheckBox( const QString & _txt, QWidget * _parent,
-				const QString & _name = QString::null,
+				const QString & _name = QString(),
 						LedColors _color = Yellow );
 	LedCheckBox( QWidget * _parent,
-				const QString & _name = QString::null,
+				const QString & _name = QString(),
 						LedColors _color = Yellow );
 
 	virtual ~LedCheckBox();

include/MainApplication.h

@@ -31,12 +31,10 @@
 
 #ifdef LMMS_BUILD_WIN32
 #include <windows.h>
-#if QT_VERSION >= 0x050000
 #include <QAbstractNativeEventFilter>
 #endif
-#endif
 
-#if defined(LMMS_BUILD_WIN32) && QT_VERSION >= 0x050000
+#if defined(LMMS_BUILD_WIN32)
 class MainApplication : public QApplication, public QAbstractNativeEventFilter
 #else
 class MainApplication : public QApplication
@@ -47,10 +45,8 @@ public:
 	bool event(QEvent* event);
 #ifdef LMMS_BUILD_WIN32
 	bool winEventFilter(MSG* msg, long* result);
-#if QT_VERSION >= 0x050000
 	bool nativeEventFilter(const QByteArray& eventType, void* message,
 				long* result);
-#endif
 #endif
 	inline QString& queuedFile()
 	{

include/MidiApple.h

@@ -47,7 +47,7 @@ public:
 
 	inline static QString probeDevice()
 	{
-		return QString::Null(); // no midi device name
+		return QString(); // no midi device name
 	}
 
 	inline static QString name()
@@ -56,7 +56,7 @@ public:
 	}
 	inline static QString configSection()
 	{
-		return QString::Null(); // no configuration settings
+		return QString(); // no configuration settings
 	}
 	
 	virtual void processOutEvent( const MidiEvent & _me,

include/MidiDummy.h

@@ -46,12 +46,12 @@ public:
 
 	inline static QString probeDevice()
 	{
-		return QString::Null(); // no midi device name
+		return QString(); // no midi device name
 	}
 
 	inline static QString configSection()
 	{
-		return QString::Null(); // no configuration settings
+		return QString(); // no configuration settings
 	}
 
 

include/MidiWinMM.h

@@ -47,7 +47,7 @@ public:
 
 	inline static QString probeDevice()
 	{
-		return QString::Null(); // no midi device name
+		return QString(); // no midi device name
 	}
 
 
@@ -58,7 +58,7 @@ public:
 
 	inline static QString configSection()
 	{
-		return QString::Null(); // no configuration settings
+		return QString(); // no configuration settings
 	}
 
 

include/Model.h

@@ -35,7 +35,7 @@ class LMMS_EXPORT Model : public QObject
 {
 	Q_OBJECT
 public:
-	Model( Model * _parent, QString _display_name = QString::null,
+	Model( Model * _parent, QString _display_name = QString(),
 					bool _default_constructed = false ) :
 		QObject( _parent ),
 		m_displayName( _display_name ),

include/PixmapButton.h

@@ -36,7 +36,7 @@ class LMMS_EXPORT PixmapButton : public AutomatableButton
 	Q_OBJECT
 public:
 	PixmapButton( QWidget * _parent,
-					const QString & _name = QString::null );
+					const QString & _name = QString() );
 	virtual ~PixmapButton();
 
 	void setActiveGraphic( const QPixmap & _pm );

include/RemotePlugin.h

@@ -138,8 +138,8 @@ public:
 		m_shmID( -1 ),
 #endif
 		m_data( NULL ),
-		m_dataSem( QString::null ),
-		m_messageSem( QString::null ),
+		m_dataSem( QString() ),
+		m_messageSem( QString() ),
 		m_lockDepth( 0 )
 	{
 #ifdef USE_QT_SHMEM
@@ -181,8 +181,8 @@ public:
 		m_shmID( shmget( _shm_key, 0, 0 ) ),
 #endif
 		m_data( NULL ),
-		m_dataSem( QString::null ),
-		m_messageSem( QString::null ),
+		m_dataSem( QString() ),
+		m_messageSem( QString() ),
 		m_lockDepth( 0 )
 	{
 #ifdef USE_QT_SHMEM

include/embed.h

@@ -60,11 +60,11 @@ class PixmapLoader
 {
 public:
 	PixmapLoader( const PixmapLoader * _ref ) :
-		m_name( _ref != NULL ? _ref->m_name : QString::null )
+		m_name( _ref != NULL ? _ref->m_name : QString() )
 	{
 	}
 
-	PixmapLoader( const QString & _name = QString::null ) :
+	PixmapLoader( const QString & _name = QString() ) :
 		m_name( _name )
 	{
 	}
@@ -96,7 +96,7 @@ protected:
 class PluginPixmapLoader : public PixmapLoader
 {
 public:
-	PluginPixmapLoader( const QString & _name = QString::null ) :
+	PluginPixmapLoader( const QString & _name = QString() ) :
 		PixmapLoader( _name )
 	{
 	}

plugins/GigPlayer/PatchesDialog.cpp

@@ -74,11 +74,7 @@ PatchesDialog::PatchesDialog( QWidget * pParent, Qt::WindowFlags wflags )
 	// Soundfonts list view...
 	QHeaderView * pHeader = m_progListView->header();
 	pHeader->setDefaultAlignment( Qt::AlignLeft );
-#if QT_VERSION >= 0x050000
 	pHeader->setSectionsMovable( false );
-#else
-	pHeader->setMovable( false );
-#endif
 	pHeader->setStretchLastSection( true );
 
 	m_progListView->resizeColumnToContents( 0 );	// Prog.

plugins/VstEffect/VstEffectControlDialog.cpp

@@ -272,12 +272,10 @@ void VstEffectControlDialog::showEvent(QShowEvent *_se)
 
 VstEffectControlDialog::~VstEffectControlDialog()
 {
-#if !(QT_VERSION < 0x050000 && defined(LMMS_BUILD_LINUX))
 	if (m_pluginWidget && layout()) {
 		layout()->removeWidget(m_pluginWidget);
 		m_pluginWidget->setParent(nullptr);
 	}
-#endif
 }
 
 

plugins/lb302/lb302.cpp

@@ -434,11 +434,7 @@ QString lb302Synth::nodeName() const
 // OBSOLETE. Break apart once we get Q_OBJECT to work. >:[
 void lb302Synth::recalcFilter()
 {
-#if QT_VERSION >= 0x050000
 	vcf.load()->recalc();
-#else
-	vcf->recalc();
-#endif
 
 	// THIS IS OLD 3pole/24dB code, I may reintegrate it.  Don't need it
 	// right now.   Should be toggled by LB_24_RES_TRICK at the moment.
@@ -464,11 +460,7 @@ int lb302Synth::process(sampleFrame *outbuf, const int size)
 	float samp;
 
 	// Hold on to the current VCF, and use it throughout this period
-#if QT_VERSION >= 0x050000
 	lb302Filter *filter = vcf.loadAcquire();
-#else
-	lb302Filter *filter = vcf;
-#endif
 
 	if( release_frame == 0 || ! m_playingNote ) 
 	{
@@ -692,11 +684,7 @@ void lb302Synth::initNote( lb302Note *n)
 
 	if(n->dead ==0){
 		// Swap next two blocks??
-#if QT_VERSION >= 0x050000
 		vcf.load()->playNote();
-#else
-		vcf->playNote();
-#endif
 		// Ensure envelope is recalculated
 		vcf_envpos = ENVINC;
 

plugins/patman/patman.cpp

@@ -78,7 +78,7 @@ PLUGIN_EXPORT Plugin * lmms_plugin_main( Model *, void * _data )
 
 patmanInstrument::patmanInstrument( InstrumentTrack * _instrument_track ) :
 	Instrument( _instrument_track, &patman_plugin_descriptor ),
-	m_patchFile( QString::null ),
+	m_patchFile( QString() ),
 	m_loopedModel( true, this ),
 	m_tunedModel( true, this )
 {
@@ -182,7 +182,7 @@ void patmanInstrument::setFile( const QString & _patch_file, bool _rename )
 {
 	if( _patch_file.size() <= 0 )
 	{
-		m_patchFile = QString::null;
+		m_patchFile = QString();
 		return;
 	}
 

plugins/sf2_player/patches_dialog.cpp

@@ -75,11 +75,7 @@ patchesDialog::patchesDialog( QWidget *pParent, Qt::WindowFlags wflags )
 //	pHeader->setResizeMode(QHeaderView::Custom);
 	pHeader->setDefaultAlignment(Qt::AlignLeft);
 //	pHeader->setDefaultSectionSize(200);
-#if QT_VERSION >= 0x050000
 	pHeader->setSectionsMovable(false);
-#else
-	pHeader->setMovable(false);
-#endif
 	pHeader->setStretchLastSection(true);
 
 	m_progListView->resizeColumnToContents(0);	// Prog.

plugins/vibed/nine_button_selector.cpp

@@ -52,8 +52,8 @@ nineButtonSelector::nineButtonSelector(	QPixmap _button0_on,
 					int _x, int _y,
 					QWidget * _parent ):
 	QWidget( _parent ),
-	IntModelView( new nineButtonSelectorModel(0, 8, _default, NULL, 
-				QString::null, true ), this )
+	IntModelView( new nineButtonSelectorModel(0, 8, _default, NULL,
+				QString(), true ), this )
 {
 	setFixedSize( 50, 50 );
 	move( _x, _y );

plugins/vst_base/VstPlugin.cpp

@@ -38,17 +38,10 @@
 
 #ifdef LMMS_BUILD_LINUX
 #	include <QX11Info>
-#	if QT_VERSION < 0x050000
-#		include <QX11EmbedContainer>
-#	else
-#		include "X11EmbedContainer.h"
-#		include <QWindow>
-#	endif
+#	include "X11EmbedContainer.h"
 #endif
 
-#if QT_VERSION >= 0x050000
-#	include <QWindow>
-#endif
+#include <QWindow>
 
 #include <QDomDocument>
 

plugins/zynaddsubfx/CMakeLists.txt

@@ -122,11 +122,6 @@ ELSE()
 ENDIF()
 TARGET_LINK_LIBRARIES(ZynAddSubFxCore zynaddsubfx_nio ${FFTW3F_LIBRARIES} ${QT_LIBRARIES} -lz -lpthread)
 
-# required libs for debug msys builds
-IF(LMMS_BUILD_MSYS AND CMAKE_BUILD_TYPE STREQUAL "Debug")
-	TARGET_LINK_LIBRARIES(ZynAddSubFxCore QtCore4 QtGui4 QtXml4)
-ENDIF()
-
 TARGET_LINK_LIBRARIES(ZynAddSubFxCore Qt5::Widgets Qt5::Xml)
 
 IF(LMMS_BUILD_WIN32)

src/CMakeLists.txt

@@ -184,11 +184,6 @@ FOREACH(LIB ${LMMS_REQUIRED_LIBS})
 ENDFOREACH()
 
 
-# Required libs for debug msys builds
-IF(LMMS_BUILD_MSYS AND CMAKE_BUILD_TYPE STREQUAL "Debug")
-	TARGET_LINK_LIBRARIES(lmms QtCore4 QtGui4 QtXml4)
-ENDIF()
-
 # Install
 IF(NOT MSVC)
 	IF(LMMS_BUILD_WIN32)

src/core/AutomatableModel.cpp

@@ -409,7 +409,7 @@ void AutomatableModel::linkModel( AutomatableModel* model )
 
 void AutomatableModel::unlinkModel( AutomatableModel* model )
 {
-	AutoModelVector::Iterator it = qFind( m_linkedModels.begin(), m_linkedModels.end(), model );
+	AutoModelVector::Iterator it = std::find( m_linkedModels.begin(), m_linkedModels.end(), model );
 	if( it != m_linkedModels.end() )
 	{
 		m_linkedModels.erase( it );

src/core/ConfigManager.cpp

@@ -26,11 +26,7 @@
 #include <QDir>
 #include <QMessageBox>
 #include <QApplication>
-#if QT_VERSION >= 0x050000
 #include <QStandardPaths>
-#else
-#include <QDesktopServices>
-#endif
 #include <QtCore/QTextStream>
 
 #include "ConfigManager.h"
@@ -55,11 +51,7 @@ ConfigManager * ConfigManager::s_instanceOfMe = NULL;
 
 ConfigManager::ConfigManager() :
 	m_lmmsRcFile( QDir::home().absolutePath() +"/.lmmsrc.xml" ),
-	#if QT_VERSION >= 0x050000
 	m_workingDir( QStandardPaths::writableLocation( QStandardPaths::DocumentsLocation ) + "/lmms/"),
-	#else
-	m_workingDir( QDesktopServices::storageLocation( QDesktopServices::DocumentsLocation ) + "/lmms/"),
-	#endif
 	m_dataDir( "data:/" ),
 	m_artworkDir( defaultArtworkDir() ),
 	m_vstDir( m_workingDir + "vst/" ),
@@ -210,13 +202,8 @@ QStringList ConfigManager::availabeVstEmbedMethods()
 	methods.append("win32");
 #endif
 #ifdef LMMS_BUILD_LINUX
-#if QT_VERSION >= 0x050000
 	if (static_cast<QGuiApplication*>(QApplication::instance())->
 		platformName() == "xcb")
-#else
-	if (qgetenv("QT_QPA_PLATFORM").isNull()
-		|| qgetenv("QT_QPA_PLATFORM") == "xcb")
-#endif
 	{
 		methods.append("xembed");
 	}

src/core/EffectChain.cpp

@@ -137,7 +137,7 @@ void EffectChain::removeEffect( Effect * _effect )
 {
 	Engine::mixer()->requestChangeInModel();
 
-	Effect ** found = qFind( m_effects.begin(), m_effects.end(), _effect );
+	Effect ** found = std::find( m_effects.begin(), m_effects.end(), _effect );
 	if( found == m_effects.end() )
 	{
 		Engine::mixer()->doneChangeInModel();

src/core/LadspaManager.cpp

@@ -103,7 +103,7 @@ LadspaManager::LadspaManager()
 	{
 		m_sortedPlugins.append( qMakePair( getName( *it ), *it ) );
 	}
-	qSort( m_sortedPlugins );
+	std::sort( m_sortedPlugins.begin(), m_sortedPlugins.end() );
 }
 
 

src/core/Mixer.cpp

@@ -393,7 +393,7 @@ const surroundSampleFrame * Mixer::renderNextBuffer()
 	ConstPlayHandleList::Iterator it_rem = m_playHandlesToRemove.begin();
 	while( it_rem != m_playHandlesToRemove.end() )
 	{
-		PlayHandleList::Iterator it = qFind( m_playHandles.begin(), m_playHandles.end(), *it_rem );
+		PlayHandleList::Iterator it = std::find( m_playHandles.begin(), m_playHandles.end(), *it_rem );
 
 		if( it != m_playHandles.end() )
 		{
@@ -659,7 +659,7 @@ void Mixer::restoreAudioDevice()
 void Mixer::removeAudioPort( AudioPort * _port )
 {
 	requestChangeInModel();
-	QVector<AudioPort *>::Iterator it = qFind( m_audioPorts.begin(),
+	QVector<AudioPort *>::Iterator it = std::find( m_audioPorts.begin(),
 							m_audioPorts.end(),
 							_port );
 	if( it != m_audioPorts.end() )
@@ -720,7 +720,7 @@ void Mixer::removePlayHandle( PlayHandle * _ph )
 			}
 		}
 		// Now check m_playHandles
-		PlayHandleList::Iterator it = qFind( m_playHandles.begin(),
+		PlayHandleList::Iterator it = std::find( m_playHandles.begin(),
 					m_playHandles.end(), _ph );
 		if( it != m_playHandles.end() )
 		{

src/core/Model.cpp

@@ -33,7 +33,7 @@ QString Model::fullDisplayName() const
 		const QString p = parentModel()->fullDisplayName();
 		if( n.isEmpty() && p.isEmpty() )
 		{
-			return QString::null;
+			return QString();
 		}
 		else if( p.isEmpty() )
 		{

src/core/SampleBuffer.cpp

@@ -1012,12 +1012,12 @@ QString SampleBuffer::openAudioFile() const
 	{
 		if( ofd.selectedFiles().isEmpty() )
 		{
-			return QString::null;
+			return QString();
 		}
 		return tryToMakeRelative( ofd.selectedFiles()[0] );
 	}
 
-	return QString::null;
+	return QString();
 }
 
 

src/core/Track.cpp

@@ -95,7 +95,7 @@ TextFloat * TrackContentObjectView::s_textFloat = NULL;
 TrackContentObject::TrackContentObject( Track * track ) :
 	Model( track ),
 	m_track( track ),
-	m_name( QString::null ),
+	m_name( QString() ),
 	m_startPosition(),
 	m_length(),
 	m_mutedModel( false, this, tr( "Mute" ) ),
@@ -870,7 +870,7 @@ void TrackContentObjectView::mouseMoveEvent( QMouseEvent * me )
 			DataFile dataFile = createTCODataFiles( tcoViews );
 
 			// TODO -- thumbnail for all selected
-			QPixmap thumbnail = QPixmap::grabWidget( this ).scaled(
+			QPixmap thumbnail = grab().scaled(
 				128, 128,
 				Qt::KeepAspectRatio,
 				Qt::SmoothTransformation );
@@ -1242,7 +1242,7 @@ void TrackContentWidget::addTCOView( TrackContentObjectView * tcov )
  */
 void TrackContentWidget::removeTCOView( TrackContentObjectView * tcov )
 {
-	tcoViewVector::iterator it = qFind( m_tcoViews.begin(),
+	tcoViewVector::iterator it = std::find( m_tcoViews.begin(),
 						m_tcoViews.end(),
 						tcov );
 	if( it != m_tcoViews.end() )
@@ -1808,8 +1808,7 @@ void TrackOperationsWidget::mousePressEvent( QMouseEvent * me )
 		m_trackView->getTrack()->saveState( dataFile, dataFile.content() );
 		new StringPairDrag( QString( "track_%1" ).arg(
 					m_trackView->getTrack()->type() ),
-			dataFile.toString(), QPixmap::grabWidget(
-				m_trackView->getTrackSettingsWidget() ),
+			dataFile.toString(), m_trackView->getTrackSettingsWidget()->grab(),
 									this );
 	}
 	else if( me->button() == Qt::LeftButton )
@@ -2259,7 +2258,7 @@ TrackContentObject * Track::addTCO( TrackContentObject * tco )
  */
 void Track::removeTCO( TrackContentObject * tco )
 {
-	tcoVector::iterator it = qFind( m_trackContentObjects.begin(),
+	tcoVector::iterator it = std::find( m_trackContentObjects.begin(),
 					m_trackContentObjects.end(),
 					tco );
 	if( it != m_trackContentObjects.end() )
@@ -2331,7 +2330,7 @@ TrackContentObject * Track::getTCO( int tcoNum )
 int Track::getTCONum( const TrackContentObject * tco )
 {
 //	for( int i = 0; i < getTrackContentWidget()->numOfTCOs(); ++i )
-	tcoVector::iterator it = qFind( m_trackContentObjects.begin(),
+	tcoVector::iterator it = std::find( m_trackContentObjects.begin(),
 					m_trackContentObjects.end(),
 					tco );
 	if( it != m_trackContentObjects.end() )

src/core/audio/AudioPort.cpp

@@ -238,7 +238,7 @@ void AudioPort::addPlayHandle( PlayHandle * handle )
 void AudioPort::removePlayHandle( PlayHandle * handle )
 {
 	m_playHandleLock.lock();
-		PlayHandleList::Iterator it =	qFind( m_playHandles.begin(), m_playHandles.end(), handle );
+		PlayHandleList::Iterator it =	std::find( m_playHandles.begin(), m_playHandles.end(), handle );
 		if( it != m_playHandles.end() )
 		{
 			m_playHandles.erase( it );

src/core/main.cpp

@@ -818,22 +818,12 @@ int main( int argc, char * * argv )
 			QPushButton * discard;
 			QPushButton * exit;
 
-			#if QT_VERSION >= 0x050000
-				// setting all buttons to the same roles allows us
-				// to have a custom layout
-				discard = mb.addButton( MainWindow::tr( "Discard" ),
-									QMessageBox::AcceptRole );
-				recover = mb.addButton( MainWindow::tr( "Recover" ),
-									QMessageBox::AcceptRole );
-
-			# else
-				// in qt4 the button order is reversed
-				recover = mb.addButton( MainWindow::tr( "Recover" ),
-									QMessageBox::AcceptRole );
-				discard = mb.addButton( MainWindow::tr( "Discard" ),
-									QMessageBox::AcceptRole );
-
-			#endif
+			// setting all buttons to the same roles allows us
+			// to have a custom layout
+			discard = mb.addButton( MainWindow::tr( "Discard" ),
+								QMessageBox::AcceptRole );
+			recover = mb.addButton( MainWindow::tr( "Recover" ),
+								QMessageBox::AcceptRole );
 
 			// have a hidden exit button
 			exit = mb.addButton( "", QMessageBox::RejectRole);

src/core/midi/MidiClient.cpp

@@ -77,7 +77,7 @@ void MidiClient::removePort( MidiPort* port )
 	}
 
 	QVector<MidiPort *>::Iterator it =
-		qFind( m_midiPorts.begin(), m_midiPorts.end(), port );
+		std::find( m_midiPorts.begin(), m_midiPorts.end(), port );
 	if( it != m_midiPorts.end() )
 	{
 		m_midiPorts.erase( it );

src/gui/AutomatableModelView.cpp

@@ -43,8 +43,8 @@ static float floatFromClipboard(bool* ok=nullptr);
 
 AutomatableModelView::AutomatableModelView( ::Model* model, QWidget* _this ) :
 	ModelView( model, _this ),
-	m_description( QString::null ),
-	m_unit( QString::null )
+	m_description( QString() ),
+	m_unit( QString() )
 {
 	widget()->setAcceptDrops( true );
 	widget()->setCursor( QCursor( embed::getIconPixmap( "hand" ), 3, 3 ) );

src/gui/AutomationPatternView.cpp

@@ -91,7 +91,7 @@ void AutomationPatternView::update()
 
 void AutomationPatternView::resetName()
 {
-	m_pat->setName( QString::null );
+	m_pat->setName( QString() );
 }
 
 
@@ -118,7 +118,7 @@ void AutomationPatternView::disconnectObject( QAction * _a )
 		float oldMin = m_pat->getMin();
 		float oldMax = m_pat->getMax();
 
-		m_pat->m_objects.erase( qFind( m_pat->m_objects.begin(),
+		m_pat->m_objects.erase( std::find( m_pat->m_objects.begin(),
 					m_pat->m_objects.end(),
 				dynamic_cast<AutomatableModel *>( j ) ) );
 		update();

src/gui/EffectSelectDialog.cpp

@@ -120,21 +120,15 @@ EffectSelectDialog::EffectSelectDialog( QWidget * _parent ) :
 	connect( ui->buttonBox, SIGNAL( accepted() ),
 				this, SLOT( acceptSelection() ) );
 
-#if QT_VERSION >= 0x050000
-#define setResizeMode setSectionResizeMode
 	ui->filterEdit->setClearButtonEnabled( true );
-#endif
-	ui->pluginList->verticalHeader()->setResizeMode(
+	ui->pluginList->verticalHeader()->setSectionResizeMode(
 						QHeaderView::ResizeToContents );
 	ui->pluginList->verticalHeader()->hide();
-	ui->pluginList->horizontalHeader()->setResizeMode( 0,
+	ui->pluginList->horizontalHeader()->setSectionResizeMode( 0,
 							QHeaderView::Stretch );
-	ui->pluginList->horizontalHeader()->setResizeMode( 1,
+	ui->pluginList->horizontalHeader()->setSectionResizeMode( 1,
 						QHeaderView::ResizeToContents );
 	ui->pluginList->sortByColumn( 0, Qt::AscendingOrder );
-#if QT_VERSION >= 0x050000
-#undef setResizeMode
-#endif
 
 	updateSelection();
 	show();

src/gui/FileBrowser.cpp

@@ -83,15 +83,13 @@ FileBrowser::FileBrowser(const QString & directories, const QString & filter,
 
 	m_filterEdit = new QLineEdit( searchWidget );
 	m_filterEdit->setPlaceholderText( tr("Search") );
-#if QT_VERSION >= 0x050000
 	m_filterEdit->setClearButtonEnabled( true );
-#endif
 	connect( m_filterEdit, SIGNAL( textEdited( const QString & ) ),
 			this, SLOT( filterItems( const QString & ) ) );
 
 	QPushButton * reload_btn = new QPushButton(
 				embed::getIconPixmap( "reload" ),
-						QString::null, searchWidget );
+						QString(), searchWidget );
 	reload_btn->setToolTip( tr( "Refresh list" ) );
 	connect( reload_btn, SIGNAL( clicked() ), this, SLOT( reloadTree() ) );
 
@@ -131,7 +129,7 @@ bool FileBrowser::filterItems( const QString & filter, QTreeWidgetItem * item )
 			{
 				// yes, then show everything below
 				it->setHidden( false );
-				filterItems( QString::null, it );
+				filterItems( QString(), it );
 				anyMatched = true;
 			}
 			else
@@ -221,7 +219,7 @@ void FileBrowser::addItems(const QString & path )
 {
 	if( m_dirsAsItems )
 	{
-		m_fileBrowserTreeWidget->addTopLevelItem( new Directory( path, QString::null, m_filter ) );
+		m_fileBrowserTreeWidget->addTopLevelItem( new Directory( path, QString(), m_filter ) );
 		return;
 	}
 

src/gui/FxMixerView.cpp

@@ -131,7 +131,7 @@ FxMixerView::FxMixerView() :
 	ml->addWidget( channelArea, 1, Qt::AlignTop );
 
 	// show the add new effect channel button
-	QPushButton * newChannelBtn = new QPushButton( embed::getIconPixmap( "new_channel" ), QString::null, this );
+	QPushButton * newChannelBtn = new QPushButton( embed::getIconPixmap( "new_channel" ), QString(), this );
 	newChannelBtn->setObjectName( "newChannelBtn" );
 	newChannelBtn->setFixedSize( fxLineSize );
 	connect( newChannelBtn, SIGNAL( clicked() ), this, SLOT( addNewChannel() ) );

src/gui/LmmsStyle.cpp

@@ -132,11 +132,7 @@ LmmsStyle::LmmsStyle() :
 
 	if( s_palette != NULL ) { qApp->setPalette( *s_palette ); }
 
-#if QT_VERSION >= 0x050000
 	setBaseStyle( QStyleFactory::create( "Fusion" ) );
-#else
-	setBaseStyle( QStyleFactory::create( "Plastique" ) );
-#endif
 }
 
 

src/gui/MainApplication.cpp

@@ -35,7 +35,7 @@ MainApplication::MainApplication(int& argc, char** argv) :
 	QApplication(argc, argv),
 	m_queuedFile()
 {
-#if defined(LMMS_BUILD_WIN32) && QT_VERSION >= 0x050000
+#if defined(LMMS_BUILD_WIN32)
 	installNativeEventFilter(this);
 #endif
 }
@@ -92,7 +92,6 @@ bool MainApplication::winEventFilter(MSG* msg, long* result)
 	}
 }
 
-#if QT_VERSION >= 0x050000
 bool MainApplication::nativeEventFilter(const QByteArray& eventType,
 					void* message, long* result)
 {
@@ -103,4 +102,3 @@ bool MainApplication::nativeEventFilter(const QByteArray& eventType,
 	return false;
 }
 #endif
-#endif

src/gui/MainWindow.cpp

@@ -69,7 +69,7 @@
 
 #include "lmmsversion.h"
 
-#if !defined(LMMS_BUILD_WIN32) && !defined(LMMS_BUILD_APPLE) && !defined(LMMS_BUILD_HAIKU) && QT_VERSION >= 0x050000
+#if !defined(LMMS_BUILD_WIN32) && !defined(LMMS_BUILD_APPLE) && !defined(LMMS_BUILD_HAIKU)
 //Work around an issue on KDE5 as per https://bugs.kde.org/show_bug.cgi?id=337491#c21
 void disableAutoKeyAccelerators(QWidget* mainWindow)
 {
@@ -96,7 +96,7 @@ MainWindow::MainWindow() :
 	m_metronomeToggle( 0 ),
 	m_session( Normal )
 {
-#if !defined(LMMS_BUILD_WIN32) && !defined(LMMS_BUILD_APPLE) && !defined(LMMS_BUILD_HAIKU) && QT_VERSION >= 0x050000
+#if !defined(LMMS_BUILD_WIN32) && !defined(LMMS_BUILD_APPLE) && !defined(LMMS_BUILD_HAIKU)
 	disableAutoKeyAccelerators(this);
 #endif
 	setAttribute( Qt::WA_DeleteOnClose );
@@ -336,7 +336,7 @@ void MainWindow::finalize()
 					Qt::CTRL + Qt::Key_M );
 
 // Prevent dangling separator at end of menu per https://bugreports.qt.io/browse/QTBUG-40071
-#if !(defined(LMMS_BUILD_APPLE) && (QT_VERSION >= 0x050000) && (QT_VERSION < 0x050600))
+#if !(defined(LMMS_BUILD_APPLE) && (QT_VERSION < 0x050600))
 	project_menu->addSeparator();
 #endif
 	project_menu->addAction( embed::getIconPixmap( "exit" ), tr( "&Quit" ),
@@ -411,7 +411,7 @@ void MainWindow::finalize()
 	}
 
 // Prevent dangling separator at end of menu per https://bugreports.qt.io/browse/QTBUG-40071
-#if !(defined(LMMS_BUILD_APPLE) && (QT_VERSION >= 0x050000) && (QT_VERSION < 0x050600))
+#if !(defined(LMMS_BUILD_APPLE) && (QT_VERSION < 0x050600))
 	help_menu->addSeparator();
 #endif
 	help_menu->addAction( embed::getIconPixmap( "icon" ), tr( "About" ),

src/gui/MidiSetupWidget.cpp

@@ -36,7 +36,7 @@ MidiSetupWidget::MidiSetupWidget( const QString & caption, const QString & confi
 	m_configSection(configSection),
 	m_device(nullptr)
 {
-	// supply devName=QString::Null() (distinct from QString(""))
+	// supply devName=QString() (distinct from QString(""))
 	//   to indicate that there is no editable DEVICE field
 	if (!devName.isNull())
 	{

src/gui/SetupDialog.cpp

@@ -1053,11 +1053,7 @@ void SetupDialog::accept()
 					QString::number( m_disableAutoQuit ) );
 	ConfigManager::inst()->setValue( "app", "language", m_lang );
 	ConfigManager::inst()->setValue( "ui", "vstembedmethod",
-#if QT_VERSION >= 0x050000
 					m_vstEmbedComboBox->currentData().toString() );
-#else
-					m_vstEmbedComboBox->itemData(m_vstEmbedComboBox->currentIndex()).toString() );
-#endif
 
 
 	ConfigManager::inst()->setWorkingDir(QDir::fromNativeSeparators(m_workingDir));
@@ -1273,7 +1269,7 @@ void SetupDialog::openWorkingDir()
 {
 	QString new_dir = FileDialog::getExistingDirectory( this,
 					tr( "Choose LMMS working directory" ), m_workingDir );
-	if( new_dir != QString::null )
+	if( new_dir != QString() )
 	{
 		m_wdLineEdit->setText( new_dir );
 	}
@@ -1284,7 +1280,7 @@ void SetupDialog::openGIGDir()
 	QString new_dir = FileDialog::getExistingDirectory( this,
 				tr( "Choose your GIG directory" ),
 							m_gigDir );
-	if( new_dir != QString::null )
+	if( new_dir != QString() )
 	{
 		m_gigLineEdit->setText( new_dir );
 	}
@@ -1295,7 +1291,7 @@ void SetupDialog::openSF2Dir()
 	QString new_dir = FileDialog::getExistingDirectory( this,
 				tr( "Choose your SF2 directory" ),
 							m_sf2Dir );
-	if( new_dir != QString::null )
+	if( new_dir != QString() )
 	{
 		m_sf2LineEdit->setText( new_dir );
 	}
@@ -1317,7 +1313,7 @@ void SetupDialog::openVSTDir()
 	QString new_dir = FileDialog::getExistingDirectory( this,
 				tr( "Choose your VST-plugin directory" ),
 							m_vstDir );
-	if( new_dir != QString::null )
+	if( new_dir != QString() )
 	{
 		m_vdLineEdit->setText( new_dir );
 	}
@@ -1349,7 +1345,7 @@ void SetupDialog::openArtworkDir()
 	QString new_dir = FileDialog::getExistingDirectory( this,
 				tr( "Choose artwork-theme directory" ),
 							m_artworkDir );
-	if( new_dir != QString::null )
+	if( new_dir != QString() )
 	{
 		m_adLineEdit->setText( new_dir );
 	}
@@ -1371,7 +1367,7 @@ void SetupDialog::openLADSPADir()
 	QString new_dir = FileDialog::getExistingDirectory( this,
 				tr( "Choose LADSPA plugin directory" ),
 							m_ladDir );
-	if( new_dir != QString::null )
+	if( new_dir != QString() )
 	{
 		if( m_ladLineEdit->text() == "" )
 		{
@@ -1393,7 +1389,7 @@ void SetupDialog::openSTKDir()
 	QString new_dir = FileDialog::getExistingDirectory( this,
 				tr( "Choose STK rawwave directory" ),
 							m_stkDir );
-	if( new_dir != QString::null )
+	if( new_dir != QString() )
 	{
 		m_stkLineEdit->setText( new_dir );
 	}
@@ -1410,7 +1406,7 @@ void SetupDialog::openDefaultSoundfont()
 				tr( "Choose default SoundFont" ), m_defaultSoundfont, 
 				"SoundFont2 Files (*.sf2)" );
 	
-	if( new_file != QString::null )
+	if( new_file != QString() )
 	{
 		m_sfLineEdit->setText( new_file );
 	}
@@ -1443,7 +1439,7 @@ void SetupDialog::openBackgroundArtwork()
 			tr( "Choose background artwork" ), dir, 
 			"Image Files (" + fileTypes + ")" );
 	
-	if( new_file != QString::null )
+	if( new_file != QString() )
 	{
 		m_baLineEdit->setText( new_file );
 	}

src/gui/StringPairDrag.cpp

@@ -40,7 +40,7 @@ StringPairDrag::StringPairDrag( const QString & _key, const QString & _value,
 {
 	if( _icon.isNull() && _w )
 	{
-		setPixmap( QPixmap::grabWidget( _w ).scaled(
+		setPixmap( _w->grab().scaled(
 						64, 64,
 						Qt::KeepAspectRatio,
 						Qt::SmoothTransformation ) );

src/gui/SubWindow.cpp

@@ -52,7 +52,7 @@ SubWindow::SubWindow( QWidget *parent, Qt::WindowFlags windowFlags ) :
 	m_borderColor = Qt::black;
 
 	// close, maximize and restore (after maximizing) buttons
-	m_closeBtn = new QPushButton( embed::getIconPixmap( "close" ), QString::null, this );
+	m_closeBtn = new QPushButton( embed::getIconPixmap( "close" ), QString(), this );
 	m_closeBtn->resize( m_buttonSize );
 	m_closeBtn->setFocusPolicy( Qt::NoFocus );
 	m_closeBtn->setCursor( Qt::ArrowCursor );
@@ -60,7 +60,7 @@ SubWindow::SubWindow( QWidget *parent, Qt::WindowFlags windowFlags ) :
 	m_closeBtn->setToolTip( tr( "Close" ) );
 	connect( m_closeBtn, SIGNAL( clicked( bool ) ), this, SLOT( close() ) );
 
-	m_maximizeBtn = new QPushButton( embed::getIconPixmap( "maximize" ), QString::null, this );
+	m_maximizeBtn = new QPushButton( embed::getIconPixmap( "maximize" ), QString(), this );
 	m_maximizeBtn->resize( m_buttonSize );
 	m_maximizeBtn->setFocusPolicy( Qt::NoFocus );
 	m_maximizeBtn->setCursor( Qt::ArrowCursor );
@@ -68,7 +68,7 @@ SubWindow::SubWindow( QWidget *parent, Qt::WindowFlags windowFlags ) :
 	m_maximizeBtn->setToolTip( tr( "Maximize" ) );
 	connect( m_maximizeBtn, SIGNAL( clicked( bool ) ), this, SLOT( showMaximized() ) );
 
-	m_restoreBtn = new QPushButton( embed::getIconPixmap( "restore" ), QString::null, this );
+	m_restoreBtn = new QPushButton( embed::getIconPixmap( "restore" ), QString(), this );
 	m_restoreBtn->resize( m_buttonSize );
 	m_restoreBtn->setFocusPolicy( Qt::NoFocus );
 	m_restoreBtn->setCursor( Qt::ArrowCursor );

src/gui/TimeLineWidget.cpp

@@ -40,11 +40,6 @@
 #include "SongEditor.h"
 
 
-#if QT_VERSION < 0x040800
-#define MiddleButton MidButton
-#endif
-
-
 QPixmap * TimeLineWidget::s_posMarkerPixmap = NULL;
 
 TimeLineWidget::TimeLineWidget( const int xoff, const int yoff, const float ppt,

src/gui/dialogs/FileDialog.cpp

@@ -35,7 +35,7 @@ FileDialog::FileDialog( QWidget *parent, const QString &caption,
 					   const QString &directory, const QString &filter ) :
 	QFileDialog( parent, caption, directory, filter )
 {
-#if (QT_VERSION >= 0x040806 && QT_VERSION < 0x050000) || QT_VERSION > 0x050200
+#if QT_VERSION > 0x050200
 	setOption( QFileDialog::DontUseCustomDirectoryIcons );
 #endif
 
@@ -43,27 +43,15 @@ FileDialog::FileDialog( QWidget *parent, const QString &caption,
 
 	// Add additional locations to the sidebar
 	QList<QUrl> urls = sidebarUrls();
-#if QT_VERSION >= 0x050000
 	urls << QUrl::fromLocalFile( QStandardPaths::writableLocation( QStandardPaths::DesktopLocation ) );
-#else
-	urls << QUrl::fromLocalFile( QDesktopServices::storageLocation( QDesktopServices::DesktopLocation ) );
-#endif
 	// Find downloads directory
 	QDir downloadDir( QDir::homePath() + "/Downloads" );
 	if ( ! downloadDir.exists() )
-#if QT_VERSION >= 0x050000
 		downloadDir = QStandardPaths::writableLocation( QStandardPaths::DownloadLocation );
-#else
-		downloadDir = QDesktopServices::storageLocation( QDesktopServices::DocumentsLocation ) + "/Downloads";
-#endif
 	if ( downloadDir.exists() )
 		urls << QUrl::fromLocalFile( downloadDir.absolutePath() );
 
-#if QT_VERSION >= 0x050000
 	urls << QUrl::fromLocalFile( QStandardPaths::writableLocation( QStandardPaths::MusicLocation ) );
-#else
-	urls << QUrl::fromLocalFile( QDesktopServices::storageLocation( QDesktopServices::MusicLocation ) );
-#endif
 	urls << QUrl::fromLocalFile( ConfigManager::inst()->workingDir() );
 
 	// Add `/Volumes` directory on OS X systems, this allows the user to browse

src/gui/editors/PianoRoll.cpp

@@ -64,10 +64,6 @@
 #include "TimeLineWidget.h"
 
 
-#if QT_VERSION < 0x040800
-#define MiddleButton MidButton
-#endif
-
 using std::move;
 
 typedef AutomationPattern::timeMap timeMap;
@@ -517,7 +513,7 @@ void PianoRoll::markSemiTone( int i )
 			break;
 		case stmaMarkCurrentSemiTone:
 		{
-			QList<int>::iterator it = qFind( m_markedSemiTones.begin(), m_markedSemiTones.end(), key );
+			QList<int>::iterator it = std::find( m_markedSemiTones.begin(), m_markedSemiTones.end(), key );
 			if( it != m_markedSemiTones.end() )
 			{
 				m_markedSemiTones.erase( it );
@@ -538,7 +534,7 @@ void PianoRoll::markSemiTone( int i )
 				QList<int>::iterator i;
 				for (int ix = 0; ix < aok.size(); ++ix)
 				{
-					i = qFind(m_markedSemiTones.begin(), m_markedSemiTones.end(), aok.at(ix));
+					i = std::find(m_markedSemiTones.begin(), m_markedSemiTones.end(), aok.at(ix));
 					m_markedSemiTones.erase(i);
 				}
 			}
@@ -592,7 +588,7 @@ void PianoRoll::markSemiTone( int i )
 			;
 	}
 
-	qSort( m_markedSemiTones.begin(), m_markedSemiTones.end(), qGreater<int>() );
+	std::sort( m_markedSemiTones.begin(), m_markedSemiTones.end(), std::greater<int>() );
 	QList<int>::iterator new_end = std::unique( m_markedSemiTones.begin(), m_markedSemiTones.end() );
 	m_markedSemiTones.erase( new_end, m_markedSemiTones.end() );
 }

src/gui/widgets/AutomatableButton.cpp

@@ -220,7 +220,7 @@ void automatableButtonGroup::addButton( AutomatableButton * _btn )
 
 void automatableButtonGroup::removeButton( AutomatableButton * _btn )
 {
-	m_buttons.erase( qFind( m_buttons.begin(), m_buttons.end(), _btn ) );
+	m_buttons.erase( std::find( m_buttons.begin(), m_buttons.end(), _btn ) );
 	_btn->m_group = NULL;
 }
 

src/gui/widgets/ComboBox.cpp

@@ -47,7 +47,7 @@ const int CB_ARROW_BTN_WIDTH = 20;
 
 ComboBox::ComboBox( QWidget * _parent, const QString & _name ) :
 	QWidget( _parent ),
-	IntModelView( new ComboBoxModel( NULL, QString::null, true ), this ),
+	IntModelView( new ComboBoxModel( NULL, QString(), true ), this ),
 	m_menu( this ),
 	m_pressed( false )
 {

src/gui/widgets/ControllerRackView.cpp

@@ -176,7 +176,7 @@ void ControllerRackView::onControllerRemoved( Controller * removedController )
 
 	if (viewOfRemovedController )
 	{
-		m_controllerViews.erase( qFind( m_controllerViews.begin(),
+		m_controllerViews.erase( std::find( m_controllerViews.begin(),
 					m_controllerViews.end(), viewOfRemovedController ) );
 
 		delete viewOfRemovedController;

src/gui/widgets/EffectRackView.cpp

@@ -126,7 +126,7 @@ void EffectRackView::moveDown( EffectView* view )
 	if( view != m_effectViews.last() )
 	{
 		// moving next effect up is the same
-		moveUp( *( qFind( m_effectViews.begin(), m_effectViews.end(), view ) + 1 ) );
+		moveUp( *( std::find( m_effectViews.begin(), m_effectViews.end(), view ) + 1 ) );
 	}
 }
 
@@ -136,7 +136,7 @@ void EffectRackView::moveDown( EffectView* view )
 void EffectRackView::deletePlugin( EffectView* view )
 {
 	Effect * e = view->effect();
-	m_effectViews.erase( qFind( m_effectViews.begin(), m_effectViews.end(), view ) );
+	m_effectViews.erase( std::find( m_effectViews.begin(), m_effectViews.end(), view ) );
 	delete view;
 	fxChain()->removeEffect( e );
 	e->deleteLater();

src/gui/widgets/Graph.cpp

@@ -510,7 +510,7 @@ void graphModel::setSampleAt( int x, float val )
 
 void graphModel::setSamples( const float * _samples )
 {
-	qCopy( _samples, _samples + length(), m_samples.begin());
+	std::copy( _samples, _samples + length(), m_samples.begin());
 
 	emit samplesChanged( 0, length()-1 );
 }

src/gui/widgets/LadspaControlView.cpp

@@ -60,7 +60,7 @@ LadspaControlView::LadspaControlView( QWidget * _parent,
 		case TOGGLED:
 		{
 			LedCheckBox * toggle = new LedCheckBox(
-				m_ctl->port()->name, this, QString::null, LedCheckBox::Green );
+				m_ctl->port()->name, this, QString(), LedCheckBox::Green );
 			toggle->setModel( m_ctl->toggledModel() );
 			layout->addWidget( toggle );
 			if( link != NULL )

src/tracks/InstrumentTrack.cpp

@@ -496,7 +496,7 @@ QString InstrumentTrack::instrumentName() const
 	{
 		return m_instrument->displayName();
 	}
-	return QString::null;
+	return QString();
 }