VST preset preview (#5441)

* Enable vestige presets preview.

* Don't destroy vestige instrument on every preset change.

* Don't reload VST dll plugin when it's not necessary. Always hide plugin UI in preview mode.

* Don't remove other instruments in preview mode, don't send instrument change signal.

* Minor changes

* Add a change I missed

Co-authored-by: Hyunjin Song <tteu.ingog@gmail.com>

include/InstrumentTrack.h

@@ -214,6 +214,10 @@ public:
 
 	void setPreviewMode( const bool );
 
+	bool isPreviewMode() const
+	{
+		return m_previewMode;
+	}
 
 signals:
 	void instrumentChanged();
@@ -230,6 +234,9 @@ protected:
 		return "instrumenttrack";
 	}
 
+	// get the name of the instrument in the saved data
+	QString getSavedInstrumentName(const QDomElement & thisElement) const;
+
 
 protected slots:
 	void updateBaseNote();

plugins/vestige/vestige.cpp

@@ -198,9 +198,15 @@ void vestigeInstrument::loadSettings( const QDomElement & _this )
 	{
 		m_plugin->loadSettings( _this );
 
-		if ( _this.attribute( "guivisible" ).toInt() ) {
+		if (instrumentTrack() != NULL && instrumentTrack()->isPreviewMode())
+		{
+			m_plugin->hideUI();
+		}
+		else if (_this.attribute( "guivisible" ).toInt())
+		{
 			m_plugin->showUI();
-		} else {
+		} else
+		{
 			m_plugin->hideUI();
 		}
 
@@ -322,12 +328,17 @@ void vestigeInstrument::loadFile( const QString & _file )
 {
 	m_pluginMutex.lock();
 	const bool set_ch_name = ( m_plugin != NULL &&
-        	instrumentTrack()->name() == m_plugin->name() ) ||
-            	instrumentTrack()->name() == InstrumentTrack::tr( "Default preset" ) ||
-            	instrumentTrack()->name() == displayName();
+			instrumentTrack()->name() == m_plugin->name() ) ||
+			instrumentTrack()->name() == InstrumentTrack::tr( "Default preset" ) ||
+			instrumentTrack()->name() == displayName();
 
 	m_pluginMutex.unlock();
 
+	// if the same is loaded don't load again (for preview)
+	if (instrumentTrack() != NULL && instrumentTrack()->isPreviewMode() &&
+			m_pluginDLL == SampleBuffer::tryToMakeRelative( _file ))
+		return;
+
 	if ( m_plugin != NULL )
 	{
 		closePlugin();
@@ -354,8 +365,11 @@ void vestigeInstrument::loadFile( const QString & _file )
 		return;
 	}
 
-	m_plugin->createUI(nullptr);
-	m_plugin->showUI();
+	if ( !(instrumentTrack() != NULL && instrumentTrack()->isPreviewMode()))
+	{
+		m_plugin->createUI(nullptr);
+		m_plugin->showUI();
+	}
 
 	if( set_ch_name )
 	{

src/core/PresetPreviewPlayHandle.cpp

@@ -156,19 +156,9 @@ PresetPreviewPlayHandle::PresetPreviewPlayHandle( const QString & _preset_file,
 			dataFileCreated = true;
 		}
 
-		// vestige previews are bug prone; fallback on 3xosc with volume of 0
-		// without an instrument in preview track, it will segfault
-		if(dataFile->content().elementsByTagName( "vestige" ).length() == 0 )
-		{
-			s_previewTC->previewInstrumentTrack()->
-					loadTrackSpecificSettings(
-						dataFile->content().firstChild().toElement() );
-		}
-		else
-		{
-			s_previewTC->previewInstrumentTrack()->loadInstrument("tripleoscillator");
-			s_previewTC->previewInstrumentTrack()->setVolume( 0 );
-		}
+		s_previewTC->previewInstrumentTrack()->loadTrackSpecificSettings(
+					dataFile->content().firstChild().toElement());
+
 		if( dataFileCreated )
 		{
 			delete dataFile;

src/tracks/InstrumentTrack.cpp

@@ -771,7 +771,11 @@ void InstrumentTrack::saveTrackSpecificSettings( QDomDocument& doc, QDomElement
 
 void InstrumentTrack::loadTrackSpecificSettings( const QDomElement & thisElement )
 {
-	silenceAllNotes( true );
+	// don't delete instrument in preview mode if it's the same
+	// we can't do this for other situations due to some issues with linked models
+	bool reuseInstrument = m_previewMode && m_instrument && m_instrument->nodeName() == getSavedInstrumentName(thisElement);
+	// remove the InstrumentPlayHandle if and only if we need to delete the instrument
+	silenceAllNotes(!reuseInstrument);
 
 	lock();
 
@@ -815,33 +819,39 @@ void InstrumentTrack::loadTrackSpecificSettings( const QDomElement & thisElement
 			{
 				m_audioPort.effects()->restoreState( node.toElement() );
 			}
-			else if( node.nodeName() == "instrument" )
+			else if(node.nodeName() == "instrument")
 			{
 				typedef Plugin::Descriptor::SubPluginFeatures::Key PluginKey;
-				PluginKey key( node.toElement().elementsByTagName( "key" ).item( 0 ).toElement() );
+				PluginKey key(node.toElement().elementsByTagName("key").item(0).toElement());
 
-				delete m_instrument;
-				m_instrument = NULL;
-				m_instrument = Instrument::instantiate(
-					node.toElement().attribute( "name" ), this, &key);
-				m_instrument->restoreState( node.firstChildElement() );
-
-				emit instrumentChanged();
+				if (reuseInstrument)
+				{
+					m_instrument->restoreState(node.firstChildElement());
+				}
+				else
+				{
+					delete m_instrument;
+					m_instrument = NULL;
+					m_instrument = Instrument::instantiate(
+						node.toElement().attribute("name"), this, &key);
+					m_instrument->restoreState(node.firstChildElement());
+					emit instrumentChanged();
+				}
 			}
 			// compat code - if node-name doesn't match any known
 			// one, we assume that it is an instrument-plugin
 			// which we'll try to load
-			else if( AutomationPattern::classNodeName() != node.nodeName() &&
+			else if(AutomationPattern::classNodeName() != node.nodeName() &&
 					ControllerConnection::classNodeName() != node.nodeName() &&
-					!node.toElement().hasAttribute( "id" ) )
+					!node.toElement().hasAttribute( "id" ))
 			{
 				delete m_instrument;
 				m_instrument = NULL;
 				m_instrument = Instrument::instantiate(
 					node.nodeName(), this, nullptr, true);
-				if( m_instrument->nodeName() == node.nodeName() )
+				if (m_instrument->nodeName() == node.nodeName())
 				{
-					m_instrument->restoreState( node.toElement() );
+					m_instrument->restoreState(node.toElement());
 				}
 				emit instrumentChanged();
 			}
@@ -863,6 +873,19 @@ void InstrumentTrack::setPreviewMode( const bool value )
 
 
 
+QString InstrumentTrack::getSavedInstrumentName(const QDomElement &thisElement) const
+{
+	QDomElement elem = thisElement.firstChildElement("instrument");
+	if (!elem.isNull())
+	{
+		return elem.attribute("name");
+	}
+	return "";
+}
+
+
+
+
 Instrument * InstrumentTrack::loadInstrument(const QString & _plugin_name,
 	const Plugin::Descriptor::SubPluginFeatures::Key *key, bool keyFromDnd)
 {