Faders with a dB scale (instead of linear/percentage)

include/Fader.h

@@ -74,8 +74,8 @@ class LMMS_EXPORT Fader : public QWidget, public FloatModelView
 	Q_PROPERTY(bool renderUnityLine READ getRenderUnityLine WRITE setRenderUnityLine)
 	Q_PROPERTY(QColor unityMarker MEMBER m_unityMarker)
 
-	Fader(FloatModel* model, const QString& name, QWidget* parent);
-	Fader(FloatModel* model, const QString& name, QWidget* parent, const QPixmap& knob);
+	Fader(FloatModel* model, const QString& name, QWidget* parent, bool modelIsLinear = true);
+	Fader(FloatModel* model, const QString& name, QWidget* parent, const QPixmap& knob, bool modelIsLinear = true);
 	~Fader() override = default;
 
 	void setPeak_L(float fPeak);
@@ -93,6 +93,17 @@ class LMMS_EXPORT Fader : public QWidget, public FloatModelView
 	inline bool getRenderUnityLine() const { return m_renderUnityLine; }
 	inline void setRenderUnityLine(bool value = true) { m_renderUnityLine = value; }
 
+	enum class AdjustmentDirection
+	{
+		Up,
+		Down
+	};
+
+	void adjust(const Qt::KeyboardModifiers & modifiers, AdjustmentDirection direction);
+	void adjustByDecibelDelta(float value);
+
+	void adjustByDialog();
+
 	void setDisplayConversion(bool b)
 	{
 		m_conversionFactor = b ? 100.0 : 1.0;
@@ -118,18 +129,34 @@ class LMMS_EXPORT Fader : public QWidget, public FloatModelView
 	void paintEvent(QPaintEvent* ev) override;
 
 	void paintLevels(QPaintEvent* ev, QPainter& painter, bool linear = false);
-
-	int knobPosY() const
-	{
-		float fRange = model()->maxValue() - model()->minValue();
-		float realVal = model()->value() - model()->minValue();
-
-		return height() - ((height() - m_knob.height()) * (realVal / fRange));
-	}
+	void paintFaderTicks(QPainter& painter);
+
+	float determineAdjustmentDelta(const Qt::KeyboardModifiers & modifiers) const;
+	void adjustModelByDBDelta(float value);
+
+	int calculateKnobPosYFromModel() const;
+	void setVolumeByLocalPixelValue(int y);
+
+	/**
+	 * @brief Computes the scaled ratio between the maximum dB value supported by the model and the minimum
+	 * dB value that's supported by the fader from the given actual dB value.
+	 * 
+	 * If the provided input value lies inside the aforementioned interval then the result will be
+	 * a value between 0 (value == minimum value) and 1 (value == maximum model value).
+	 * If you look at the graphical representation of the fader then 0 represents a point at the bottom
+	 * of the fader and 1 a point at the top of the fader.
+	 * The ratio is scaled by an internal exponent which is an implementation detail that cannot be
+	 * changed for now.
+	 */
+	float computeScaledRatio(float dBValue) const;
 
 	void setPeak(float fPeak, float& targetPeak, float& persistentPeak, QElapsedTimer& lastPeakTimer);
 
 	void updateTextFloat();
+	void modelValueChanged();
+	QString getModelValueAsDbString() const;
+
+	bool modelIsLinear() const { return m_modelIsLinear; }
 
 	// Private members
 private:
@@ -145,10 +172,16 @@ class LMMS_EXPORT Fader : public QWidget, public FloatModelView
 
 	QPixmap m_knob {embed::getIconPixmap("fader_knob")};
 
-	bool m_levelsDisplayedInDBFS {true};
+	/**
+	 * @brief Stores the offset to the knob center when the user drags the fader knob
+	 * 
+	 * This is needed to make it feel like the users drag the knob without it
+	 * jumping immediately to the click position.
+	 */
+	int m_knobCenterOffset {0};
 
-	int m_moveStartPoint {-1};
-	float m_startValue {0.};
+	bool m_levelsDisplayedInDBFS {true};
+	bool m_modelIsLinear {false};
 
 	static SimpleTextFloat* s_textFloat;
 

include/MixerChannelView.h

@@ -82,6 +82,8 @@ class MixerChannelView : public QWidget
 	QColor strokeInnerInactive() const { return m_strokeInnerInactive; }
 	void setStrokeInnerInactive(const QColor& c) { m_strokeInnerInactive = c; }
 
+	Fader* fader() const { return m_fader; }
+
 public slots:
 	void renameChannel();
 	void resetColor();

include/SetupDialog.h

@@ -72,10 +72,10 @@ protected slots:
 
 private slots:
 	// General settings widget.
-	void toggleDisplaydBFS(bool enabled);
 	void toggleTooltips(bool enabled);
 	void toggleDisplayWaveform(bool enabled);
 	void toggleNoteLabels(bool enabled);
+	void toggleShowFaderTicks(bool enabled);
 	void toggleCompactTrackButtons(bool enabled);
 	void toggleOneInstrumentTrackWindow(bool enabled);
 	void toggleSideBarOnRight(bool enabled);
@@ -134,10 +134,10 @@ private slots:
 	TabBar * m_tabBar;
 
 	// General settings widgets.
-	bool m_displaydBFS;
 	bool m_tooltips;
 	bool m_displayWaveform;
 	bool m_printNoteLabels;
+	bool m_showFaderTicks;
 	bool m_compactTrackButtons;
 	bool m_oneInstrumentTrackWindow;
 	bool m_sideBarOnRight;

plugins/CrossoverEQ/CrossoverEQControlDialog.cpp

@@ -70,25 +70,25 @@ CrossoverEQControlDialog::CrossoverEQControlDialog( CrossoverEQControls * contro
 	QPixmap const fader_knob(PLUGIN_NAME::getIconPixmap("fader_knob2"));
 
 	// faders
-	auto gain1 = new Fader(&controls->m_gain1, tr("Band 1 gain"), this, fader_knob);
+	auto gain1 = new Fader(&controls->m_gain1, tr("Band 1 gain"), this, fader_knob, false);
 	gain1->move( 7, 56 );
 	gain1->setDisplayConversion( false );
 	gain1->setHintText( tr( "Band 1 gain:" ), " dBFS" );
 	gain1->setRenderUnityLine(false);
 
-	auto gain2 = new Fader(&controls->m_gain2, tr("Band 2 gain"), this, fader_knob);
+	auto gain2 = new Fader(&controls->m_gain2, tr("Band 2 gain"), this, fader_knob, false);
 	gain2->move( 47, 56 );
 	gain2->setDisplayConversion( false );
 	gain2->setHintText( tr( "Band 2 gain:" ), " dBFS" );
 	gain2->setRenderUnityLine(false);
 
-	auto gain3 = new Fader(&controls->m_gain3, tr("Band 3 gain"), this, fader_knob);
+	auto gain3 = new Fader(&controls->m_gain3, tr("Band 3 gain"), this, fader_knob, false);
 	gain3->move( 87, 56 );
 	gain3->setDisplayConversion( false );
 	gain3->setHintText( tr( "Band 3 gain:" ), " dBFS" );
 	gain3->setRenderUnityLine(false);
 
-	auto gain4 = new Fader(&controls->m_gain4, tr("Band 4 gain"), this, fader_knob);
+	auto gain4 = new Fader(&controls->m_gain4, tr("Band 4 gain"), this, fader_knob, false);
 	gain4->move( 127, 56 );
 	gain4->setDisplayConversion( false );
 	gain4->setHintText( tr( "Band 4 gain:" ), " dBFS" );

plugins/Eq/EqFader.h

@@ -43,7 +43,7 @@ class EqFader : public Fader
 	Q_OBJECT
 public:
 	EqFader( FloatModel * model, const QString & name, QWidget * parent,  float* lPeak, float* rPeak ) :
-		Fader( model, name, parent )
+		Fader(model, name, parent, false)
 	{
 		setMinimumSize( 23, 116 );
 		setMaximumSize( 23, 116 );

src/gui/MainWindow.cpp

@@ -1099,13 +1099,7 @@ void MainWindow::updateViewMenu()
 	// Here we should put all look&feel -stuff from configmanager
 	// that is safe to change on the fly. There is probably some
 	// more elegant way to do this.
-	auto qa = new QAction(tr("Volume as dBFS"), this);
-	qa->setData("displaydbfs");
-	qa->setCheckable( true );
-	qa->setChecked( ConfigManager::inst()->value( "app", "displaydbfs" ).toInt() );
-	m_viewMenu->addAction(qa);
-
-	qa = new QAction(tr( "Smooth scroll" ), this);
+	auto qa = new QAction(tr("Smooth scroll"), this);
 	qa->setData("smoothscroll");
 	qa->setCheckable( true );
 	qa->setChecked( ConfigManager::inst()->value( "ui", "smoothscroll" ).toInt() );
@@ -1135,12 +1129,7 @@ void MainWindow::updateConfig( QAction * _who )
 	QString tag = _who->data().toString();
 	bool checked = _who->isChecked();
 
-	if( tag == "displaydbfs" )
-	{
-		ConfigManager::inst()->setValue( "app", "displaydbfs",
-						 QString::number(checked) );
-	}
-	else if ( tag == "tooltips" )
+	if (tag == "tooltips")
 	{
 		ConfigManager::inst()->setValue( "tooltips", "disabled",
 						 QString::number(!checked) );

src/gui/MixerView.cpp

@@ -479,51 +479,79 @@
 
 
 
 void MixerView::keyPressEvent(QKeyEvent * e)
 {
+	auto adjustCurrentFader = [this](const Qt::KeyboardModifiers& modifiers, Fader::AdjustmentDirection direction)
+	{
+		auto* mixerChannel = currentMixerChannel();
+
+		if (mixerChannel)
+		{
+			mixerChannel->fader()->adjust(modifiers, direction);
+		}
+	};
+
 	switch(e->key())
 	{
 		case Qt::Key_Delete:
 			deleteChannel(m_currentMixerChannel->channelIndex());
 			break;
 		case Qt::Key_Left:
 			if (e->modifiers() & Qt::AltModifier)
 			{
 				moveChannelLeft(m_currentMixerChannel->channelIndex());
 			}
 			else
 			{
 				// select channel to the left
 				setCurrentMixerChannel(m_currentMixerChannel->channelIndex() - 1);
 			}
 			break;
 		case Qt::Key_Right:
 			if (e->modifiers() & Qt::AltModifier)
 			{
 				moveChannelRight(m_currentMixerChannel->channelIndex());
 			}
 			else
 			{
 				// select channel to the right
 				setCurrentMixerChannel(m_currentMixerChannel->channelIndex() + 1);
 			}
 			break;
+		case Qt::Key_Up:
+		case Qt::Key_Plus:
+			adjustCurrentFader(e->modifiers(), Fader::AdjustmentDirection::Up);
+			break;
+		case Qt::Key_Down:
+		case Qt::Key_Minus:
+			adjustCurrentFader(e->modifiers(), Fader::AdjustmentDirection::Down);
+			break;
 		case Qt::Key_Insert:
 			if (e->modifiers() & Qt::ShiftModifier)
 			{
 				addNewChannel();
 			}
 			break;
 		case Qt::Key_Enter:
 		case Qt::Key_Return:
 		case Qt::Key_F2:
 			renameChannel(m_currentMixerChannel->channelIndex());
 			break;
+		case Qt::Key_Space:
+			{
+				auto* mixerChannel = currentMixerChannel();
+
+				if (mixerChannel)
+				{
+					mixerChannel->fader()->adjustByDialog();
+				}
+			}
+			break;
 	}
 }
 
 
 
 void MixerView::closeEvent(QCloseEvent * ce)
  {
 	if (parentWidget())

src/gui/modals/SetupDialog.cpp

@@ -91,14 +91,14 @@ inline void labelWidget(QWidget * w, const QString & txt)
 
 
 SetupDialog::SetupDialog(ConfigTab tab_to_open) :
-	m_displaydBFS(ConfigManager::inst()->value(
-			"app", "displaydbfs").toInt()),
 	m_tooltips(!ConfigManager::inst()->value(
 			"tooltips", "disabled").toInt()),
 	m_displayWaveform(ConfigManager::inst()->value(
 			"ui", "displaywaveform").toInt()),
 	m_printNoteLabels(ConfigManager::inst()->value(
 			"ui", "printnotelabels").toInt()),
+	m_showFaderTicks(ConfigManager::inst()->value(
+			"ui", "showfaderticks").toInt()),
 	m_compactTrackButtons(ConfigManager::inst()->value(
 			"ui", "compacttrackbuttons").toInt()),
 	m_oneInstrumentTrackWindow(ConfigManager::inst()->value(
@@ -231,14 +231,14 @@ SetupDialog::SetupDialog(ConfigTab tab_to_open) :
 	QGroupBox * guiGroupBox = new QGroupBox(tr("Graphical user interface (GUI)"), generalControls);
 	QVBoxLayout * guiGroupLayout = new QVBoxLayout(guiGroupBox);
 
-	addCheckBox(tr("Display volume as dBFS "), guiGroupBox, guiGroupLayout,
-		m_displaydBFS, SLOT(toggleDisplaydBFS(bool)), true);
 	addCheckBox(tr("Enable tooltips"), guiGroupBox, guiGroupLayout,
 		m_tooltips, SLOT(toggleTooltips(bool)), true);
 	addCheckBox(tr("Enable master oscilloscope by default"), guiGroupBox, guiGroupLayout,
 		m_displayWaveform, SLOT(toggleDisplayWaveform(bool)), true);
 	addCheckBox(tr("Enable all note labels in piano roll"), guiGroupBox, guiGroupLayout,
 		m_printNoteLabels, SLOT(toggleNoteLabels(bool)), false);
+	addCheckBox(tr("Show fader ticks"), guiGroupBox, guiGroupLayout,
+		m_showFaderTicks, SLOT(toggleShowFaderTicks(bool)), false);
 	addCheckBox(tr("Enable compact track buttons"), guiGroupBox, guiGroupLayout,
 		m_compactTrackButtons, SLOT(toggleCompactTrackButtons(bool)), true);
 	addCheckBox(tr("Enable one instrument-track-window mode"), guiGroupBox, guiGroupLayout,
@@ -913,14 +913,14 @@ void SetupDialog::accept()
 	from taking mouse input, rendering the application unusable. */
 	QDialog::accept();
 
-	ConfigManager::inst()->setValue("app", "displaydbfs",
-					QString::number(m_displaydBFS));
 	ConfigManager::inst()->setValue("tooltips", "disabled",
 					QString::number(!m_tooltips));
 	ConfigManager::inst()->setValue("ui", "displaywaveform",
 					QString::number(m_displayWaveform));
 	ConfigManager::inst()->setValue("ui", "printnotelabels",
 					QString::number(m_printNoteLabels));
+	ConfigManager::inst()->setValue("ui", "showfaderticks",
+					QString::number(m_showFaderTicks));
 	ConfigManager::inst()->setValue("ui", "compacttrackbuttons",
 					QString::number(m_compactTrackButtons));
 	ConfigManager::inst()->setValue("ui", "oneinstrumenttrackwindow",
@@ -1003,12 +1003,6 @@ void SetupDialog::accept()
 
 // General settings slots.
 
-void SetupDialog::toggleDisplaydBFS(bool enabled)
-{
-	m_displaydBFS = enabled;
-}
-
-
 void SetupDialog::toggleTooltips(bool enabled)
 {
 	m_tooltips = enabled;
@@ -1026,6 +1020,10 @@ void SetupDialog::toggleNoteLabels(bool enabled)
 	m_printNoteLabels = enabled;
 }
 
+void SetupDialog::toggleShowFaderTicks(bool enabled)
+{
+	m_showFaderTicks = enabled;
+}
 
 void SetupDialog::toggleCompactTrackButtons(bool enabled)
 {