Add option to show note values on notes in Piano Roll (LMMS#4466)

Add the option to show note values on notes in the Piano Roll. This
functionality is currently coupled with the option "Enable note labels
in piano roll" which can be found in the main menu.

The notes are rendered at about 80% of the notes height. They are only
rendered if they fit on the whole note and if the font does not become
too tiny.

Enable the configuration of the note value text's color via the
stylesheets and set the value to white for both shipped themes.

Other changes:
* Clean up some warnings about old school casts and implicit casts.

data/themes/classic/style.css

@@ -123,6 +123,7 @@ PianoRoll {
 	qproperty-backgroundShade: rgba( 255, 255, 255, 10 );
 	qproperty-noteModeColor: rgb( 255, 255, 255 );
 	qproperty-noteColor: rgb( 119, 199, 216 );
+        qproperty-noteTextColor: rgb( 255, 255, 255 );
 	qproperty-noteOpacity: 128;
 	qproperty-noteBorders: true; /* boolean property, set false to have borderless notes */
 	qproperty-selectedNoteColor: rgb( 0, 125, 255 );

data/themes/default/style.css

@@ -142,6 +142,7 @@ PianoRoll {
 	qproperty-backgroundShade: rgba(255, 255, 255, 10);
 	qproperty-noteModeColor: #0bd556;
 	qproperty-noteColor: #0bd556;
+        qproperty-noteTextColor: #ffffff;
 	qproperty-noteOpacity: 165;
 	qproperty-noteBorders: false; /* boolean property, set false to have borderless notes */
 	qproperty-selectedNoteColor: #064d79;

include/PianoRoll.h

@@ -59,6 +59,7 @@ class PianoRoll : public QWidget
 	Q_PROPERTY( QColor lineColor READ lineColor WRITE setLineColor )
 	Q_PROPERTY( QColor noteModeColor READ noteModeColor WRITE setNoteModeColor )
 	Q_PROPERTY( QColor noteColor READ noteColor WRITE setNoteColor )
+	Q_PROPERTY( QColor noteTextColor READ noteTextColor WRITE setNoteTextColor )
 	Q_PROPERTY( QColor barColor READ barColor WRITE setBarColor )
 	Q_PROPERTY( QColor selectedNoteColor READ selectedNoteColor WRITE setSelectedNoteColor )
 	Q_PROPERTY( QColor textColor READ textColor WRITE setTextColor )
@@ -122,6 +123,8 @@ class PianoRoll : public QWidget
 	void setNoteModeColor( const QColor & c );
 	QColor noteColor() const;
 	void setNoteColor( const QColor & c );
+	QColor noteTextColor() const;
+	void setNoteTextColor( const QColor & c );
 	QColor barColor() const;
 	void setBarColor( const QColor & c );
 	QColor selectedNoteColor() const;
@@ -157,8 +160,8 @@ class PianoRoll : public QWidget
 
 	int getKey( int y ) const;
 	static void drawNoteRect( QPainter & p, int x, int y,
-					int  width, const Note * n, const QColor & noteCol,
-					const QColor & selCol, const int noteOpc, const bool borderless );
+					int  width, const Note * n, const QColor & noteCol, const QColor & noteTextColor,
+					const QColor & selCol, const int noteOpc, const bool borderless, bool drawNoteName );
 	void removeSelection();
 	void selectAll();
 	NoteVector getSelectedNotes();
@@ -384,6 +387,7 @@ protected slots:
 	QColor m_lineColor;
 	QColor m_noteModeColor;
 	QColor m_noteColor;
+	QColor m_noteTextColor;
 	QColor m_barColor;
 	QColor m_selectedNoteColor;
 	QColor m_textColor;

src/gui/editors/PianoRoll.cpp

@@ -751,6 +751,12 @@ QColor PianoRoll::noteColor() const
 void PianoRoll::setNoteColor( const QColor & c )
 { m_noteColor = c; }
 
+QColor PianoRoll::noteTextColor() const
+{ return m_noteTextColor; }
+
+void PianoRoll::setNoteTextColor( const QColor & c )
+{ m_noteTextColor = c; }
+
 QColor PianoRoll::barColor() const
 { return m_barColor; }
 
@@ -810,8 +816,8 @@ void PianoRoll::setBackgroundShade( const QColor & c )
 
 
 void PianoRoll::drawNoteRect( QPainter & p, int x, int y,
-				int width, const Note * n, const QColor & noteCol,
-				const QColor & selCol, const int noteOpc, const bool borders )
+				int width, const Note * n, const QColor & noteCol, const QColor & noteTextColor,
+				const QColor & selCol, const int noteOpc, const bool borders, bool drawNoteName )
 {
 	++x;
 	++y;
@@ -822,15 +828,19 @@ void PianoRoll::drawNoteRect( QPainter & p, int x, int y,
 		width = 2;
 	}
 
-	int volVal = qMin( 255, 100 + (int) ( ( (float)( n->getVolume() - MinVolume ) ) /
-			( (float)( MaxVolume - MinVolume ) ) * 155.0f) );
-	float rightPercent = qMin<float>( 1.0f,
-			( (float)( n->getPanning() - PanningLeft ) ) /
-			( (float)( PanningRight - PanningLeft ) ) * 2.0f );
+	// Volume
+	float const volumeRange = static_cast<float>(MaxVolume - MinVolume);
+	float const volumeSpan = static_cast<float>(n->getVolume() - MinVolume);
+	float const volumeRatio = volumeSpan / volumeRange;
+	int volVal = qMin( 255, 100 + static_cast<int>( volumeRatio * 155.0f) );
 
-	float leftPercent = qMin<float>( 1.0f,
-			( (float)( PanningRight - n->getPanning() ) ) /
-			( (float)( PanningRight - PanningLeft ) ) * 2.0f );
+	// Panning
+	float const panningRange = static_cast<float>(PanningRight - PanningLeft);
+	float const leftPanSpan = static_cast<float>(PanningRight - n->getPanning());
+	float const rightPanSpan = static_cast<float>(n->getPanning() - PanningLeft);
+
+	float leftPercent = qMin<float>( 1.0f, leftPanSpan / panningRange * 2.0f );
+	float rightPercent = qMin<float>( 1.0f, rightPanSpan / panningRange * 2.0f );
 
 	QColor col = QColor( noteCol );
 	QPen pen;
@@ -848,9 +858,9 @@ void PianoRoll::drawNoteRect( QPainter & p, int x, int y,
 	// adjust note to make it a bit faded if it has a lower volume
 	// in stereo using gradients
 	QColor lcol = QColor::fromHsv( col.hue(), col.saturation(),
-						volVal * leftPercent, noteOpc );
+				       static_cast<int>(volVal * leftPercent), noteOpc );
 	QColor rcol = QColor::fromHsv( col.hue(), col.saturation(),
-						volVal * rightPercent, noteOpc );
+				       static_cast<int>(volVal * rightPercent), noteOpc );
 
 	QLinearGradient gradient( x, y, x, y + noteHeight );
 	gradient.setColorAt( 0, rcol );
@@ -868,6 +878,35 @@ void PianoRoll::drawNoteRect( QPainter & p, int x, int y,
 
 	p.drawRect( x, y, noteWidth, noteHeight );
 
+	// Draw note key text
+	if (drawNoteName)
+	{
+		p.save();
+		int const noteTextHeight = static_cast<int>(noteHeight * 0.8);
+		if (noteTextHeight > 6)
+		{
+			QString noteKeyString = getNoteString(n->key());
+
+			QFont noteFont(p.font());
+			noteFont.setPixelSize(noteTextHeight);
+			QFontMetrics fontMetrics(noteFont);
+			QSize textSize = fontMetrics.size(Qt::TextSingleLine, noteKeyString);
+
+			int const distanceToBorder = 2;
+			int const xOffset = borderWidth + distanceToBorder;
+
+			if (textSize.width() < noteWidth - xOffset)
+			{
+				p.setPen(noteTextColor);
+				p.setFont(noteFont);
+				QPoint textStart(x + xOffset, y + (noteTextHeight + (noteHeight - noteTextHeight) / 2));
+
+				p.drawText(textStart, noteKeyString);
+			}
+		}
+		p.restore();
+	}
+
 	// draw the note endmark, to hint the user to resize
 	p.setBrush( col );
 	if( width > 2 )
@@ -3022,8 +3061,8 @@ void PianoRoll::paintEvent(QPaintEvent * pe )
 				// note
 				drawNoteRect( p, x + WHITE_KEY_WIDTH,
 						y_base - key * KEY_LINE_HEIGHT,
-								note_width, note, noteColor(), selectedNoteColor(),
-							 	noteOpacity(), noteBorders() );
+								note_width, note, noteColor(), noteTextColor(), selectedNoteColor(),
+								noteOpacity(), noteBorders(), drawNoteNames );
 			}
 
 			// draw note editing stuff