Add the ability to zoom and scroll horizontally in the pattern editor

include/PatternEditor.h

@@ -27,19 +27,24 @@
 
 #include "Editor.h"
 #include "TrackContainerView.h"
+#include "AutomatableModel.h"
+
+class QLabel;
+class QScrollBar;
 
 namespace lmms
 {
 
+class IntModel;
 class PatternStore;
 
 namespace gui
 {
 
+class AutomatableSlider;
 class ComboBox;
 class TimeLineWidget;
 
-
 class PatternEditor : public TrackContainerView
 {
 	Q_OBJECT
@@ -65,18 +70,44 @@ public slots:
 	void cloneClip();
 	void updateMaxSteps();
 
+signals:
+	void zoomLevelChanged();
+	void offsetValueChanged();
+	void zoomControlsVisibilityChanged(bool show);
+
+protected:
+	double getZoom() const
+	{
+		// The zoom level is calculated such as exactly one bar is visible when the zoom slider is at its maximum value,
+		// and the whole pattern is visible when the zoom slider is at its minimum value.
+		return 1 + m_zoomingModel->value() * (m_maxClipLength / TimePos::ticksPerBar() - 1)
+			/ static_cast<double>(m_zoomingModel->maxValue());
+	}
+
 protected slots:
 	void dropEvent(QDropEvent * de ) override;
 	void resizeEvent(QResizeEvent* de) override;
 	void updatePosition();
 	void updatePixelsPerBar();
+	void updateScrollBar();
 
 private:
+	void wheelEvent(QWheelEvent* we) override;
+
+	IntModel* m_zoomingModel;
+	QScrollBar* m_leftRightScroll;
+
 	PatternStore* m_ps;
 	TimeLineWidget* m_timeLine;
 	int m_trackHeadWidth;
 	tick_t m_maxClipLength;
 	void makeSteps( bool clone );
+
+private slots:
+	void zoomingChanged();
+	void horizontalScrollChanged();
+
+	friend class PatternEditorWindow;
 };
 
 
@@ -89,14 +120,27 @@ Q_OBJECT
 
 	QSize sizeHint() const override;
 
+	double zoomLevel() const
+	{
+		return m_editor->getZoom();
+	}
+
+	double horizontalScrollValue() const;
+
 	PatternEditor* m_editor;
 
 public slots:
 	void play() override;
 	void stop() override;
 
+	void showZoomControls(bool show);
+
 private:
+	AutomatableSlider* m_zoomingSlider;
 	ComboBox* m_patternComboBox;
+
+	QAction* m_zoomIconAction;
+	QAction* m_zoomSliderAction;
 };
 
 

src/gui/clips/ClipView.cpp

@@ -42,6 +42,7 @@
 #include "KeyboardShortcuts.h"
 #include "lmms_math.h"
 #include "MidiClipView.h"
+#include "PatternEditor.h"
 #include "PatternClip.h"
 #include "PatternStore.h"
 #include "Song.h"
@@ -119,6 +120,8 @@ ClipView::ClipView( Clip * clip,
 	connect( m_clip, SIGNAL(lengthChanged()),
 			this, SLOT(updateLength()));
 	connect(getGUI()->songEditor()->m_editor, &SongEditor::pixelsPerBarChanged, this, &ClipView::updateLength);
+	connect(getGUI()->patternEditor()->m_editor, &PatternEditor::zoomLevelChanged, this, &ClipView::updateLength);
+	connect(getGUI()->patternEditor()->m_editor, &PatternEditor::offsetValueChanged, this, &ClipView::updatePosition);
 	connect( m_clip, SIGNAL(positionChanged()),
 			this, SLOT(updatePosition()));
 	connect( m_clip, SIGNAL(destroyedClip()), this, SLOT(close()));
@@ -314,7 +317,7 @@ void ClipView::updateLength()
 {
 	if( fixedClips() )
 	{
-		setFixedWidth( parentWidget()->width() );
+		setFixedWidth(parentWidget()->width() * getGUI()->patternEditor()->zoomLevel());
 	}
 	else
 	{
@@ -337,10 +340,17 @@ void ClipView::updateLength()
  */
 void ClipView::updatePosition()
 {
-	m_trackView->getTrackContentWidget()->changePosition();
-	// moving a Clip can result in change of song-length etc.,
-	// therefore we update the track-container
-	m_trackView->trackContainerView()->update();
+	if (fixedClips())
+	{
+		move(-parentWidget()->width() * getGUI()->patternEditor()->horizontalScrollValue(), 0);
+	}
+	else
+	{	
+		m_trackView->getTrackContentWidget()->changePosition();
+		// moving a Clip can result in change of song-length etc.,
+		// therefore we update the track-container
+		m_trackView->trackContainerView()->update();
+	}
 }
 
 void ClipView::selectColor()

src/gui/clips/MidiClipView.cpp

@@ -498,7 +498,8 @@ void MidiClipView::wheelEvent(QWheelEvent * we)
 	const auto pos = we->position().toPoint();
 	if(m_clip->m_clipType == MidiClip::Type::BeatClip &&
 				(fixedClips() || pixelsPerBar() >= 96) &&
-				pos.y() > height() - m_stepBtnOff.height())
+				pos.y() > height() - m_stepBtnOff.height() &&
+				!(we->modifiers() & (Qt::ControlModifier | Qt::ShiftModifier)))
 	{
 //	get the step number that was wheeled on and
 //	do calculations in floats to prevent rounding errors...
@@ -822,16 +823,46 @@ void MidiClipView::paintEvent( QPaintEvent * )
 	const int lineSize = 3;
 	p.setPen( c.darker( 200 ) );
 
-	for(float t = (offset % TimePos::ticksPerBar()) * pixelsPerBar / TimePos::ticksPerBar(); t < m_clip->length(); t += pixelsPerBar)
+	if (fixedClips())
 	{
-		p.drawLine( x_base + t - 1,
+		// We don't draw the bar lines the same way in the pattern editor as the view's lenght and position are
+		// modified arbitrarily by zoom and scroll values, and the clip always start at t=0
+		const int steps = std::max(1, m_clip->m_steps);
+		const int w = width() - 2 * BORDER_WIDTH;
+
+		for (int step = TimePos::stepsPerBar(); step < steps; step += TimePos::stepsPerBar())
+		{
+			p.drawLine(
+				BORDER_WIDTH + step * w / static_cast<float>(steps),
 				BORDER_WIDTH,
+				BORDER_WIDTH + step * w / static_cast<float>(steps),
+				BORDER_WIDTH + lineSize
+			);
+			p.drawLine(
+				BORDER_WIDTH + step * w / static_cast<float>(steps),
+				rect().bottom() - (lineSize + BORDER_WIDTH),
+				BORDER_WIDTH + step * w / static_cast<float>(steps),
+				rect().bottom() - BORDER_WIDTH
+			);
+		}
+	}
+	else
+	{
+		for(float t = (offset % TimePos::ticksPerBar()) * pixelsPerBar / TimePos::ticksPerBar(); t < m_clip->length(); t += pixelsPerBar)
+		{
+			p.drawLine(
+				x_base + t - 1,
+				BORDER_WIDTH,
+				x_base + t - 1,
+				BORDER_WIDTH + lineSize
+			);
+			p.drawLine(
 				x_base + t - 1,
-				BORDER_WIDTH + lineSize );
-		p.drawLine( x_base + t - 1,
-				rect().bottom() - ( lineSize + BORDER_WIDTH ),
+				rect().bottom() - (lineSize + BORDER_WIDTH),
 				x_base + t - 1,
-				rect().bottom() - BORDER_WIDTH );
+				rect().bottom() - BORDER_WIDTH
+			);
+		}
 	}
 
 	// clip name