# HG changeset patch
# User Chris Cannam
# Date 1427208031 0
# Node ID 2a9f1eb6e0edb56f2df64355656e7819c2330c6a
# Parent  26da827e8fb52d5fa599b05c01e9360481fdccb9
Try adding a combined simple level/pan widget

diff -r 26da827e8fb5 -r 2a9f1eb6e0ed svgui.pro
--- a/svgui.pro	Mon Mar 23 11:26:28 2015 +0000
+++ b/svgui.pro	Tue Mar 24 14:40:31 2015 +0000
@@ -116,6 +116,7 @@
            widgets/LayerTree.h \
            widgets/LayerTreeDialog.h \
            widgets/LEDButton.h \
+           widgets/LevelPanWidget.h \
            widgets/ListInputDialog.h \
            widgets/MIDIFileImportDialog.h \
            widgets/ModelDataTableDialog.h \
@@ -154,6 +155,7 @@
            widgets/LayerTree.cpp \
            widgets/LayerTreeDialog.cpp \
            widgets/LEDButton.cpp \
+           widgets/LevelPanWidget.cpp \
            widgets/ListInputDialog.cpp \
            widgets/MIDIFileImportDialog.cpp \
            widgets/ModelDataTableDialog.cpp \
diff -r 26da827e8fb5 -r 2a9f1eb6e0ed widgets/LevelPanWidget.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widgets/LevelPanWidget.cpp	Tue Mar 24 14:40:31 2015 +0000
@@ -0,0 +1,253 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#include "LevelPanWidget.h"
+
+#include <QPainter>
+#include <QMouseEvent>
+#include <QWheelEvent>
+
+#include "layer/ColourMapper.h"
+
+#include <iostream>
+
+using std::cerr;
+using std::endl;
+
+static const int maxLevel = 5;
+static const int maxPan = 2; // range is -maxPan to maxPan
+
+LevelPanWidget::LevelPanWidget(QWidget *parent) :
+    QWidget(parent),
+    m_level(maxLevel),
+    m_pan(0),
+    m_editable(true)
+{
+}
+
+LevelPanWidget::~LevelPanWidget()
+{
+}
+
+void
+LevelPanWidget::setLevel(float level)
+{
+    m_level = int(round(level * maxLevel));
+    if (m_level < 0) m_level = 0;
+    if (m_level > maxLevel) m_level = maxLevel;
+    update();
+}
+
+void
+LevelPanWidget::setPan(float pan)
+{
+    m_pan = int(round(pan * maxPan));
+    if (m_pan < -maxPan) m_pan = -maxPan;
+    if (m_pan > maxPan) m_pan = maxPan;
+    update();
+}
+
+void
+LevelPanWidget::setEditable(bool editable)
+{
+    m_editable = editable;
+    update();
+}
+
+float
+LevelPanWidget::getLevel() const
+{
+    return float(m_level) / float(maxLevel);
+}
+
+float
+LevelPanWidget::getPan() const
+{
+    return float(m_pan) / float(maxPan);
+}
+
+void
+LevelPanWidget::emitLevelChanged()
+{
+    cerr << "emitting levelChanged(" << getLevel() << ")" << endl;
+    emit levelChanged(getLevel());
+}
+
+void
+LevelPanWidget::emitPanChanged()
+{
+    cerr << "emitting panChanged(" << getPan() << ")" << endl;
+    emit panChanged(getPan());
+}
+
+void
+LevelPanWidget::mousePressEvent(QMouseEvent *e)
+{
+    mouseMoveEvent(e);
+}
+
+void
+LevelPanWidget::mouseMoveEvent(QMouseEvent *e)
+{
+    if (!m_editable) return;
+    
+    int level, pan;
+    toCell(e->pos(), level, pan);
+    if (level == m_level && pan == m_pan) {
+	return;
+    }
+    if (level != m_level) {
+	m_level = level;
+	emitLevelChanged();
+    }
+    if (pan != m_pan) {
+	m_pan = pan;
+	emitPanChanged();
+    }
+    update();
+}
+
+void
+LevelPanWidget::mouseReleaseEvent(QMouseEvent *e)
+{
+    mouseMoveEvent(e);
+}
+
+void
+LevelPanWidget::wheelEvent(QWheelEvent *e)
+{
+    if (e->modifiers() & Qt::ControlModifier) {
+	if (e->delta() > 0) {
+	    if (m_pan < maxPan) {
+		++m_pan;
+		emitPanChanged();
+		update();
+	    }
+	} else {
+	    if (m_pan > -maxPan) {
+		--m_pan;
+		emitPanChanged();
+		update();
+	    }
+	}
+    } else {
+	if (e->delta() > 0) {
+	    if (m_level < maxLevel) {
+		++m_level;
+		emitLevelChanged();
+		update();
+	    }
+	} else {
+	    if (m_level > 0) {
+		--m_level;
+		emitLevelChanged();
+		update();
+	    }
+	}
+    }
+}
+
+void
+LevelPanWidget::toCell(QPointF loc, int &level, int &pan) const
+{
+    double w = width(), h = height();
+    int npan = maxPan * 2 + 1;
+    double wcell = w / npan, hcell = h / maxLevel;
+    level = int((h - loc.y()) / hcell) + 1;
+    if (level < 1) level = 1;
+    if (level > maxLevel) level = maxLevel;
+    pan = int(loc.x() / wcell) - maxPan;
+    if (pan < -maxPan) pan = -maxPan;
+    if (pan > maxPan) pan = maxPan;
+}
+
+QSizeF
+LevelPanWidget::cellSize() const
+{
+    double w = width(), h = height();
+    int npan = maxPan * 2 + 1;
+    double wcell = w / npan, hcell = h / maxLevel;
+    return QSizeF(wcell, hcell);
+}
+
+QPointF
+LevelPanWidget::cellCentre(int level, int pan) const
+{
+    QSizeF cs = cellSize();
+    return QPointF(cs.width() * (pan + maxPan) + cs.width() / 2.,
+		   height() - cs.height() * level + cs.height() / 2.);
+}
+
+QSizeF
+LevelPanWidget::cellLightSize() const
+{
+    double extent = 3. / 4.;
+    QSizeF cs = cellSize();
+    double m = std::min(cs.width(), cs.height());
+    return QSizeF(m * extent, m * extent);
+}
+
+QRectF
+LevelPanWidget::cellLightRect(int level, int pan) const
+{
+    QSizeF cls = cellLightSize();
+    QPointF cc = cellCentre(level, pan);
+    return QRectF(cc.x() - cls.width() / 2., 
+		  cc.y() - cls.height() / 2.,
+		  cls.width(),
+		  cls.height());
+}
+
+double
+LevelPanWidget::thinLineWidth() const
+{
+    double tw = ceil(width() / (maxPan * 2. * 10.));
+    double th = ceil(height() / (maxLevel * 10.));
+    return std::min(th, tw);
+}
+
+void
+LevelPanWidget::paintEvent(QPaintEvent *)
+{
+    QPainter paint(this);
+    ColourMapper mapper(ColourMapper::Sunset, 0, maxLevel);
+
+    paint.setRenderHint(QPainter::Antialiasing, true);
+
+    QPen pen;
+
+    double thin = thinLineWidth();
+    
+    pen.setColor(QColor(127, 127, 127, 127));
+    pen.setWidthF(cellLightSize().width() + thin);
+    pen.setCapStyle(Qt::RoundCap);
+    paint.setPen(pen);
+
+    for (int pan = -maxPan; pan <= maxPan; ++pan) {
+	paint.drawLine(cellCentre(1, pan), cellCentre(maxLevel, pan));
+    }
+    
+    pen.setColor(Qt::black);
+    pen.setWidthF(thin);
+    pen.setCapStyle(Qt::FlatCap);
+    paint.setPen(pen);
+    
+    for (int level = 1; level <= m_level; ++level) {
+	// level starts at 1 because we handle mute separately
+	paint.setBrush(mapper.map(level));
+	paint.drawEllipse(cellLightRect(level, m_pan));
+    }
+}
+
+
diff -r 26da827e8fb5 -r 2a9f1eb6e0ed widgets/LevelPanWidget.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widgets/LevelPanWidget.h	Tue Mar 24 14:40:31 2015 +0000
@@ -0,0 +1,81 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Sonic Visualiser
+    An audio file viewer and annotation editor.
+    Centre for Digital Music, Queen Mary, University of London.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#ifndef LEVEL_PAN_WIDGET_H
+#define LEVEL_PAN_WIDGET_H
+
+#include <QWidget>
+
+/**
+ * A simple widget for coarse level and pan control.
+ *
+ * For this initial implementation at least, pan is in five steps only
+ * (hard left, mid-left, centre, mid-right, hard right) and level is
+ * in five plus mute.
+ */
+
+class LevelPanWidget : public QWidget
+{
+    Q_OBJECT
+
+public:
+    LevelPanWidget(QWidget *parent = 0);
+    ~LevelPanWidget();
+    
+    /// Return level as a gain value in the range [0,1]
+    float getLevel() const; 
+    
+    /// Return pan as a value in the range [-1,1]
+    float getPan() const;
+
+    /// Find out whether the widget is editable
+    bool isEditable() const;
+
+public slots:
+    /// Set level in the range [0,1] -- will be rounded
+    void setLevel(float);
+
+    /// Set pan in the range [-1,1] -- will be rounded
+    void setPan(float);
+
+    /// Specify whether the widget is editable or read-only (default editable)
+    void setEditable(bool);
+    
+signals:
+    void levelChanged(float);
+    void panChanged(float);
+
+protected:
+    virtual void mousePressEvent(QMouseEvent *ev);
+    virtual void mouseMoveEvent(QMouseEvent *ev);
+    virtual void mouseReleaseEvent(QMouseEvent *ev);
+    virtual void wheelEvent(QWheelEvent *ev);
+    virtual void paintEvent(QPaintEvent *ev);
+
+    void emitLevelChanged();
+    void emitPanChanged();
+    
+    int m_level;
+    int m_pan;
+    bool m_editable;
+
+    QSizeF cellSize() const;
+    QPointF cellCentre(int level, int pan) const;
+    QSizeF cellLightSize() const;
+    QRectF cellLightRect(int level, int pan) const;
+    double thinLineWidth() const;
+    void toCell(QPointF loc, int &level, int &pan) const;
+};
+
+#endif