# HG changeset patch
# User Chris Cannam
# Date 1569415684 -3600
# Node ID d5ef91dc2ea71cd79a81648742c8441d4955122b
# Parent  872873aa64632ac5c484e490b1b72736821b10f5# Parent  d3ef60b6ae93f069252cd854d904893ad3f6b72e
Merge from branch time-frequency-boxes

diff -r 872873aa6463 -r d5ef91dc2ea7 files.pri
--- a/files.pri	Tue Sep 17 12:50:58 2019 +0100
+++ b/files.pri	Wed Sep 25 13:48:04 2019 +0100
@@ -32,6 +32,7 @@
            layer/SpectrumLayer.h \
            layer/TextLayer.h \
            layer/TimeInstantLayer.h \
+           layer/BoxLayer.h \
            layer/TimeRulerLayer.h \
            layer/TimeValueLayer.h \
            layer/VerticalScaleLayer.h \
@@ -121,6 +122,7 @@
            layer/SpectrumLayer.cpp \
            layer/TextLayer.cpp \
            layer/TimeInstantLayer.cpp \
+           layer/BoxLayer.cpp \
            layer/TimeRulerLayer.cpp \
            layer/TimeValueLayer.cpp \
            layer/WaveformLayer.cpp \
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/BoxLayer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layer/BoxLayer.cpp	Wed Sep 25 13:48:04 2019 +0100
@@ -0,0 +1,1208 @@
+/* -*- 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 "BoxLayer.h"
+
+#include "data/model/Model.h"
+#include "base/RealTime.h"
+#include "base/Profiler.h"
+#include "base/LogRange.h"
+
+#include "ColourDatabase.h"
+#include "ColourMapper.h"
+#include "LinearNumericalScale.h"
+#include "LogNumericalScale.h"
+#include "PaintAssistant.h"
+
+#include "view/View.h"
+
+#include "data/model/BoxModel.h"
+
+#include "widgets/ItemEditDialog.h"
+#include "widgets/TextAbbrev.h"
+
+#include <QPainter>
+#include <QPainterPath>
+#include <QMouseEvent>
+#include <QTextStream>
+#include <QMessageBox>
+
+#include <iostream>
+#include <cmath>
+
+BoxLayer::BoxLayer() :
+    SingleColourLayer(),
+    m_editing(false),
+    m_dragPointX(0),
+    m_dragPointY(0),
+    m_dragStartX(0),
+    m_dragStartY(0),
+    m_originalPoint(0, 0.0, 0, tr("New Box")),
+    m_editingPoint(0, 0.0, 0, tr("New Box")),
+    m_editingCommand(nullptr),
+    m_verticalScale(AutoAlignScale)
+{
+    
+}
+
+int
+BoxLayer::getCompletion(LayerGeometryProvider *) const
+{
+    auto model = ModelById::get(m_model);
+    if (model) return model->getCompletion();
+    else return 0;
+}
+
+void
+BoxLayer::setModel(ModelId modelId)
+{
+    auto oldModel = ModelById::getAs<BoxModel>(m_model);
+    auto newModel = ModelById::getAs<BoxModel>(modelId);
+    
+    if (!modelId.isNone() && !newModel) {
+        throw std::logic_error("Not a BoxModel");
+    }
+    
+    if (m_model == modelId) return;
+    m_model = modelId;
+
+    if (newModel) {
+        connectSignals(m_model);
+    }
+    
+    emit modelReplaced();
+}
+
+Layer::PropertyList
+BoxLayer::getProperties() const
+{
+    PropertyList list = SingleColourLayer::getProperties();
+    list.push_back("Vertical Scale");
+    list.push_back("Scale Units");
+    return list;
+}
+
+QString
+BoxLayer::getPropertyLabel(const PropertyName &name) const
+{
+    if (name == "Vertical Scale") return tr("Vertical Scale");
+    if (name == "Scale Units") return tr("Scale Units");
+    return SingleColourLayer::getPropertyLabel(name);
+}
+
+Layer::PropertyType
+BoxLayer::getPropertyType(const PropertyName &name) const
+{
+    if (name == "Vertical Scale") return ValueProperty;
+    if (name == "Scale Units") return UnitsProperty;
+    return SingleColourLayer::getPropertyType(name);
+}
+
+QString
+BoxLayer::getPropertyGroupName(const PropertyName &name) const
+{
+    if (name == "Vertical Scale" || name == "Scale Units") {
+        return tr("Scale");
+    }
+    return SingleColourLayer::getPropertyGroupName(name);
+}
+
+int
+BoxLayer::getPropertyRangeAndValue(const PropertyName &name,
+                                    int *min, int *max, int *deflt) const
+{
+    int val = 0;
+
+    if (name == "Vertical Scale") {
+        
+        if (min) *min = 0;
+        if (max) *max = 2;
+        if (deflt) *deflt = int(LinearScale);
+        
+        val = int(m_verticalScale);
+
+    } else if (name == "Scale Units") {
+
+        if (deflt) *deflt = 0;
+        auto model = ModelById::getAs<BoxModel>(m_model);
+        if (model) {
+            val = UnitDatabase::getInstance()->getUnitId
+                (model->getScaleUnits());
+        }
+
+    } else {
+        val = SingleColourLayer::getPropertyRangeAndValue(name, min, max, deflt);
+    }
+
+    return val;
+}
+
+QString
+BoxLayer::getPropertyValueLabel(const PropertyName &name,
+                                   int value) const
+{
+    if (name == "Vertical Scale") {
+        switch (value) {
+        default:
+        case 0: return tr("Auto-Align");
+        case 1: return tr("Linear");
+        case 2: return tr("Log");
+        }
+    }
+    return SingleColourLayer::getPropertyValueLabel(name, value);
+}
+
+void
+BoxLayer::setProperty(const PropertyName &name, int value)
+{
+    if (name == "Vertical Scale") {
+        setVerticalScale(VerticalScale(value));
+    } else if (name == "Scale Units") {
+        auto model = ModelById::getAs<BoxModel>(m_model);
+        if (model) {
+            model->setScaleUnits
+                (UnitDatabase::getInstance()->getUnitById(value));
+            emit modelChanged(m_model);
+        }
+    } else {
+        return SingleColourLayer::setProperty(name, value);
+    }
+}
+
+void
+BoxLayer::setVerticalScale(VerticalScale scale)
+{
+    if (m_verticalScale == scale) return;
+    m_verticalScale = scale;
+    emit layerParametersChanged();
+}
+
+bool
+BoxLayer::isLayerScrollable(const LayerGeometryProvider *v) const
+{
+    QPoint discard;
+    return !v->shouldIlluminateLocalFeatures(this, discard);
+}
+
+bool
+BoxLayer::getValueExtents(double &min, double &max,
+                          bool &logarithmic, QString &unit) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return false;
+    min = model->getValueMinimum();
+    max = model->getValueMaximum();
+    unit = getScaleUnits();
+
+    if (m_verticalScale == LogScale) logarithmic = true;
+
+    return true;
+}
+
+bool
+BoxLayer::getDisplayExtents(double &min, double &max) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || m_verticalScale == AutoAlignScale) return false;
+
+    min = model->getValueMinimum();
+    max = model->getValueMaximum();
+
+    return true;
+}
+
+bool
+BoxLayer::adoptExtents(double min, double max, QString unit)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return false;
+    if (model->getScaleUnits() == "") {
+        model->setScaleUnits(unit);
+        return true;
+    } else {
+        return false;
+    }
+}
+
+EventVector
+BoxLayer::getLocalPoints(LayerGeometryProvider *v, int x) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return EventVector();
+
+    sv_frame_t frame = v->getFrameForX(x);
+
+    EventVector local = model->getEventsCovering(frame);
+    if (!local.empty()) return local;
+
+    int fuzz = ViewManager::scalePixelSize(2);
+    sv_frame_t start = v->getFrameForX(x - fuzz);
+    sv_frame_t end = v->getFrameForX(x + fuzz);
+
+    local = model->getEventsStartingWithin(frame, end - frame);
+    if (!local.empty()) return local;
+
+    local = model->getEventsSpanning(start, frame - start);
+    if (!local.empty()) return local;
+
+    return {};
+}
+
+bool
+BoxLayer::getPointToDrag(LayerGeometryProvider *v, int x, int y,
+                                      Event &point) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return false;
+
+    sv_frame_t frame = v->getFrameForX(x);
+
+    EventVector onPoints = model->getEventsCovering(frame);
+    if (onPoints.empty()) return false;
+
+    int nearestDistance = -1;
+    for (const auto &p: onPoints) {
+        int distance = getYForValue(v, p.getValue()) - y;
+        if (distance < 0) distance = -distance;
+        if (nearestDistance == -1 || distance < nearestDistance) {
+            nearestDistance = distance;
+            point = p;
+        }
+    }
+
+    return true;
+}
+
+QString
+BoxLayer::getLabelPreceding(sv_frame_t frame) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return "";
+    EventVector points = model->getEventsStartingWithin
+        (model->getStartFrame(), frame - model->getStartFrame());
+    if (!points.empty()) {
+        for (auto i = points.rbegin(); i != points.rend(); ++i) {
+            if (i->getLabel() != QString()) {
+                return i->getLabel();
+            }
+        }
+    }
+    return QString();
+}
+
+QString
+BoxLayer::getFeatureDescription(LayerGeometryProvider *v,
+                                             QPoint &pos) const
+{
+    int x = pos.x();
+
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || !model->getSampleRate()) return "";
+
+    EventVector points = getLocalPoints(v, x);
+
+    if (points.empty()) {
+        if (!model->isReady()) {
+            return tr("In progress");
+        } else {
+            return tr("No local points");
+        }
+    }
+
+    Event box;
+    EventVector::iterator i;
+
+    for (i = points.begin(); i != points.end(); ++i) {
+
+        int y0 = getYForValue(v, i->getValue());
+        int y1 = getYForValue(v, i->getValue() + fabsf(i->getLevel()));
+
+        if (pos.y() >= y0 && pos.y() <= y1) {
+            box = *i;
+            break;
+        }
+    }
+
+    if (i == points.end()) return tr("No local points");
+
+    RealTime rt = RealTime::frame2RealTime(box.getFrame(),
+                                           model->getSampleRate());
+    RealTime rd = RealTime::frame2RealTime(box.getDuration(),
+                                           model->getSampleRate());
+    
+    QString rangeText;
+
+    rangeText = tr("%1 %2 - %3 %4")
+        .arg(box.getValue()).arg(getScaleUnits())
+        .arg(box.getValue() + fabsf(box.getLevel())).arg(getScaleUnits());
+
+    QString text;
+
+    if (box.getLabel() == "") {
+        text = QString(tr("Time:\t%1\nDuration:\t%2\nValue:\t%3\nNo label"))
+            .arg(rt.toText(true).c_str())
+            .arg(rd.toText(true).c_str())
+            .arg(rangeText);
+    } else {
+        text = QString(tr("Time:\t%1\nDuration:\t%2\nValue:\t%3\nLabel:\t%4"))
+            .arg(rt.toText(true).c_str())
+            .arg(rd.toText(true).c_str())
+            .arg(rangeText)
+            .arg(box.getLabel());
+    }
+
+    pos = QPoint(v->getXForFrame(box.getFrame()),
+                 getYForValue(v, box.getValue()));
+    return text;
+}
+
+bool
+BoxLayer::snapToFeatureFrame(LayerGeometryProvider *v,
+                                          sv_frame_t &frame,
+                                          int &resolution,
+                                          SnapType snap) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) {
+        return Layer::snapToFeatureFrame(v, frame, resolution, snap);
+    }
+
+    // SnapLeft / SnapRight: return frame of nearest feature in that
+    // direction no matter how far away
+    //
+    // SnapNeighbouring: return frame of feature that would be used in
+    // an editing operation, i.e. closest feature in either direction
+    // but only if it is "close enough"
+
+    resolution = model->getResolution();
+
+    if (snap == SnapNeighbouring) {
+        EventVector points = getLocalPoints(v, v->getXForFrame(frame));
+        if (points.empty()) return false;
+        frame = points.begin()->getFrame();
+        return true;
+    }    
+
+    // Normally we snap to the start frame of whichever event we
+    // find. However here, for SnapRight only, if the end frame of
+    // whichever event we would have snapped to had we been snapping
+    // left is closer than the start frame of the next event to the
+    // right, then we snap to that frame instead. Clear?
+    
+    Event left;
+    bool haveLeft = false;
+    if (model->getNearestEventMatching
+        (frame, [](Event) { return true; }, EventSeries::Backward, left)) {
+        haveLeft = true;
+    }
+
+    if (snap == SnapLeft) {
+        frame = left.getFrame();
+        return haveLeft;
+    }
+
+    Event right;
+    bool haveRight = false;
+    if (model->getNearestEventMatching
+        (frame, [](Event) { return true; }, EventSeries::Forward, right)) {
+        haveRight = true;
+    }
+
+    if (haveLeft) {
+        sv_frame_t leftEnd = left.getFrame() + left.getDuration();
+        if (leftEnd > frame) {
+            if (haveRight) {
+                if (leftEnd - frame < right.getFrame() - frame) {
+                    frame = leftEnd;
+                } else {
+                    frame = right.getFrame();
+                }
+            } else {
+                frame = leftEnd;
+            }
+            return true;
+        }
+    }
+
+    if (haveRight) {
+        frame = right.getFrame();
+        return true;
+    }
+
+    return false;
+}
+
+QString
+BoxLayer::getScaleUnits() const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (model) return model->getScaleUnits();
+    else return "";
+}
+
+void
+BoxLayer::getScaleExtents(LayerGeometryProvider *v,
+                                       double &min, double &max,
+                                       bool &log) const
+{
+    min = 0.0;
+    max = 0.0;
+    log = false;
+
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return;
+
+    QString queryUnits;
+    queryUnits = getScaleUnits();
+
+    if (m_verticalScale == AutoAlignScale) {
+
+        if (!v->getValueExtents(queryUnits, min, max, log)) {
+
+            min = model->getValueMinimum();
+            max = model->getValueMaximum();
+
+//            cerr << "BoxLayer[" << this << "]::getScaleExtents: min = " << min << ", max = " << max << ", log = " << log << endl;
+
+        } else if (log) {
+
+            LogRange::mapRange(min, max);
+
+//            cerr << "BoxLayer[" << this << "]::getScaleExtents: min = " << min << ", max = " << max << ", log = " << log << endl;
+
+        }
+
+    } else {
+
+        min = model->getValueMinimum();
+        max = model->getValueMaximum();
+
+        if (m_verticalScale == LogScale) {
+            LogRange::mapRange(min, max);
+            log = true;
+        }
+    }
+
+    if (max == min) max = min + 1.0;
+}
+
+int
+BoxLayer::getYForValue(LayerGeometryProvider *v, double val) const
+{
+    double min = 0.0, max = 0.0;
+    bool logarithmic = false;
+    int h = v->getPaintHeight();
+
+    getScaleExtents(v, min, max, logarithmic);
+
+//    cerr << "BoxLayer[" << this << "]::getYForValue(" << val << "): min = " << min << ", max = " << max << ", log = " << logarithmic << endl;
+//    cerr << "h = " << h << ", margin = " << margin << endl;
+
+    if (logarithmic) {
+        val = LogRange::map(val);
+    }
+
+    return int(h - ((val - min) * h) / (max - min));
+}
+
+double
+BoxLayer::getValueForY(LayerGeometryProvider *v, int y) const
+{
+    double min = 0.0, max = 0.0;
+    bool logarithmic = false;
+    int h = v->getPaintHeight();
+
+    getScaleExtents(v, min, max, logarithmic);
+
+    double val = min + (double(h - y) * double(max - min)) / h;
+
+    if (logarithmic) {
+        val = pow(10.0, val);
+    }
+
+    return val;
+}
+
+void
+BoxLayer::paint(LayerGeometryProvider *v, QPainter &paint,
+                             QRect rect) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || !model->isOK()) return;
+
+    sv_samplerate_t sampleRate = model->getSampleRate();
+    if (!sampleRate) return;
+
+//    Profiler profiler("BoxLayer::paint", true);
+
+    int x0 = rect.left() - 40, x1 = rect.right();
+
+    sv_frame_t wholeFrame0 = v->getFrameForX(0);
+    sv_frame_t wholeFrame1 = v->getFrameForX(v->getPaintWidth());
+
+    EventVector points(model->getEventsSpanning(wholeFrame0,
+                                                wholeFrame1 - wholeFrame0));
+    if (points.empty()) return;
+
+    paint.setPen(getBaseQColor());
+
+//    SVDEBUG << "BoxLayer::paint: resolution is "
+//              << model->getResolution() << " frames" << endl;
+
+    double min = model->getValueMinimum();
+    double max = model->getValueMaximum();
+    if (max == min) max = min + 1.0;
+
+    QPoint localPos;
+    Event illuminatePoint(0);
+    bool shouldIlluminate = false;
+
+    if (v->shouldIlluminateLocalFeatures(this, localPos)) {
+        shouldIlluminate = getPointToDrag(v, localPos.x(), localPos.y(),
+                                          illuminatePoint);
+    }
+
+    paint.save();
+    paint.setRenderHint(QPainter::Antialiasing, false);
+
+    QFontMetrics fm = paint.fontMetrics();
+        
+    for (EventVector::const_iterator i = points.begin();
+         i != points.end(); ++i) {
+
+        const Event &p(*i);
+
+        int x = v->getXForFrame(p.getFrame());
+        int w = v->getXForFrame(p.getFrame() + p.getDuration()) - x;
+        int y = getYForValue(v, p.getValue());
+        int h = getYForValue(v, p.getValue() + fabsf(p.getLevel())) - y;
+        int ex = x + w;
+        int gap = v->scalePixelSize(2);
+
+        EventVector::const_iterator j = i;
+        ++j;
+
+        if (j != points.end()) {
+            const Event &q(*j);
+            int nx = v->getXForFrame(q.getFrame());
+            if (nx < ex) ex = nx;
+        }
+
+        if (w < 1) w = 1;
+
+        paint.setPen(getBaseQColor());
+        paint.setBrush(Qt::NoBrush);
+
+        if ((shouldIlluminate && illuminatePoint == p) ||
+            (m_editing && m_editingPoint == p)) {
+
+            paint.setPen(QPen(getBaseQColor(), v->scalePixelSize(2)));
+                
+            // Qt 5.13 deprecates QFontMetrics::width(), but its suggested
+            // replacement (horizontalAdvance) was only added in Qt 5.11
+            // which is too new for us
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+
+            if (abs(h) > 2 * fm.height()) {
+            
+                QString y0label = QString("%1 %2")
+                    .arg(p.getValue())
+                    .arg(getScaleUnits());
+
+                QString y1label = QString("%1 %2")
+                    .arg(p.getValue() + fabsf(p.getLevel()))
+                    .arg(getScaleUnits());
+
+                PaintAssistant::drawVisibleText
+                    (v, paint, 
+                     x - fm.width(y0label) - gap,
+                     y - fm.descent(), 
+                     y0label, PaintAssistant::OutlinedText);
+
+                PaintAssistant::drawVisibleText
+                    (v, paint, 
+                     x - fm.width(y1label) - gap,
+                     y + h + fm.ascent(), 
+                     y1label, PaintAssistant::OutlinedText);
+
+            } else {
+            
+                QString ylabel = QString("%1 %2 - %3 %4")
+                    .arg(p.getValue())
+                    .arg(getScaleUnits())
+                    .arg(p.getValue() + fabsf(p.getLevel()))
+                    .arg(getScaleUnits());
+
+                PaintAssistant::drawVisibleText
+                    (v, paint, 
+                     x - fm.width(ylabel) - gap,
+                     y - fm.descent(), 
+                     ylabel, PaintAssistant::OutlinedText);
+            }
+            
+            QString t0label = RealTime::frame2RealTime
+                (p.getFrame(), model->getSampleRate()).toText(true).c_str();
+
+            QString t1label = RealTime::frame2RealTime
+                (p.getFrame() + p.getDuration(), model->getSampleRate())
+                .toText(true).c_str();
+
+            PaintAssistant::drawVisibleText
+                (v, paint, x, y + fm.ascent() + gap,
+                 t0label, PaintAssistant::OutlinedText);
+
+            if (w > fm.width(t0label) + fm.width(t1label) + gap * 3) {
+
+                PaintAssistant::drawVisibleText
+                    (v, paint,
+                     x + w - fm.width(t1label),
+                     y + fm.ascent() + gap,
+                     t1label, PaintAssistant::OutlinedText);
+
+            } else {
+
+                PaintAssistant::drawVisibleText
+                    (v, paint,
+                     x + w - fm.width(t1label),
+                     y + fm.ascent() + fm.height() + gap,
+                     t1label, PaintAssistant::OutlinedText);
+            }                
+        }
+
+        paint.drawRect(x, y, w, h);
+    }
+
+    for (EventVector::const_iterator i = points.begin();
+         i != points.end(); ++i) {
+
+        const Event &p(*i);
+
+        QString label = p.getLabel();
+        if (label == "") continue;
+
+        if (shouldIlluminate && illuminatePoint == p) {
+            continue; // already handled this in illumination special case
+        }
+        
+        int x = v->getXForFrame(p.getFrame());
+        int w = v->getXForFrame(p.getFrame() + p.getDuration()) - x;
+        int y = getYForValue(v, p.getValue());
+
+        int labelWidth = fm.width(label);
+
+        int gap = v->scalePixelSize(2);
+
+        if (x + w < x0 || x - labelWidth - gap > x1) {
+            continue;
+        }
+        
+        int labelX, labelY;
+
+        labelX = x - labelWidth - gap;
+        labelY = y - fm.descent();
+
+        PaintAssistant::drawVisibleText(v, paint, labelX, labelY, label,
+                                        PaintAssistant::OutlinedText);
+    }
+
+    paint.restore();
+}
+
+int
+BoxLayer::getVerticalScaleWidth(LayerGeometryProvider *v,
+                                             bool, QPainter &paint) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || m_verticalScale == AutoAlignScale) {
+        return 0;
+    } else {
+        if (m_verticalScale == LogScale) {
+            return LogNumericalScale().getWidth(v, paint);
+        } else {
+            return LinearNumericalScale().getWidth(v, paint);
+        }
+    }
+}
+
+void
+BoxLayer::paintVerticalScale(LayerGeometryProvider *v,
+                                          bool, QPainter &paint, QRect) const
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || model->isEmpty()) return;
+
+    QString unit;
+    double min, max;
+    bool logarithmic;
+
+    int w = getVerticalScaleWidth(v, false, paint);
+
+    getScaleExtents(v, min, max, logarithmic);
+
+    if (logarithmic) {
+        LogNumericalScale().paintVertical(v, this, paint, 0, min, max);
+    } else {
+        LinearNumericalScale().paintVertical(v, this, paint, 0, min, max);
+    }
+        
+    if (getScaleUnits() != "") {
+        int mw = w - 5;
+        paint.drawText(5,
+                       5 + paint.fontMetrics().ascent(),
+                       TextAbbrev::abbreviate(getScaleUnits(),
+                                              paint.fontMetrics(),
+                                              mw));
+    }
+}
+
+void
+BoxLayer::drawStart(LayerGeometryProvider *v, QMouseEvent *e)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return;
+
+    sv_frame_t frame = v->getFrameForX(e->x());
+    if (frame < 0) frame = 0;
+    frame = frame / model->getResolution() * model->getResolution();
+
+    double value = getValueForY(v, e->y());
+
+    m_editingPoint = Event(frame, float(value), 0, "");
+    m_originalPoint = m_editingPoint;
+
+    if (m_editingCommand) finish(m_editingCommand);
+    m_editingCommand = new ChangeEventsCommand(m_model.untyped,
+                                               tr("Draw Box"));
+    m_editingCommand->add(m_editingPoint);
+
+    m_editing = true;
+}
+
+void
+BoxLayer::drawDrag(LayerGeometryProvider *v, QMouseEvent *e)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || !m_editing) return;
+
+    sv_frame_t dragFrame = v->getFrameForX(e->x());
+    if (dragFrame < 0) dragFrame = 0;
+    dragFrame = dragFrame / model->getResolution() * model->getResolution();
+
+    sv_frame_t eventFrame = m_originalPoint.getFrame();
+    sv_frame_t eventDuration = dragFrame - eventFrame;
+    if (eventDuration < 0) {
+        eventFrame = eventFrame + eventDuration;
+        eventDuration = -eventDuration;
+    } else if (eventDuration == 0) {
+        eventDuration = model->getResolution();
+    }
+
+    double dragValue = getValueForY(v, e->y());
+
+    double eventValue = m_originalPoint.getValue();
+    double eventFreqDiff = dragValue - eventValue;
+    if (eventFreqDiff < 0) {
+        eventValue = eventValue + eventFreqDiff;
+        eventFreqDiff = -eventFreqDiff;
+    }
+
+    m_editingCommand->remove(m_editingPoint);
+    m_editingPoint = m_editingPoint
+        .withFrame(eventFrame)
+        .withDuration(eventDuration)
+        .withValue(float(eventValue))
+        .withLevel(float(eventFreqDiff));
+    m_editingCommand->add(m_editingPoint);
+}
+
+void
+BoxLayer::drawEnd(LayerGeometryProvider *, QMouseEvent *)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || !m_editing) return;
+    finish(m_editingCommand);
+    m_editingCommand = nullptr;
+    m_editing = false;
+}
+
+void
+BoxLayer::eraseStart(LayerGeometryProvider *v, QMouseEvent *e)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return;
+
+    if (!getPointToDrag(v, e->x(), e->y(), m_editingPoint)) return;
+
+    if (m_editingCommand) {
+        finish(m_editingCommand);
+        m_editingCommand = nullptr;
+    }
+
+    m_editing = true;
+}
+
+void
+BoxLayer::eraseDrag(LayerGeometryProvider *, QMouseEvent *)
+{
+}
+
+void
+BoxLayer::eraseEnd(LayerGeometryProvider *v, QMouseEvent *e)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || !m_editing) return;
+
+    m_editing = false;
+
+    Event p(0);
+    if (!getPointToDrag(v, e->x(), e->y(), p)) return;
+    if (p.getFrame() != m_editingPoint.getFrame() ||
+        p.getValue() != m_editingPoint.getValue()) return;
+
+    m_editingCommand = new ChangeEventsCommand
+        (m_model.untyped, tr("Erase Box"));
+
+    m_editingCommand->remove(m_editingPoint);
+
+    finish(m_editingCommand);
+    m_editingCommand = nullptr;
+    m_editing = false;
+}
+
+void
+BoxLayer::editStart(LayerGeometryProvider *v, QMouseEvent *e)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return;
+
+    if (!getPointToDrag(v, e->x(), e->y(), m_editingPoint)) {
+        return;
+    }
+
+    m_dragPointX = v->getXForFrame(m_editingPoint.getFrame());
+    m_dragPointY = getYForValue(v, m_editingPoint.getValue());
+
+    m_originalPoint = m_editingPoint;
+
+    if (m_editingCommand) {
+        finish(m_editingCommand);
+        m_editingCommand = nullptr;
+    }
+
+    m_editing = true;
+    m_dragStartX = e->x();
+    m_dragStartY = e->y();
+}
+
+void
+BoxLayer::editDrag(LayerGeometryProvider *v, QMouseEvent *e)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || !m_editing) return;
+
+    int xdist = e->x() - m_dragStartX;
+    int ydist = e->y() - m_dragStartY;
+    int newx = m_dragPointX + xdist;
+    int newy = m_dragPointY + ydist;
+
+    sv_frame_t frame = v->getFrameForX(newx);
+    if (frame < 0) frame = 0;
+    frame = frame / model->getResolution() * model->getResolution();
+
+    double value = getValueForY(v, newy);
+
+    if (!m_editingCommand) {
+        m_editingCommand = new ChangeEventsCommand
+            (m_model.untyped,
+             tr("Drag Box"));
+    }
+
+    m_editingCommand->remove(m_editingPoint);
+    m_editingPoint = m_editingPoint
+        .withFrame(frame)
+        .withValue(float(value));
+    m_editingCommand->add(m_editingPoint);
+}
+
+void
+BoxLayer::editEnd(LayerGeometryProvider *, QMouseEvent *)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || !m_editing) return;
+
+    if (m_editingCommand) {
+
+        QString newName = m_editingCommand->getName();
+
+        if (m_editingPoint.getFrame() != m_originalPoint.getFrame()) {
+            if (m_editingPoint.getValue() != m_originalPoint.getValue()) {
+                newName = tr("Edit Box");
+            } else {
+                newName = tr("Relocate Box");
+            }
+        } else {
+            newName = tr("Change Point Value");
+        }
+
+        m_editingCommand->setName(newName);
+        finish(m_editingCommand);
+    }
+
+    m_editingCommand = nullptr;
+    m_editing = false;
+}
+
+bool
+BoxLayer::editOpen(LayerGeometryProvider *v, QMouseEvent *e)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return false;
+
+    Event region(0);
+    if (!getPointToDrag(v, e->x(), e->y(), region)) return false;
+
+    ItemEditDialog::LabelOptions labelOptions;
+    labelOptions.valueLabel = tr("Minimum Value");
+    labelOptions.levelLabel = tr("Value Extent");
+    labelOptions.valueUnits = getScaleUnits();
+    labelOptions.levelUnits = getScaleUnits();
+    
+    ItemEditDialog *dialog = new ItemEditDialog
+        (model->getSampleRate(),
+         ItemEditDialog::ShowTime |
+         ItemEditDialog::ShowDuration |
+         ItemEditDialog::ShowValue |
+         ItemEditDialog::ShowLevel |
+         ItemEditDialog::ShowText,
+         labelOptions);
+
+    dialog->setFrameTime(region.getFrame());
+    dialog->setValue(region.getValue());
+    dialog->setLevel(region.getLevel());
+    dialog->setFrameDuration(region.getDuration());
+    dialog->setText(region.getLabel());
+
+    if (dialog->exec() == QDialog::Accepted) {
+
+        Event newBox = region
+            .withFrame(dialog->getFrameTime())
+            .withValue(dialog->getValue())
+            .withLevel(dialog->getLevel())
+            .withDuration(dialog->getFrameDuration())
+            .withLabel(dialog->getText());
+        
+        ChangeEventsCommand *command = new ChangeEventsCommand
+            (m_model.untyped, tr("Edit Box"));
+        command->remove(region);
+        command->add(newBox);
+        finish(command);
+    }
+
+    delete dialog;
+    return true;
+}
+
+void
+BoxLayer::moveSelection(Selection s, sv_frame_t newStartFrame)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return;
+
+    ChangeEventsCommand *command =
+        new ChangeEventsCommand(m_model.untyped, tr("Drag Selection"));
+
+    EventVector points =
+        model->getEventsStartingWithin(s.getStartFrame(), s.getDuration());
+
+    for (EventVector::iterator i = points.begin();
+         i != points.end(); ++i) {
+
+        Event newPoint = (*i)
+            .withFrame(i->getFrame() + newStartFrame - s.getStartFrame());
+        command->remove(*i);
+        command->add(newPoint);
+    }
+
+    finish(command);
+}
+
+void
+BoxLayer::resizeSelection(Selection s, Selection newSize)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model || !s.getDuration()) return;
+
+    ChangeEventsCommand *command =
+        new ChangeEventsCommand(m_model.untyped, tr("Resize Selection"));
+
+    EventVector points =
+        model->getEventsStartingWithin(s.getStartFrame(), s.getDuration());
+
+    double ratio = double(newSize.getDuration()) / double(s.getDuration());
+    double oldStart = double(s.getStartFrame());
+    double newStart = double(newSize.getStartFrame());
+    
+    for (Event p: points) {
+
+        double newFrame = (double(p.getFrame()) - oldStart) * ratio + newStart;
+        double newDuration = double(p.getDuration()) * ratio;
+
+        Event newPoint = p
+            .withFrame(lrint(newFrame))
+            .withDuration(lrint(newDuration));
+        command->remove(p);
+        command->add(newPoint);
+    }
+
+    finish(command);
+}
+
+void
+BoxLayer::deleteSelection(Selection s)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return;
+
+    ChangeEventsCommand *command =
+        new ChangeEventsCommand(m_model.untyped, tr("Delete Selected Points"));
+
+    EventVector points =
+        model->getEventsStartingWithin(s.getStartFrame(), s.getDuration());
+
+    for (EventVector::iterator i = points.begin();
+         i != points.end(); ++i) {
+
+        if (s.contains(i->getFrame())) {
+            command->remove(*i);
+        }
+    }
+
+    finish(command);
+}    
+
+void
+BoxLayer::copy(LayerGeometryProvider *v, Selection s, Clipboard &to)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return;
+
+    EventVector points =
+        model->getEventsStartingWithin(s.getStartFrame(), s.getDuration());
+
+    for (Event p: points) {
+        to.addPoint(p.withReferenceFrame(alignToReference(v, p.getFrame())));
+    }
+}
+
+bool
+BoxLayer::paste(LayerGeometryProvider *v, const Clipboard &from, sv_frame_t /* frameOffset */, bool /* interactive */)
+{
+    auto model = ModelById::getAs<BoxModel>(m_model);
+    if (!model) return false;
+
+    const EventVector &points = from.getPoints();
+
+    bool realign = false;
+
+    if (clipboardHasDifferentAlignment(v, from)) {
+
+        QMessageBox::StandardButton button =
+            QMessageBox::question(v->getView(), tr("Re-align pasted items?"),
+                                  tr("The items you are pasting came from a layer with different source material from this one.  Do you want to re-align them in time, to match the source material for this layer?"),
+                                  QMessageBox::Yes | QMessageBox::No | QMessageBox::Cancel,
+                                  QMessageBox::Yes);
+
+        if (button == QMessageBox::Cancel) {
+            return false;
+        }
+
+        if (button == QMessageBox::Yes) {
+            realign = true;
+        }
+    }
+
+    ChangeEventsCommand *command =
+        new ChangeEventsCommand(m_model.untyped, tr("Paste"));
+
+    for (EventVector::const_iterator i = points.begin();
+         i != points.end(); ++i) {
+        
+        sv_frame_t frame = 0;
+
+        if (!realign) {
+            
+            frame = i->getFrame();
+
+        } else {
+
+            if (i->hasReferenceFrame()) {
+                frame = i->getReferenceFrame();
+                frame = alignFromReference(v, frame);
+            } else {
+                frame = i->getFrame();
+            }
+        }
+
+        Event p = *i;
+        Event newPoint = p;
+        if (!p.hasValue()) {
+            newPoint = newPoint.withValue((model->getValueMinimum() +
+                                           model->getValueMaximum()) / 2);
+        }
+        if (!p.hasDuration()) {
+            sv_frame_t nextFrame = frame;
+            EventVector::const_iterator j = i;
+            for (; j != points.end(); ++j) {
+                if (j != i) break;
+            }
+            if (j != points.end()) {
+                nextFrame = j->getFrame();
+            }
+            if (nextFrame == frame) {
+                newPoint = newPoint.withDuration(model->getResolution());
+            } else {
+                newPoint = newPoint.withDuration(nextFrame - frame);
+            }
+        }
+        
+        command->add(newPoint);
+    }
+
+    finish(command);
+    return true;
+}
+
+void
+BoxLayer::toXml(QTextStream &stream,
+                             QString indent, QString extraAttributes) const
+{
+    QString s;
+
+    s += QString("verticalScale=\"%1\" ").arg(m_verticalScale);
+    
+    SingleColourLayer::toXml(stream, indent, extraAttributes + " " + s);
+}
+
+void
+BoxLayer::setProperties(const QXmlAttributes &attributes)
+{
+    SingleColourLayer::setProperties(attributes);
+
+    bool ok;
+    VerticalScale scale = (VerticalScale)
+        attributes.value("verticalScale").toInt(&ok);
+    if (ok) setVerticalScale(scale);
+}
+
+
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/BoxLayer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layer/BoxLayer.h	Wed Sep 25 13:48:04 2019 +0100
@@ -0,0 +1,143 @@
+/* -*- 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 SV_BOX_LAYER_H
+#define SV_BOX_LAYER_H
+
+#include "SingleColourLayer.h"
+#include "VerticalScaleLayer.h"
+
+#include "data/model/BoxModel.h"
+
+#include <QObject>
+#include <QColor>
+
+#include <map>
+
+class View;
+class QPainter;
+
+class BoxLayer : public SingleColourLayer,
+                              public VerticalScaleLayer
+{
+    Q_OBJECT
+
+public:
+    BoxLayer();
+
+    void paint(LayerGeometryProvider *v, QPainter &paint, QRect rect) const override;
+
+    int getVerticalScaleWidth(LayerGeometryProvider *v, bool, QPainter &) const override;
+    void paintVerticalScale(LayerGeometryProvider *v, bool, QPainter &paint, QRect rect) const override;
+
+    QString getFeatureDescription(LayerGeometryProvider *v, QPoint &) const override;
+    QString getLabelPreceding(sv_frame_t) const override;
+
+    bool snapToFeatureFrame(LayerGeometryProvider *v, sv_frame_t &frame,
+                            int &resolution,
+                            SnapType snap) const override;
+
+    void drawStart(LayerGeometryProvider *v, QMouseEvent *) override;
+    void drawDrag(LayerGeometryProvider *v, QMouseEvent *) override;
+    void drawEnd(LayerGeometryProvider *v, QMouseEvent *) override;
+
+    void eraseStart(LayerGeometryProvider *v, QMouseEvent *) override;
+    void eraseDrag(LayerGeometryProvider *v, QMouseEvent *) override;
+    void eraseEnd(LayerGeometryProvider *v, QMouseEvent *) override;
+
+    void editStart(LayerGeometryProvider *v, QMouseEvent *) override;
+    void editDrag(LayerGeometryProvider *v, QMouseEvent *) override;
+    void editEnd(LayerGeometryProvider *v, QMouseEvent *) override;
+
+    bool editOpen(LayerGeometryProvider *v, QMouseEvent *) override;
+
+    void moveSelection(Selection s, sv_frame_t newStartFrame) override;
+    void resizeSelection(Selection s, Selection newSize) override;
+    void deleteSelection(Selection s) override;
+
+    void copy(LayerGeometryProvider *v, Selection s, Clipboard &to) override;
+    bool paste(LayerGeometryProvider *v, const Clipboard &from,
+               sv_frame_t frameOffset, bool interactive) override;
+
+    ModelId getModel() const override { return m_model; }
+    void setModel(ModelId model); // a BoxModel
+
+    PropertyList getProperties() const override;
+    QString getPropertyLabel(const PropertyName &) const override;
+    PropertyType getPropertyType(const PropertyName &) const override;
+    QString getPropertyGroupName(const PropertyName &) const override;
+    int getPropertyRangeAndValue(const PropertyName &,
+                                 int *min, int *max, int *deflt) const override;
+    QString getPropertyValueLabel(const PropertyName &,
+                                  int value) const override;
+    void setProperty(const PropertyName &, int value) override;
+
+    enum VerticalScale {
+        AutoAlignScale,
+        LinearScale,
+        LogScale,
+    };
+
+    void setVerticalScale(VerticalScale scale);
+    VerticalScale getVerticalScale() const { return m_verticalScale; }
+
+    bool isLayerScrollable(const LayerGeometryProvider *v) const override;
+
+    bool isLayerEditable() const override { return true; }
+
+    int getCompletion(LayerGeometryProvider *) const override;
+
+    bool getValueExtents(double &min, double &max,
+                                 bool &log, QString &unit) const override;
+
+    bool getDisplayExtents(double &min, double &max) const override;
+
+    bool adoptExtents(double min, double max, QString unit) override;
+
+    void toXml(QTextStream &stream, QString indent = "",
+                       QString extraAttributes = "") const override;
+
+    void setProperties(const QXmlAttributes &attributes) override;
+
+    /// VerticalScaleLayer methods
+    int getYForValue(LayerGeometryProvider *v, double value) const override;
+    double getValueForY(LayerGeometryProvider *v, int y) const override;
+    QString getScaleUnits() const override;
+
+protected:
+    void getScaleExtents(LayerGeometryProvider *, double &min, double &max, bool &log) const;
+
+    EventVector getLocalPoints(LayerGeometryProvider *v, int x) const;
+
+    bool getPointToDrag(LayerGeometryProvider *v, int x, int y, Event &) const;
+
+    ModelId m_model;
+    bool m_editing;
+    int m_dragPointX;
+    int m_dragPointY;
+    int m_dragStartX;
+    int m_dragStartY;
+    Event m_originalPoint;
+    Event m_editingPoint;
+    ChangeEventsCommand *m_editingCommand;
+    VerticalScale m_verticalScale;
+
+    void finish(ChangeEventsCommand *command) {
+        Command *c = command->finish();
+        if (c) CommandHistory::getInstance()->addCommand(c, false);
+    }
+};
+
+#endif
+
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/FlexiNoteLayer.cpp
--- a/layer/FlexiNoteLayer.cpp	Tue Sep 17 12:50:58 2019 +0100
+++ b/layer/FlexiNoteLayer.cpp	Wed Sep 25 13:48:04 2019 +0100
@@ -1604,13 +1604,12 @@
     Event note(0);
     if (!getPointToDrag(v, e->x(), e->y(), note)) return false;
 
-//    Event note = *points.begin();
-
     ItemEditDialog *dialog = new ItemEditDialog
         (model->getSampleRate(),
          ItemEditDialog::ShowTime |
          ItemEditDialog::ShowDuration |
          ItemEditDialog::ShowValue |
+         ItemEditDialog::ShowLevel |
          ItemEditDialog::ShowText,
          getScaleUnits());
 
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/Layer.h
--- a/layer/Layer.h	Tue Sep 17 12:50:58 2019 +0100
+++ b/layer/Layer.h	Wed Sep 25 13:48:04 2019 +0100
@@ -488,6 +488,17 @@
     }
 
     /**
+     * Consider using the given value extents and units for this
+     * layer. This may be called on a new layer when added, to prepare
+     * it for editing, and the extents are those of the layer
+     * underneath it. May not be appropriate for most layer types.
+     */
+    virtual bool adoptExtents(double /* min */, double /* max */,
+                              QString /* unit */) {
+        return false;
+    }
+    
+    /**
      * Return the value and unit at the given x coordinate in the
      * given view.  This is for descriptive purposes using the
      * measurement tool.  The default implementation works correctly
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/LayerFactory.cpp
--- a/layer/LayerFactory.cpp	Tue Sep 17 12:50:58 2019 +0100
+++ b/layer/LayerFactory.cpp	Wed Sep 25 13:48:04 2019 +0100
@@ -23,6 +23,7 @@
 #include "NoteLayer.h"
 #include "FlexiNoteLayer.h"
 #include "RegionLayer.h"
+#include "BoxLayer.h"
 #include "TextLayer.h"
 #include "ImageLayer.h"
 #include "Colour3DPlotLayer.h"
@@ -38,6 +39,7 @@
 #include "data/model/SparseTimeValueModel.h"
 #include "data/model/NoteModel.h"
 #include "data/model/RegionModel.h"
+#include "data/model/BoxModel.h"
 #include "data/model/TextModel.h"
 #include "data/model/ImageModel.h"
 #include "data/model/DenseThreeDimensionalModel.h"
@@ -76,6 +78,7 @@
     case Notes:        return Layer::tr("Notes");
     case FlexiNotes:   return Layer::tr("Flexible Notes");
     case Regions:      return Layer::tr("Regions");
+    case Boxes:        return Layer::tr("Boxes");
     case Text:         return Layer::tr("Text");
     case Image:        return Layer::tr("Images");
     case Colour3DPlot: return Layer::tr("Colour 3D Plot");
@@ -173,6 +176,10 @@
         types.insert(Regions);
     }
 
+    if (ModelById::getAs<BoxModel>(modelId)) {
+        types.insert(Boxes);
+    }
+
     if (ModelById::getAs<TextModel>(modelId)) {
         types.insert(Text);
     }
@@ -203,6 +210,7 @@
 //    types.insert(FlexiNotes);
     types.insert(Notes);
     types.insert(Regions);
+    types.insert(Boxes);
     types.insert(Text);
     types.insert(Image);
     //!!! and in principle Colour3DPlot -- now that's a challenge
@@ -220,6 +228,7 @@
     if (dynamic_cast<const FlexiNoteLayer *>(layer)) return FlexiNotes;
     if (dynamic_cast<const NoteLayer *>(layer)) return Notes;
     if (dynamic_cast<const RegionLayer *>(layer)) return Regions;
+    if (dynamic_cast<const BoxLayer *>(layer)) return Boxes;
     if (dynamic_cast<const TextLayer *>(layer)) return Text;
     if (dynamic_cast<const ImageLayer *>(layer)) return Image;
     if (dynamic_cast<const Colour3DPlotLayer *>(layer)) return Colour3DPlot;
@@ -240,6 +249,7 @@
     case Notes: return "notes";
     case FlexiNotes: return "flexinotes";
     case Regions: return "regions";
+    case Boxes: return "boxes";
     case Text: return "text";
     case Image: return "image";
     case Colour3DPlot: return "colour3d";
@@ -266,6 +276,7 @@
     case Notes: return "notes";
     case FlexiNotes: return "flexinotes";
     case Regions: return "regions";
+    case Boxes: return "boxes";
     case Text: return "text";
     case Image: return "image";
     case Colour3DPlot: return "colour3dplot";
@@ -291,6 +302,7 @@
     if (name == "notes") return Notes;
     if (name == "flexinotes") return FlexiNotes;
     if (name == "regions") return Regions;
+    if (name == "boxes" || name == "timefrequencybox") return Boxes;
     if (name == "text") return Text;
     if (name == "image") return Image;
     if (name == "colour3dplot") return Colour3DPlot;
@@ -329,6 +341,9 @@
     if (trySetModel<RegionLayer, RegionModel>(layer, model))
         return;
 
+    if (trySetModel<BoxLayer, BoxModel>(layer, model))
+        return;
+
     if (trySetModel<TextLayer, TextModel>(layer, model))
         return;
 
@@ -360,6 +375,8 @@
         return std::make_shared<NoteModel>(rate, 1, true);
     } else if (layerType == Regions) {
         return std::make_shared<RegionModel>(rate, 1, true);
+    } else if (layerType == Boxes) {
+        return std::make_shared<BoxModel>(rate, 1, true);
     } else if (layerType == Text) {
         return std::make_shared<TextModel>(rate, 1, true);
     } else if (layerType == Image) {
@@ -437,6 +454,10 @@
         layer = new RegionLayer;
         break;
 
+    case Boxes:
+        layer = new BoxLayer;
+        break;
+
     case Text:
         layer = new TextLayer;
         break;
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/LayerFactory.h
--- a/layer/LayerFactory.h	Tue Sep 17 12:50:58 2019 +0100
+++ b/layer/LayerFactory.h	Wed Sep 25 13:48:04 2019 +0100
@@ -38,6 +38,7 @@
         Notes,
         FlexiNotes,
         Regions,
+        Boxes,
         Text,
         Image,
         Colour3DPlot,
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/NoteLayer.cpp
--- a/layer/NoteLayer.cpp	Tue Sep 17 12:50:58 2019 +0100
+++ b/layer/NoteLayer.cpp	Wed Sep 25 13:48:04 2019 +0100
@@ -1062,13 +1062,12 @@
     Event note(0);
     if (!getPointToDrag(v, e->x(), e->y(), note)) return false;
 
-//    Event note = *points.begin();
-
     ItemEditDialog *dialog = new ItemEditDialog
         (model->getSampleRate(),
          ItemEditDialog::ShowTime |
          ItemEditDialog::ShowDuration |
          ItemEditDialog::ShowValue |
+         ItemEditDialog::ShowLevel |
          ItemEditDialog::ShowText,
          getScaleUnits());
 
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/SliceableLayer.h
--- a/layer/SliceableLayer.h	Tue Sep 17 12:50:58 2019 +0100
+++ b/layer/SliceableLayer.h	Wed Sep 25 13:48:04 2019 +0100
@@ -35,14 +35,6 @@
     // The SliceableLayer retains ownership of the model, and will
     // emit sliceableModelReplaced if it is about to become invalid.
     virtual ModelId getSliceableModel() const = 0;
-/*!!!
-signals:
-    // Emitted when a model that was obtained through
-    // getSliceableModel is about to be deleted.  If replacement is
-    // non-NULL, it may be used instead.
-    void sliceableModelReplaced(const Model *modelToBeReplaced,
-                                const Model *replacement);
-*/
 };
 
 #endif
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/SpectrogramLayer.h
--- a/layer/SpectrogramLayer.h	Tue Sep 17 12:50:58 2019 +0100
+++ b/layer/SpectrogramLayer.h	Wed Sep 25 13:48:04 2019 +0100
@@ -230,7 +230,7 @@
     QString getError(LayerGeometryProvider *v) const override;
 
     bool getValueExtents(double &min, double &max,
-                                 bool &logarithmic, QString &unit) const override;
+                         bool &logarithmic, QString &unit) const override;
 
     bool getDisplayExtents(double &min, double &max) const override;
 
diff -r 872873aa6463 -r d5ef91dc2ea7 layer/VerticalBinLayer.h
--- a/layer/VerticalBinLayer.h	Tue Sep 17 12:50:58 2019 +0100
+++ b/layer/VerticalBinLayer.h	Wed Sep 25 13:48:04 2019 +0100
@@ -20,9 +20,10 @@
 
 /**
  * Interface for layers in which the Y axis corresponds to bin number
- * rather than scale value. Colour3DPlotLayer is the obvious example.
- * Conceptually these are always SliceableLayers as well, and this
- * subclasses from SliceableLayer to avoid a big inheritance mess.
+ * rather than scale value. Colour3DPlotLayer and SpectrogramLayer are
+ * obvious examples.  Conceptually these are always SliceableLayers as
+ * well, and this subclasses from SliceableLayer to avoid a big
+ * inheritance mess.
  */
 class VerticalBinLayer : public SliceableLayer
 {
diff -r 872873aa6463 -r d5ef91dc2ea7 view/Pane.h
--- a/view/Pane.h	Tue Sep 17 12:50:58 2019 +0100
+++ b/view/Pane.h	Wed Sep 25 13:48:04 2019 +0100
@@ -106,6 +106,10 @@
     void mouseEnteredWidget();
     void mouseLeftWidget();
 
+    bool getTopLayerDisplayExtents(double &valueMin, double &valueMax,
+                                   double &displayMin, double &displayMax,
+                                   QString *unit = 0);
+
 protected slots:
     void playbackScheduleTimerElapsed();
 
@@ -149,9 +153,6 @@
     void updateVerticalPanner();
 
     bool canTopLayerMoveVertical();
-    bool getTopLayerDisplayExtents(double &valueMin, double &valueMax,
-                                   double &displayMin, double &displayMax,
-                                   QString *unit = 0);
     bool setTopLayerDisplayExtents(double displayMin, double displayMax);
 
     void dragTopLayer(QMouseEvent *e);
diff -r 872873aa6463 -r d5ef91dc2ea7 view/View.h
--- a/view/View.h	Tue Sep 17 12:50:58 2019 +0100
+++ b/view/View.h	Wed Sep 25 13:48:04 2019 +0100
@@ -354,7 +354,7 @@
     int getTextLabelHeight(const Layer *layer, QPainter &) const override;
 
     bool getValueExtents(QString unit, double &min, double &max,
-                                 bool &log) const override;
+                         bool &log) const override;
 
     void toXml(QTextStream &stream, QString indent = "",
                        QString extraAttributes = "") const override;
diff -r 872873aa6463 -r d5ef91dc2ea7 widgets/CSVFormatDialog.cpp
--- a/widgets/CSVFormatDialog.cpp	Tue Sep 17 12:50:58 2019 +0100
+++ b/widgets/CSVFormatDialog.cpp	Wed Sep 25 13:48:04 2019 +0100
@@ -318,6 +318,9 @@
     case CSVFormat::TwoDimensionalModelWithDurationAndPitch:
         s = f->getLayerPresentationName(LayerFactory::Notes);
         break;
+    case CSVFormat::TwoDimensionalModelWithDurationAndExtent:
+        s = f->getLayerPresentationName(LayerFactory::Boxes);
+        break;
     case CSVFormat::ThreeDimensionalModel:
         s = f->getLayerPresentationName(LayerFactory::Colour3DPlot);
         break;
@@ -582,6 +585,8 @@
     if (haveStartTime && haveDuration) {
         if (havePitch) {
             m_format.setModelType(CSVFormat::TwoDimensionalModelWithDurationAndPitch);
+        } else if (valueCount == 2) {
+            m_format.setModelType(CSVFormat::TwoDimensionalModelWithDurationAndExtent);
         } else {
             m_format.setModelType(CSVFormat::TwoDimensionalModelWithDuration);
         }
diff -r 872873aa6463 -r d5ef91dc2ea7 widgets/ItemEditDialog.cpp
--- a/widgets/ItemEditDialog.cpp	Tue Sep 17 12:50:58 2019 +0100
+++ b/widgets/ItemEditDialog.cpp	Wed Sep 25 13:48:04 2019 +0100
@@ -28,13 +28,30 @@
 #include <float.h> // for FLT_MIN/MAX
 
 
+ItemEditDialog::LabelOptions::LabelOptions() :
+    valueLabel(tr("Value")),
+    levelLabel(tr("Level"))
+{
+}
+
 ItemEditDialog::ItemEditDialog(sv_samplerate_t sampleRate, int options,
-                               QString valueUnits, QWidget *parent) :
+                               QString scaleUnits, QWidget *parent) :
+    ItemEditDialog(sampleRate, options,
+                   [] (QString units) {
+                       ItemEditDialog::LabelOptions labelOptions;
+                       labelOptions.valueUnits = units;
+                       return labelOptions;
+                   }(scaleUnits),
+                   parent) {};
+
+ItemEditDialog::ItemEditDialog(sv_samplerate_t sampleRate, int options,
+                               LabelOptions labelOptions, QWidget *parent) :
     QDialog(parent),
     m_sampleRate(sampleRate),
     m_defaultFrame(0),
     m_defaultDuration(0),
     m_defaultValue(0),
+    m_defaultLevel(0),
     m_frameTimeSpinBox(nullptr),
     m_realTimeSecsSpinBox(nullptr),
     m_realTimeUSecsSpinBox(nullptr),
@@ -42,6 +59,7 @@
     m_realDurationSecsSpinBox(nullptr),
     m_realDurationUSecsSpinBox(nullptr),
     m_valueSpinBox(nullptr),
+    m_levelSpinBox(nullptr),
     m_textField(nullptr)
 {
     QGridLayout *grid = new QGridLayout;
@@ -129,7 +147,9 @@
         ++subrow;
     }
 
-    if ((options & ShowValue) || (options & ShowText)) {
+    if ((options & ShowValue) ||
+        (options & ShowLevel) ||
+        (options & ShowText)) {
 
         valueBox = new QGroupBox;
         valueBox->setTitle(tr("Properties"));
@@ -145,10 +165,11 @@
 
     if (options & ShowValue) {
         
-        subgrid->addWidget(new QLabel(tr("Value:")), subrow, 0);
+        subgrid->addWidget(new QLabel(tr("%1:").arg(labelOptions.valueLabel)),
+                           subrow, 0);
 
         m_valueSpinBox = new QDoubleSpinBox;
-        m_valueSpinBox->setSuffix(QString(" %1").arg(valueUnits));
+        m_valueSpinBox->setSuffix(QString(" %1").arg(labelOptions.valueUnits));
         m_valueSpinBox->setDecimals(10);
         m_valueSpinBox->setMinimum(-1e10);
         m_valueSpinBox->setMaximum(1e10);
@@ -159,6 +180,23 @@
         ++subrow;
     }
 
+    if (options & ShowLevel) {
+        
+        subgrid->addWidget(new QLabel(tr("%1:").arg(labelOptions.levelLabel)),
+                           subrow, 0);
+
+        m_levelSpinBox = new QDoubleSpinBox;
+        m_levelSpinBox->setSuffix(QString(" %1").arg(labelOptions.levelUnits));
+        m_levelSpinBox->setDecimals(10);
+        m_levelSpinBox->setMinimum(-1e10);
+        m_levelSpinBox->setMaximum(1e10);
+        connect(m_levelSpinBox, SIGNAL(levelChanged(double)),
+                this, SLOT(levelChanged(double)));
+        subgrid->addWidget(m_levelSpinBox, subrow, 1);
+
+        ++subrow;
+    }
+
     if (options & ShowText) {
         
         subgrid->addWidget(new QLabel(tr("Text:")), subrow, 0);
@@ -175,6 +213,8 @@
         m_textField->setFocus(Qt::OtherFocusReason);
     } else if (options & ShowValue) {
         m_valueSpinBox->setFocus(Qt::OtherFocusReason);
+    } else if (options & ShowLevel) {
+        m_levelSpinBox->setFocus(Qt::OtherFocusReason);
     }
     
     QDialogButtonBox *bb = new QDialogButtonBox(Qt::Horizontal);
@@ -271,6 +311,22 @@
 }
 
 void
+ItemEditDialog::setLevel(float v)
+{
+    if (!m_levelSpinBox) return;
+
+    m_levelSpinBox->setValue(v);
+    m_defaultLevel = v;
+    m_resetButton->setEnabled(false);
+}
+
+float
+ItemEditDialog::getLevel() const
+{
+    return float(m_levelSpinBox->value());
+}
+
+void
 ItemEditDialog::setText(QString text)
 {
     if (!m_textField) return;
@@ -363,6 +419,12 @@
 }
 
 void
+ItemEditDialog::levelChanged(double)
+{
+    m_resetButton->setEnabled(true);
+}
+
+void
 ItemEditDialog::textChanged(QString)
 {
     m_resetButton->setEnabled(true);
@@ -374,6 +436,7 @@
     setFrameTime(m_defaultFrame);
     setFrameDuration(m_defaultDuration);
     setValue(m_defaultValue);
+    setLevel(m_defaultLevel);
     setText(m_defaultText);
     m_resetButton->setEnabled(false);
 }
diff -r 872873aa6463 -r d5ef91dc2ea7 widgets/ItemEditDialog.h
--- a/widgets/ItemEditDialog.h	Tue Sep 17 12:50:58 2019 +0100
+++ b/widgets/ItemEditDialog.h	Wed Sep 25 13:48:04 2019 +0100
@@ -34,10 +34,26 @@
         ShowTime       = 1 << 0,
         ShowDuration   = 1 << 1,
         ShowValue      = 1 << 2,
-        ShowText       = 1 << 3
+        ShowText       = 1 << 3,
+        ShowLevel      = 1 << 4
     };
 
-    ItemEditDialog(sv_samplerate_t sampleRate, int options, QString valueUnits = "",
+    struct LabelOptions {
+        LabelOptions();
+        QString valueLabel;
+        QString levelLabel;
+        QString valueUnits;
+        QString levelUnits;
+    };
+    
+    ItemEditDialog(sv_samplerate_t sampleRate,
+                   int options,
+                   LabelOptions labelOptions = {},
+                   QWidget *parent = 0);
+    
+    ItemEditDialog(sv_samplerate_t sampleRate,
+                   int options,
+                   QString scaleUnits,
                    QWidget *parent = 0);
 
     void setFrameTime(sv_frame_t frame);
@@ -55,6 +71,9 @@
     void setValue(float value);
     float getValue() const;
 
+    void setLevel(float level);
+    float getLevel() const;
+
     void setText(QString text);
     QString getText() const;
 
@@ -66,6 +85,7 @@
     void realDurationSecsChanged(int);
     void realDurationUSecsChanged(int);
     void valueChanged(double);
+    void levelChanged(double);
     void textChanged(QString);
     void reset();
 
@@ -74,6 +94,7 @@
     sv_frame_t m_defaultFrame;
     sv_frame_t m_defaultDuration;
     float m_defaultValue;
+    float m_defaultLevel;
     QString m_defaultText;
     QSpinBox *m_frameTimeSpinBox;
     QSpinBox *m_realTimeSecsSpinBox;
@@ -82,6 +103,7 @@
     QSpinBox *m_realDurationSecsSpinBox;
     QSpinBox *m_realDurationUSecsSpinBox;
     QDoubleSpinBox *m_valueSpinBox;
+    QDoubleSpinBox *m_levelSpinBox;
     QLineEdit *m_textField;
     QPushButton *m_resetButton;
 };