view layer/TimeValueLayer.cpp @ 1534:bfd8b22fd67c

Fix #1904 Scrolling colour 3d plot does not always work when in View normalisation mode. We shouldn't imagine we've just invalidated the cache if the truth is that we've only just created the renderer

/* -*- 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 file copyright 2006 Chris Cannam.
    
    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 "TimeValueLayer.h"

#include "data/model/Model.h"
#include "base/RealTime.h"
#include "base/Profiler.h"
#include "base/LogRange.h"
#include "base/RangeMapper.h"
#include "base/Pitch.h"
#include "view/View.h"

#include "data/model/SparseTimeValueModel.h"
#include "data/model/Labeller.h"

#include "widgets/ItemEditDialog.h"
#include "widgets/ListInputDialog.h"
#include "widgets/TextAbbrev.h"

#include "ColourDatabase.h"
#include "ColourMapper.h"
#include "PianoScale.h"
#include "LinearNumericalScale.h"
#include "LogNumericalScale.h"
#include "LinearColourScale.h"
#include "LogColourScale.h"
#include "PaintAssistant.h"

#include <QPainter>
#include <QPainterPath>
#include <QMouseEvent>
#include <QRegExp>
#include <QTextStream>
#include <QMessageBox>
#include <QInputDialog>

#include <iostream>
#include <cmath>

//#define DEBUG_TIME_VALUE_LAYER 1

TimeValueLayer::TimeValueLayer() :
    SingleColourLayer(),
    m_editing(false),
    m_originalPoint(0, 0.0, tr("New Point")),
    m_editingPoint(0, 0.0, tr("New Point")),
    m_editingCommand(nullptr),
    m_colourMap(0),
    m_colourInverted(false),
    m_plotStyle(PlotConnectedPoints),
    m_verticalScale(AutoAlignScale),
    m_drawSegmentDivisions(true),
    m_derivative(false),
    m_scaleMinimum(0),
    m_scaleMaximum(0)
{
    
}

int
TimeValueLayer::getCompletion(LayerGeometryProvider *) const
{
    auto model = ModelById::get(m_model);
    if (model) return model->getCompletion();
    else return 0;
}

void
TimeValueLayer::setModel(ModelId modelId)
{
    auto newModel = ModelById::getAs<SparseTimeValueModel>(modelId);
    
    if (!modelId.isNone() && !newModel) {
        throw std::logic_error("Not a SparseTimeValueModel");
    }
    
    if (m_model == modelId) return;
    m_model = modelId;

    if (newModel) {
        
        connectSignals(m_model);

        m_scaleMinimum = 0;
        m_scaleMaximum = 0;

        if (newModel->getRDFTypeURI().endsWith("Segment")) {
            setPlotStyle(PlotSegmentation);
        }
        if (newModel->getRDFTypeURI().endsWith("Change")) {
            setPlotStyle(PlotSegmentation);
        }
    }
    
    emit modelReplaced();
}

Layer::PropertyList
TimeValueLayer::getProperties() const
{
    PropertyList list = SingleColourLayer::getProperties();
    list.push_back("Plot Type");
    list.push_back("Vertical Scale");
    list.push_back("Scale Units");
    list.push_back("Draw Segment Division Lines");
    list.push_back("Show Derivative");
    return list;
}

QString
TimeValueLayer::getPropertyLabel(const PropertyName &name) const
{
    if (name == "Plot Type") return tr("Plot Type");
    if (name == "Vertical Scale") return tr("Vertical Scale");
    if (name == "Scale Units") return tr("Scale Units");
    if (name == "Draw Segment Division Lines") return tr("Draw Segment Division Lines");
    if (name == "Show Derivative") return tr("Show Derivative");
    return SingleColourLayer::getPropertyLabel(name);
}

QString
TimeValueLayer::getPropertyIconName(const PropertyName &name) const
{
    if (name == "Draw Segment Division Lines") return "lines";
    if (name == "Show Derivative") return "derivative";
    return "";
}

Layer::PropertyType
TimeValueLayer::getPropertyType(const PropertyName &name) const
{
    if (name == "Plot Type") return ValueProperty;
    if (name == "Vertical Scale") return ValueProperty;
    if (name == "Scale Units") return UnitsProperty;
    if (name == "Colour" && m_plotStyle == PlotSegmentation) return ColourMapProperty;
    if (name == "Draw Segment Division Lines") return ToggleProperty;
    if (name == "Show Derivative") return ToggleProperty;
    return SingleColourLayer::getPropertyType(name);
}

QString
TimeValueLayer::getPropertyGroupName(const PropertyName &name) const
{
    if (name == "Vertical Scale" || name == "Scale Units") {
        return tr("Scale");
    }
    if (name == "Plot Type" || name == "Draw Segment Division Lines" ||
        name == "Show Derivative") {
        return tr("Plot Type");
    }
    return SingleColourLayer::getPropertyGroupName(name);
}

bool
TimeValueLayer::needsTextLabelHeight() const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return false;
    return m_plotStyle == PlotSegmentation && model->hasTextLabels();
}

QString
TimeValueLayer::getScaleUnits() const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (model) return model->getScaleUnits();
    else return "";
}

int
TimeValueLayer::getPropertyRangeAndValue(const PropertyName &name,
                                         int *min, int *max, int *deflt) const
{
    int val = 0;

    if (name == "Colour" && m_plotStyle == PlotSegmentation) {
            
        if (min) *min = 0;
        if (max) *max = ColourMapper::getColourMapCount() - 1;
        if (deflt) *deflt = 0;
        
        val = m_colourMap;

    } else if (name == "Plot Type") {
        
        if (min) *min = 0;
        if (max) *max = 6;
        if (deflt) *deflt = int(PlotConnectedPoints);
        
        val = int(m_plotStyle);

    } else if (name == "Vertical Scale") {
        
        if (min) *min = 0;
        if (max) *max = 3;
        if (deflt) *deflt = int(AutoAlignScale);
        
        val = int(m_verticalScale);

    } else if (name == "Scale Units") {

        if (deflt) *deflt = 0;
        auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
        if (model) {
            val = UnitDatabase::getInstance()->getUnitId
                (getScaleUnits());
        }

    } else if (name == "Draw Segment Division Lines") {

        if (min) *min = 0;
        if (max) *max = 1;
        if (deflt) *deflt = 1;
        val = (m_drawSegmentDivisions ? 1.0 : 0.0);

    } else if (name == "Show Derivative") {

        if (min) *min = 0;
        if (max) *max = 1;
        if (deflt) *deflt = 0;
        val = (m_derivative ? 1.0 : 0.0);

    } else {
        
        val = SingleColourLayer::getPropertyRangeAndValue(name, min, max, deflt);
    }

    return val;
}

QString
TimeValueLayer::getPropertyValueLabel(const PropertyName &name,
                                    int value) const
{
    if (name == "Colour" && m_plotStyle == PlotSegmentation) {
        return ColourMapper::getColourMapLabel(value);
    } else if (name == "Plot Type") {
        switch (value) {
        default:
        case 0: return tr("Points");
        case 1: return tr("Stems");
        case 2: return tr("Connected Points");
        case 3: return tr("Lines");
        case 4: return tr("Curve");
        case 5: return tr("Segmentation");
        case 6: return tr("Discrete Curves");
        }
    } else if (name == "Vertical Scale") {
        switch (value) {
        default:
        case 0: return tr("Auto-Align");
        case 1: return tr("Linear");
        case 2: return tr("Log");
        case 3: return tr("+/-1");
        }
    }
    return SingleColourLayer::getPropertyValueLabel(name, value);
}

void
TimeValueLayer::setProperty(const PropertyName &name, int value)
{
    if (name == "Colour" && m_plotStyle == PlotSegmentation) {
        setFillColourMap(value);
    } else if (name == "Plot Type") {
        setPlotStyle(PlotStyle(value));
    } else if (name == "Vertical Scale") {
        setVerticalScale(VerticalScale(value));
    } else if (name == "Scale Units") {
        auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
        if (model) {
            model->setScaleUnits
                (UnitDatabase::getInstance()->getUnitById(value));
            emit modelChanged(m_model);
        }
    } else if (name == "Draw Segment Division Lines") {
        setDrawSegmentDivisions(value > 0.5);
    } else if (name == "Show Derivative") {
        setShowDerivative(value > 0.5);
    } else {
        SingleColourLayer::setProperty(name, value);
    }
}

void
TimeValueLayer::setFillColourMap(int map)
{
    if (m_colourMap == map) return;
    m_colourMap = map;
    emit layerParametersChanged();
}

void
TimeValueLayer::setPlotStyle(PlotStyle style)
{
    if (m_plotStyle == style) return;
    bool colourTypeChanged = (style == PlotSegmentation ||
                              m_plotStyle == PlotSegmentation);
    m_plotStyle = style;
    if (colourTypeChanged) {
        emit layerParameterRangesChanged();
    }
    emit layerParametersChanged();
}

void
TimeValueLayer::setVerticalScale(VerticalScale scale)
{
    if (m_verticalScale == scale) return;
    m_verticalScale = scale;
    emit layerParametersChanged();
}

void
TimeValueLayer::setDrawSegmentDivisions(bool draw)
{
    if (m_drawSegmentDivisions == draw) return;
    m_drawSegmentDivisions = draw;
    emit layerParametersChanged();
}

void
TimeValueLayer::setShowDerivative(bool show)
{
    if (m_derivative == show) return;
    m_derivative = show;
    emit layerParametersChanged();
}

bool
TimeValueLayer::isLayerScrollable(const LayerGeometryProvider *v) const
{
    // We don't illuminate sections in the line or curve modes, so
    // they're always scrollable

    if (m_plotStyle == PlotLines ||
        m_plotStyle == PlotCurve ||
        m_plotStyle == PlotDiscreteCurves) return true;

    QPoint discard;
    return !v->shouldIlluminateLocalFeatures(this, discard);
}

bool
TimeValueLayer::getValueExtents(double &min, double &max,
                                bool &logarithmic, QString &unit) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return false;

    min = model->getValueMinimum();
    max = model->getValueMaximum();

    logarithmic = (m_verticalScale == LogScale);

    unit = getScaleUnits();

    if (m_derivative) {
        max = std::max(fabs(min), fabs(max));
        min = -max;
    }

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::getValueExtents: min = " << min << ", max = " << max << endl;
#endif

    if (!shouldAutoAlign() && !logarithmic && !m_derivative) {

        if (max == min) {
            max = max + 0.5;
            min = min - 0.5;
        } else {
            double margin = (max - min) / 10.0;
            max = max + margin;
            min = min - margin;
        }

#ifdef DEBUG_TIME_VALUE_LAYER
        cerr << "TimeValueLayer::getValueExtents: min = " << min << ", max = " << max << " (after adjustment)" << endl;
#endif
    }

    return true;
}

bool
TimeValueLayer::getDisplayExtents(double &min, double &max) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || shouldAutoAlign()) return false;

    if (m_scaleMinimum == m_scaleMaximum) {
        bool log;
        QString unit;
        getValueExtents(min, max, log, unit);
    } else {
        min = m_scaleMinimum;
        max = m_scaleMaximum;
    }

    if (m_derivative) {
        max = std::max(fabs(min), fabs(max));
        min = -max;
    }

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::getDisplayExtents: min = " << min << ", max = " << max << endl;
#endif

    return true;
}

bool
TimeValueLayer::setDisplayExtents(double min, double max)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return false;

    if (min == max) {
        if (min == 0.f) {
            max = 1.f;
        } else {
            max = min * 1.0001;
        }
    }

    m_scaleMinimum = min;
    m_scaleMaximum = max;

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::setDisplayExtents: min = " << min << ", max = " << max << endl;
#endif
    
    emit layerParametersChanged();
    return true;
}

int
TimeValueLayer::getVerticalZoomSteps(int &defaultStep) const
{
    if (shouldAutoAlign()) return 0;
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return 0;

    defaultStep = 0;
    return 100;
}

int
TimeValueLayer::getCurrentVerticalZoomStep() const
{
    if (shouldAutoAlign()) return 0;
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return 0;

    RangeMapper *mapper = getNewVerticalZoomRangeMapper();
    if (!mapper) return 0;

    double dmin, dmax;
    getDisplayExtents(dmin, dmax);

    int nr = mapper->getPositionForValue(dmax - dmin);

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::getCurrentVerticalZoomStep: dmin = " << dmin << ", dmax = " << dmax << ", nr = " << nr << endl;
#endif

    delete mapper;

    return 100 - nr;
}

void
TimeValueLayer::setVerticalZoomStep(int step)
{
    if (shouldAutoAlign()) return;
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return;

    RangeMapper *mapper = getNewVerticalZoomRangeMapper();
    if (!mapper) return;
    
    double min, max;
    bool logarithmic;
    QString unit;
    getValueExtents(min, max, logarithmic, unit);
    
    double dmin, dmax;
    getDisplayExtents(dmin, dmax);

    double newdist = mapper->getValueForPosition(100 - step);

    double newmin, newmax;

    if (logarithmic) {

        // see SpectrogramLayer::setVerticalZoomStep

        newmax = (newdist + sqrt(newdist*newdist + 4*dmin*dmax)) / 2;
        newmin = newmax - newdist;

#ifdef DEBUG_TIME_VALUE_LAYER
        cerr << "newmin = " << newmin << ", newmax = " << newmax << endl;
#endif

    } else {
        double dmid = (dmax + dmin) / 2;
        newmin = dmid - newdist / 2;
        newmax = dmid + newdist / 2;
    }

    if (newmin < min) {
        newmax += (min - newmin);
        newmin = min;
    }
    if (newmax > max) {
        newmax = max;
    }
    
#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::setVerticalZoomStep: " << step << ": " << newmin << " -> " << newmax << " (range " << newdist << ")" << endl;
#endif

    setDisplayExtents(newmin, newmax);
}

RangeMapper *
TimeValueLayer::getNewVerticalZoomRangeMapper() const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return nullptr;
    
    RangeMapper *mapper;

    double min, max;
    bool logarithmic;
    QString unit;
    getValueExtents(min, max, logarithmic, unit);

    if (min == max) return nullptr;
    
    if (logarithmic) {
        mapper = new LogRangeMapper(0, 100, min, max, unit);
    } else {
        mapper = new LinearRangeMapper(0, 100, min, max, unit);
    }

    return mapper;
}

EventVector
TimeValueLayer::getLocalPoints(LayerGeometryProvider *v, int x) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return {};

    // Return all points at a frame f, where f is the closest frame to
    // pixel coordinate x whose pixel coordinate is both within a
    // small (but somewhat arbitrary) fuzz distance from x and within
    // the current view. If there is no such frame, return an empty
    // vector.
    
    sv_frame_t frame = v->getFrameForX(x);
    
    EventVector exact = model->getEventsStartingAt(frame);
    if (!exact.empty()) return exact;

    // overspill == 1, so one event either side of the given span
    EventVector neighbouring = model->getEventsWithin
        (frame, model->getResolution(), 1);

    double fuzz = v->scaleSize(2);
    sv_frame_t suitable = 0;
    bool have = false;
    
    for (Event e: neighbouring) {
        sv_frame_t f = e.getFrame();
        if (f < v->getStartFrame() || f > v->getEndFrame()) {
            continue;
        }
        int px = v->getXForFrame(f);
        if ((px > x && px - x > fuzz) || (px < x && x - px > fuzz + 3)) {
            continue;
        }
        if (!have) {
            suitable = f;
            have = true;
        } else if (llabs(frame - f) < llabs(suitable - f)) {
            suitable = f;
        }
    }

    if (have) {
        return model->getEventsStartingAt(suitable);
    } else {
        return {};
    }
}

QString
TimeValueLayer::getLabelPreceding(sv_frame_t frame) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || !model->hasTextLabels()) return "";

    Event e;
    if (model->getNearestEventMatching
        (frame,
         [](Event e) { return e.hasLabel() && e.getLabel() != ""; },
         EventSeries::Backward,
         e)) {
        return e.getLabel();
    }

    return "";
}

QString
TimeValueLayer::getFeatureDescription(LayerGeometryProvider *v, QPoint &pos) const
{
    int x = pos.x();

    auto model = ModelById::getAs<SparseTimeValueModel>(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");
        }
    }

    sv_frame_t useFrame = points.begin()->getFrame();

    RealTime rt = RealTime::frame2RealTime(useFrame, model->getSampleRate());
    
    QString valueText;
    float value = points.begin()->getValue();
    QString unit = getScaleUnits();

    if (unit == "Hz") {
        valueText = tr("%1 Hz (%2, %3)")
            .arg(value)
            .arg(Pitch::getPitchLabelForFrequency(value))
            .arg(Pitch::getPitchForFrequency(value));
    } else if (unit != "") {
        valueText = tr("%1 %2").arg(value).arg(unit);
    } else {
        valueText = tr("%1").arg(value);
    }
    
    QString text;

    if (points.begin()->getLabel() == "") {
        text = QString(tr("Time:\t%1\nValue:\t%2\nNo label"))
            .arg(rt.toText(true).c_str())
            .arg(valueText);
    } else {
        text = QString(tr("Time:\t%1\nValue:\t%2\nLabel:\t%4"))
            .arg(rt.toText(true).c_str())
            .arg(valueText)
            .arg(points.begin()->getLabel());
    }

    pos = QPoint(v->getXForFrame(useFrame),
                 getYForValue(v, points.begin()->getValue()));
    return text;
}

bool
TimeValueLayer::snapToFeatureFrame(LayerGeometryProvider *v,
                                   sv_frame_t &frame,
                                   int &resolution,
                                   SnapType snap) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(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;
    }

    Event e;
    if (model->getNearestEventMatching
        (frame,
         [](Event) { return true; },
         snap == SnapLeft ? EventSeries::Backward : EventSeries::Forward,
         e)) {
        frame = e.getFrame();
        return true;
    }

    return false;
}

bool
TimeValueLayer::snapToSimilarFeature(LayerGeometryProvider *v,
                                     sv_frame_t &frame,
                                     int &resolution,
                                     SnapType snap) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) {
        return Layer::snapToSimilarFeature(v, frame, resolution, snap);
    }

    // snap is only permitted to be SnapLeft or SnapRight here.
    
    resolution = model->getResolution();

    Event ref;
    Event e;
    float matchvalue;
    bool found;

    found = model->getNearestEventMatching
        (frame, [](Event) { return true; }, EventSeries::Backward, ref);

    if (!found) {
        return false;
    }

    matchvalue = ref.getValue();
    
    found = model->getNearestEventMatching
        (frame,
         [matchvalue](Event e) {
             double epsilon = 0.0001;
             return fabs(e.getValue() - matchvalue) < epsilon;
         },
         snap == SnapLeft ? EventSeries::Backward : EventSeries::Forward,
         e);

    if (!found) {
        return false;
    }

    frame = e.getFrame();
    return true;
}

void
TimeValueLayer::getScaleExtents(LayerGeometryProvider *v, double &min, double &max, bool &log) const
{
    min = 0.0;
    max = 0.0;
    log = false;

    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return;

    if (shouldAutoAlign()) {

        if (!v->getValueExtents(getScaleUnits(), min, max, log)) {
            min = model->getValueMinimum();
            max = model->getValueMaximum();
        } else if (log) {
            LogRange::mapRange(min, max);
        }

    } else if (m_verticalScale == PlusMinusOneScale) {

        min = -1.0;
        max = 1.0;

    } else {

        getDisplayExtents(min, max);
        
        if (m_verticalScale == LogScale) {
            LogRange::mapRange(min, max);
            log = true;
        }
    }

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::getScaleExtents: min = " << min << ", max = " << max << endl;
#endif
}

int
TimeValueLayer::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);

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "getYForValue(" << val << "): min " << min << ", max "
              << max << ", log " << logarithmic << endl;
#endif

    if (logarithmic) {
        val = LogRange::map(val);
    }

    return int(h - ((val - min) * h) / (max - min));
}

double
TimeValueLayer::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 = LogRange::map(val);
    }

    return val;
}

bool
TimeValueLayer::shouldAutoAlign() const
{
    QString unit = getScaleUnits();
    return (m_verticalScale == AutoAlignScale && unit != "");
}

QColor
TimeValueLayer::getColourForValue(LayerGeometryProvider *v, double val) const
{
    double min, max;
    bool log;
    getScaleExtents(v, min, max, log);

    if (min > max) std::swap(min, max);
    if (max == min) max = min + 1;

    if (log) {
        val = LogRange::map(val);
    }

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::getColourForValue: min " << min << ", max "
              << max << ", log " << log << ", value " << val << endl;
#endif

    QColor solid = ColourMapper(m_colourMap, m_colourInverted, min, max).map(val);
    return QColor(solid.red(), solid.green(), solid.blue(), 120);
}

int
TimeValueLayer::getDefaultColourHint(bool darkbg, bool &impose)
{
    impose = false;
    return ColourDatabase::getInstance()->getColourIndex
        (QString(darkbg ? "Bright Green" : "Green"));
}

void
TimeValueLayer::paint(LayerGeometryProvider *v, QPainter &paint, QRect rect) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || !model->isOK()) return;

    sv_samplerate_t sampleRate = model->getSampleRate();
    if (!sampleRate) return;

#ifdef DEBUG_TIME_VALUE_LAYER
    SVCERR << "TimeValueLayer[" << this << ", model " << getModel() << "]::paint in " << v->getId() << endl;
#endif
    
    paint.setRenderHint(QPainter::Antialiasing, false);

//    Profiler profiler("TimeValueLayer::paint", true);

    int x0 = rect.left(), x1 = rect.right();
    sv_frame_t frame0 = v->getFrameForX(x0);
    sv_frame_t frame1 = v->getFrameForX(x1);
    if (m_derivative) --frame0;

    EventVector points(model->getEventsWithin(frame0, frame1 - frame0, 1));

#ifdef DEBUG_TIME_VALUE_LAYER
    SVCERR << "TimeValueLayer[" << this << "]::paint in " << v->getId()
           << ": pixel extents " << x0 << " to " << x1 << ", frame extents "
           << frame0 << " to " << frame1 << " yielding " << points.size()
           << " points (of " << model->getAllEvents().size()
           << " from frames " << model->getStartFrame() << " to "
           << model->getEndFrame() << ")" << endl;
#endif
    
    if (points.empty()) return;

    paint.setPen(getBaseQColor());

    QColor brushColour(getBaseQColor());
    brushColour.setAlpha(80);
    paint.setBrush(brushColour);

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::paint: resolution is "
         << model->getResolution() << " frames" << endl;
#endif

    double min = model->getValueMinimum();
    double max = model->getValueMaximum();
    if (max == min) max = min + 1.0;

    int origin = int(nearbyint(v->getPaintHeight() -
                               (-min * v->getPaintHeight()) / (max - min)));

    QPoint localPos;
    sv_frame_t illuminateFrame = -1;

    if (v->shouldIlluminateLocalFeatures(this, localPos)) {
        EventVector localPoints = getLocalPoints(v, localPos.x());
#ifdef DEBUG_TIME_VALUE_LAYER
        cerr << "TimeValueLayer: " << localPoints.size() << " local points" << endl;
#endif
        if (!localPoints.empty()) {
            illuminateFrame = localPoints.begin()->getFrame();
        }
    }

    int w =
        v->getXForFrame(frame0 + model->getResolution()) -
        v->getXForFrame(frame0);

    if (m_plotStyle == PlotStems) {
        if (w < 2) w = 2;
    } else {
        if (w < 1) w = 1;
    }

    paint.save();

    QPainterPath path;
    int pointCount = 0;

    int textY = 0;
    if (m_plotStyle == PlotSegmentation) {
        textY = v->getTextLabelHeight(this, paint);
    } else {
        int originY = getYForValue(v, 0.f);
        if (originY > 0 && originY < v->getPaintHeight()) {
            paint.save();
            paint.setPen(getPartialShades(v)[1]);
            paint.drawLine(x0, originY, x1, originY);
            paint.restore();
        }
    }
    
    sv_frame_t prevFrame = 0;

    for (EventVector::const_iterator i = points.begin();
         i != points.end(); ++i) {

        if (m_derivative && i == points.begin()) continue;

        Event p(*i);

        double value = p.getValue();
        if (m_derivative) {
            EventVector::const_iterator j = i;
            --j;
            value -= j->getValue();
        }

        int x = v->getXForFrame(p.getFrame());
        int y = getYForValue(v, value);

        bool gap = false;
        if (m_plotStyle == PlotDiscreteCurves) { 
            if (value == 0.0) {
                // Treat zeros as gaps
                continue;
            }
            gap = (p.getFrame() > prevFrame &&
                   (p.getFrame() - prevFrame >= model->getResolution() * 2));
        }

        if (m_plotStyle != PlotSegmentation) {
            textY = y - paint.fontMetrics().height()
                      + paint.fontMetrics().ascent() - 1;
            if (textY < paint.fontMetrics().ascent() + 1) {
                textY = paint.fontMetrics().ascent() + 1;
            }
        }

        bool haveNext = false;
        double nvalue = 0.f;
        sv_frame_t nf = v->getModelsEndFrame();
        int nx = v->getXForFrame(nf);
        int ny = y;

        EventVector::const_iterator j = i;
        ++j;

        if (j != points.end()) {
            Event q(*j);
            nvalue = q.getValue();
            if (m_derivative) nvalue -= p.getValue();
            nf = q.getFrame();
            nx = v->getXForFrame(nf);
            ny = getYForValue(v, nvalue);
            haveNext = true;
        }

//        cout << "frame = " << p.getFrame() << ", x = " << x << ", haveNext = " << haveNext 
//                  << ", nx = " << nx << endl;

        QPen pen(getBaseQColor());
        QBrush brush(brushColour);
        
        if (m_plotStyle == PlotDiscreteCurves) {
            pen = QPen(getBaseQColor(), 3);
            brush = QBrush(Qt::NoBrush);
        } else if (m_plotStyle == PlotSegmentation) {
            pen = QPen(getForegroundQColor(v));
            brush = QBrush(getColourForValue(v, value));
        } else if (m_plotStyle == PlotLines ||
                   m_plotStyle == PlotCurve) {
            brush = QBrush(Qt::NoBrush);
        }
        
        paint.setPen(v->scalePen(pen));
        paint.setBrush(brush);
        
        if (m_plotStyle == PlotStems) {
            if (y < origin - 1) {
                paint.drawLine(x + w/2, y + 1, x + w/2, origin);
            } else if (y > origin + 1) {
                paint.drawLine(x + w/2, origin, x + w/2, y - 1);
            }
        }

        bool illuminate = false;

        if (illuminateFrame == p.getFrame()) {

            // not equipped to illuminate the right section in line
            // or curve mode

            if (m_plotStyle != PlotCurve &&
                m_plotStyle != PlotDiscreteCurves &&
                m_plotStyle != PlotLines) {
                illuminate = true;
            }
        }

        if (m_plotStyle != PlotLines &&
            m_plotStyle != PlotCurve &&
            m_plotStyle != PlotDiscreteCurves &&
            m_plotStyle != PlotSegmentation) {
            if (illuminate) {
                paint.save();
                paint.setPen(v->scalePen(getForegroundQColor(v)));
                paint.setBrush(getForegroundQColor(v));
            }
            if (m_plotStyle != PlotStems ||
                w > 1) {
                paint.drawRect(x, y - 1, w, 2);
            }
            if (illuminate) {
                paint.restore();
            }
        }

        if (m_plotStyle == PlotConnectedPoints ||
            m_plotStyle == PlotLines ||
            m_plotStyle == PlotDiscreteCurves ||
            m_plotStyle == PlotCurve) {

            if (haveNext) {

                if (m_plotStyle == PlotConnectedPoints) {
                    
                    paint.save();
                    paint.setPen(v->scalePen(brushColour));
                    paint.drawLine(x + w, y, nx, ny);
                    paint.restore();

                } else if (m_plotStyle == PlotLines) {
                    
                    if (pointCount == 0) {
                        path.moveTo(x + w/2, y);
                    }

//                    paint.drawLine(x + w/2, y, nx + w/2, ny);
                    path.lineTo(nx + w/2, ny);

                } else {

                    double x0 = x + double(w)/2;
                    double x1 = nx + double(w)/2;
                    
                    double y0 = y;
                    double y1 = ny;

                    if (m_plotStyle == PlotDiscreteCurves) {
                        bool nextGap =
                            (nvalue == 0.0) ||
                            (nf - p.getFrame() >= model->getResolution() * 2);
                        if (nextGap) {
                            x1 = x0;
                            y1 = y0;
                        }
                    }

                    if (pointCount == 0 || gap) {
                        path.moveTo((x0 + x1) / 2, (y0 + y1) / 2);
                    }

                    if (nx - x > 5) {
                        path.cubicTo(x0, y0,
                                     x0, y0,
                                     (x0 + x1) / 2, (y0 + y1) / 2);

                        // // or
                        // path.quadTo(x0, y0, (x0 + x1) / 2, (y0 + y1) / 2);

                    } else {
                        path.lineTo(x0, y0);
                        path.lineTo((x0 + x1) / 2, (y0 + y1) / 2);
                    }
                }
            }
        }

        if (m_plotStyle == PlotSegmentation) {

#ifdef DEBUG_TIME_VALUE_LAYER
            cerr << "drawing rect" << endl;
#endif
            
            if (nx <= x) continue;

            paint.setPen(v->scalePen(QPen(getForegroundQColor(v), 2)));

            if (!illuminate) {
                if (!m_drawSegmentDivisions ||
                    nx < x + 5 ||
                    x >= v->getPaintWidth() - 1) {
                    paint.setPen(Qt::NoPen);
                }
            }

            paint.drawRect(x, -1, nx - x, v->getPaintHeight() + 1);
        }

        if (v->shouldShowFeatureLabels()) {

            QString label = p.getLabel();
            bool italic = false;

            if (label == "" &&
                (m_plotStyle == PlotPoints ||
                 m_plotStyle == PlotSegmentation ||
                 m_plotStyle == PlotConnectedPoints)) {
                char lc[20];
                snprintf(lc, 20, "%.3g", p.getValue());
                label = lc;
                italic = true;
            }

    // 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 (label != "") {
                // Quick test for 20px before we do the slower test using metrics
                bool haveRoom = (nx > x + 20);
                haveRoom = (haveRoom &&
                            (nx > x + 6 + paint.fontMetrics().width(label)));
                if (haveRoom ||
                    (!haveNext &&
                     (pointCount == 0 || !italic))) {
                    PaintAssistant::drawVisibleText
                        (v, paint, x + 5, textY, label,
                         italic ?
                         PaintAssistant::OutlinedItalicText :
                         PaintAssistant::OutlinedText);
                }
            }
        }

        prevFrame = p.getFrame();
        ++pointCount;
    }

    if (m_plotStyle == PlotDiscreteCurves) {
        paint.setRenderHint(QPainter::Antialiasing, true);
        paint.drawPath(path);
    } else if ((m_plotStyle == PlotCurve || m_plotStyle == PlotLines)
               && !path.isEmpty()) {
        paint.setRenderHint(QPainter::Antialiasing, pointCount <= v->getPaintWidth());
        paint.drawPath(path);
    }

    paint.restore();

    // looks like save/restore doesn't deal with this:
    paint.setRenderHint(QPainter::Antialiasing, false);
}

int
TimeValueLayer::getVerticalScaleWidth(LayerGeometryProvider *v, bool, QPainter &paint) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) {
        return 0;
    } else if (shouldAutoAlign() && !valueExtentsMatchMine(v)) {
        return 0;
    } else if (m_plotStyle == PlotSegmentation) {
        if (m_verticalScale == LogScale) {
            return LogColourScale().getWidth(v, paint);
        } else {
            return LinearColourScale().getWidth(v, paint);
        }
    } else {
        if (m_verticalScale == LogScale) {
            return LogNumericalScale().getWidth(v, paint) + 10; // for piano
        } else {
            return LinearNumericalScale().getWidth(v, paint);
        }
    }
}

void
TimeValueLayer::paintVerticalScale(LayerGeometryProvider *v, bool, QPainter &paint, QRect) const
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || model->isEmpty()) return;

    QString unit;
    double min, max;
    bool logarithmic;

    int w = getVerticalScaleWidth(v, false, paint);
    int h = v->getPaintHeight();

    if (m_plotStyle == PlotSegmentation) {

        getValueExtents(min, max, logarithmic, unit);

        if (logarithmic) {
            LogRange::mapRange(min, max);
            LogColourScale().paintVertical(v, this, paint, 0, min, max);
        } else {
            LinearColourScale().paintVertical(v, this, paint, 0, min, max);
        }

    } else {

        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 (logarithmic && (getScaleUnits() == "Hz")) {
            PianoScale().paintPianoVertical
                (v, paint, QRect(w - 10, 0, 10, h), 
                 LogRange::unmap(min), 
                 LogRange::unmap(max));
            paint.drawLine(w, 0, w, h);
        }
    }
        
    if (getScaleUnits() != "") {
        int mw = w - 5;
        paint.drawText(5,
                       5 + paint.fontMetrics().ascent(),
                       TextAbbrev::abbreviate(getScaleUnits(),
                                              paint.fontMetrics(),
                                              mw));
    }
}

void
TimeValueLayer::drawStart(LayerGeometryProvider *v, QMouseEvent *e)
{
#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::drawStart(" << e->x() << "," << e->y() << ")" << endl;
#endif

    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return;

    sv_frame_t frame = v->getFrameForX(e->x());
    int resolution = model->getResolution();
    if (frame < 0) frame = 0;
    frame = (frame / resolution) * resolution;

    double value = getValueForY(v, e->y());

    bool havePoint = false;

    EventVector points = getLocalPoints(v, e->x());
    if (!points.empty()) {
        for (EventVector::iterator i = points.begin();
             i != points.end(); ++i) {
            if (((i->getFrame() / resolution) * resolution) != frame) {
#ifdef DEBUG_TIME_VALUE_LAYER
                cerr << "ignoring out-of-range frame at " << i->getFrame() << endl;
#endif
                continue;
            }
            m_editingPoint = *i;
            havePoint = true;
        }
    }

    if (!havePoint) {
        m_editingPoint = Event(frame, float(value), tr("New Point"));
    }

    m_originalPoint = m_editingPoint;

    if (m_editingCommand) finish(m_editingCommand);
    m_editingCommand = new ChangeEventsCommand(m_model.untyped, tr("Draw Point"));
    if (!havePoint) {
        m_editingCommand->add(m_editingPoint);
    }

    m_editing = true;
}

void
TimeValueLayer::drawDrag(LayerGeometryProvider *v, QMouseEvent *e)
{
#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::drawDrag(" << e->x() << "," << e->y() << ")" << endl;
#endif

    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || !m_editing) return;

    sv_frame_t frame = v->getFrameForX(e->x());
    int resolution = model->getResolution();
    if (frame < 0) frame = 0;
    frame = (frame / resolution) * resolution;

    double value = getValueForY(v, e->y());

    EventVector points = getLocalPoints(v, e->x());

#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << points.size() << " points" << endl;
#endif

    bool havePoint = false;

    if (!points.empty()) {
        for (EventVector::iterator i = points.begin();
             i != points.end(); ++i) {
            if (i->getFrame() == m_editingPoint.getFrame() &&
                i->getValue() == m_editingPoint.getValue()) {
#ifdef DEBUG_TIME_VALUE_LAYER
                cerr << "ignoring current editing point at " << i->getFrame() << ", " << i->getValue() << endl;
#endif
                continue;
            }
            if (((i->getFrame() / resolution) * resolution) != frame) {
#ifdef DEBUG_TIME_VALUE_LAYER
                cerr << "ignoring out-of-range frame at " << i->getFrame() << endl;
#endif
                continue;
            }
#ifdef DEBUG_TIME_VALUE_LAYER
            cerr << "adjusting to new point at " << i->getFrame() << ", " << i->getValue() << endl;
#endif
            m_editingPoint = *i;
            m_originalPoint = m_editingPoint;
            m_editingCommand->remove(m_editingPoint);
            havePoint = true;
        }
    }

    if (!havePoint) {
        if (frame == m_editingPoint.getFrame()) {
            m_editingCommand->remove(m_editingPoint);
        }
    }

    m_editingPoint = m_editingPoint
        .withFrame(frame)
        .withValue(float(value));
    m_editingCommand->add(m_editingPoint);
}

void
TimeValueLayer::drawEnd(LayerGeometryProvider *, QMouseEvent *)
{
#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::drawEnd" << endl;
#endif
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || !m_editing) return;
    finish(m_editingCommand);
    m_editingCommand = nullptr;
    m_editing = false;
}

void
TimeValueLayer::eraseStart(LayerGeometryProvider *v, QMouseEvent *e)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return;

    EventVector points = getLocalPoints(v, e->x());
    if (points.empty()) return;

    m_editingPoint = *points.begin();

    if (m_editingCommand) {
        finish(m_editingCommand);
        m_editingCommand = nullptr;
    }

    m_editing = true;
}

void
TimeValueLayer::eraseDrag(LayerGeometryProvider *, QMouseEvent *)
{
}

void
TimeValueLayer::eraseEnd(LayerGeometryProvider *v, QMouseEvent *e)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || !m_editing) return;

    m_editing = false;

    EventVector points = getLocalPoints(v, e->x());
    if (points.empty()) return;
    if (points.begin()->getFrame() != m_editingPoint.getFrame() ||
        points.begin()->getValue() != m_editingPoint.getValue()) return;

    m_editingCommand = new ChangeEventsCommand(m_model.untyped, tr("Erase Point"));
    m_editingCommand->remove(m_editingPoint);
    finish(m_editingCommand);
    m_editingCommand = nullptr;
    m_editing = false;
}

void
TimeValueLayer::editStart(LayerGeometryProvider *v, QMouseEvent *e)
{
#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::editStart(" << e->x() << "," << e->y() << ")" << endl;
#endif

    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return;

    EventVector points = getLocalPoints(v, e->x());
    if (points.empty()) return;

    m_editingPoint = *points.begin();
    m_originalPoint = m_editingPoint;

    if (m_editingCommand) {
        finish(m_editingCommand);
        m_editingCommand = nullptr;
    }

    m_editing = true;
}

void
TimeValueLayer::editDrag(LayerGeometryProvider *v, QMouseEvent *e)
{
#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::editDrag(" << e->x() << "," << e->y() << ")" << endl;
#endif

    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || !m_editing) 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());

    if (!m_editingCommand) {
        m_editingCommand = new ChangeEventsCommand(m_model.untyped, tr("Drag Point"));
    }

    m_editingCommand->remove(m_editingPoint);
    m_editingPoint = m_editingPoint
        .withFrame(frame)
        .withValue(float(value));
    m_editingCommand->add(m_editingPoint);
}

void
TimeValueLayer::editEnd(LayerGeometryProvider *, QMouseEvent *)
{
#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "TimeValueLayer::editEnd" << endl;
#endif
    auto model = ModelById::getAs<SparseTimeValueModel>(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 Point");
            } else {
                newName = tr("Relocate Point");
            }
        } else {
            newName = tr("Change Point Value");
        }

        m_editingCommand->setName(newName);
        finish(m_editingCommand);
    }

    m_editingCommand = nullptr;
    m_editing = false;
}

bool
TimeValueLayer::editOpen(LayerGeometryProvider *v, QMouseEvent *e)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return false;

    EventVector points = getLocalPoints(v, e->x());
    if (points.empty()) return false;

    Event point = *points.begin();

    ItemEditDialog *dialog = new ItemEditDialog
        (model->getSampleRate(),
         ItemEditDialog::ShowTime |
         ItemEditDialog::ShowValue |
         ItemEditDialog::ShowText,
         getScaleUnits());

    dialog->setFrameTime(point.getFrame());
    dialog->setValue(point.getValue());
    dialog->setText(point.getLabel());

    if (dialog->exec() == QDialog::Accepted) {

        Event newPoint = point
            .withFrame(dialog->getFrameTime())
            .withValue(dialog->getValue())
            .withLabel(dialog->getText());
        
        ChangeEventsCommand *command =
            new ChangeEventsCommand(m_model.untyped, tr("Edit Point"));
        command->remove(point);
        command->add(newPoint);
        finish(command);
    }

    delete dialog;
    return true;
}

void
TimeValueLayer::moveSelection(Selection s, sv_frame_t newStartFrame)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return;

    ChangeEventsCommand *command =
        new ChangeEventsCommand(m_model.untyped, tr("Drag Selection"));

    EventVector points =
        model->getEventsWithin(s.getStartFrame(), s.getDuration());

    for (Event p: points) {

        Event newPoint = p.withFrame
            (p.getFrame() + newStartFrame - s.getStartFrame());
        command->remove(p);
        command->add(newPoint);
    }

    finish(command);
}

void
TimeValueLayer::resizeSelection(Selection s, Selection newSize)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model || !s.getDuration()) return;

    ChangeEventsCommand *command =
        new ChangeEventsCommand(m_model.untyped, tr("Resize Selection"));

    EventVector points =
        model->getEventsWithin(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;

        Event newPoint = p
            .withFrame(lrint(newFrame));
        command->remove(p);
        command->add(newPoint);
    }

    finish(command);
}

void
TimeValueLayer::deleteSelection(Selection s)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return;

    ChangeEventsCommand *command =
        new ChangeEventsCommand(m_model.untyped, tr("Delete Selected Points"));

    EventVector points =
        model->getEventsWithin(s.getStartFrame(), s.getDuration());

    for (Event p: points) {
        command->remove(p);
    }

    finish(command);
}    

void
TimeValueLayer::copy(LayerGeometryProvider *v, Selection s, Clipboard &to)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return;

    EventVector points =
        model->getEventsWithin(s.getStartFrame(), s.getDuration());

    for (Event p: points) {
        to.addPoint(p.withReferenceFrame(alignToReference(v, p.getFrame())));
    }
}

bool
TimeValueLayer::paste(LayerGeometryProvider *v, const Clipboard &from,
                      sv_frame_t /* frameOffset */, bool interactive)
{
    auto model = ModelById::getAs<SparseTimeValueModel>(m_model);
    if (!model) return false;

    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"));

    enum ValueAvailability {
        UnknownAvailability,
        NoValues,
        SomeValues,
        AllValues
    };

    Labeller::ValueType generation = Labeller::ValueNone;

    bool haveUsableLabels = false;
    Labeller labeller;
    labeller.setSampleRate(model->getSampleRate());

    if (interactive) {

        ValueAvailability availability = UnknownAvailability;

        for (EventVector::const_iterator i = points.begin();
             i != points.end(); ++i) {
        
            if (availability == UnknownAvailability) {
                if (i->hasValue()) availability = AllValues;
                else availability = NoValues;
                continue;
            }

            if (i->hasValue()) {
                if (availability == NoValues) {
                    availability = SomeValues;
                }
            } else {
                if (availability == AllValues) {
                    availability = SomeValues;
                }
            }

            if (!haveUsableLabels) {
                if (i->hasLabel()) {
                    if (i->getLabel().contains(QRegExp("[0-9]"))) {
                        haveUsableLabels = true;
                    }
                }
            }

            if (availability == SomeValues && haveUsableLabels) break;
        }

        if (availability == NoValues || availability == SomeValues) {
            
            QString text;
            if (availability == NoValues) {
                text = tr("The items you are pasting do not have values.\nWhat values do you want to use for these items?");
            } else {
                text = tr("Some of the items you are pasting do not have values.\nWhat values do you want to use for these items?");
            }

            Labeller::TypeNameMap names = labeller.getTypeNames();

            QStringList options;
            std::vector<Labeller::ValueType> genopts;

            for (Labeller::TypeNameMap::const_iterator i = names.begin();
                 i != names.end(); ++i) {
                if (i->first == Labeller::ValueNone) options << tr("Zero for all items");
                else options << i->second;
                genopts.push_back(i->first);
            }

            static int prevSelection = 0;

            bool ok = false;
            QString selected = ListInputDialog::getItem
                (nullptr, tr("Choose value calculation"),
                 text, options, prevSelection, &ok);

            if (!ok) {
                delete command;
                return false;
            }
            int selection = 0;
            generation = Labeller::ValueNone;

            for (QStringList::const_iterator i = options.begin();
                 i != options.end(); ++i) {
                if (selected == *i) {
                    generation = genopts[selection];
                    break;
                }
                ++selection;
            }
            
            labeller.setType(generation);

            if (generation == Labeller::ValueFromCyclicalCounter ||
                generation == Labeller::ValueFromTwoLevelCounter) {
                int cycleSize = QInputDialog::getInt
                    (nullptr, tr("Select cycle size"),
                     tr("Cycle size:"), 4, 2, 16, 1);
                labeller.setCounterCycleSize(cycleSize);
            }

            prevSelection = selection;
        }
    }

    Event prevPoint;

    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 newPoint = i->withFrame(frame);
        
        if (!i->hasLabel() && i->hasValue()) {
            newPoint = newPoint.withLabel(QString("%1").arg(i->getValue()));
        }

        bool usePrev = false;
        Event formerPrevPoint = prevPoint;

        if (!i->hasValue()) {
#ifdef DEBUG_TIME_VALUE_LAYER
            cerr << "Setting value on point at " << newPoint.getFrame() << " from labeller";
            if (i == points.begin()) {
                cerr << ", no prev point" << endl;
            } else {
                cerr << ", prev point is at " << prevPoint.getFrame() << endl;
            }
#endif

            Labeller::Revaluing valuing = 
                labeller.revalue
                (newPoint, (i == points.begin()) ? nullptr : &prevPoint);
            
#ifdef DEBUG_TIME_VALUE_LAYER
            cerr << "New point value = " << newPoint.getValue() << endl;
#endif
            if (valuing.first == Labeller::AppliesToPreviousEvent) {
                usePrev = true;
                prevPoint = valuing.second;
            } else {
                newPoint = valuing.second;
            }
        }

        if (usePrev) {
            command->remove(formerPrevPoint);
            command->add(prevPoint);
        }

        prevPoint = newPoint;
        command->add(newPoint);
    }

    finish(command);
    return true;
}

void
TimeValueLayer::toXml(QTextStream &stream,
                      QString indent, QString extraAttributes) const
{
    QString s;

    s += QString("plotStyle=\"%1\" "
                 "verticalScale=\"%2\" "
                 "scaleMinimum=\"%3\" "
                 "scaleMaximum=\"%4\" "
                 "drawDivisions=\"%5\" "
                 "derivative=\"%6\" ")
        .arg(m_plotStyle)
        .arg(m_verticalScale)
        .arg(m_scaleMinimum)
        .arg(m_scaleMaximum)
        .arg(m_drawSegmentDivisions ? "true" : "false")
        .arg(m_derivative ? "true" : "false");
    
    // New-style colour map attribute, by string id rather than by
    // number

    s += QString("fillColourMap=\"%1\" ")
        .arg(ColourMapper::getColourMapId(m_colourMap));

    // Old-style colour map attribute

    s += QString("colourMap=\"%1\" ")
        .arg(ColourMapper::getBackwardCompatibilityColourMap(m_colourMap));
    
    SingleColourLayer::toXml(stream, indent, extraAttributes + " " + s);
}

void
TimeValueLayer::setProperties(const QXmlAttributes &attributes)
{
    SingleColourLayer::setProperties(attributes);

    bool ok, alsoOk;

    QString colourMapId = attributes.value("fillColourMap");
    int colourMap = ColourMapper::getColourMapById(colourMapId);
    if (colourMap >= 0) {
        setFillColourMap(colourMap);
    } else {
        colourMap = attributes.value("colourMap").toInt(&ok);
        if (ok && colourMap < ColourMapper::getColourMapCount()) {
            setFillColourMap(colourMap);
        }
    }

    PlotStyle style = (PlotStyle)
        attributes.value("plotStyle").toInt(&ok);
    if (ok) setPlotStyle(style);

    VerticalScale scale = (VerticalScale)
        attributes.value("verticalScale").toInt(&ok);
    if (ok) setVerticalScale(scale);

    bool draw = (attributes.value("drawDivisions").trimmed() == "true");
    setDrawSegmentDivisions(draw);

    bool derivative = (attributes.value("derivative").trimmed() == "true");
    setShowDerivative(derivative);

    float min = attributes.value("scaleMinimum").toFloat(&ok);
    float max = attributes.value("scaleMaximum").toFloat(&alsoOk);
#ifdef DEBUG_TIME_VALUE_LAYER
    cerr << "from properties: min = " << min << ", max = " << max << endl;
#endif
    if (ok && alsoOk && min != max) setDisplayExtents(min, max);
}