annotate layer/TimeValueLayer.cpp @ 561:aced8ec09bc8

* Complete the overhaul of CSV file import; now you can pick the purpose for
  each column in the file, and SV should do the rest.  The most significant
  practical improvement here is that we can now handle files in which time
  and duration do not necessarily appear in known columns.

/* -*- 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 "ColourDatabase.h"
#include "view/View.h"

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

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

#include "ColourMapper.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_model(0),
    m_editing(false),
    m_originalPoint(0, 0.0, tr("New Point")),
    m_editingPoint(0, 0.0, tr("New Point")),
    m_editingCommand(0),
    m_colourMap(0),
    m_plotStyle(PlotConnectedPoints),
    m_verticalScale(AutoAlignScale),
    m_drawSegmentDivisions(true),
    m_derivative(false),
    m_scaleMinimum(0),
    m_scaleMaximum(0)
{
    
}

void
TimeValueLayer::setModel(SparseTimeValueModel *model)
{
    if (m_model == model) return;
    m_model = model;

    connectSignals(m_model);

    m_scaleMinimum = 0;
    m_scaleMaximum = 0;

    if (m_model && m_model->getRDFTypeURI().endsWith("Segment")) {
        setPlotStyle(PlotSegmentation);
    }
    if (m_model && m_model->getRDFTypeURI().endsWith("Change")) {
        setPlotStyle(PlotSegmentation);
    }

#ifdef DEBUG_TIME_VALUE_LAYER
    std::cerr << "TimeValueLayer::setModel(" << model << ")" << std::endl;
#endif

    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 ValueProperty;
    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);
}

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 = 5;
        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;
        if (m_model) {
            val = UnitDatabase::getInstance()->getUnitId
                (m_model->getScaleUnits());
        }

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

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

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

        if (min) *min = 0;
        if (max) *max = 0;
        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::getColourMapName(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");
	}
    } 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") {
        if (m_model) {
            m_model->setScaleUnits
                (UnitDatabase::getInstance()->getUnitById(value));
            emit modelChanged();
        }
    } 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 View *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) return true;

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

bool
TimeValueLayer::getValueExtents(float &min, float &max,
                                bool &logarithmic, QString &unit) const
{
    if (!m_model) return false;
    min = m_model->getValueMinimum();
    max = m_model->getValueMaximum();
    logarithmic = (m_verticalScale == LogScale);
    unit = m_model->getScaleUnits();
    if (m_derivative) {
        max = std::max(fabsf(min), fabsf(max));
        min = -max;
    }
    return true;
}

bool
TimeValueLayer::getDisplayExtents(float &min, float &max) const
{
    if (!m_model || shouldAutoAlign()) return false;

    if (m_scaleMinimum == m_scaleMaximum) {
        min = m_model->getValueMinimum();
        max = m_model->getValueMaximum();
    } else {
        min = m_scaleMinimum;
        max = m_scaleMaximum;
    }

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

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

    return true;
}

bool
TimeValueLayer::setDisplayExtents(float min, float max)
{
    if (!m_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
    std::cerr << "TimeValueLayer::setDisplayExtents: min = " << min << ", max = " << max << std::endl;
#endif
    
    emit layerParametersChanged();
    return true;
}

int
TimeValueLayer::getVerticalZoomSteps(int &defaultStep) const
{
    if (shouldAutoAlign()) return 0;
    if (!m_model) return 0;

    defaultStep = 0;
    return 100;
}

int
TimeValueLayer::getCurrentVerticalZoomStep() const
{
    if (shouldAutoAlign()) return 0;
    if (!m_model) return 0;

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

    float dmin, dmax;
    getDisplayExtents(dmin, dmax);

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

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

    delete mapper;

    return 100 - nr;
}

void
TimeValueLayer::setVerticalZoomStep(int step)
{
    if (shouldAutoAlign()) return;
    if (!m_model) return;

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

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

    float newmin, newmax;

    if (logarithmic) {

        // see SpectrogramLayer::setVerticalZoomStep

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

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

    } else {
        float 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
    std::cerr << "TimeValueLayer::setVerticalZoomStep: " << step << ": " << newmin << " -> " << newmax << " (range " << newdist << ")" << std::endl;
#endif

    setDisplayExtents(newmin, newmax);
}

RangeMapper *
TimeValueLayer::getNewVerticalZoomRangeMapper() const
{
    if (!m_model) return 0;
    
    RangeMapper *mapper;

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

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

    return mapper;
}

SparseTimeValueModel::PointList
TimeValueLayer::getLocalPoints(View *v, int x) const
{
    if (!m_model) return SparseTimeValueModel::PointList();

    long frame = v->getFrameForX(x);

    SparseTimeValueModel::PointList onPoints =
	m_model->getPoints(frame);

    if (!onPoints.empty()) {
	return onPoints;
    }

    SparseTimeValueModel::PointList prevPoints =
	m_model->getPreviousPoints(frame);
    SparseTimeValueModel::PointList nextPoints =
	m_model->getNextPoints(frame);

    SparseTimeValueModel::PointList usePoints = prevPoints;

    if (prevPoints.empty()) {
	usePoints = nextPoints;
    } else if (long(prevPoints.begin()->frame) < v->getStartFrame() &&
	       !(nextPoints.begin()->frame > v->getEndFrame())) {
	usePoints = nextPoints;
    } else if (nextPoints.begin()->frame - frame <
	       frame - prevPoints.begin()->frame) {
	usePoints = nextPoints;
    }

    if (!usePoints.empty()) {
	int fuzz = 2;
	int px = v->getXForFrame(usePoints.begin()->frame);
	if ((px > x && px - x > fuzz) ||
	    (px < x && x - px > fuzz + 1)) {
	    usePoints.clear();
	}
    }

    return usePoints;
}

QString
TimeValueLayer::getLabelPreceding(size_t frame) const
{
    if (!m_model) return "";
    SparseTimeValueModel::PointList points = m_model->getPreviousPoints(frame);
    for (SparseTimeValueModel::PointList::const_iterator i = points.begin();
         i != points.end(); ++i) {
        if (i->label != "") return i->label;
    }
    return "";
}

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

    if (!m_model || !m_model->getSampleRate()) return "";

    SparseTimeValueModel::PointList points = getLocalPoints(v, x);

    if (points.empty()) {
	if (!m_model->isReady()) {
	    return tr("In progress");
	} else {
	    return tr("No local points");
	}
    }

    long useFrame = points.begin()->frame;

    RealTime rt = RealTime::frame2RealTime(useFrame, m_model->getSampleRate());
    
    QString text;
    QString unit = m_model->getScaleUnits();
    if (unit != "") unit = " " + unit;

    if (points.begin()->label == "") {
	text = QString(tr("Time:\t%1\nValue:\t%2%3\nNo label"))
	    .arg(rt.toText(true).c_str())
	    .arg(points.begin()->value)
            .arg(unit);
    } else {
	text = QString(tr("Time:\t%1\nValue:\t%2%3\nLabel:\t%4"))
	    .arg(rt.toText(true).c_str())
	    .arg(points.begin()->value)
            .arg(unit)
	    .arg(points.begin()->label);
    }

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

bool
TimeValueLayer::snapToFeatureFrame(View *v, int &frame,
				   size_t &resolution,
				   SnapType snap) const
{
    if (!m_model) {
	return Layer::snapToFeatureFrame(v, frame, resolution, snap);
    }

    resolution = m_model->getResolution();
    SparseTimeValueModel::PointList points;

    if (snap == SnapNeighbouring) {
	
	points = getLocalPoints(v, v->getXForFrame(frame));
	if (points.empty()) return false;
	frame = points.begin()->frame;
	return true;
    }    

    points = m_model->getPoints(frame, frame);
    int snapped = frame;
    bool found = false;

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

	if (snap == SnapRight) {

	    if (i->frame > frame) {
		snapped = i->frame;
		found = true;
		break;
	    }

	} else if (snap == SnapLeft) {

	    if (i->frame <= frame) {
		snapped = i->frame;
		found = true; // don't break, as the next may be better
	    } else {
		break;
	    }

	} else { // nearest

	    SparseTimeValueModel::PointList::const_iterator j = i;
	    ++j;

	    if (j == points.end()) {

		snapped = i->frame;
		found = true;
		break;

	    } else if (j->frame >= frame) {

		if (j->frame - frame < frame - i->frame) {
		    snapped = j->frame;
		} else {
		    snapped = i->frame;
		}
		found = true;
		break;
	    }
	}
    }

    frame = snapped;
    return found;
}

bool
TimeValueLayer::snapToSimilarFeature(View *v, int &frame,
                                     size_t &resolution,
                                     SnapType snap) const
{
    if (!m_model) {
	return Layer::snapToSimilarFeature(v, frame, resolution, snap);
    }

    resolution = m_model->getResolution();

    const SparseTimeValueModel::PointList &points = m_model->getPoints();
    SparseTimeValueModel::PointList close = m_model->getPoints(frame, frame);

    SparseTimeValueModel::PointList::const_iterator i;

    int matchframe = frame;
    float matchvalue = 0.f;

    for (i = close.begin(); i != close.end(); ++i) {
        if (i->frame > frame) break;
        matchvalue = i->value;
        matchframe = i->frame;
    }

    int snapped = frame;
    bool found = false;
    bool distant = false;
    float epsilon = 0.0001;

    i = close.begin();

    // Scan through the close points first, then the more distant ones
    // if no suitable close one is found

    while (i != points.end()) {

        if (i == close.end()) {
            i = points.begin();
            distant = true;
        }

	if (snap == SnapRight) {

	    if (i->frame > matchframe &&
                fabsf(i->value - matchvalue) < epsilon) {
		snapped = i->frame;
		found = true;
		break;
	    }

	} else if (snap == SnapLeft) {

	    if (i->frame < matchframe) {
                if (fabsf(i->value - matchvalue) < epsilon) {
                    snapped = i->frame;
                    found = true; // don't break, as the next may be better
                }
	    } else if (found || distant) {
		break;
	    }

	} else { 
            // no other snap types supported
	}

        ++i;
    }

    frame = snapped;
    return found;
}

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

    if (shouldAutoAlign()) {

        if (!v->getValueExtents(m_model->getScaleUnits(), min, max, log)) {
            min = m_model->getValueMinimum();
            max = m_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;
        }
    }

    if (max == min) max = min + 1.0;
}

int
TimeValueLayer::getYForValue(View *v, float val) const
{
    float min = 0.0, max = 0.0;
    bool logarithmic = false;
    int h = v->height();

    getScaleExtents(v, min, max, logarithmic);

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

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

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

float
TimeValueLayer::getValueForY(View *v, int y) const
{
    float min = 0.0, max = 0.0;
    bool logarithmic = false;
    int h = v->height();

    getScaleExtents(v, min, max, logarithmic);

    float val = min + (float(h - y) * float(max - min)) / h;

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

    return val;
}

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

QColor
TimeValueLayer::getColourForValue(View *v, float val) const
{
    float 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
    std::cerr << "TimeValueLayer::getColourForValue: min " << min << ", max "
              << max << ", log " << log << ", value " << val << std::endl;
#endif

    QColor solid = ColourMapper(m_colourMap, 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(View *v, QPainter &paint, QRect rect) const
{
    if (!m_model || !m_model->isOK()) return;

    int sampleRate = m_model->getSampleRate();
    if (!sampleRate) return;

    paint.setRenderHint(QPainter::Antialiasing, false);

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

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

    SparseTimeValueModel::PointList points(m_model->getPoints
					   (frame0, frame1));
    if (points.empty()) return;

    paint.setPen(getBaseQColor());

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

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

    float min = m_model->getValueMinimum();
    float max = m_model->getValueMaximum();
    if (max == min) max = min + 1.0;

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

    QPoint localPos;
    long illuminateFrame = -1;

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

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

    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->height()) {
            paint.save();
            paint.setPen(getPartialShades(v)[1]);
            paint.drawLine(x0, originY, x1, originY);
            paint.restore();
        }
    }
    
    for (SparseTimeValueModel::PointList::const_iterator i = points.begin();
	 i != points.end(); ++i) {

        if (m_derivative && i == points.begin()) continue;
        
	const SparseTimeValueModel::Point &p(*i);

        float value = p.value;
        if (m_derivative) {
            SparseTimeValueModel::PointList::const_iterator j = i;
            --j;
            value -= j->value;
        }

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

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

	bool haveNext = false;
	int nx = v->getXForFrame(v->getModelsEndFrame());
	int ny = y;

	SparseTimeValueModel::PointList::const_iterator j = i;
	++j;

	if (j != points.end()) {
	    const SparseTimeValueModel::Point &q(*j);
            float nvalue = q.value;
            if (m_derivative) nvalue -= p.value;
	    nx = v->getXForFrame(q.frame);
	    ny = getYForValue(v, nvalue);
	    haveNext = true;
        }

//        std::cout << "frame = " << p.frame << ", x = " << x << ", haveNext = " << haveNext 
//                  << ", nx = " << nx << std::endl;

	if (w < 1) w = 1;
	paint.setPen(getBaseQColor());

	if (m_plotStyle == PlotSegmentation) {
            paint.setPen(getForegroundQColor(v));
            paint.setBrush(getColourForValue(v, value));
	} else if (m_plotStyle == PlotLines ||
		   m_plotStyle == PlotCurve) {
	    paint.setBrush(Qt::NoBrush);
	} else {
	    paint.setBrush(brushColour);
	}	    

	if (m_plotStyle == PlotStems) {
/*
	    paint.setPen(brushColour);
	    if (y < origin - 1) {
		paint.drawRect(x + w/2, y + 1, 1, origin - y);
	    } else if (y > origin + 1) {
		paint.drawRect(x + w/2, origin, 1, y - origin - 1);
	    }
*/
	    paint.setPen(getBaseQColor());
	    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);
	    }
	}

	if (illuminateFrame == p.frame) {

	    //!!! aside from the problem of choosing a colour, it'd be
	    //better to save the highlighted rects and draw them at
	    //the end perhaps

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

	    if (m_plotStyle != PlotCurve &&
		m_plotStyle != PlotLines) {
		paint.setPen(getForegroundQColor(v));
	    }	    
	}

	if (m_plotStyle != PlotLines &&
	    m_plotStyle != PlotCurve &&
	    m_plotStyle != PlotSegmentation) {
            if (m_plotStyle != PlotStems ||
                w > 1) {
                paint.drawRect(x, y - 1, w, 2);
            }
	}

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

	    if (haveNext) {

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

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

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

		} else {

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

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

		    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 + x1) / 2, (y0 + y1) / 2);
		    }
		}
	    }
	}

	if (m_plotStyle == PlotSegmentation) {

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

            paint.setPen(QPen(getForegroundQColor(v), 2));

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

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

	if (p.label != "") {
            if (!haveNext || nx > x + 6 + paint.fontMetrics().width(p.label)) {
                paint.drawText(x + 5, textY, p.label);
            }
	}
    }

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

    paint.restore();

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

int
TimeValueLayer::getVerticalScaleWidth(View *, QPainter &paint) const
{
    int w = paint.fontMetrics().width("-000.000");
    if (m_plotStyle == PlotSegmentation) return w + 20;
    else return w + 10;
}

void
TimeValueLayer::paintVerticalScale(View *v, QPainter &paint, QRect) const
{
    if (!m_model) return;

    int h = v->height();

    int n = 10;

    float min, max;
    bool logarithmic;
    getScaleExtents(v, min, max, logarithmic);

    if (m_plotStyle == PlotSegmentation) {
        QString unit;
        getValueExtents(min, max, logarithmic, unit);
        if (logarithmic) {
            LogRange::mapRange(min, max);
        }
    }

    float val = min;
    float inc = (max - val) / n;

    char buffer[40];

    int w = getVerticalScaleWidth(v, paint);

    int tx = 5;

    int boxx = 5, boxy = 5;
    if (m_model->getScaleUnits() != "") {
        boxy += paint.fontMetrics().height();
    }
    int boxw = 10, boxh = h - boxy - 5;

    if (m_plotStyle == PlotSegmentation) {
        tx += boxx + boxw;
        paint.drawRect(boxx, boxy, boxw, boxh);
    }

    if (m_plotStyle == PlotSegmentation) {
        paint.save();
        for (int y = 0; y < boxh; ++y) {
            float val = ((boxh - y) * (max - min)) / boxh + min;
            if (logarithmic) {
                paint.setPen(getColourForValue(v, LogRange::unmap(val)));
            } else {
                paint.setPen(getColourForValue(v, val));
            }
            paint.drawLine(boxx + 1, y + boxy + 1, boxx + boxw, y + boxy + 1);
        }
        paint.restore();
    }
    
    float round = 1.f;
    int dp = 0;
    if (inc > 0) {
        int prec = trunc(log10f(inc));
        prec -= 1;
        if (prec < 0) dp = -prec;
        round = powf(10.f, prec);
#ifdef DEBUG_TIME_VALUE_LAYER
        std::cerr << "inc = " << inc << ", round = " << round << std::endl;
#endif
    }

    int prevy = -1;
                
    for (int i = 0; i < n; ++i) {

	int y, ty;
        bool drawText = true;

        float dispval = val;

        if (m_plotStyle == PlotSegmentation) {
            y = boxy + int(boxh - ((val - min) * boxh) / (max - min));
            ty = y;
        } else {
            if (i == n-1 &&
                v->height() < paint.fontMetrics().height() * (n*2)) {
                if (m_model->getScaleUnits() != "") drawText = false;
            }
            dispval = lrintf(val / round) * round;
#ifdef DEBUG_TIME_VALUE_LAYER
            std::cerr << "val = " << val << ", dispval = " << dispval << std::endl;
#endif
            if (logarithmic) {
                y = getYForValue(v, LogRange::unmap(dispval));
            } else {
                y = getYForValue(v, dispval);
            }                
            ty = y - paint.fontMetrics().height() +
                     paint.fontMetrics().ascent() + 2;

            if (prevy >= 0 && (prevy - y) < paint.fontMetrics().height()) {
                val += inc;
                continue;
            }
        }

        if (logarithmic) {
            sprintf(buffer, "%.*g", dp < 2 ? 2 : dp, LogRange::unmap(dispval));
        } else {
            sprintf(buffer, "%.*f", dp, dispval);
        }            
	QString label = QString(buffer);

        if (m_plotStyle != PlotSegmentation) {
            paint.drawLine(w - 5, y, w, y);
        } else {
            paint.drawLine(boxx + boxw - boxw/3, y, boxx + boxw, y);
        }

        if (drawText) {
            if (m_plotStyle != PlotSegmentation) {
                paint.drawText(tx + w - paint.fontMetrics().width(label) - 8,
                               ty, label);
            } else {
                paint.drawText(tx, ty, label);
            }
        }

        prevy = y;
	val += inc;
    }
    
    if (m_model->getScaleUnits() != "") {
        paint.drawText(5, 5 + paint.fontMetrics().ascent(),
                       m_model->getScaleUnits());
    }
}

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

    if (!m_model) return;

    long frame = v->getFrameForX(e->x());
    long resolution = m_model->getResolution();
    if (frame < 0) frame = 0;
    frame = (frame / resolution) * resolution;

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

    bool havePoint = false;

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

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

    m_originalPoint = m_editingPoint;

    if (m_editingCommand) finish(m_editingCommand);
    m_editingCommand = new SparseTimeValueModel::EditCommand(m_model,
							     tr("Draw Point"));
    if (!havePoint) {
        m_editingCommand->addPoint(m_editingPoint);
    }

    m_editing = true;
}

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

    if (!m_model || !m_editing) return;

    long frame = v->getFrameForX(e->x());
    long resolution = m_model->getResolution();
    if (frame < 0) frame = 0;
    frame = (frame / resolution) * resolution;

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

    SparseTimeValueModel::PointList points = getLocalPoints(v, e->x());

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

    bool havePoint = false;

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

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

//    m_editingCommand->deletePoint(m_editingPoint);
    m_editingPoint.frame = frame;
    m_editingPoint.value = value;
    m_editingCommand->addPoint(m_editingPoint);
}

void
TimeValueLayer::drawEnd(View *, QMouseEvent *)
{
#ifdef DEBUG_TIME_VALUE_LAYER
    std::cerr << "TimeValueLayer::drawEnd" << std::endl;
#endif
    if (!m_model || !m_editing) return;
    finish(m_editingCommand);
    m_editingCommand = 0;
    m_editing = false;
}

void
TimeValueLayer::eraseStart(View *v, QMouseEvent *e)
{
    if (!m_model) return;

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

    m_editingPoint = *points.begin();

    if (m_editingCommand) {
	finish(m_editingCommand);
	m_editingCommand = 0;
    }

    m_editing = true;
}

void
TimeValueLayer::eraseDrag(View *v, QMouseEvent *e)
{
}

void
TimeValueLayer::eraseEnd(View *v, QMouseEvent *e)
{
    if (!m_model || !m_editing) return;

    m_editing = false;

    SparseTimeValueModel::PointList points = getLocalPoints(v, e->x());
    if (points.empty()) return;
    if (points.begin()->frame != m_editingPoint.frame ||
        points.begin()->value != m_editingPoint.value) return;

    m_editingCommand = new SparseTimeValueModel::EditCommand
        (m_model, tr("Erase Point"));

    m_editingCommand->deletePoint(m_editingPoint);

    finish(m_editingCommand);
    m_editingCommand = 0;
    m_editing = false;
}

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

    if (!m_model) return;

    SparseTimeValueModel::PointList 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 = 0;
    }

    m_editing = true;
}

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

    if (!m_model || !m_editing) return;

    long frame = v->getFrameForX(e->x());
    if (frame < 0) frame = 0;
    frame = frame / m_model->getResolution() * m_model->getResolution();

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

    if (!m_editingCommand) {
	m_editingCommand = new SparseTimeValueModel::EditCommand(m_model,
								 tr("Drag Point"));
    }

    m_editingCommand->deletePoint(m_editingPoint);
    m_editingPoint.frame = frame;
    m_editingPoint.value = value;
    m_editingCommand->addPoint(m_editingPoint);
}

void
TimeValueLayer::editEnd(View *, QMouseEvent *)
{
#ifdef DEBUG_TIME_VALUE_LAYER
    std::cerr << "TimeValueLayer::editEnd" << std::endl;
#endif
    if (!m_model || !m_editing) return;

    if (m_editingCommand) {

	QString newName = m_editingCommand->getName();

	if (m_editingPoint.frame != m_originalPoint.frame) {
	    if (m_editingPoint.value != m_originalPoint.value) {
		newName = tr("Edit Point");
	    } else {
		newName = tr("Relocate Point");
	    }
	} else {
	    newName = tr("Change Point Value");
	}

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

    m_editingCommand = 0;
    m_editing = false;
}

bool
TimeValueLayer::editOpen(View *v, QMouseEvent *e)
{
    if (!m_model) return false;

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

    SparseTimeValueModel::Point point = *points.begin();

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

    dialog->setFrameTime(point.frame);
    dialog->setValue(point.value);
    dialog->setText(point.label);

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

        SparseTimeValueModel::Point newPoint = point;
        newPoint.frame = dialog->getFrameTime();
        newPoint.value = dialog->getValue();
        newPoint.label = dialog->getText();
        
        SparseTimeValueModel::EditCommand *command =
            new SparseTimeValueModel::EditCommand(m_model, tr("Edit Point"));
        command->deletePoint(point);
        command->addPoint(newPoint);
        finish(command);
    }

    delete dialog;
    return true;
}

void
TimeValueLayer::moveSelection(Selection s, size_t newStartFrame)
{
    if (!m_model) return;

    SparseTimeValueModel::EditCommand *command =
	new SparseTimeValueModel::EditCommand(m_model,
					      tr("Drag Selection"));

    SparseTimeValueModel::PointList points =
	m_model->getPoints(s.getStartFrame(), s.getEndFrame());

    for (SparseTimeValueModel::PointList::iterator i = points.begin();
	 i != points.end(); ++i) {

	if (s.contains(i->frame)) {
	    SparseTimeValueModel::Point newPoint(*i);
	    newPoint.frame = i->frame + newStartFrame - s.getStartFrame();
	    command->deletePoint(*i);
	    command->addPoint(newPoint);
	}
    }

    finish(command);
}

void
TimeValueLayer::resizeSelection(Selection s, Selection newSize)
{
    if (!m_model) return;

    SparseTimeValueModel::EditCommand *command =
	new SparseTimeValueModel::EditCommand(m_model,
					      tr("Resize Selection"));

    SparseTimeValueModel::PointList points =
	m_model->getPoints(s.getStartFrame(), s.getEndFrame());

    double ratio =
	double(newSize.getEndFrame() - newSize.getStartFrame()) /
	double(s.getEndFrame() - s.getStartFrame());

    for (SparseTimeValueModel::PointList::iterator i = points.begin();
	 i != points.end(); ++i) {

	if (s.contains(i->frame)) {

	    double target = i->frame;
	    target = newSize.getStartFrame() + 
		double(target - s.getStartFrame()) * ratio;

	    SparseTimeValueModel::Point newPoint(*i);
	    newPoint.frame = lrint(target);
	    command->deletePoint(*i);
	    command->addPoint(newPoint);
	}
    }

    finish(command);
}

void
TimeValueLayer::deleteSelection(Selection s)
{
    if (!m_model) return;

    SparseTimeValueModel::EditCommand *command =
	new SparseTimeValueModel::EditCommand(m_model,
					      tr("Delete Selected Points"));

    SparseTimeValueModel::PointList points =
	m_model->getPoints(s.getStartFrame(), s.getEndFrame());

    for (SparseTimeValueModel::PointList::iterator i = points.begin();
	 i != points.end(); ++i) {

        if (s.contains(i->frame)) {
            command->deletePoint(*i);
        }
    }

    finish(command);
}    

void
TimeValueLayer::copy(View *v, Selection s, Clipboard &to)
{
    if (!m_model) return;

    SparseTimeValueModel::PointList points =
	m_model->getPoints(s.getStartFrame(), s.getEndFrame());

    for (SparseTimeValueModel::PointList::iterator i = points.begin();
	 i != points.end(); ++i) {
	if (s.contains(i->frame)) {
            Clipboard::Point point(i->frame, i->value, i->label);
            point.setReferenceFrame(alignToReference(v, i->frame));
            to.addPoint(point);
        }
    }
}

bool
TimeValueLayer::paste(View *v, const Clipboard &from, int frameOffset,
                      bool interactive)
{
    if (!m_model) return false;

    const Clipboard::PointList &points = from.getPoints();

    bool realign = false;

    if (clipboardHasDifferentAlignment(v, from)) {

        QMessageBox::StandardButton button =
            QMessageBox::question(v, 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;
        }
    }

    SparseTimeValueModel::EditCommand *command =
	new SparseTimeValueModel::EditCommand(m_model, tr("Paste"));

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

    Labeller::ValueType generation = Labeller::ValueNone;

    bool haveUsableLabels = false;
    bool haveExistingItems = !(m_model->isEmpty());
    Labeller labeller;
    labeller.setSampleRate(m_model->getSampleRate());

    if (interactive) {

        ValueAvailability availability = UnknownAvailability;

        for (Clipboard::PointList::const_iterator i = points.begin();
             i != points.end(); ++i) {
        
            if (!i->haveFrame()) continue;

            if (availability == UnknownAvailability) {
                if (i->haveValue()) availability = AllValues;
                else availability = NoValues;
                continue;
            }

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

            if (!haveUsableLabels) {
                if (i->haveLabel()) {
                    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
                (0, tr("Choose value calculation"),
                 text, options, prevSelection, &ok);

            if (!ok) 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::getInteger
                    (0, tr("Select cycle size"),
                     tr("Cycle size:"), 4, 2, 16, 1);
                labeller.setCounterCycleSize(cycleSize);
            }

            prevSelection = selection;
        }
    }

    SparseTimeValueModel::Point prevPoint(0);

    for (Clipboard::PointList::const_iterator i = points.begin();
         i != points.end(); ++i) {
        
        if (!i->haveFrame()) continue;

        size_t frame = 0;

        if (!realign) {
            
            frame = i->getFrame();

        } else {

            if (i->haveReferenceFrame()) {
                frame = i->getReferenceFrame();
                frame = alignFromReference(v, frame);
            } else {
                frame = i->getFrame();
            }
        }

        SparseTimeValueModel::Point newPoint(frame);
  
        if (i->haveLabel()) {
            newPoint.label = i->getLabel();
        } else if (i->haveValue()) {
            newPoint.label = QString("%1").arg(i->getValue());
        }

        bool usePrev = false;
        SparseTimeValueModel::Point formerPrevPoint = prevPoint;

        if (i->haveValue()) {
            newPoint.value = i->getValue();
        } else {
#ifdef DEBUG_TIME_VALUE_LAYER
            std::cerr << "Setting value on point at " << newPoint.frame << " from labeller";
            if (i == points.begin()) {
                std::cerr << ", no prev point" << std::endl;
            } else {
                std::cerr << ", prev point is at " << prevPoint.frame << std::endl;
            }
#endif
            labeller.setValue<SparseTimeValueModel::Point>
                (newPoint, (i == points.begin()) ? 0 : &prevPoint);
#ifdef DEBUG_TIME_VALUE_LAYER
            std::cerr << "New point value = " << newPoint.value << std::endl;
#endif
            if (labeller.actingOnPrevPoint() && i != points.begin()) {
                usePrev = true;
            }
        }

        if (usePrev) {
            command->deletePoint(formerPrevPoint);
            command->addPoint(prevPoint);
        }

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

    finish(command);
    return true;
}

void
TimeValueLayer::toXml(QTextStream &stream,
                      QString indent, QString extraAttributes) const
{
    SingleColourLayer::toXml(stream, indent,
                             extraAttributes +
                             QString(" colourMap=\"%1\" plotStyle=\"%2\" verticalScale=\"%3\" scaleMinimum=\"%4\" scaleMaximum=\"%5\" drawDivisions=\"%6\" derivative=\"%7\" ")
                             .arg(m_colourMap)
                             .arg(m_plotStyle)
                             .arg(m_verticalScale)
                             .arg(m_scaleMinimum)
                             .arg(m_scaleMaximum)
                             .arg(m_drawSegmentDivisions ? "true" : "false")
                             .arg(m_derivative ? "true" : "false"));
}

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

    bool ok, alsoOk;

    int cmap = attributes.value("colourMap").toInt(&ok);
    if (ok) setFillColourMap(cmap);

    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
    std::cerr << "from properties: min = " << min << ", max = " << max << std::endl;
#endif
    if (ok && alsoOk && min != max) setDisplayExtents(min, max);
}