annotate layer/TimeInstantLayer.cpp @ 1127:9fb8dfd7ce4c spectrogram-minor-refactor

Fix threshold in spectrogram -- it wasn't working in the last release.
There is a new protocol for this. Formerly the threshold parameter had a
range from -50dB to 0 with the default at -50, and -50 treated internally
as "no threshold". However, there was a hardcoded, hidden internal threshold
for spectrogram colour mapping at -80dB with anything below this being rounded
to zero. Now the threshold parameter has range -81 to -1 with the default
at -80, -81 is treated internally as "no threshold", and there is no hidden
internal threshold. So the default behaviour is the same as before, an
effective -80dB threshold, but it is now possible to change this in both
directions. Sessions reloaded from prior versions may look slightly different
because, if the session says there should be no threshold, there will now
actually be no threshold instead of having the hidden internal one.

Still need to do something in the UI to make it apparent that the -81dB
setting removes the threshold entirely. This is at least no worse than the
previous, also obscured, magic -50dB setting.

/* -*- 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 "TimeInstantLayer.h"

#include "data/model/Model.h"
#include "base/RealTime.h"
#include "view/View.h"
#include "base/Profiler.h"
#include "base/Clipboard.h"

#include "ColourDatabase.h"
#include "PaintAssistant.h"

#include "data/model/SparseOneDimensionalModel.h"

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

#include <QPainter>
#include <QMouseEvent>
#include <QTextStream>
#include <QMessageBox>

#include <iostream>
#include <cmath>

//#define DEBUG_TIME_INSTANT_LAYER 1

TimeInstantLayer::TimeInstantLayer() :
    SingleColourLayer(),
    m_model(0),
    m_editing(false),
    m_editingPoint(0, tr("New Point")),
    m_editingCommand(0),
    m_plotStyle(PlotInstants)
{
}

TimeInstantLayer::~TimeInstantLayer()
{
}

void
TimeInstantLayer::setModel(SparseOneDimensionalModel *model)
{
    if (m_model == model) return;
    m_model = model;

    connectSignals(m_model);

#ifdef DEBUG_TIME_INSTANT_LAYER
    cerr << "TimeInstantLayer::setModel(" << model << ")" << endl;
#endif

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

    emit modelReplaced();
}

Layer::PropertyList
TimeInstantLayer::getProperties() const
{
    PropertyList list = SingleColourLayer::getProperties();
    list.push_back("Plot Type");
    return list;
}

QString
TimeInstantLayer::getPropertyLabel(const PropertyName &name) const
{
    if (name == "Plot Type") return tr("Plot Type");
    return SingleColourLayer::getPropertyLabel(name);
}

Layer::PropertyType
TimeInstantLayer::getPropertyType(const PropertyName &name) const
{
    if (name == "Plot Type") return ValueProperty;
    return SingleColourLayer::getPropertyType(name);
}

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

    if (name == "Plot Type") {
	
	if (min) *min = 0;
	if (max) *max = 1;
        if (deflt) *deflt = 0;
	
	val = int(m_plotStyle);

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

    return val;
}

QString
TimeInstantLayer::getPropertyValueLabel(const PropertyName &name,
                                        int value) const
{
    if (name == "Plot Type") {
	switch (value) {
	default:
	case 0: return tr("Instants");
	case 1: return tr("Segmentation");
	}
    }
    return SingleColourLayer::getPropertyValueLabel(name, value);
}

void
TimeInstantLayer::setProperty(const PropertyName &name, int value)
{
    if (name == "Plot Type") {
	setPlotStyle(PlotStyle(value));
    } else {
        SingleColourLayer::setProperty(name, value);
    }
}

void
TimeInstantLayer::setPlotStyle(PlotStyle style)
{
    if (m_plotStyle == style) return;
    m_plotStyle = style;
    emit layerParametersChanged();
}

bool
TimeInstantLayer::isLayerScrollable(const LayerGeometryProvider *v) const
{
    QPoint discard;
    return !v->shouldIlluminateLocalFeatures(this, discard);
}

SparseOneDimensionalModel::PointList
TimeInstantLayer::getLocalPoints(LayerGeometryProvider *v, int x) const
{
    // Return a set of points that all have the same frame number, the
    // nearest to the given x coordinate, and that are within a
    // certain fuzz distance of that x coordinate.

    if (!m_model) return SparseOneDimensionalModel::PointList();

    sv_frame_t frame = v->getFrameForX(x);

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

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

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

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

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

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

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

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

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

    RealTime rt = RealTime::frame2RealTime(useFrame, m_model->getSampleRate());
    
    QString text;

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

    pos = QPoint(v->getXForFrame(useFrame), pos.y());
    return text;
}

bool
TimeInstantLayer::snapToFeatureFrame(LayerGeometryProvider *v, sv_frame_t &frame,
				     int &resolution,
				     SnapType snap) const
{
    if (!m_model) {
	return Layer::snapToFeatureFrame(v, frame, resolution, snap);
    }

    resolution = m_model->getResolution();
    SparseOneDimensionalModel::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);
    sv_frame_t snapped = frame;
    bool found = false;

    for (SparseOneDimensionalModel::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

	    SparseOneDimensionalModel::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;
}

void
TimeInstantLayer::paint(LayerGeometryProvider *v, QPainter &paint, QRect rect) const
{
    if (!m_model || !m_model->isOK()) return;

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

    int x0 = rect.left(), x1 = rect.right();

    sv_frame_t frame0 = v->getFrameForX(x0);
    sv_frame_t frame1 = v->getFrameForX(x1);

    SparseOneDimensionalModel::PointList points(m_model->getPoints
						(frame0, frame1));

    bool odd = false;
    if (m_plotStyle == PlotSegmentation && !points.empty()) {
	int index = m_model->getIndexOf(*points.begin());
	odd = ((index % 2) == 1);
    }

    paint.setPen(getBaseQColor());

    QColor brushColour(getBaseQColor());
    brushColour.setAlpha(100);
    paint.setBrush(brushColour);

    QColor oddBrushColour(brushColour);
    if (m_plotStyle == PlotSegmentation) {
	if (getBaseQColor() == Qt::black) {
	    oddBrushColour = Qt::gray;
	} else if (getBaseQColor() == Qt::darkRed) {
	    oddBrushColour = Qt::red;
	} else if (getBaseQColor() == Qt::darkBlue) {
	    oddBrushColour = Qt::blue;
	} else if (getBaseQColor() == Qt::darkGreen) {
	    oddBrushColour = Qt::green;
	} else {
	    oddBrushColour = oddBrushColour.light(150);
	}
	oddBrushColour.setAlpha(100);
    }

//    SVDEBUG << "TimeInstantLayer::paint: resolution is "
//	      << m_model->getResolution() << " frames" << endl;

    QPoint localPos;
    sv_frame_t illuminateFrame = -1;

    if (v->shouldIlluminateLocalFeatures(this, localPos)) {
	SparseOneDimensionalModel::PointList localPoints =
	    getLocalPoints(v, localPos.x());
	if (!localPoints.empty()) illuminateFrame = localPoints.begin()->frame;
    }
	
    int prevX = -1;
    int textY = v->getTextLabelHeight(this, paint);
    
    for (SparseOneDimensionalModel::PointList::const_iterator i = points.begin();
	 i != points.end(); ++i) {

	const SparseOneDimensionalModel::Point &p(*i);
	SparseOneDimensionalModel::PointList::const_iterator j = i;
	++j;

	int x = v->getXForFrame(p.frame);
        if (x == prevX && m_plotStyle == PlotInstants &&
            p.frame != illuminateFrame) continue;

	int iw = v->getXForFrame(p.frame + m_model->getResolution()) - x;
	if (iw < 2) {
	    if (iw < 1) {
		iw = 2;
		if (j != points.end()) {
		    int nx = v->getXForFrame(j->frame);
		    if (nx < x + 3) iw = 1;
		}
	    } else {
		iw = 2;
	    }
	}
		
	if (p.frame == illuminateFrame) {
	    paint.setPen(getForegroundQColor(v->getView()));
	} else {
	    paint.setPen(brushColour);
	}

	if (m_plotStyle == PlotInstants) {
	    if (iw > 1) {
		paint.drawRect(x, 0, iw - 1, v->getPaintHeight() - 1);
	    } else {
		paint.drawLine(x, 0, x, v->getPaintHeight() - 1);
	    }
	} else {

	    if (odd) paint.setBrush(oddBrushColour);
	    else paint.setBrush(brushColour);
	    
	    int nx;
	    
	    if (j != points.end()) {
		const SparseOneDimensionalModel::Point &q(*j);
		nx = v->getXForFrame(q.frame);
	    } else {
		nx = v->getXForFrame(m_model->getEndFrame());
	    }

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

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

	    odd = !odd;
	}

	paint.setPen(getBaseQColor());
	
	if (p.label != "") {

	    // only draw if there's enough room from here to the next point

	    int lw = paint.fontMetrics().width(p.label);
	    bool good = true;

	    if (j != points.end()) {
		int nx = v->getXForFrame(j->frame);
		if (nx >= x && nx - x - iw - 3 <= lw) good = false;
	    }

	    if (good) {
                PaintAssistant::drawVisibleText(v, paint, x + iw + 2, textY, p.label, PaintAssistant::OutlinedText);
//		paint.drawText(x + iw + 2, textY, p.label);
	    }
	}

	prevX = x;
    }
}

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

    if (!m_model) return;

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

    m_editingPoint = SparseOneDimensionalModel::Point(frame, tr("New Point"));

    if (m_editingCommand) finish(m_editingCommand);
    m_editingCommand = new SparseOneDimensionalModel::EditCommand(m_model,
								  tr("Draw Point"));
    m_editingCommand->addPoint(m_editingPoint);

    m_editing = true;
}

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

    if (!m_model || !m_editing) return;

    sv_frame_t frame = v->getFrameForX(e->x());
    if (frame < 0) frame = 0;
    frame = frame / m_model->getResolution() * m_model->getResolution();
    m_editingCommand->deletePoint(m_editingPoint);
    m_editingPoint.frame = frame;
    m_editingCommand->addPoint(m_editingPoint);
}

void
TimeInstantLayer::drawEnd(LayerGeometryProvider *, QMouseEvent *)
{
#ifdef DEBUG_TIME_INSTANT_LAYER
    cerr << "TimeInstantLayer::drawEnd(" << e->x() << ")" << endl;
#endif
    if (!m_model || !m_editing) return;
    QString newName = tr("Add Point at %1 s")
	.arg(RealTime::frame2RealTime(m_editingPoint.frame,
				      m_model->getSampleRate())
	     .toText(false).c_str());
    m_editingCommand->setName(newName);
    finish(m_editingCommand);
    m_editingCommand = 0;
    m_editing = false;
}

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

    SparseOneDimensionalModel::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
TimeInstantLayer::eraseDrag(LayerGeometryProvider *, QMouseEvent *)
{
}

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

    m_editing = false;

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

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

    m_editingCommand->deletePoint(m_editingPoint);

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

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

    if (!m_model) return;

    SparseOneDimensionalModel::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
TimeInstantLayer::editDrag(LayerGeometryProvider *v, QMouseEvent *e)
{
#ifdef DEBUG_TIME_INSTANT_LAYER
    cerr << "TimeInstantLayer::editDrag(" << e->x() << ")" << endl;
#endif

    if (!m_model || !m_editing) return;

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

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

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

void
TimeInstantLayer::editEnd(LayerGeometryProvider *, QMouseEvent *)
{
#ifdef DEBUG_TIME_INSTANT_LAYER
    cerr << "TimeInstantLayer::editEnd(" << e->x() << ")" << endl;
#endif
    if (!m_model || !m_editing) return;
    if (m_editingCommand) {
	QString newName = tr("Move Point to %1 s")
	    .arg(RealTime::frame2RealTime(m_editingPoint.frame,
					  m_model->getSampleRate())
		 .toText(false).c_str());
	m_editingCommand->setName(newName);
	finish(m_editingCommand);
    }
    m_editingCommand = 0;
    m_editing = false;
}

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

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

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

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

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

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

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

    delete dialog;
    return true;
}

void
TimeInstantLayer::moveSelection(Selection s, sv_frame_t newStartFrame)
{
    if (!m_model) return;

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

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

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

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

    finish(command);
}

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

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

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

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

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

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

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

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

    finish(command);
}

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

    SparseOneDimensionalModel::EditCommand *command =
	new SparseOneDimensionalModel::EditCommand(m_model,
						   tr("Delete Selection"));

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

    for (SparseOneDimensionalModel::PointList::iterator i = points.begin();
	 i != points.end(); ++i) {
	if (s.contains(i->frame)) command->deletePoint(*i);
    }

    finish(command);
}

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

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

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

bool
TimeInstantLayer::paste(LayerGeometryProvider *v, const Clipboard &from, sv_frame_t frameOffset, bool)
{
    if (!m_model) return false;

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

    bool realign = false;

    if (clipboardHasDifferentAlignment(v, from)) {

        QMessageBox::StandardButton button =
            QMessageBox::question(v->getView(), tr("Re-align pasted instants?"),
                                  tr("The instants 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;
        }
    }

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

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

        sv_frame_t frame = 0;

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

        } else {

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

        if (frameOffset > 0) frame += frameOffset;
        else if (frameOffset < 0) {
            if (frame > -frameOffset) frame += frameOffset;
            else frame = 0;
        }

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

    finish(command);
    return true;
}

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

void
TimeInstantLayer::toXml(QTextStream &stream,
                        QString indent, QString extraAttributes) const
{
    SingleColourLayer::toXml(stream, indent,
                             extraAttributes +
                             QString(" plotStyle=\"%1\"")
                             .arg(m_plotStyle));
}

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

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