view layer/TimeInstantLayer.cpp @ 1551:e79731086b0f

Fixes to NoteLayer, particularly to calculation of vertical scale when model unit is not Hz. To avoid inconsistency we now behave as if the unit is always Hz from the point of view of the external API and display, converting at the point where we obtain values from the events themselves. Also various fixes to editing.
author Chris Cannam
date Thu, 21 Nov 2019 14:02:57 +0000
parents e6362cf5ff1d
children 9a5eede01869
line wrap: on
line source
/* -*- 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_editing(false),
    m_editingPoint(0, tr("New Point")),
    m_editingCommand(nullptr),
    m_plotStyle(PlotInstants)
{
}

TimeInstantLayer::~TimeInstantLayer()
{
}

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

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

    if (newModel) {
        connectSignals(m_model);
        if (newModel->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::needsTextLabelHeight() const
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(m_model);
    if (model) return model->hasTextLabels();
    else return false;
}

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

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

    // 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.

    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
TimeInstantLayer::getLabelPreceding(sv_frame_t frame) const
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(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
TimeInstantLayer::getFeatureDescription(LayerGeometryProvider *v, QPoint &pos) const
{
    int x = pos.x();

    auto model = ModelById::getAs<SparseOneDimensionalModel>(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 text;

    if (points.begin()->getLabel() == "") {
        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()->getLabel());
    }

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

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

    // 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;
}

void
TimeInstantLayer::paint(LayerGeometryProvider *v, QPainter &paint, QRect rect) const
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(m_model);
    if (!model || !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);

    int overspill = 0;
    if (m_plotStyle == PlotSegmentation) {
        // We need to start painting at the prior point, so we can
        // fill in the visible part of its segmentation area
        overspill = 1;
    }
    
    EventVector points(model->getEventsWithin(frame0, frame1 - frame0,
                                                overspill));

    bool odd = false;
    if (m_plotStyle == PlotSegmentation && !points.empty()) {
        int index = model->getRowForFrame(points.begin()->getFrame());
        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.lighter(150);
        }
        oddBrushColour.setAlpha(100);
    }

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

    QPoint localPos;
    sv_frame_t illuminateFrame = -1;

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

        Event p(*i);
        EventVector::const_iterator j = i;
        ++j;

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

        int iw = v->getXForFrame(p.getFrame() + model->getResolution()) - x;
        if (iw < 2) {
            if (iw < 1) {
                iw = 2;
                if (j != points.end()) {
                    int nx = v->getXForFrame(j->getFrame());
                    if (nx < x + 3) iw = 1;
                }
            } else {
                iw = 2;
            }
        }
                
        if (p.getFrame() == 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()) {
                Event q(*j);
                nx = v->getXForFrame(q.getFrame());
            } else {
                nx = v->getXForFrame(model->getEndFrame());
            }

            if (nx >= x) {
                
                if (illuminateFrame != p.getFrame() &&
                    (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.getLabel() != "") {
            
    // 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"

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

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

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

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

        prevX = x;
    }
}

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

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

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

    m_editingPoint = Event(frame, tr("New Point"));

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

    m_editing = true;
}

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

    auto model = ModelById::getAs<SparseOneDimensionalModel>(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();
    m_editingCommand->remove(m_editingPoint);
    m_editingPoint = m_editingPoint.withFrame(frame);
    m_editingCommand->add(m_editingPoint);
}

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

void
TimeInstantLayer::eraseStart(LayerGeometryProvider *v, QMouseEvent *e)
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(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
TimeInstantLayer::eraseDrag(LayerGeometryProvider *, QMouseEvent *)
{
}

void
TimeInstantLayer::eraseEnd(LayerGeometryProvider *v, QMouseEvent *e)
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(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()) 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
TimeInstantLayer::editStart(LayerGeometryProvider *v, QMouseEvent *e)
{
#ifdef DEBUG_TIME_INSTANT_LAYER
    cerr << "TimeInstantLayer::editStart(" << e->x() << ")" << endl;
#endif

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

    auto model = ModelById::getAs<SparseOneDimensionalModel>(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();

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

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

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

bool
TimeInstantLayer::editOpen(LayerGeometryProvider *v, QMouseEvent *e)
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(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::ShowText);

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

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

        Event newPoint = point
            .withFrame(dialog->getFrameTime())
            .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
TimeInstantLayer::moveSelection(Selection s, sv_frame_t newStartFrame)
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(m_model);
    if (!model) return;

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

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

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

    finish(command);
}

void
TimeInstantLayer::resizeSelection(Selection s, Selection newSize)
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(m_model);
    if (!model) 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 (auto 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
TimeInstantLayer::deleteSelection(Selection s)
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(m_model);
    if (!model) return;

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

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

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

    finish(command);
}

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

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

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

bool
TimeInstantLayer::paste(LayerGeometryProvider *v, const Clipboard &from,
                        sv_frame_t frameOffset, bool)
{
    auto model = ModelById::getAs<SparseOneDimensionalModel>(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 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;
        }
    }

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

    for (EventVector::const_iterator i = points.begin();
         i != points.end(); ++i) {
        
        sv_frame_t frame = 0;

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

        } else {

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

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

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