WCartesianChart.C

/*
 * Copyright (C) 2008 Emweb bvba, Kessel-Lo, Belgium.
 *
 * See the LICENSE file for terms of use.
 */

#include <boost/lexical_cast.hpp>
#include <cmath>

#include "Wt/Chart/WChart2DImplementation"
#include "Wt/Chart/WDataSeries"
#include "Wt/Chart/WCartesianChart"
#include "Wt/Chart/WStandardPalette"

#include "Wt/WAbstractArea"
#include "Wt/WAbstractItemModel"
#include "Wt/WException"
#include "Wt/WMeasurePaintDevice"
#include "Wt/WPainter"
#include "Wt/WCircleArea"
#include "Wt/WPolygonArea"
#include "Wt/WRectArea"
#include "Wt/WText"

#include "WebUtils.h"

namespace {
const int TICK_LENGTH = 5;
}

namespace Wt {
  namespace Chart {

SeriesIterator::~SeriesIterator()
{ }

void SeriesIterator::startSegment(int currentXSegment, int currentYSegment,
				  const WRectF& currentSegmentArea)
{
  currentXSegment_ = currentXSegment;
  currentYSegment_ = currentYSegment;
}

void SeriesIterator::endSegment()
{
}

bool SeriesIterator::startSeries(const WDataSeries& series, double groupWidth,
				 int numBarGroups, int currentBarGroup)
{
  return true;
}

void SeriesIterator::endSeries()
{ }

void SeriesIterator::newValue(const WDataSeries& series,
			      double x, double y, double stackY,
			      const WModelIndex& xIndex,
			      const WModelIndex& yIndex)
{ }


void SeriesIterator::setPenColor(WPen& pen,
				 const WModelIndex& xIndex,
				 const WModelIndex& yIndex,
				 int colorRole)
{
  boost::any color;

  if (yIndex.isValid())
    color = yIndex.data(colorRole);

  if (color.empty() && xIndex.isValid())
    color = xIndex.data(colorRole);

  if (!color.empty())
    pen.setColor(boost::any_cast<WColor>(color));
}

void SeriesIterator::setBrushColor(WBrush& brush,
				   const WModelIndex& xIndex,
				   const WModelIndex& yIndex,
				   int colorRole) 
{
  boost::any color;

  if (yIndex.isValid())
    color = yIndex.data(colorRole);

  if (color.empty() && xIndex.isValid())
    color = xIndex.data(colorRole);

  if (!color.empty())
    brush.setColor(boost::any_cast<WColor>(color));
}

class SeriesRenderer;

class SeriesRenderIterator : public SeriesIterator
{
public:
  SeriesRenderIterator(const WCartesianChart& chart, WPainter& painter);

  virtual void startSegment(int currentXSegment, int currentYSegment,
			    const WRectF& currentSegmentArea);
  virtual void endSegment();

  virtual bool startSeries(const WDataSeries& series, double groupWidth,
			   int numBarGroups, int currentBarGroup);
  virtual void endSeries();

  virtual void newValue(const WDataSeries& series, double x, double y,
			double stackY,
			const WModelIndex& xIndex,
			const WModelIndex& yIndex);

  double breakY(double y);

private:
  const WCartesianChart& chart_;
  WPainter& painter_;
  const WDataSeries *series_;
  SeriesRenderer *seriesRenderer_;
  double minY_, maxY_;
};

class SeriesRenderer {
public:
  virtual ~SeriesRenderer() { }
  virtual void addValue(double x, double y, double stacky,
			const WModelIndex& xIndex, const WModelIndex& yIndex)
    = 0;
  virtual void paint() = 0;

protected:
  const WCartesianChart& chart_;
  WPainter& painter_;
  const WDataSeries& series_;
  SeriesRenderIterator& it_;

  SeriesRenderer(const WCartesianChart& chart, WPainter& painter,
		 const WDataSeries& series, SeriesRenderIterator& it)
    : chart_(chart),
      painter_(painter),
      series_(series),
      it_(it)
  { }

  static double crisp(double u) {
    return std::floor(u) + 0.5;
  }

  WPointF hv(const WPointF& p) {
    return chart_.hv(p);
  }

  WPointF hv(double x, double y) {
    return chart_.hv(x, y);
  }
};

class LineSeriesRenderer : public SeriesRenderer {
public:
  LineSeriesRenderer(const WCartesianChart& chart, WPainter& painter,
		     const WDataSeries& series,
		     SeriesRenderIterator& it)
    : SeriesRenderer(chart, painter, series, it),
      curveLength_(0)
  { }

  virtual void addValue(double x, double y, double stacky,
			const WModelIndex& xIndex, const WModelIndex& yIndex) {
    WPointF p = chart_.map(x, y, series_.axis(),
			   it_.currentXSegment(), it_.currentYSegment());

    if (curveLength_ == 0) {
      curve_.moveTo(hv(p));

      if (series_.fillRange() != NoFill
	  && series_.brush() != NoBrush) {
	fill_.moveTo(hv(fillOtherPoint(x)));
	fill_.lineTo(hv(p));
      }
    } else {
      if (series_.type() == LineSeries) {
	curve_.lineTo(hv(p));
	fill_.lineTo(hv(p));
      } else {
	if (curveLength_ == 1) {
	  computeC(p0, p, c_);
	} else {
	  WPointF c1, c2;
	  computeC(p_1, p0, p, c1, c2);
	  curve_.cubicTo(hv(c_), hv(c1), hv(p0));
	  fill_.cubicTo(hv(c_), hv(c1), hv(p0));
	  c_ = c2;
	}
      }
    }

    p_1 = p0;
    p0 = p;
    lastX_ = x;
    ++curveLength_;
  }

  virtual void paint() {
    if (curveLength_ > 1) {
      if (series_.type() == CurveSeries) {
	WPointF c1;
	computeC(p0, p_1, c1);
	curve_.cubicTo(hv(c_), hv(c1), hv(p0));
	fill_.cubicTo(hv(c_), hv(c1), hv(p0));
      }

      if (series_.fillRange() != NoFill
	  && series_.brush() != NoBrush) {
	fill_.lineTo(hv(fillOtherPoint(lastX_)));
	fill_.closeSubPath();
	painter_.setShadow(series_.shadow());
	painter_.fillPath(fill_, series_.brush());
      }

      if (series_.fillRange() == NoFill)
	painter_.setShadow(series_.shadow());
      else
	painter_.setShadow(WShadow());

      painter_.strokePath(curve_, series_.pen());
    }

    curveLength_ = 0;
    curve_ = WPainterPath();
    fill_ = WPainterPath();
  }

private:
  int curveLength_;
  WPainterPath curve_;
  WPainterPath fill_;

  double  lastX_;
  WPointF p_1, p0, c_;

  static double dist(const WPointF& p1, const WPointF& p2) {
    double dx = p2.x() - p1.x();
    double dy = p2.y() - p1.y();
    return std::sqrt (dx*dx + dy*dy);
  }

  static void computeC(const WPointF& p, const WPointF& p1, WPointF& c) {
    c.setX(p.x() + 0.3 * (p1.x() - p.x()));
    c.setY(p.y() + 0.3 * (p1.y() - p.y()));
  }

  static void computeC(const WPointF& p_1, const WPointF& p0,
		       const WPointF& p1,
		       WPointF& c1, WPointF& c2) {
    double m1x = (p_1.x() + p0.x())/2.0;
    double m1y = (p_1.y() + p0.y())/2.0;

    double m2x = (p0.x() + p1.x())/2.0;
    double m2y = (p0.y() + p1.y())/2.0;

    double L1 = dist(p_1, p0);
    double L2 = dist(p0, p1);
    double r = L1/(L1 + L2);

    c1.setX(p0.x() - r * (m2x - m1x));
    c1.setY(p0.y() - r * (m2y - m1y));

    r = 1-r;

    c2.setX(p0.x() - r * (m1x - m2x));
    c2.setY(p0.y() - r * (m1y - m2y));
  }

  WPointF fillOtherPoint(double x) const {
    FillRangeType fr = series_.fillRange();

    switch (fr) {
    case MinimumValueFill:
      return WPointF(chart_.map(x, 0, series_.axis(),
				it_.currentXSegment(),
				it_.currentYSegment()).x(),
		     chart_.chartArea_.bottom());
    case MaximumValueFill:
      return WPointF(chart_.map(x, 0, series_.axis(),
				it_.currentXSegment(),
				it_.currentYSegment()).x(),
		     chart_.chartArea_.top());
    case ZeroValueFill:
      return WPointF(chart_.map(x, 0, series_.axis(),
				it_.currentXSegment(),
				it_.currentYSegment()));
    default:
      return WPointF();
    }
  }
};

class BarSeriesRenderer : public SeriesRenderer {
public:
  BarSeriesRenderer(const WCartesianChart& chart, WPainter& painter,
		    const WDataSeries& series,
		    SeriesRenderIterator& it,
		    double groupWidth, int numGroups, int group)
    : SeriesRenderer(chart, painter, series, it),
      groupWidth_(groupWidth),
      numGroups_(numGroups),
      group_(group)
  { }

  virtual void addValue(double x, double y, double stacky,
			const WModelIndex& xIndex, const WModelIndex& yIndex) {
    WPainterPath bar;
    const WAxis& yAxis = chart_.axis(series_.axis());

    WPointF topMid = chart_.map(x, y, yAxis.id(),
				it_.currentXSegment(),
				it_.currentYSegment());
    WPointF bottomMid = chart_.map(x, stacky, yAxis.id(),
				   it_.currentXSegment(),
				   it_.currentYSegment());

    FillRangeType fr = series_.fillRange();
    switch (fr) {
    case MinimumValueFill:
      bottomMid = WPointF(chart_.map(x, stacky, yAxis.id(),
				     it_.currentXSegment(),
				     it_.currentYSegment()).x(),
			  chart_.chartArea_.bottom());
      break;
    case MaximumValueFill:
      bottomMid = WPointF(chart_.map(x, stacky, yAxis.id(),
				     it_.currentXSegment(),
				     it_.currentYSegment()).x(),
			  chart_.chartArea_.top());
      break;
    default:
      break;
    }

    double g = numGroups_ + (numGroups_ - 1) * chart_.barMargin();

    double width = groupWidth_ / g;
    double left = topMid.x() - groupWidth_ / 2
      + group_ * width * (1 + chart_.barMargin());

    bar.moveTo(hv(crisp(left), crisp(topMid.y())));
    bar.lineTo(hv(crisp(left + width), crisp(topMid.y())));
    bar.lineTo(hv(crisp(left + width), crisp(bottomMid.y())));
    bar.lineTo(hv(crisp(left), crisp(bottomMid.y())));
    bar.closeSubPath();

    painter_.setShadow(series_.shadow());

    WBrush brush = WBrush(series_.brush());
    SeriesIterator::setBrushColor(brush, xIndex, yIndex, BarBrushColorRole);
    painter_.fillPath(bar, brush);

    painter_.setShadow(WShadow());

    WPen pen = WPen(series_.pen());
    SeriesIterator::setPenColor(pen, xIndex, yIndex, BarPenColorRole);
    painter_.strokePath(bar, pen);

    boost::any toolTip = yIndex.data(ToolTipRole);
    if (!toolTip.empty()) {
      WTransform t = painter_.worldTransform();

      WPointF tl = t.map(segmentPoint(bar, 0));
      WPointF tr = t.map(segmentPoint(bar, 1));
      WPointF br = t.map(segmentPoint(bar, 2));
      WPointF bl = t.map(segmentPoint(bar, 3));

      double tlx = 0, tly = 0, brx = 0, bry = 0;
      bool useRect = false;
      if (fequal(tl.y(), tr.y())) {
	tlx = std::min(tl.x(), tr.x());
	brx = std::max(tl.x(), tr.x());
	tly = std::min(tl.y(), bl.y());
	bry = std::max(tl.y(), br.y());

	useRect = true;
      } else if (fequal(tl.x(), tr.x())) {
	tlx = std::min(tl.x(), bl.x());
	brx = std::max(tl.x(), bl.x());
	tly = std::min(tl.y(), tr.y());
	bry = std::max(tl.y(), tr.y());

	useRect = true;
      }

      WAbstractArea *area;
      if (useRect)
	area = new WRectArea(tlx, tly, (brx - tlx), (bry - tly));
      else {
	WPolygonArea *poly = new WPolygonArea();
	poly->addPoint(tl.x(), tl.y());
	poly->addPoint(tr.x(), tr.y());
	poly->addPoint(br.x(), br.y());
	poly->addPoint(bl.x(), bl.y());
	area = poly;
      }

      area->setToolTip(asString(toolTip));

      const_cast<WCartesianChart&>(chart_)
	.addDataPointArea(series_, xIndex, area);
    }

    double bTopMidY = it_.breakY(topMid.y());
    double bBottomMidY = it_.breakY(bottomMid.y());

    if (bTopMidY > topMid.y() && bBottomMidY <= bottomMid.y()) {
      WPainterPath breakPath;
      breakPath.moveTo(hv(left - 10, bTopMidY + 10));
      breakPath.lineTo(hv(left + width + 10, bTopMidY + 1));
      breakPath.lineTo(hv(left + width + 10, bTopMidY - 1));
      breakPath.lineTo(hv(left - 10, bTopMidY - 1));
      painter_.setPen(NoPen);
      painter_.setBrush(chart_.background());
      painter_.drawPath(breakPath);
      painter_.setPen(WPen());
      painter_.drawLine(hv(left - 10, bTopMidY + 10),
			hv(left + width + 10, bTopMidY + 1));
    }

    if (bBottomMidY < bottomMid.y() && bTopMidY >= topMid.y()) {
      WPainterPath breakPath;
      breakPath.moveTo(hv(left + width + 10, bBottomMidY - 10));
      breakPath.lineTo(hv(left - 10, bBottomMidY - 1));
      breakPath.lineTo(hv(left - 10, bBottomMidY + 1));
      breakPath.lineTo(hv(left + width + 10, bBottomMidY + 1));
      painter_.setBrush(chart_.background());
      painter_.setPen(NoPen);
      painter_.drawPath(breakPath);
      painter_.setPen(WPen());
      painter_.drawLine(hv(left - 10, bBottomMidY - 1),
			hv(left + width + 10, bBottomMidY - 10));
    }
  }

  void paint() { }

private:
  static Wt::WPointF segmentPoint(const Wt::WPainterPath& path, int segment)
  {
    const Wt::WPainterPath::Segment& s = path.segments()[segment];
    return Wt::WPointF(s.x(), s.y());
  }

  static bool fequal(double d1, double d2) {
    return std::fabs(d1 - d2) < 1E-5;
  }

private:
  double groupWidth_;
  int numGroups_;
  int group_;
};

SeriesRenderIterator::SeriesRenderIterator(const WCartesianChart& chart,
					   WPainter& painter)
  : chart_(chart),
    painter_(painter),
    series_(0)
{ }

void SeriesRenderIterator::startSegment(int currentXSegment,
					int currentYSegment,
					const WRectF& currentSegmentArea)
{
  SeriesIterator::startSegment(currentXSegment, currentYSegment,
			       currentSegmentArea);

  const WAxis& yAxis = chart_.axis(series_->axis());

  if (currentYSegment == 0)
    maxY_ = DBL_MAX;
  else
    maxY_ = currentSegmentArea.bottom();

  if (currentYSegment == yAxis.segmentCount() - 1)
    minY_ = -DBL_MAX;
  else
    minY_ = currentSegmentArea.top();
}

void SeriesRenderIterator::endSegment()
{
  SeriesIterator::endSegment();

  seriesRenderer_->paint();
}

bool SeriesRenderIterator::startSeries(const WDataSeries& series,
				       double groupWidth,
				       int numBarGroups, int currentBarGroup)
{
  seriesRenderer_ = 0;

  switch (series.type()) {
  case LineSeries:
  case CurveSeries:
    seriesRenderer_ = new LineSeriesRenderer(chart_, painter_, series, *this);
    break;
  case BarSeries:
    seriesRenderer_ = new BarSeriesRenderer(chart_, painter_, series, *this,
					    groupWidth,
					    numBarGroups, currentBarGroup);
  default:
    break;
  }

  series_ = &series;

  painter_.save();

  return seriesRenderer_ != 0;
}

void SeriesRenderIterator::endSeries()
{
  seriesRenderer_->paint();
  painter_.restore();

  delete seriesRenderer_;
  series_ = 0;
}

void SeriesRenderIterator::newValue(const WDataSeries& series,
				    double x, double y,
				    double stackY,
				    const WModelIndex& xIndex,
				    const WModelIndex& yIndex)
{
  if (Utils::isNaN(x) || Utils::isNaN(y))
    seriesRenderer_->paint();
  else
    seriesRenderer_->addValue(x, y, stackY, xIndex, yIndex);
}

double SeriesRenderIterator::breakY(double y)
{
  if (y < minY_)
    return minY_;
  else if (y > maxY_)
    return maxY_;
  else
    return y;
}

class LabelRenderIterator : public SeriesIterator
{
public:
  LabelRenderIterator(const WCartesianChart& chart, WPainter& painter)
    : chart_(chart),
      painter_(painter)
  { }

  virtual bool startSeries(const WDataSeries& series, double groupWidth,
			   int numBarGroups, int currentBarGroup)
  {
    if (series.isLabelsEnabled(XAxis) || series.isLabelsEnabled(YAxis)) {
      groupWidth_ = groupWidth;
      numGroups_ = numBarGroups;
      group_ = currentBarGroup;
      return true;
    } else
      return false;
  }

  virtual void newValue(const WDataSeries& series, double x, double y,
			double stackY,
			const WModelIndex& xIndex,
			const WModelIndex& yIndex)
  {
    if (Utils::isNaN(x) || Utils::isNaN(y))
      return;

    WString text;

    if (series.isLabelsEnabled(XAxis)) {
      text = chart_.axis(XAxis).label(x);
    }

    if (series.isLabelsEnabled(YAxis)) {
      if (!text.empty())
	text += ": ";
      text += chart_.axis(series.axis()).label(y - stackY);
    }

    if (!text.empty()) {
      WPointF p = chart_.map(x, y, series.axis(),
			     currentXSegment(), currentYSegment());
      if (series.type() == BarSeries) {
	double g = numGroups_ + (numGroups_ - 1) * chart_.barMargin();

	double width = groupWidth_ / g;
	double left = p.x() - groupWidth_ / 2 
	  + group_ * width * (1 + chart_.barMargin());

	p = WPointF(left + width/2, p.y());
      }

      WColor c(black);

      WFlags<AlignmentFlag> alignment;
      if (series.type() == BarSeries) {
	if (y < 0)
	  alignment = AlignCenter | AlignBottom;
	else
	  alignment = AlignCenter | AlignTop;

	c = series.labelColor();
      } else {
	alignment = AlignCenter | AlignBottom;
	p.setY(p.y() - 3);
      }

      chart_.renderLabel(painter_, text, p, c, alignment, 0, 3);
    }
  }

private:
  const WCartesianChart& chart_;
  WPainter& painter_;

  double groupWidth_;
  int numGroups_;
  int group_;
};

class MarkerRenderIterator : public SeriesIterator
{
public:
  MarkerRenderIterator(const WCartesianChart& chart, WPainter& painter)
    : chart_(chart),
      painter_(painter)
  { }

  virtual bool startSeries(const WDataSeries& series, double groupWidth,
			   int numBarGroups, int currentBarGroup)
  {
    marker_ = WPainterPath();

    if (series.marker() != NoMarker) {
      chart_.drawMarker(series, marker_);
      painter_.save();
      needRestore_ = true;
    } else
      needRestore_ = false;

    return true;
  }

  virtual void endSeries()
  {
    if (needRestore_)
      painter_.restore();
  }

  virtual void newValue(const WDataSeries& series, double x, double y,
			double stackY,
			const WModelIndex& xIndex,
			const WModelIndex& yIndex)
  {
    if (!Utils::isNaN(x) && !Utils::isNaN(y)) {
      WPointF p = chart_.map(x, y, series.axis(),
			     currentXSegment(), currentYSegment());
      
      if (!marker_.isEmpty()) {
	painter_.save();
	painter_.translate(hv(p));

	WPen pen = WPen(series.markerPen());
	setPenColor(pen, xIndex, yIndex, MarkerPenColorRole);

	WBrush brush = WBrush(series.markerBrush());
	setBrushColor(brush, xIndex, yIndex, MarkerBrushColorRole);
	setMarkerSize(painter_, xIndex, yIndex, series.markerSize());

	painter_.setShadow(series.shadow());
	painter_.fillPath(marker_, brush);
	painter_.setShadow(WShadow());
	painter_.strokePath(marker_, pen);

	painter_.restore();
      }

      if (series.type() != BarSeries) {
	boost::any toolTip = yIndex.data(ToolTipRole);
	if (!toolTip.empty()) {
	  WTransform t = painter_.worldTransform();

	  p = t.map(hv(p));

	  WCircleArea *circleArea
	    = new WCircleArea(static_cast<int>(p.x()),
			      static_cast<int>(p.y()), 5);
	  circleArea->setToolTip(asString(toolTip));

	  const_cast<WCartesianChart&>(chart_)
	    .addDataPointArea(series, xIndex, circleArea);
	}
      }
    }
  }

  WPointF hv(const WPointF& p) {
    return chart_.hv(p);
  }

  WPointF hv(double x, double y) {
    return chart_.hv(x, y);
  }

private:
  const WCartesianChart& chart_;
  WPainter& painter_;
  WPainterPath marker_;
  bool needRestore_;

  void setMarkerSize(WPainter& painter,
	  	     const WModelIndex& xIndex,
		     const WModelIndex& yIndex,
		     double markerSize)
  {
    boost::any scale;
    double dScale = 1;
    if (yIndex.isValid())
      scale = yIndex.data(MarkerScaleFactorRole);

    if (scale.empty() && xIndex.isValid())
      scale = xIndex.data(MarkerScaleFactorRole);

    if(!scale.empty())
      dScale = asNumber(scale);

  dScale = markerSize / 6 * dScale;

  painter.scale(dScale, dScale);
}

};

WCartesianChart::WCartesianChart(WContainerWidget *parent)
  : WAbstractChart(parent),
    interface_(new WChart2DImplementation(this)),
    orientation_(Vertical),
    XSeriesColumn_(-1),
    type_(CategoryChart),
    barMargin_(0),
    axisPadding_(5)
{
  init();
}

WCartesianChart::WCartesianChart(ChartType type, WContainerWidget *parent)
  : WAbstractChart(parent),
    interface_(new WChart2DImplementation(this)),
    orientation_(Vertical),
    XSeriesColumn_(-1),
    type_(type),
    barMargin_(0),
    axisPadding_(5)
{
  init();
}

WCartesianChart::~WCartesianChart()
{
  delete interface_;
}

void WCartesianChart::init()
{
  setPalette(new WStandardPalette(WStandardPalette::Muted));
	
#ifdef WT_TARGET_JAVA
  for (int i = 0; i < 3; ++i)
    axes_[i] = WAxis();
#endif //WT_TARGET_JAVA
  axes_[XAxis].init(interface_, XAxis);
  axes_[YAxis].init(interface_, YAxis);
  axes_[Y2Axis].init(interface_, Y2Axis);
  
  setPlotAreaPadding(40, Left | Right);
  setPlotAreaPadding(30, Top | Bottom);
}

void WCartesianChart::setOrientation(Orientation orientation)
{
  if (orientation_ != orientation) {
    orientation_ = orientation;
    update();
  }
}

void WCartesianChart::setXSeriesColumn(int modelColumn)
{
  if (XSeriesColumn_ != modelColumn) {
    XSeriesColumn_ = modelColumn;
    update();
  }
}

void WCartesianChart::setType(ChartType type)
{
  if (type_ != type) {
    type_ = type;
    axes_[XAxis].init(interface_, XAxis);
    update();
  }
}

void WCartesianChart::addSeries(const WDataSeries& series)
{
  series_.push_back(series);
  series_.back().setChart(this);
  update();
}

void WCartesianChart::removeSeries(int modelColumn)
{
  int index = seriesIndexOf(modelColumn);

  if (index != -1) {
    series_.erase(series_.begin() + index);
    update();
  }
}

int WCartesianChart::seriesIndexOf(int modelColumn) const
{
  for (unsigned i = 0; i < series_.size(); ++i)
    if (series_[i].modelColumn() == modelColumn)
      return i;

  return -1;
}

WDataSeries& WCartesianChart::series(int modelColumn)
{
  int index = seriesIndexOf(modelColumn);

  if (index != -1)
    return series_[index];

  throw WException("Column " + boost::lexical_cast<std::string>(modelColumn)
		   + " not in plot");
}

const WDataSeries& WCartesianChart::series(int modelColumn) const
{
  int index = seriesIndexOf(modelColumn);

  if (index != -1)
    return series_[index];

  throw WException("Column " + boost::lexical_cast<std::string>(modelColumn)
		   + " not in plot");
}

void WCartesianChart::setSeries(const std::vector<WDataSeries>& series)
{
  series_ = series;

  for (unsigned i = 0; i < series_.size(); ++i)
    series_[i].setChart(this);

  update();
}

WAxis& WCartesianChart::axis(Axis axis)
{
  return axes_[axis];
}

const WAxis& WCartesianChart::axis(Axis axis) const
{
  return axes_[axis];
}

void WCartesianChart::setBarMargin(double margin)
{
  if (barMargin_ != margin) {
    barMargin_ = margin;

    update();
  }
}

void WCartesianChart::setLegendEnabled(bool enabled)
{
  legend_.setLegendEnabled(enabled);

  update();
}

void WCartesianChart::setLegendLocation(LegendLocation location, 
					Side side,
					AlignmentFlag alignment)
{
  legend_.setLegendLocation(location, side, alignment);

  update();
}

void WCartesianChart::setLegendColumns(int columns, const WLength& columnWidth)
{
  legend_.setLegendColumns(columns);
  legend_.setLegendColumnWidth(columnWidth);

  update();
}

void WCartesianChart::setLegendStyle(const WFont& font,
				     const WPen& border,
				     const WBrush& background)
{
  legend_.setLegendStyle(font, border, background);

  update();
}

WWidget *WCartesianChart::createLegendItemWidget(int index)
{
  WContainerWidget *legendItem = new WContainerWidget();

  legendItem->addWidget(new IconWidget(this, index));
  WText *label = new WText(asString(model()->headerData(index)));
  label->setVerticalAlignment(AlignTop);
  legendItem->addWidget(label);

  return legendItem;
}

void WCartesianChart::addDataPointArea(const WDataSeries& series,
				       const WModelIndex& xIndex,
				       WAbstractArea *area)
{
  addArea(area);
}

WPointF WCartesianChart::mapFromDevice(const WPointF& point, Axis ordinateAxis)
  const
{
  const WAxis& xAxis = axis(XAxis);
  const WAxis& yAxis = axis(ordinateAxis);

  WPointF p = inverseHv(point.x(), point.y(), width().toPixels());

  return WPointF(xAxis.mapFromDevice(p.x() - chartArea_.left()),
		 yAxis.mapFromDevice(chartArea_.bottom() - p.y()));
}

WPointF WCartesianChart::mapToDevice(const boost::any& xValue,
				     const boost::any& yValue,
				     Axis ordinateAxis, int xSegment,
				     int ySegment) const
{
  const WAxis& xAxis = axis(XAxis);
  const WAxis& yAxis = axis(ordinateAxis);
  
  double x = chartArea_.left() + xAxis.mapToDevice(xValue, xSegment);
  double y = chartArea_.bottom() - yAxis.mapToDevice(yValue, ySegment);

  return hv(x, y, width().toPixels());
}

WPointF WCartesianChart::hv(double x, double y,
			    double width) const
{
  if (orientation_ == Vertical)
    return WPointF(x, y);
  else
    return WPointF(width - y, x);
}

WPointF WCartesianChart::inverseHv(double x, double y, double width) const
{
   if (orientation_ == Vertical)
    return WPointF(x, y);
  else
    return WPointF(y, width - x); 
}

void WCartesianChart::modelColumnsInserted(const WModelIndex& parent,
					   int start, int end)
{
  for (unsigned i = 0; i < series_.size(); ++i)
    if (series_[i].modelColumn() >= start)
      series_[i].modelColumn_ += (end - start + 1);
}

void WCartesianChart::modelColumnsRemoved(const WModelIndex& parent,
					  int start, int end)
{
  bool needUpdate = false;

  for (unsigned i = 0; i < series_.size(); ++i)
    if (series_[i].modelColumn() >= start) {
      if (series_[i].modelColumn() <= end) {
	series_.erase(series_.begin() + i);
	needUpdate = true;
	--i;
      } else {
	series_[i].modelColumn_ -= (end - start + 1);
      }
    }

  if (needUpdate)
    update();
}

void WCartesianChart::modelRowsInserted(const WModelIndex& parent,
					int start, int end)
{
  update();
}

void WCartesianChart::modelRowsRemoved(const WModelIndex& parent,
				       int start, int end)
{
  update();
}

void WCartesianChart::modelDataChanged(const WModelIndex& topLeft,
				       const WModelIndex& bottomRight)
{
  if (XSeriesColumn_ >= topLeft.column() &&
      XSeriesColumn_ <= bottomRight.column()) {
    update();
    return;
  }

  for (unsigned i = 0; i < series_.size(); ++i) {
    if ((series_[i].modelColumn() >= topLeft.column() &&
	 series_[i].modelColumn() <= bottomRight.column()) ||
	(series_[i].XSeriesColumn() >= topLeft.column() &&
	 series_[i].XSeriesColumn() <= bottomRight.column())) {
      update();
      break;
    }
  }
}

void WCartesianChart::modelHeaderDataChanged(Orientation orientation,
					     int start, int end)
{
  if (orientation == Horizontal) {
    if (XSeriesColumn_ >= start && XSeriesColumn_ <= end) {
      update();
      return;
    }

    for (unsigned i = 0; i < series_.size(); ++i) {
      if ((series_[i].modelColumn() >= start &&
	   series_[i].modelColumn() <= end) ||
	  (series_[i].XSeriesColumn() >= start &&
	   series_[i].XSeriesColumn() <= end)) {
	update();
	break;
      }
    }
  }
}

void WCartesianChart::modelChanged()
{
  XSeriesColumn_ = -1;
  series_.clear();

  update();
}

void WCartesianChart::modelReset()
{
  update();
}

WCartesianChart::IconWidget::IconWidget(WCartesianChart *chart, 
					int index, 
					WContainerWidget *parent) 
  : WPaintedWidget(parent),
    chart_(chart),
    index_(index)
{
  setInline(true);
  resize(20, 20);
}

void WCartesianChart::IconWidget::paintEvent(Wt::WPaintDevice *paintDevice) 
{
  Wt::WPainter painter(paintDevice);
  chart_->renderLegendIcon(painter, 
			   WPointF(2.5, 10.0), 
			   chart_->series(index_));
}

void WCartesianChart::setAxisPadding(int padding)
{
  axisPadding_ = padding;
}

int WCartesianChart::calcNumBarGroups() const
{
  int numBarGroups = 0;

  bool newGroup = true;
  for (unsigned i = 0; i < series_.size(); ++i)
    if (series_[i].type() == BarSeries) {
      if (newGroup || !series_[i].isStacked())
	++numBarGroups;
      newGroup = false;
    } else
      newGroup = true;

  return numBarGroups;
}

void WCartesianChart::iterateSeries(SeriesIterator *iterator,
				    WPainter *painter,
				    bool reverseStacked) const
{
  WAbstractItemModel *chart_model = model();
  unsigned rows = chart_model ? chart_model->rowCount() : 0;

  double groupWidth = 0.0;
  int numBarGroups;
  int currentBarGroup;

#ifndef WT_TARGET_JAVA
  std::vector<double> stackedValuesInit(rows);
#else
  std::vector<double> stackedValuesInit;
  stackedValuesInit.insert(stackedValuesInit.begin(), rows, 0.0);
#endif // WT_TARGET_JAVA

  const bool scatterPlot = type_ == ScatterPlot;

  if (scatterPlot) {
    numBarGroups = 1;
    currentBarGroup = 0;
  } else {
    numBarGroups = calcNumBarGroups();
    currentBarGroup = 0;
  }

  bool containsBars = false;

  for (unsigned g = 0; g < series_.size(); ++g) {
    if (series_[g].isHidden())
      continue;

    groupWidth = series_[g].barWidth() * (map(2, 0).x() - map(1, 0).x());

    if (containsBars)
      ++currentBarGroup;
    containsBars = false;

    int startSeries, endSeries;

    if (scatterPlot) {
      startSeries = endSeries = g;
    } else {
      for (unsigned i = 0; i < rows; ++i)
	stackedValuesInit[i] = 0.0;

      if (reverseStacked) {
	endSeries = g;

	Axis a = series_[g].axis();

	for (;;) {
	  if (g < series_.size()
	      && (((int)g == endSeries) || series_[g].isStacked())
	      && (series_[g].axis() == a)) {
	    if (series_[g].type() == BarSeries)
	      containsBars = true;

	    for (unsigned row = 0; row < rows; ++row) {
	      double y
		= asNumber(chart_model->data(row, series_[g].modelColumn()));

	      if (!Utils::isNaN(y))
		stackedValuesInit[row] += y;
	    }

	    ++g;
	  } else
	    break;
	}

	--g;
	startSeries = g;
      } else {
	startSeries = g;

	Axis a = series_[g].axis();

	if (series_[g].type() == BarSeries)
	  containsBars = true;
	++g;

	for (;;) {
	  if (g < series_.size() && series_[g].isStacked()
	      && series_[g].axis() == a) {
	    if (series_[g].type() == BarSeries)
	      containsBars = true;
	    ++g;
	  } else
	    break;
	}

	--g;

	endSeries = g;
      }
    }

    int i = startSeries;
    for (;;) {
      bool doSeries = 
	iterator->startSeries(series_[i], groupWidth, numBarGroups,
			      currentBarGroup);

      std::vector<double> stackedValues;

      if (doSeries ||
	  (!scatterPlot && i != endSeries)) {

	for (int currentXSegment = 0;
	     currentXSegment < axis(XAxis).segmentCount();
	     ++currentXSegment) {

	  for (int currentYSegment = 0;
	       currentYSegment < axis(series_[i].axis()).segmentCount();
	       ++currentYSegment) {

	    stackedValues.clear();
	    Utils::insert(stackedValues, stackedValuesInit);

	    if (painter) {
	      WRectF csa = chartSegmentArea(axis(series_[i].axis()),
					    currentXSegment, 
					    currentYSegment);
	      iterator->startSegment(currentXSegment, currentYSegment, csa);
	      
	      painter->save();
	      
	      WPainterPath clipPath;
	      
	      clipPath.addRect(hv(csa));
	      painter->setClipPath(clipPath);
	      painter->setClipping(true);
	    } else {
	      iterator->startSegment(currentXSegment, currentYSegment, 
				     WRectF());
	    }

	    for (unsigned row = 0; row < rows; ++row) {
	      WModelIndex xIndex, yIndex;

	      double x;
	      if (scatterPlot) {
		int c = series_[i].XSeriesColumn();
		if (c == -1)
		  c = XSeriesColumn();
		if (c != -1) {
		  xIndex = chart_model->index(row, c);
		  x = asNumber(chart_model->data(xIndex));
		} else
		  x = row;
	      } else
		x = row;

	      yIndex = chart_model->index(row, series_[i].modelColumn());
	      double y = asNumber(chart_model->data(yIndex));

	      double prevStack;

	      if (scatterPlot)
		iterator->newValue(series_[i], x, y, 0, xIndex, yIndex);
	      else {
		prevStack = stackedValues[row];

		double nextStack = stackedValues[row];

		bool hasValue = !Utils::isNaN(y);

		if (hasValue) {
		  if (reverseStacked)
		    nextStack -= y;
		  else
		    nextStack += y;
		}

		stackedValues[row] = nextStack;

		if (doSeries) {
		  if (reverseStacked)
		    iterator->newValue(series_[i], x, hasValue ? prevStack : y,
				       nextStack, xIndex, yIndex);
		  else
		    iterator->newValue(series_[i], x, hasValue ? nextStack : y,
				       prevStack, xIndex, yIndex);
		}
	      }
	    }

	    iterator->endSegment();

	    if (painter)
	      painter->restore();
	  }
	}

	stackedValuesInit.clear();
	Utils::insert(stackedValuesInit, stackedValues);
      }

      if (doSeries)
	iterator->endSeries();

      if (i == endSeries)
	break;
      else {
	if (endSeries < startSeries)
	  --i;
	else
	  ++i;
      }
    }
  }
}

/*
 * ------ Rendering logic.
 */

void WCartesianChart::paint(WPainter& painter, const WRectF& rectangle) const
{
  if (!painter.isActive())
    throw WException("WCartesianChart::paint(): painter is not active.");

  WRectF rect = rectangle;

  if (rect.isNull() || rect.isEmpty())
    rect = painter.window();

  render(painter, rect);
}

void WCartesianChart::paintEvent(WPaintDevice *paintDevice)
{
  while (!areas().empty())
    delete areas().front();

  WPainter painter(paintDevice);
  painter.setRenderHint(WPainter::Antialiasing);
  paint(painter);
}

void WCartesianChart::render(WPainter& painter, const WRectF& rectangle) const
{
  painter.save();
  painter.translate(rectangle.topLeft());

  if (initLayout(rectangle, painter.device())) {
    renderBackground(painter);
    renderGrid(painter, axis(XAxis));
    renderGrid(painter, axis(Y1Axis));
    renderGrid(painter, axis(Y2Axis));
    renderSeries(painter);              // render the data series
    renderAxes(painter, Line | Labels); // render the axes (lines & labels)
    renderLegend(painter);
  }

  painter.restore();
}

bool WCartesianChart::initLayout(const WRectF& rectangle, WPaintDevice *device)
  const
{
  WRectF rect = rectangle;
  if (rect.isNull() || rect.isEmpty())
    rect = WRectF(0.0, 0.0, width().toPixels(), height().toPixels());

  if (orientation() == Vertical) {
    width_ = (int)rect.width();
    height_ = (int)rect.height();
  } else {
    width_ = (int)rect.height();
    height_ = (int)rect.width();
  }

  for (int i = 0; i < 3; ++i)
    location_[i] = MinimumValue;

  if (isAutoLayoutEnabled()) {
    WCartesianChart *self = const_cast<WCartesianChart *>(this);
    self->setPlotAreaPadding(40, Left | Right);
    self->setPlotAreaPadding(30, Top | Bottom);

    calcChartArea();

    if (chartArea_.width() <= 5 || chartArea_.height() <= 5 || !prepareAxes())
      return false;

    WPaintDevice *d = device;
    if (!d)
      d = createPaintDevice();
    WMeasurePaintDevice md(d);
    WPainter painter(&md);

    renderAxes(painter, Line | Labels);
    renderLegend(painter);

    WRectF bounds = md.boundingRect();

    /* bounds should be within rect with a 5 pixel margin */
    const int MARGIN = 5;
    int corrLeft = (int)std::max(0.0, rect.left() - bounds.left() + MARGIN);
    int corrRight = (int)std::max(0.0, bounds.right() - rect.right() + MARGIN);
    int corrTop = (int)std::max(0.0, rect.top() - bounds.top() + MARGIN);
    int corrBottom = (int)std::max(0.0, bounds.bottom() - rect.bottom()
				   + MARGIN);

    self->setPlotAreaPadding(plotAreaPadding(Left) + corrLeft, Left);
    self->setPlotAreaPadding(plotAreaPadding(Right) + corrRight, Right);
    self->setPlotAreaPadding(plotAreaPadding(Top) + corrTop, Top);
    self->setPlotAreaPadding(plotAreaPadding(Bottom) + corrBottom, Bottom);

    if (!device)
      delete d;
  }

  calcChartArea();

  return chartArea_.width() > 5 && chartArea_.height() > 5 && prepareAxes();
}

void WCartesianChart::drawMarker(const WDataSeries& series,
				 WPainterPath& result) const
{
  const double size = 6.0;
  const double hsize = size/2;

  switch (series.marker()) {
  case CircleMarker:
    result.addEllipse(-hsize, -hsize, size, size);
    break;
  case SquareMarker:
    result.addRect(WRectF(-hsize, -hsize, size, size));
    break;
  case CrossMarker:
    result.moveTo(-1.3 * hsize, 0);
    result.lineTo(1.3 * hsize, 0);
    result.moveTo(0, -1.3 * hsize);
    result.lineTo(0, 1.3 * hsize);
    break;
  case XCrossMarker:
    result.moveTo(-hsize, -hsize);
    result.lineTo(hsize, hsize);
    result.moveTo(-hsize, hsize);
    result.lineTo(hsize, -hsize);
    break;
  case TriangleMarker:
    result.moveTo(0, 0.6 * hsize);
    result.lineTo(-hsize, 0.6 * hsize);
    result.lineTo(0, -hsize);
    result.lineTo(hsize, 0.6 * hsize);
    result.closeSubPath();
    break;
  case CustomMarker:
    result = series.customMarker();
    break;
  default:
    ;
  }
}

void WCartesianChart::renderLegendIcon(WPainter& painter,
				       const WPointF& pos,
				       const WDataSeries& series) const
{
  WShadow shadow = painter.shadow();
  switch (series.type()) {
  case BarSeries: {
    WPainterPath path;
    path.moveTo(-6, 8);
    path.lineTo(-6, -8);
    path.lineTo(6, -8);
    path.lineTo(6, 8);
    painter.translate(pos.x() + 7.5, pos.y());  
    painter.setShadow(series.shadow());
    painter.fillPath(path, series.brush());
    painter.setShadow(shadow);
    painter.strokePath(path, series.pen());
    painter.translate(-(pos.x() + 7.5), -pos.y());
    break;
  }
  case LineSeries:
  case CurveSeries: {
    painter.setPen(series.pen());
    double offset = (series.pen().width() == 0 ? 0.5 : 0);
    painter.setShadow(series.shadow());
    painter.drawLine(pos.x(), pos.y() + offset, pos.x() + 16, pos.y() + offset);
    painter.setShadow(shadow);
  }
    // no break;
  case PointSeries: {
    WPainterPath path;
    drawMarker(series, path);
    if (!path.isEmpty()) {
      painter.translate(pos.x() + 8, pos.y());  
      painter.setShadow(series.shadow());
      painter.fillPath(path, series.markerBrush());
      painter.setShadow(shadow);
      painter.strokePath(path, series.markerPen());
      painter.translate(- (pos.x() + 8), -pos.y());
    }

    break;
  }
  }
}

void WCartesianChart::renderLegendItem(WPainter& painter,
				       const WPointF& pos,
				       const WDataSeries& series) const
{
  WPen fontPen = painter.pen();

  renderLegendIcon(painter, pos, series);

  painter.setPen(fontPen);
  painter.drawText(pos.x() + 23, pos.y() - 9, 100, 20,
		   AlignLeft | AlignMiddle,
		   asString(model()->headerData(series.modelColumn())));
}

bool WCartesianChart::prepareAxes() const
{
  const WAxis& xAxis = axis(XAxis);
  const WAxis& yAxis = axis(YAxis);
  const WAxis& y2Axis = axis(Y2Axis);

  Orientation yDir = orientation_;
  Orientation xDir = orientation_ == Vertical ? Horizontal : Vertical;

  if (!xAxis.prepareRender(xDir, chartArea_.width()))
    return false;

  if (!yAxis.prepareRender(yDir, chartArea_.height()))
    return false;

  if (!y2Axis.prepareRender(yDir, chartArea_.height()))
    return false;

  if (xAxis.scale() == CategoryScale) {
    switch (xAxis.location()) {
    case MinimumValue:
    case ZeroValue:
      location_[XAxis] = MinimumValue;
      break;
    case MaximumValue:
      location_[XAxis] = MaximumValue;
    }
  }

  for (int i = 0; i < 2; ++i) {
    WAxis axis = i == 0 ? xAxis : yAxis;
    WAxis other = i == 0 ? yAxis : xAxis;
    AxisValue location = axis.location();

    if (location == ZeroValue) {
      if (other.segments_.front().renderMaximum < 0)
	location = MaximumValue;
      else if (other.segments_.front().renderMinimum > 0)
	location = MinimumValue;
    } else if (location == MinimumValue) {
      if (other.segments_.front().renderMinimum == 0)
	location = ZeroValue;
    } else
      if (other.segments_.front().renderMaximum == 0)
	location = MaximumValue;

    location_[axis.id()] = location;
  }

  // force Y axes to the sides when dual Y axes
  if (y2Axis.isVisible()) {
    if (!(location_[Y1Axis] == ZeroValue
	  && (xAxis.segments_.front().renderMinimum == 0)))
      location_[Y1Axis] = MinimumValue;

    location_[Y2Axis] = MaximumValue;
  } else
    location_[Y2Axis] = MaximumValue;

  // adjust axis borders to make them look neat and polished
  xAxis.setOtherAxisLocation(location_[YAxis]);
  yAxis.setOtherAxisLocation(location_[XAxis]);
  y2Axis.setOtherAxisLocation(location_[XAxis]);

  return true;
}

WPointF WCartesianChart::map(double xValue, double yValue,
			     Axis yAxis, int currentXSegment,
			     int currentYSegment) const
{
  const WAxis& xAx = axis(XAxis);
  const WAxis& yAx = axis(yAxis);

  double x = chartArea_.left() + xAx.mapToDevice(xValue, currentXSegment);
  double y = chartArea_.bottom() - yAx.mapToDevice(yValue, currentYSegment);

  return WPointF(x, y);
}

void WCartesianChart::calcChartArea() const
{
  if (orientation_ == Vertical)
    chartArea_ = WRectF(plotAreaPadding(Left),
			plotAreaPadding(Top),
			std::max(10, width_ - plotAreaPadding(Left)
				 - plotAreaPadding(Right)),
			std::max(10, height_ - plotAreaPadding(Top)
				 - plotAreaPadding(Bottom)));
  else
    chartArea_ = WRectF(plotAreaPadding(Top),
			plotAreaPadding(Right),
			std::max(10, width_ - plotAreaPadding(Top)
				 - plotAreaPadding(Bottom)),
			std::max(10, height_ - plotAreaPadding(Right)
				 - plotAreaPadding(Left)));
}

WRectF WCartesianChart::chartSegmentArea(WAxis yAxis, int xSegment,
					 int ySegment) const
{
  const WAxis& xAxis = axis(XAxis);

  const WAxis::Segment& xs = xAxis.segments_[xSegment];
  const WAxis::Segment& ys = yAxis.segments_[ySegment];

  // margin used when clipping, see also WAxis::prepareRender(),
  // when the renderMinimum/maximum is 0, clipping is done exact

  double x1 = chartArea_.left() + xs.renderStart
    + (xSegment == 0
       ? (xs.renderMinimum == 0 ? 0 : -axisPadding())
       : -xAxis.segmentMargin() / 2);
  double x2 = chartArea_.left() + xs.renderStart + xs.renderLength
    + (xSegment == xAxis.segmentCount() - 1
       ? (xs.renderMaximum == 0 ? 0 : axisPadding())
       : xAxis.segmentMargin() / 2);

  double y1 = chartArea_.bottom() - ys.renderStart - ys.renderLength
    - (ySegment == yAxis.segmentCount() - 1
       ? (ys.renderMaximum == 0 ? 0 : axisPadding())
       : yAxis.segmentMargin() / 2);
  double y2 = chartArea_.bottom() - ys.renderStart
    + (ySegment == 0
       ? (ys.renderMinimum == 0 ? 0 : axisPadding())
       : yAxis.segmentMargin() / 2);

  return WRectF(std::floor(x1 + 0.5), std::floor(y1 + 0.5),
		std::floor(x2 - x1), std::floor(y2 - y1));
}

void WCartesianChart::renderBackground(WPainter& painter) const
{
  if (background().style() != NoBrush)
    painter.fillRect(hv(chartArea_), background());
}

void WCartesianChart::renderGrid(WPainter& painter, const WAxis& ax) const
{
  if (!ax.isGridLinesEnabled())
    return;

  bool vertical = ax.id() != XAxis;

  const WAxis& other = vertical ? axis(XAxis) : axis(Y1Axis);
  const WAxis::Segment& s0 = other.segments_.front();
  const WAxis::Segment& sn = other.segments_.back();

  double ou0 = s0.renderStart;
  double oun = sn.renderStart + sn.renderLength;
  
  bool otherVertical = !vertical;

  if (otherVertical) {
    ou0 = chartArea_.bottom() - ou0 + 0.5;
    oun = chartArea_.bottom() - oun + 0.5;
  } else {
    ou0 = chartArea_.left() + ou0 + 0.5;
    oun = chartArea_.left() + oun + 0.5;
  }

  WPainterPath gridPath;

  std::vector<double> gridPos = ax.gridLinePositions();
  
  for (unsigned i = 0; i < gridPos.size(); ++i) {
    double u = gridPos[i];

    if (vertical) {
      u = std::floor(chartArea_.bottom() - u) + 0.5;
      gridPath.moveTo(hv(ou0, u));
      gridPath.lineTo(hv(oun, u));
    } else {
      u = std::floor(chartArea_.left() + u) + 0.5;
      gridPath.moveTo(hv(u, ou0));
      gridPath.lineTo(hv(u, oun));
    }
  }

  painter.strokePath(gridPath, ax.gridLinesPen());
}

void WCartesianChart::renderAxis(WPainter& painter, const WAxis& axis,
				 WFlags<AxisProperty> properties) const
{
  if (!axis.isVisible())
    return;

  bool vertical = axis.id() != XAxis;

  WPointF axisStart, axisEnd;
  double tickStart = 0.0, tickEnd = 0.0, labelPos = 0.0;
  AlignmentFlag labelHFlag = AlignCenter, labelVFlag = AlignMiddle;

  if (vertical) {
    labelVFlag = AlignMiddle;
    axisStart.setY(chartArea_.bottom() + 0.5);
    axisEnd.setY(chartArea_.top() + 0.5);
  } else {
    labelHFlag = AlignCenter;
    axisStart.setX(chartArea_.left() + 0.5);
    axisEnd.setX(chartArea_.right() + 0.5);
  }

  switch (location_[axis.id()]) {
  case MinimumValue:
    if (vertical) {
      tickStart = -TICK_LENGTH;
      tickEnd = 0;
      labelPos = -TICK_LENGTH;
      labelHFlag = AlignRight;

      double x = chartArea_.left() - axis.margin() + 0.5;
      axisStart.setX(x);
      axisEnd.setX(x);
    } else {
      tickStart = 0;
      tickEnd = TICK_LENGTH;
      labelPos = TICK_LENGTH;
      labelVFlag = AlignTop;

      double y = chartArea_.bottom() + axis.margin() + 0.5;
      axisStart.setY(y);
      axisEnd.setY(y);
    }

    break;
  case MaximumValue:
    if (vertical) {
      tickStart = 0;
      tickEnd = TICK_LENGTH;
      labelPos = TICK_LENGTH;
      labelHFlag = AlignLeft;

      double x = chartArea_.right() + axis.margin() + 0.5;
      axisStart.setX(x);
      axisEnd.setX(x);
    } else {
      tickStart = -TICK_LENGTH;
      tickEnd = 0;
      labelPos = -TICK_LENGTH;
      labelVFlag = AlignBottom;

      double y = chartArea_.top() - axis.margin() + 0.5;
      axisStart.setY(y);
      axisEnd.setY(y);
    }

    break;
  case ZeroValue:
    tickStart = -TICK_LENGTH;
    tickEnd = TICK_LENGTH;

    if (vertical) {
      double x = std::floor(map(0, 0, YAxis).x()) + 0.5;
      axisStart.setX(x);
      axisEnd.setX(x);

      labelHFlag = AlignRight;

      /* force labels left even if axis is in middle */
      if (type() == CategoryChart)
	labelPos = chartArea_.left() - axisStart.x() - TICK_LENGTH;
      else
	labelPos = -TICK_LENGTH;

    } else {
      double y = std::floor(map(0, 0, YAxis).y()) + 0.5;
      axisStart.setY(y);
      axisEnd.setY(y);

      labelVFlag = AlignTop;

      /* force labels bottom even if axis is in middle */
      if (type() == CategoryChart)
	labelPos = chartArea_.bottom() - axisStart.y() + TICK_LENGTH;
      else
	labelPos = TICK_LENGTH;
    }

    break;
  }

  if ((properties & Labels) && !axis.title().empty()) {
    WFont oldFont2 = painter.font();
    WFont titleFont = axis.titleFont();
    painter.setFont(titleFont);

    bool chartVertical = orientation() == Vertical;

    if (vertical) {
      double u = axisStart.x();
      if (chartVertical)
	renderLabel(painter, axis.title(),
		    WPointF(u + (labelHFlag == AlignRight ? 15 : -15),
			    chartArea_.top() - 8),
		    black, labelHFlag | AlignBottom, 0, 0);
      else
	renderLabel(painter, axis.title(),
		    WPointF(u + (labelHFlag == AlignRight ? -40 : +40),
			    chartArea_.center().y()),
		    black,
		    (labelHFlag == AlignRight ? AlignLeft : AlignRight) |
		    AlignMiddle, 0, 0);
    } else {
      double u = axisStart.y();
      if (chartVertical)
	renderLabel(painter, axis.title(),
		    WPointF(chartArea_.center().x(), u + 22),
		    black, AlignTop | AlignCenter, 0, 0);
      else
	renderLabel(painter, axis.title(),
		    WPointF(chartArea_.right(), u),
		    black, AlignTop | AlignLeft, 0, 8);
    }

    painter.setFont(oldFont2);
  }

  const double ANGLE1 = 15;
  const double ANGLE2 = 80;

  /* Adjust alignment when rotating the labels */
  if (vertical) {
    if (axis.labelAngle() > ANGLE1) {
      labelVFlag = labelPos < 0 ? AlignBottom : AlignTop;
      if (axis.labelAngle() > ANGLE2)
	labelHFlag = AlignCenter;
    } else if (axis.labelAngle() < -ANGLE1) {
      labelVFlag = labelPos < 0 ? AlignTop : AlignBottom;
      if (axis.labelAngle() < -ANGLE2)
	labelHFlag = AlignCenter;
    }
  } else {
    if (axis.labelAngle() > ANGLE1) {
      labelHFlag = labelPos > 0 ? AlignRight : AlignLeft;
      if (axis.labelAngle() > ANGLE2)
	labelVFlag = AlignMiddle;
    } else if (axis.labelAngle() < -ANGLE1) {
      labelHFlag = labelPos > 0 ? AlignLeft : AlignRight;
      if (axis.labelAngle() < -ANGLE2)
	labelVFlag = AlignMiddle;
    }
  }

  /* perform hv() if necessary */
  if (orientation() == Horizontal) {
    axisStart = hv(axisStart);
    axisEnd = hv(axisEnd);

    AlignmentFlag rHFlag = AlignCenter, rVFlag = AlignMiddle;

    switch (labelHFlag) {
    case AlignLeft: rVFlag = AlignTop; break;
    case AlignCenter: rVFlag = AlignMiddle; break;
    case AlignRight: rVFlag = AlignBottom; break;
    default: break;
    }

    switch (labelVFlag) {
    case AlignTop: rHFlag = AlignRight; break;
    case AlignMiddle: rHFlag = AlignCenter; break;
    case AlignBottom: rHFlag = AlignLeft; break;
    default: break;
    }

    labelHFlag = rHFlag;
    labelVFlag = rVFlag;

    bool invertTicks = !vertical;
    if (invertTicks) {
      tickStart = -tickStart;
      tickEnd = -tickEnd;
      labelPos = -labelPos;
    }
  }

  axis.render(painter, properties, axisStart, axisEnd, tickStart, tickEnd,
	      labelPos, labelHFlag | labelVFlag);
}

void WCartesianChart::renderAxes(WPainter& painter,
				 WFlags<AxisProperty> properties) const
{
  renderAxis(painter, axis(XAxis), properties);
  renderAxis(painter, axis(Y1Axis), properties);
  renderAxis(painter, axis(Y2Axis), properties);
}

void WCartesianChart::renderSeries(WPainter& painter) const
{
  {
    SeriesRenderIterator iterator(*this, painter);
    iterateSeries(&iterator, &painter, true);
  }

  {
    LabelRenderIterator iterator(*this, painter);
    iterateSeries(&iterator, &painter);
  }

  {
    MarkerRenderIterator iterator(*this, painter);
    iterateSeries(&iterator, &painter);
  }
}

int WCartesianChart::calcNumBarGroups()
{
  int numBarGroups = 0;

  bool newGroup = true;
  for (unsigned i = 0; i < series().size(); ++i)
    if (series()[i].type() == BarSeries) {
      if (newGroup || !series()[i].isStacked())
	++numBarGroups;
      newGroup = false;
    } else
      newGroup = true;

  return numBarGroups;
}

void WCartesianChart::renderLegend(WPainter& painter) const
{
  bool vertical = orientation() == Vertical;

  int w = vertical ? width_ : height_;
  int h = vertical ? height_ : width_;

  const int margin = 10;

  if (isLegendEnabled()) {
    painter.save();

    int numSeriesWithLegend = 0;

    for (unsigned i = 0; i < series().size(); ++i)
      if (series()[i].isLegendEnabled())
	++numSeriesWithLegend;

    painter.setFont(legendFont());
    WFont f = painter.font();

    if (isAutoLayoutEnabled()) {
      int columnWidth = 0;
      for (unsigned i = 0; i < series().size(); ++i)
	if (series()[i].isLegendEnabled()) {
	  WString s = asString(model()->headerData(series()[i].modelColumn()));
	  WTextItem t = painter.device()->measureText(s);
	  columnWidth = std::max(columnWidth, (int)t.width());
	}

      WCartesianChart *self = const_cast<WCartesianChart *>(this);
      self->legend_.setLegendColumnWidth(columnWidth + 25);
    }

    int numLegendRows = (numSeriesWithLegend - 1) / legendColumns() + 1;
    double lineHeight = f.sizeLength().toPixels() * 1.5;

    int legendWidth = (int)legendColumnWidth().toPixels()
      * std::min(legendColumns(), numSeriesWithLegend);
    int legendHeight = (int) (numLegendRows * lineHeight);

    int x = 0;
    int y = 0;

    switch (legendSide()) {
    case Left:
      if (legendLocation() == LegendInside)
	x = plotAreaPadding(Left) + margin;
      else
	x = plotAreaPadding(Left) - margin - legendWidth;
      break;
    case Right:
      x = w - plotAreaPadding(Right);
      if (legendLocation() == LegendInside)
	x -= margin + legendWidth;
      else
	x += margin;
      break;
    case Top:
      if (legendLocation() == LegendInside)
	y = plotAreaPadding(Top) + margin;
      else
	y = plotAreaPadding(Top) - margin - legendHeight;
      break;
    case Bottom:
      y = h - plotAreaPadding(Bottom);
      if (legendLocation() == LegendInside)
	y -= margin + legendHeight;
      else
	y += margin;
    default:
      break;
    }

    switch (legendAlignment()) {
    case AlignTop:
      y = plotAreaPadding(Top) + margin;
      break;
    case AlignMiddle:
      {
	double middle = plotAreaPadding(Top)
	  + (h - plotAreaPadding(Top) - plotAreaPadding(Bottom)) / 2; 

	y = (int) (middle - legendHeight/2);
      }
      break;
    case AlignBottom:
      y = h - plotAreaPadding(Bottom) - margin - legendHeight;
      break;
    case AlignLeft:
      x = plotAreaPadding(Left) + margin;
      break;
    case AlignCenter:
      {
	double center = plotAreaPadding(Left)
	  + (w - plotAreaPadding(Left) - plotAreaPadding(Right)) / 2; 

	x = (int) (center - legendWidth/2);
      } 
      break;
    case AlignRight:
      x = w - plotAreaPadding(Right) - margin - legendWidth;
      break;
    default:
      break;
    }

    if (legendLocation() == LegendOutside) {
      if (legendSide() == Top && !vertical && axis(Y1Axis).isVisible())
	y -= 16;

      if (legendSide() == Right && vertical && axis(Y2Axis).isVisible())
	x += 40;

      if (legendSide() == Bottom
	  && ((vertical && axis(XAxis).isVisible()) ||
	      (!vertical && axis(Y2Axis).isVisible())))
	y += 16;

      if (legendSide() == Left
	  && ((vertical && axis(Y1Axis).isVisible()) ||
	      (!vertical && axis(XAxis).isVisible())))
	x -= 40;
    }

    painter.setPen(legendBorder());
    painter.setBrush(legendBackground());

    painter.drawRect(x - margin/2, y - margin/2, legendWidth + margin,
		      legendHeight + margin);

    painter.setPen(WPen());

    painter.setFont(legendFont());

    int item = 0;
    for (unsigned i = 0; i < series().size(); ++i)
      if (series()[i].isLegendEnabled()) {
	int col = item % legendColumns();
	int row = item / legendColumns();
	double itemX = x + col * legendColumnWidth().toPixels();
	double itemY = y + row * lineHeight;

	renderLegendItem(painter, WPointF(itemX, itemY + lineHeight/2),
			 series()[i]);

	++item;
      }

    painter.restore();
  }

  if (!title().empty()) {
    int x = w / 2;
    painter.save();
    painter.setFont(titleFont());
    painter.drawText(x - 500, 5, 1000, 50, AlignCenter | AlignTop, title());
    painter.restore();
  }
}

void WCartesianChart::renderLabel(WPainter& painter, const WString& text,
				  const WPointF& p, const WColor& color,
				  WFlags<AlignmentFlag> flags,
				  double angle, int margin) const
{
  AlignmentFlag horizontalAlign = flags & AlignHorizontalMask;
  AlignmentFlag verticalAlign = flags & AlignVerticalMask;

  AlignmentFlag rHorizontalAlign = horizontalAlign;
  AlignmentFlag rVerticalAlign = verticalAlign;

  double width = 1000;
  double height = 20;

  WPointF pos = hv(p);

  if (orientation() == Horizontal) {
    switch (horizontalAlign) {
    case AlignLeft:
      rVerticalAlign = AlignTop; break;
    case AlignCenter:
      rVerticalAlign = AlignMiddle; break;
    case AlignRight:
      rVerticalAlign = AlignBottom; break;
    default:
      break;
    }

    switch (verticalAlign) {
    case AlignTop:
      rHorizontalAlign = AlignRight; break;
    case AlignMiddle:
      rHorizontalAlign = AlignCenter; break;
    case AlignBottom:
      rHorizontalAlign = AlignLeft; break;
    default:
      break;
    }
  }

  double left = pos.x();
  double top = pos.y();

  switch (rHorizontalAlign) {
  case AlignLeft:
    left += margin; break;
  case AlignCenter:
    left -= width/2; break;
  case AlignRight:
    left -= width + margin;
  default:
    break;
  }

  switch (rVerticalAlign) {
  case AlignTop:
    top += margin; break;
  case AlignMiddle:
    top -= height/2; break;
  case AlignBottom:
    top -= height + margin; break;
  default:
    break;
  }

  WPen pen(color);
  WPen oldPen = painter.pen();
  painter.setPen(pen);

  if (angle == 0)
    painter.drawText(WRectF(left, top, width, height),
		     rHorizontalAlign | rVerticalAlign, text);
  else {
    painter.save();
    painter.translate(pos);
    painter.rotate(-angle);
    painter.drawText(WRectF(left - pos.x(), top - pos.y(), width, height),
		     rHorizontalAlign | rVerticalAlign, text);
    painter.restore();
  }

  painter.setPen(oldPen);
}

WPointF WCartesianChart::hv(const WPointF& p) const
{
  return hv(p.x(), p.y());
}

WPointF WCartesianChart::hv(double x, double y) const
{
  return hv(x, y, height_);
}

WRectF WCartesianChart::hv(const WRectF& r) const
{
  if (orientation() == Vertical)
    return r;
  else {
    WPointF tl = hv(r.bottomLeft());
    return WRectF(tl.x(), tl.y(), r.height(), r.width());
  }
}

  }
}