GPXSee/src/graph.cpp

#include <float.h>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QEvent>
#include "graph.h"

#include <QDebug>

#define MARGIN 10.0

Graph::Graph(QWidget *parent)
	: QGraphicsView(parent)
{
	_scene = new QGraphicsScene(this);
	setScene(_scene);

	_xAxis = new AxisItem(AxisItem::X);
	_yAxis = new AxisItem(AxisItem::Y);

	_slider = new SliderItem();
	connect(_slider, SIGNAL(positionChanged(const QPointF&)), this,
	  SLOT(emitSliderPositionChanged(const QPointF&)));

	_xMax = -FLT_MAX;
	_xMin = FLT_MAX;
	_yMax = -FLT_MAX;
	_yMin = FLT_MAX;

	_xScale = 1;
	_yScale = 1;
}

Graph::~Graph()
{
	if (_xAxis->scene() != _scene)
		delete _xAxis;
	if (_yAxis->scene() != _scene)
		delete _yAxis;

	if (_slider->scene() != _scene)
		delete _slider;

	delete _scene;
}

void Graph::updateBounds(const QPointF &point)
{
	if (point.x() < _xMin)
		_xMin = point.x();
	if (point.x() > _xMax)
		_xMax = point.x();
	if (point.y() < _yMin)
		_yMin = point.y();
	if (point.y() > _yMax)
		_yMax = point.y();
}

void Graph::loadData(const QVector<QPointF> &data)
{
	QPainterPath path;
	QGraphicsPathItem *pi;
	QColor color = _colorShop.color();


	if (data.size() < 2)
		return;

	updateBounds(data.at(0));
	path.moveTo(data.at(0).x(), -data.at(0).y());
	for (int i = 1; i < data.size(); i++) {
		path.lineTo(data.at(i).x(), -data.at(i).y());
		updateBounds(data.at(i));
	}

	QBrush brush(color, Qt::SolidPattern);
	QPen pen(brush, 0);

	pi = new QGraphicsPathItem(path);
	pi->setPen(pen);
	_scene->addItem(pi);
	_graphs.append(pi);

	resize(viewport()->size() - QSizeF(MARGIN, MARGIN));
}

void Graph::resize(const QSizeF &size)
{
	QRectF r;
	QSizeF mx, my;
	QTransform transform;
	qreal xs, ys;


	if (_xAxis->scene() == _scene)
		_scene->removeItem(_xAxis);
	if (_yAxis->scene() == _scene)
		_scene->removeItem(_yAxis);
	_xAxis->setRange(QPointF(_xMin * _xScale, _xMax * _xScale));
	_yAxis->setRange(QPointF(_yMin * _yScale, _yMax * _yScale));

	if (_slider->scene() == _scene)
		_scene->removeItem(_slider);

	for (int i = 0; i < _graphs.size(); i++)
		_graphs.at(i)->resetTransform();

	mx = _xAxis->margin();
	my = _yAxis->margin();
	r = _scene->itemsBoundingRect();
	xs = (size.width() - (my.width() + mx.width())) / r.width();
	ys = (size.height() - (mx.height() + my.height())) / r.height();
	transform.scale(xs, ys);

	for (int i = 0; i < _graphs.size(); i++)
		_graphs.at(i)->setTransform(transform);

	r = _scene->itemsBoundingRect();
	_xAxis->setSize(r.width());
	_yAxis->setSize(r.height());
	_xAxis->setPos(r.bottomLeft());
	_yAxis->setPos(r.bottomLeft());
	_scene->addItem(_xAxis);
	_scene->addItem(_yAxis);

	_slider->setArea(r);
	_slider->setPos(r.bottomLeft());
	_scene->addItem(_slider);

	_scene->setSceneRect(_scene->itemsBoundingRect());
}

void Graph::resizeEvent(QResizeEvent *)
{
	if (!_graphs.empty())
		resize(viewport()->size() - QSizeF(MARGIN, MARGIN));
}

void Graph::plot(QPainter *painter, const QRectF &target)
{
	qreal ratio = target.width() / target.height();
	QSizeF orig = _scene->sceneRect().size();
	QSizeF canvas = QSizeF(orig.height() * ratio, orig.height());

	resize(canvas);
	_slider->setVisible(false);
	_scene->render(painter, target, QRectF(), Qt::KeepAspectRatioByExpanding);
	_slider->setVisible(true);
	resize(orig);
}

void Graph::clear()
{
	if (_xAxis->scene() == _scene)
		_scene->removeItem(_xAxis);
	if (_yAxis->scene() == _scene)
		_scene->removeItem(_yAxis);

	if (_slider->scene() == _scene)
		_scene->removeItem(_slider);

	_scene->clear();
	_graphs.clear();
	_colorShop.reset();

	_xMax = -FLT_MAX;
	_xMin = FLT_MAX;
	_yMax = -FLT_MAX;
	_yMin = FLT_MAX;

	_scene->setSceneRect(0, 0, 0, 0);
}

void Graph::emitSliderPositionChanged(const QPointF &pos)
{
	qreal val = pos.x() / _slider->area().width();
	emit sliderPositionChanged(val);
}

qreal Graph::sliderPosition() const
{
	return _slider->pos().x() / _slider->area().width();
}

void Graph::setSliderPosition(qreal pos)
{
	_slider->setPos(pos * _slider->area().width(), 0);
}