##// END OF EJS Templates
Add possibility to set reverse values to axes...
Add possibility to set reverse values to axes Added support for reverse axis. This works with line, spline, scatter and area series with cartesian chart. QBarCategoryAxis is not supported, nor different bar series. Change-Id: I60f21372ea9cee7b49918d7d99de24671bdc42c3 Reviewed-by: Miikka Heikkinen <miikka.heikkinen@theqtcompany.com>

File last commit:

r2781:7c9f8e5a27d8
r2781:7c9f8e5a27d8
Show More
splinechartitem.cpp
506 lines | 20.2 KiB | text/x-c | CppLexer
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd
** All rights reserved.
** For any questions to The Qt Company, please use contact form at http://qt.io
**
** This file is part of the Qt Charts module.
**
** Licensees holding valid commercial license for Qt may use this file in
** accordance with the Qt License Agreement provided with the Software
** or, alternatively, in accordance with the terms contained in a written
** agreement between you and The Qt Company.
**
** If you have questions regarding the use of this file, please use
** contact form at http://qt.io
**
****************************************************************************/
#include <private/splinechartitem_p.h>
#include <private/qsplineseries_p.h>
#include <private/chartpresenter_p.h>
#include <private/splineanimation_p.h>
#include <private/polardomain_p.h>
#include <QtGui/QPainter>
#include <QtWidgets/QGraphicsSceneMouseEvent>
QT_CHARTS_BEGIN_NAMESPACE
SplineChartItem::SplineChartItem(QSplineSeries *series, QGraphicsItem *item)
: XYChart(series,item),
m_series(series),
m_pointsVisible(false),
m_animation(0),
m_pointLabelsVisible(false),
m_pointLabelsFormat(series->pointLabelsFormat()),
m_pointLabelsFont(series->pointLabelsFont()),
m_pointLabelsColor(series->pointLabelsColor()),
m_mousePressed(false)
{
setAcceptHoverEvents(true);
setFlag(QGraphicsItem::ItemIsSelectable);
setZValue(ChartPresenter::SplineChartZValue);
QObject::connect(m_series->d_func(), SIGNAL(updated()), this, SLOT(handleUpdated()));
QObject::connect(series, SIGNAL(visibleChanged()), this, SLOT(handleUpdated()));
QObject::connect(series, SIGNAL(opacityChanged()), this, SLOT(handleUpdated()));
QObject::connect(series, SIGNAL(pointLabelsFormatChanged(QString)),
this, SLOT(handleUpdated()));
QObject::connect(series, SIGNAL(pointLabelsVisibilityChanged(bool)),
this, SLOT(handleUpdated()));
QObject::connect(series, SIGNAL(pointLabelsFontChanged(QFont)), this, SLOT(handleUpdated()));
QObject::connect(series, SIGNAL(pointLabelsColorChanged(QColor)), this, SLOT(handleUpdated()));
handleUpdated();
}
QRectF SplineChartItem::boundingRect() const
{
return m_rect;
}
QPainterPath SplineChartItem::shape() const
{
return m_fullPath;
}
void SplineChartItem::setAnimation(SplineAnimation *animation)
{
m_animation = animation;
XYChart::setAnimation(animation);
}
ChartAnimation *SplineChartItem::animation() const
{
return m_animation;
}
void SplineChartItem::setControlGeometryPoints(QVector<QPointF>& points)
{
m_controlPoints = points;
}
QVector<QPointF> SplineChartItem::controlGeometryPoints() const
{
return m_controlPoints;
}
void SplineChartItem::updateChart(QVector<QPointF> &oldPoints, QVector<QPointF> &newPoints, int index)
{
QVector<QPointF> controlPoints;
if (newPoints.count() >= 2)
controlPoints = calculateControlPoints(newPoints);
if (m_animation)
m_animation->setup(oldPoints, newPoints, m_controlPoints, controlPoints, index);
m_points = newPoints;
m_controlPoints = controlPoints;
setDirty(false);
if (m_animation)
presenter()->startAnimation(m_animation);
else
updateGeometry();
}
void SplineChartItem::updateGeometry()
{
const QVector<QPointF> &points = m_points;
const QVector<QPointF> &controlPoints = m_controlPoints;
if ((points.size() < 2) || (controlPoints.size() < 2)) {
prepareGeometryChange();
m_path = QPainterPath();
m_rect = QRect();
return;
}
Q_ASSERT(points.count() * 2 - 2 == controlPoints.count());
QPainterPath splinePath;
QPainterPath fullPath;
// Use worst case scenario to determine required margin.
qreal margin = m_linePen.width() * 1.42;
if (m_series->chart()->chartType() == QChart::ChartTypePolar) {
QPainterPath splinePathLeft;
QPainterPath splinePathRight;
QPainterPath *currentSegmentPath = 0;
QPainterPath *previousSegmentPath = 0;
qreal minX = domain()->minX();
qreal maxX = domain()->maxX();
qreal minY = domain()->minY();
QPointF currentSeriesPoint = m_series->at(0);
QPointF currentGeometryPoint = points.at(0);
QPointF previousGeometryPoint = points.at(0);
bool pointOffGrid = false;
bool previousPointWasOffGrid = (currentSeriesPoint.x() < minX || currentSeriesPoint.x() > maxX);
m_visiblePoints.clear();
m_visiblePoints.reserve(points.size());
qreal domainRadius = domain()->size().height() / 2.0;
const QPointF centerPoint(domainRadius, domainRadius);
if (!previousPointWasOffGrid) {
fullPath.moveTo(points.at(0));
// Do not draw points for points below minimum Y.
if (m_pointsVisible && currentSeriesPoint.y() >= minY)
m_visiblePoints.append(currentGeometryPoint);
}
qreal leftMarginLine = centerPoint.x() - margin;
qreal rightMarginLine = centerPoint.x() + margin;
qreal horizontal = centerPoint.y();
// See ScatterChartItem::updateGeometry() for explanation why seriesLastIndex is needed
const int seriesLastIndex = m_series->count() - 1;
for (int i = 1; i < points.size(); i++) {
// Interpolating spline fragments accurately is not trivial, and would anyway be ugly
// when thick pen is used, so we work around it by utilizing three separate
// paths for spline segments and clip those with custom regions at paint time.
// "Right" path contains segments that cross the axis line with visible point on the
// right side of the axis line, as well as segments that have one point within the margin
// on the right side of the axis line and another point on the right side of the chart.
// "Left" path contains points with similarly on the left side.
// "Full" path contains rest of the points.
// This doesn't yield perfect results always. E.g. when segment covers more than 90
// degrees and both of the points are within the margin, one in the top half and one in the
// bottom half of the chart, the bottom one gets clipped incorrectly.
// However, this should be rare occurrence in any sensible chart.
currentSeriesPoint = m_series->at(qMin(seriesLastIndex, i));
currentGeometryPoint = points.at(i);
pointOffGrid = (currentSeriesPoint.x() < minX || currentSeriesPoint.x() > maxX);
// Draw something unless both off-grid
if (!pointOffGrid || !previousPointWasOffGrid) {
bool dummyOk; // We know points are ok, but this is needed
qreal currentAngle = static_cast<PolarDomain *>(domain())->toAngularCoordinate(currentSeriesPoint.x(), dummyOk);
qreal previousAngle = static_cast<PolarDomain *>(domain())->toAngularCoordinate(m_series->at(i - 1).x(), dummyOk);
if ((qAbs(currentAngle - previousAngle) > 180.0)) {
// If the angle between two points is over 180 degrees (half X range),
// any direct segment between them becomes meaningless.
// In this case two line segments are drawn instead, from previous
// point to the center and from center to current point.
if ((previousAngle < 0.0 || (previousAngle <= 180.0 && previousGeometryPoint.x() < rightMarginLine))
&& previousGeometryPoint.y() < horizontal) {
currentSegmentPath = &splinePathRight;
} else if ((previousAngle > 360.0 || (previousAngle > 180.0 && previousGeometryPoint.x() > leftMarginLine))
&& previousGeometryPoint.y() < horizontal) {
currentSegmentPath = &splinePathLeft;
} else if (previousAngle > 0.0 && previousAngle < 360.0) {
currentSegmentPath = &splinePath;
} else {
currentSegmentPath = 0;
}
if (currentSegmentPath) {
if (previousSegmentPath != currentSegmentPath)
currentSegmentPath->moveTo(previousGeometryPoint);
if (!previousSegmentPath)
fullPath.moveTo(previousGeometryPoint);
currentSegmentPath->lineTo(centerPoint);
fullPath.lineTo(centerPoint);
}
previousSegmentPath = currentSegmentPath;
if ((currentAngle < 0.0 || (currentAngle <= 180.0 && currentGeometryPoint.x() < rightMarginLine))
&& currentGeometryPoint.y() < horizontal) {
currentSegmentPath = &splinePathRight;
} else if ((currentAngle > 360.0 || (currentAngle > 180.0 &&currentGeometryPoint.x() > leftMarginLine))
&& currentGeometryPoint.y() < horizontal) {
currentSegmentPath = &splinePathLeft;
} else if (currentAngle > 0.0 && currentAngle < 360.0) {
currentSegmentPath = &splinePath;
} else {
currentSegmentPath = 0;
}
if (currentSegmentPath) {
if (previousSegmentPath != currentSegmentPath)
currentSegmentPath->moveTo(centerPoint);
if (!previousSegmentPath)
fullPath.moveTo(centerPoint);
currentSegmentPath->lineTo(currentGeometryPoint);
fullPath.lineTo(currentGeometryPoint);
}
} else {
QPointF cp1 = controlPoints[2 * (i - 1)];
QPointF cp2 = controlPoints[(2 * i) - 1];
if (previousAngle < 0.0 || currentAngle < 0.0
|| ((previousAngle <= 180.0 && currentAngle <= 180.0)
&& ((previousGeometryPoint.x() < rightMarginLine && previousGeometryPoint.y() < horizontal)
|| (currentGeometryPoint.x() < rightMarginLine && currentGeometryPoint.y() < horizontal)))) {
currentSegmentPath = &splinePathRight;
} else if (previousAngle > 360.0 || currentAngle > 360.0
|| ((previousAngle > 180.0 && currentAngle > 180.0)
&& ((previousGeometryPoint.x() > leftMarginLine && previousGeometryPoint.y() < horizontal)
|| (currentGeometryPoint.x() > leftMarginLine && currentGeometryPoint.y() < horizontal)))) {
currentSegmentPath = &splinePathLeft;
} else {
currentSegmentPath = &splinePath;
}
if (currentSegmentPath != previousSegmentPath)
currentSegmentPath->moveTo(previousGeometryPoint);
if (!previousSegmentPath)
fullPath.moveTo(previousGeometryPoint);
fullPath.cubicTo(cp1, cp2, currentGeometryPoint);
currentSegmentPath->cubicTo(cp1, cp2, currentGeometryPoint);
}
} else {
currentSegmentPath = 0;
}
previousPointWasOffGrid = pointOffGrid;
if (!pointOffGrid && m_pointsVisible && currentSeriesPoint.y() >= minY)
m_visiblePoints.append(currentGeometryPoint);
previousSegmentPath = currentSegmentPath;
previousGeometryPoint = currentGeometryPoint;
}
m_pathPolarRight = splinePathRight;
m_pathPolarLeft = splinePathLeft;
// Note: This construction of m_fullpath is not perfect. The partial segments that are
// outside left/right clip regions at axis boundary still generate hover/click events,
// because shape doesn't get clipped. It doesn't seem possible to do sensibly.
} else { // not polar
splinePath.moveTo(points.at(0));
for (int i = 0; i < points.size() - 1; i++) {
const QPointF &point = points.at(i + 1);
splinePath.cubicTo(controlPoints[2 * i], controlPoints[2 * i + 1], point);
}
fullPath = splinePath;
}
QPainterPathStroker stroker;
// The full path is comprised of three separate paths.
// This is why we are prepared for the "worst case" scenario, i.e. use always MiterJoin and
// multiply line width with square root of two when defining shape and bounding rectangle.
stroker.setWidth(margin);
stroker.setJoinStyle(Qt::MiterJoin);
stroker.setCapStyle(Qt::SquareCap);
stroker.setMiterLimit(m_linePen.miterLimit());
// Only zoom in if the bounding rects of the path fit inside int limits. QWidget::update() uses
// a region that has to be compatible with QRect.
QPainterPath checkShapePath = stroker.createStroke(fullPath);
if (checkShapePath.boundingRect().height() <= INT_MAX
&& checkShapePath.boundingRect().width() <= INT_MAX
&& splinePath.boundingRect().height() <= INT_MAX
&& splinePath.boundingRect().width() <= INT_MAX) {
m_path = splinePath;
prepareGeometryChange();
m_fullPath = checkShapePath;
m_rect = m_fullPath.boundingRect();
}
}
/*!
Calculates control points which are needed by QPainterPath.cubicTo function to draw the cubic Bezier cureve between two points.
*/
QVector<QPointF> SplineChartItem::calculateControlPoints(const QVector<QPointF> &points)
{
QVector<QPointF> controlPoints;
controlPoints.resize(points.count() * 2 - 2);
int n = points.count() - 1;
if (n == 1) {
//for n==1
controlPoints[0].setX((2 * points[0].x() + points[1].x()) / 3);
controlPoints[0].setY((2 * points[0].y() + points[1].y()) / 3);
controlPoints[1].setX(2 * controlPoints[0].x() - points[0].x());
controlPoints[1].setY(2 * controlPoints[0].y() - points[0].y());
return controlPoints;
}
// Calculate first Bezier control points
// Set of equations for P0 to Pn points.
//
// | 2 1 0 0 ... 0 0 0 ... 0 0 0 | | P1_1 | | P0 + 2 * P1 |
// | 1 4 1 0 ... 0 0 0 ... 0 0 0 | | P1_2 | | 4 * P1 + 2 * P2 |
// | 0 1 4 1 ... 0 0 0 ... 0 0 0 | | P1_3 | | 4 * P2 + 2 * P3 |
// | . . . . . . . . . . . . | | ... | | ... |
// | 0 0 0 0 ... 1 4 1 ... 0 0 0 | * | P1_i | = | 4 * P(i-1) + 2 * Pi |
// | . . . . . . . . . . . . | | ... | | ... |
// | 0 0 0 0 0 0 0 0 ... 1 4 1 | | P1_(n-1)| | 4 * P(n-2) + 2 * P(n-1) |
// | 0 0 0 0 0 0 0 0 ... 0 2 7 | | P1_n | | 8 * P(n-1) + Pn |
//
QVector<qreal> vector;
vector.resize(n);
vector[0] = points[0].x() + 2 * points[1].x();
for (int i = 1; i < n - 1; ++i)
vector[i] = 4 * points[i].x() + 2 * points[i + 1].x();
vector[n - 1] = (8 * points[n - 1].x() + points[n].x()) / 2.0;
QVector<qreal> xControl = firstControlPoints(vector);
vector[0] = points[0].y() + 2 * points[1].y();
for (int i = 1; i < n - 1; ++i)
vector[i] = 4 * points[i].y() + 2 * points[i + 1].y();
vector[n - 1] = (8 * points[n - 1].y() + points[n].y()) / 2.0;
QVector<qreal> yControl = firstControlPoints(vector);
for (int i = 0, j = 0; i < n; ++i, ++j) {
controlPoints[j].setX(xControl[i]);
controlPoints[j].setY(yControl[i]);
j++;
if (i < n - 1) {
controlPoints[j].setX(2 * points[i + 1].x() - xControl[i + 1]);
controlPoints[j].setY(2 * points[i + 1].y() - yControl[i + 1]);
} else {
controlPoints[j].setX((points[n].x() + xControl[n - 1]) / 2);
controlPoints[j].setY((points[n].y() + yControl[n - 1]) / 2);
}
}
return controlPoints;
}
QVector<qreal> SplineChartItem::firstControlPoints(const QVector<qreal>& vector)
{
QVector<qreal> result;
int count = vector.count();
result.resize(count);
result[0] = vector[0] / 2.0;
QVector<qreal> temp;
temp.resize(count);
temp[0] = 0;
qreal b = 2.0;
for (int i = 1; i < count; i++) {
temp[i] = 1 / b;
b = (i < count - 1 ? 4.0 : 3.5) - temp[i];
result[i] = (vector[i] - result[i - 1]) / b;
}
for (int i = 1; i < count; i++)
result[count - i - 1] -= temp[count - i] * result[count - i];
return result;
}
//handlers
void SplineChartItem::handleUpdated()
{
setVisible(m_series->isVisible());
setOpacity(m_series->opacity());
m_pointsVisible = m_series->pointsVisible();
m_linePen = m_series->pen();
m_pointPen = m_series->pen();
m_pointPen.setWidthF(2 * m_pointPen.width());
m_pointLabelsFormat = m_series->pointLabelsFormat();
m_pointLabelsVisible = m_series->pointLabelsVisible();
m_pointLabelsFont = m_series->pointLabelsFont();
m_pointLabelsColor = m_series->pointLabelsColor();
update();
}
//painter
void SplineChartItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
Q_UNUSED(widget)
Q_UNUSED(option)
QRectF clipRect = QRectF(QPointF(0, 0), domain()->size());
painter->save();
painter->setPen(m_linePen);
painter->setBrush(Qt::NoBrush);
if (m_series->chart()->chartType() == QChart::ChartTypePolar) {
qreal halfWidth = domain()->size().width() / 2.0;
QRectF clipRectLeft = QRectF(0, 0, halfWidth, domain()->size().height());
QRectF clipRectRight = QRectF(halfWidth, 0, halfWidth, domain()->size().height());
QRegion fullPolarClipRegion(clipRect.toRect(), QRegion::Ellipse);
QRegion clipRegionLeft(fullPolarClipRegion.intersected(clipRectLeft.toRect()));
QRegion clipRegionRight(fullPolarClipRegion.intersected(clipRectRight.toRect()));
painter->setClipRegion(clipRegionLeft);
painter->drawPath(m_pathPolarLeft);
painter->setClipRegion(clipRegionRight);
painter->drawPath(m_pathPolarRight);
painter->setClipRegion(fullPolarClipRegion);
} else {
painter->setClipRect(clipRect);
}
reversePainter(painter, clipRect);
painter->drawPath(m_path);
if (m_pointsVisible) {
painter->setPen(m_pointPen);
if (m_series->chart()->chartType() == QChart::ChartTypePolar)
painter->drawPoints(m_visiblePoints);
else
painter->drawPoints(geometryPoints());
}
reversePainter(painter, clipRect);
if (m_pointLabelsVisible)
m_series->d_func()->drawSeriesPointLabels(painter, m_points, m_linePen.width() / 2);
painter->restore();
}
void SplineChartItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
emit XYChart::pressed(domain()->calculateDomainPoint(event->pos()));
m_lastMousePos = event->pos();
m_mousePressed = true;
QGraphicsItem::mousePressEvent(event);
}
void SplineChartItem::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
{
emit XYChart::hovered(domain()->calculateDomainPoint(event->pos()), true);
QGraphicsItem::hoverEnterEvent(event);
}
void SplineChartItem::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
{
emit XYChart::hovered(domain()->calculateDomainPoint(event->pos()), false);
QGraphicsItem::hoverLeaveEvent(event);
}
void SplineChartItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
{
emit XYChart::released(domain()->calculateDomainPoint(m_lastMousePos));
if (m_mousePressed)
emit XYChart::clicked(domain()->calculateDomainPoint(m_lastMousePos));
m_mousePressed = false;
QGraphicsItem::mouseReleaseEvent(event);
}
void SplineChartItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
{
emit XYChart::doubleClicked(domain()->calculateDomainPoint(m_lastMousePos));
QGraphicsItem::mouseDoubleClickEvent(event);
}
#include "moc_splinechartitem_p.cpp"
QT_CHARTS_END_NAMESPACE