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QML bar series categories
QML bar series categories

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piesliceitem.cpp
185 lines | 5.0 KiB | text/x-c | CppLexer
#include "piesliceitem_p.h"
#include "piechartitem_p.h"
#include "qpieseries.h"
#include "qpieslice.h"
#include "chartpresenter_p.h"
#include <QPainter>
#include <QDebug>
#include <qmath.h>
#include <QGraphicsSceneEvent>
#include <QTime>
QTCOMMERCIALCHART_BEGIN_NAMESPACE
#define PI 3.14159265 // TODO: is this defined in some header?
QPointF offset(qreal angle, qreal length)
{
qreal dx = qSin(angle*(PI/180)) * length;
qreal dy = qCos(angle*(PI/180)) * length;
return QPointF(dx, -dy);
}
PieSliceItem::PieSliceItem(QGraphicsItem* parent)
:QGraphicsObject(parent)
{
setAcceptHoverEvents(true);
setAcceptedMouseButtons(Qt::MouseButtonMask);
setZValue(ChartPresenter::PieSeriesZValue);
}
PieSliceItem::~PieSliceItem()
{
}
QRectF PieSliceItem::boundingRect() const
{
return m_boundingRect;
}
QPainterPath PieSliceItem::shape() const
{
// Don't include the label and label arm.
// This is used to detect a mouse clicks. We do not want clicks from label.
return m_slicePath;
}
void PieSliceItem::paint(QPainter* painter, const QStyleOptionGraphicsItem* /*option*/, QWidget* /*widget*/)
{
painter->setClipRect(parentItem()->boundingRect());
painter->save();
painter->setPen(m_data.m_slicePen);
painter->setBrush(m_data.m_sliceBrush);
painter->drawPath(m_slicePath);
painter->restore();
if (m_data.m_isLabelVisible) {
painter->setPen(m_data.m_labelPen);
painter->drawPath(m_labelArmPath);
// the pen color will affect the font color as well
painter->setFont(m_data.m_labelFont);
painter->drawText(m_labelTextRect.bottomLeft(), m_data.m_labelText);
}
}
void PieSliceItem::hoverEnterEvent(QGraphicsSceneHoverEvent* /*event*/)
{
emit hoverEnter();
}
void PieSliceItem::hoverLeaveEvent(QGraphicsSceneHoverEvent* /*event*/)
{
emit hoverLeave();
}
void PieSliceItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
emit clicked(event->buttons());
}
void PieSliceItem::setSliceData(PieSliceData sliceData)
{
m_data = sliceData;
}
void PieSliceItem::updateGeometry()
{
if (m_data.m_radius <= 0)
return;
prepareGeometryChange();
// update slice path
qreal centerAngle;
QPointF armStart;
m_slicePath = slicePath(m_data.m_center, m_data.m_radius, m_data.m_startAngle, m_data.m_angleSpan, &centerAngle, &armStart);
// update text rect
m_labelTextRect = labelTextRect(m_data.m_labelFont, m_data.m_labelText);
// update label arm path
QPointF labelTextStart;
m_labelArmPath = labelArmPath(armStart, centerAngle, m_data.m_radius * m_data.m_labelArmLengthFactor, m_labelTextRect.width(), &labelTextStart);
// update text position
m_labelTextRect.moveBottomLeft(labelTextStart);
// update bounding rect
if (m_data.m_isLabelVisible)
m_boundingRect = m_slicePath.boundingRect().united(m_labelArmPath.boundingRect()).united(m_labelTextRect);
else
m_boundingRect = m_slicePath.boundingRect();
}
QPointF PieSliceItem::sliceCenter(QPointF point, qreal radius, QPieSlice *slice)
{
if (slice->isExploded()) {
qreal centerAngle = slice->startAngle() + ((slice->endAngle() - slice->startAngle())/2);
qreal len = radius * slice->explodeDistanceFactor();
qreal dx = qSin(centerAngle*(PI/180)) * len;
qreal dy = -qCos(centerAngle*(PI/180)) * len;
point += QPointF(dx, dy);
}
return point;
}
QPainterPath PieSliceItem::slicePath(QPointF center, qreal radius, qreal startAngle, qreal angleSpan, qreal* centerAngle, QPointF* armStart)
{
// calculate center angle
*centerAngle = startAngle + (angleSpan/2);
// calculate slice rectangle
QRectF rect(center.x()-radius, center.y()-radius, radius*2, radius*2);
// slice path
// TODO: draw the shape so that it might have a hole in the center
QPainterPath path;
path.moveTo(rect.center());
path.arcTo(rect, -startAngle + 90, -angleSpan);
path.closeSubpath();
// calculate label arm start point
*armStart = center;
*armStart += offset(*centerAngle, radius + PIESLICE_LABEL_GAP);
return path;
}
QPainterPath PieSliceItem::labelArmPath(QPointF start, qreal angle, qreal length, qreal textWidth, QPointF* textStart)
{
qreal dx = qSin(angle*(PI/180)) * length;
qreal dy = -qCos(angle*(PI/180)) * length;
QPointF parm1 = start + QPointF(dx, dy);
QPointF parm2 = parm1;
if (angle < 180) { // arm swings the other way on the left side
parm2 += QPointF(textWidth, 0);
*textStart = parm1;
}
else {
parm2 += QPointF(-textWidth,0);
*textStart = parm2;
}
// elevate the text position a bit so that it does not hit the line
*textStart += QPointF(0, -5);
QPainterPath path;
path.moveTo(start);
path.lineTo(parm1);
path.lineTo(parm2);
return path;
}
QRectF PieSliceItem::labelTextRect(QFont font, QString text)
{
QFontMetricsF fm(font);
return fm.boundingRect(text);
}
#include "moc_piesliceitem_p.cpp"
QTCOMMERCIALCHART_END_NAMESPACE