##// END OF EJS Templates
added description of using barcategory axis with line chart
added description of using barcategory axis with line chart

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piesliceitem.cpp
234 lines | 7.2 KiB | text/x-c | CppLexer
/****************************************************************************
**
** Copyright (C) 2012 Digia Plc
** All rights reserved.
** For any questions to Digia, please use contact form at http://qt.digia.com
**
** This file is part of the Qt Commercial Charts Add-on.
**
** $QT_BEGIN_LICENSE$
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.
**
** If you have questions regarding the use of this file, please use
** contact form at http://qt.digia.com
** $QT_END_LICENSE$
**
****************************************************************************/
#include "piesliceitem_p.h"
#include "piechartitem_p.h"
#include "qpieseries.h"
#include "qpieslice.h"
#include "chartpresenter_p.h"
#include <QPainter>
#include <qmath.h>
#include <QGraphicsSceneEvent>
#include <QTime>
#include <QDebug>
QTCOMMERCIALCHART_BEGIN_NAMESPACE
QPointF offset(qreal angle, qreal length)
{
qreal dx = qSin(angle*(M_PI/180)) * length;
qreal dy = qCos(angle*(M_PI/180)) * length;
return QPointF(dx, -dy);
}
PieSliceItem::PieSliceItem(QGraphicsItem* parent)
:QGraphicsObject(parent),
m_hovered(false)
{
setAcceptHoverEvents(true);
setAcceptedMouseButtons(Qt::MouseButtonMask);
setZValue(ChartPresenter::PieSeriesZValue);
}
PieSliceItem::~PieSliceItem()
{
// If user is hovering over the slice and it gets destroyed we do
// not get a hover leave event. So we must emit the signal here.
if (m_hovered)
emit hovered(false);
}
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->save();
painter->setClipRect(parentItem()->boundingRect());
painter->setPen(m_data.m_slicePen);
painter->setBrush(m_data.m_sliceBrush);
painter->drawPath(m_slicePath);
painter->restore();
if (m_data.m_isLabelVisible) {
painter->save();
// Pen for label arm not defined in the QPieSeries api, let's use brush's color instead
// Also, the drawText actually uses the pen color for the text color (unlike QGraphicsSimpleTextItem)
painter->setPen(m_data.m_labelBrush.color());
painter->setBrush(m_data.m_labelBrush);
painter->setFont(m_data.m_labelFont);
if (m_data.m_labelPosition == QPieSlice::LabelOutside) {
painter->setClipRect(parentItem()->boundingRect());
painter->strokePath(m_labelArmPath, m_data.m_labelBrush.color());
} else { // QPieSlice::LabelInside
painter->setClipPath(m_slicePath);
}
painter->drawText(m_labelTextRect, Qt::AlignCenter, m_data.m_labelText);
painter->restore();
}
}
void PieSliceItem::hoverEnterEvent(QGraphicsSceneHoverEvent* /*event*/)
{
m_hovered = true;
emit hovered(true);
}
void PieSliceItem::hoverLeaveEvent(QGraphicsSceneHoverEvent* /*event*/)
{
m_hovered = false;
emit hovered(false);
}
void PieSliceItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
emit clicked(event->buttons());
}
void PieSliceItem::setLayout(const PieSliceData &sliceData)
{
m_data = sliceData;
updateGeometry();
update();
}
void PieSliceItem::updateGeometry()
{
if (m_data.m_radius <= 0)
return;
prepareGeometryChange();
// 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);
// text rect
QFontMetricsF fm(m_data.m_labelFont);
m_labelTextRect = QRectF(0, 0, fm.width(m_data.m_labelText), fm.height());
// label arm path
QPointF labelTextStart;
m_labelArmPath = labelArmPath(armStart, centerAngle, m_data.m_radius * m_data.m_labelArmLengthFactor, m_labelTextRect.width(), &labelTextStart);
// text position
if (m_data.m_labelPosition == QPieSlice::LabelOutside)
m_labelTextRect.moveBottomLeft(labelTextStart);
else {// QPieSlice::LabelInside
QPointF sliceCenter = m_data.m_center + offset(centerAngle, m_data.m_radius / 2);
m_labelTextRect.moveCenter(sliceCenter);
}
// 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->angleSpan()/2);
qreal len = radius * slice->explodeDistanceFactor();
point += offset(centerAngle, len);
}
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)
{
// Normalize the angle to 0-360 range
// NOTE: We are using int here on purpose. Depenging on platform and hardware
// qreal can be a double, float or something the user gives to the Qt configure
// (QT_COORD_TYPE). Compilers do not seem to support modulo for double or float
// but there are fmod() and fmodf() functions for that. So instead of some #ifdef
// that might break we just use int. Precision for this is just fine for our needs.
int normalized = angle * 10.0;
normalized = normalized % 3600;
if (normalized < 0)
normalized += 3600;
angle = (qreal) normalized / 10.0;
// prevent label arm pointing straight down because it will look bad
if (angle < 180 && angle > 170)
angle = 170;
if (angle > 180 && angle < 190)
angle = 190;
// line from slice to label
QPointF parm1 = start + offset(angle, length);
// line to underline the label
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;
}
QPainterPath path;
path.moveTo(start);
path.lineTo(parm1);
path.lineTo(parm2);
return path;
}
#include "moc_piesliceitem_p.cpp"
QTCOMMERCIALCHART_END_NAMESPACE