main.cpp
168 lines
| 3.8 KiB
| text/x-c
|
CppLexer
Jani Honkonen
|
r9 | #include <QtGui/QApplication> | ||
| #include <QtGui> | ||||
| #include <QDebug> | ||||
| class Slice : public QGraphicsItem | ||||
| { | ||||
| public: | ||||
| Slice(const QColor& color, qreal startAngle, qreal span) | ||||
| :m_color(color), | ||||
| m_startAngle(startAngle), | ||||
| m_span(span) | ||||
| { | ||||
| setAcceptHoverEvents(true); | ||||
| } | ||||
| ~Slice() | ||||
| { | ||||
| } | ||||
| virtual QRectF boundingRect() const | ||||
| { | ||||
| return parentItem()->boundingRect(); | ||||
| } | ||||
| QPainterPath shape() const | ||||
| { | ||||
| qreal angle = (-m_startAngle) + (90); | ||||
| qreal span = -m_span; | ||||
| QPainterPath path; | ||||
| path.moveTo(boundingRect().center()); | ||||
| path.arcTo(boundingRect(), angle, span); | ||||
| // TODO: draw the shape so that it might have a hole in the center | ||||
| // - Sin & Cos will be needed to find inner/outer arc endpoints | ||||
| // dx, dy are offsets from the center | ||||
| //qreal l = boundingRect().height(); | ||||
| //qreal dx = qSin(angle*(M_PI/180)) * l; | ||||
| //qreal dy = qCos(angle*(M_PI/180)) * l; | ||||
| // TODO: exploded slice? | ||||
| return path; | ||||
| } | ||||
| virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) | ||||
| { | ||||
| // Setup painter | ||||
| painter->setBrush(m_color); | ||||
| QPen pen; | ||||
| //pen.setColor(m_color.darker()); | ||||
| pen.setColor(Qt::gray); | ||||
| pen.setWidth(1); | ||||
| painter->setPen(pen); | ||||
| // From Qt docs: | ||||
| // The startAngle and spanAngle must be specified in 1/16th of a degree, i.e. a full circle equals 5760 (16 * 360). | ||||
| // Positive values for the angles mean counter-clockwise while negative values mean the clockwise direction. | ||||
| // Zero degrees is at the 3 o'clock position. | ||||
| // | ||||
| // For sake of simplicity convert this so that zero degrees is at 12 o'clock and full circle is 360. | ||||
| //qreal angle = (-m_startAngle*16) + (90*16); | ||||
| //qreal span = -m_span*16; | ||||
| //painter->drawPie(boundingRect(), angle, span); | ||||
| painter->drawPath(shape()); | ||||
| } | ||||
| virtual void hoverEnterEvent( QGraphicsSceneHoverEvent * event) | ||||
| { | ||||
| QGraphicsItem::hoverEnterEvent(event); | ||||
| qDebug() << "hover" << m_color << m_startAngle << m_span; | ||||
| } | ||||
| private: | ||||
| QColor m_color; | ||||
| qreal m_startAngle; | ||||
| qreal m_span; | ||||
| }; | ||||
| class PieChart : public QGraphicsItem | ||||
| { | ||||
| public: | ||||
| PieChart() | ||||
| { | ||||
| qsrand(QTime::currentTime().msec()); | ||||
| } | ||||
| ~PieChart() | ||||
| { | ||||
| } | ||||
| QColor randomColor() | ||||
| { | ||||
| QColor c; | ||||
| c.setRed(qrand() % 255); | ||||
| c.setGreen(qrand() % 255); | ||||
| c.setBlue(qrand() % 255); | ||||
| return c; | ||||
| } | ||||
| void setData(QList<int> data) | ||||
| { | ||||
| qreal fullPie = 360; | ||||
| qreal total = 0; | ||||
| foreach (qreal value, data) | ||||
| total += value; | ||||
| qreal angle = 0; | ||||
| foreach (qreal value, data) { | ||||
| qreal span = value / total * fullPie; | ||||
| Slice *slice = new Slice(randomColor(), angle, span); | ||||
| slice->setParentItem(this); | ||||
| m_slices.append(slice); | ||||
| angle += span; | ||||
| } | ||||
| } | ||||
| virtual QRectF boundingRect() const | ||||
| { | ||||
| return QRectF(-200, -200, 200, 200); | ||||
| } | ||||
| virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) | ||||
| { | ||||
| //painter->setBrush(Qt::red); | ||||
| //painter->drawRect(boundingRect()); | ||||
| } | ||||
| private: | ||||
| QList<Slice*> m_slices; | ||||
| QSizeF m_size; | ||||
| }; | ||||
| int main(int argc, char *argv[]) | ||||
| { | ||||
| QApplication a(argc, argv); | ||||
| QGraphicsScene scene; | ||||
| PieChart *pieChart = new PieChart(); | ||||
| scene.addItem(pieChart); | ||||
| QGraphicsView view(&scene); | ||||
| view.setRenderHint(QPainter::Antialiasing); | ||||
| view.resize(400, 300); | ||||
| view.show(); | ||||
| QList<int> data; | ||||
| data << 1; | ||||
| data << 2; | ||||
| data << 3; | ||||
| data << 20; | ||||
| data << 2; | ||||
| data << 3; | ||||
| data << 10; | ||||
| data << 2; | ||||
| data << 1; | ||||
| data << 5; | ||||
| pieChart->setData(data); | ||||
| return a.exec(); | ||||
| } | ||||