From de2fd29c3347e4c738f306c784b20382260c4bc9 2012-01-12 10:20:59
From: Jani Honkonen <jani.honkonen@digia.com>
Date: 2012-01-12 10:20:59
Subject: [PATCH] Piechart drafting

---

diff --git a/src/pie/main.cpp b/src/pie/main.cpp
new file mode 100644
index 0000000..9e45e97
--- /dev/null
+++ b/src/pie/main.cpp
@@ -0,0 +1,168 @@
+#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();
+}
diff --git a/src/pie/pie.pro b/src/pie/pie.pro
new file mode 100644
index 0000000..97a82f4
--- /dev/null
+++ b/src/pie/pie.pro
@@ -0,0 +1,15 @@
+#-------------------------------------------------
+#
+# Project created by QtCreator 2012-01-11T14:41:14
+#
+#-------------------------------------------------
+
+QT       += core gui
+
+TARGET = pie
+TEMPLATE = app
+
+
+SOURCES += main.cpp
+
+HEADERS  +=