From 8d9e377a106572b4396ea96c0eedbb42611536d8 2012-03-02 14:47:03
From: Jani Honkonen <jani.honkonen@digia.com>
Date: 2012-03-02 14:47:03
Subject: [PATCH] Added a pie chart customization example and refactoring the pie interface.

---

diff --git a/example/example.pro b/example/example.pro
index 2266f09..738ee74 100644
--- a/example/example.pro
+++ b/example/example.pro
@@ -7,6 +7,7 @@ SUBDIRS += linechart \
            percentbarchart \
            scatter \
            piechart \
+           piechartcustomization \
            piechartdrilldown \
            dynamiclinechart \
            axischart \
diff --git a/example/piechartcustomization/main.cpp b/example/piechartcustomization/main.cpp
new file mode 100644
index 0000000..ad4a782
--- /dev/null
+++ b/example/piechartcustomization/main.cpp
@@ -0,0 +1,224 @@
+#include <QtGui/QApplication>
+#include <QMainWindow>
+#include <qchartglobal.h>
+#include <qchartview.h>
+#include <qpieseries.h>
+#include <qpieslice.h>
+#include <QGridLayout>
+#include <QFormLayout>
+#include <QComboBox>
+#include <QSpinBox>
+#include <QCheckBox>
+#include <QGroupBox>
+#include <QLabel>
+
+QTCOMMERCIALCHART_USE_NAMESPACE
+
+Q_DECLARE_METATYPE(QPieSeries::PiePosition)
+
+class CustomSlice : public QPieSlice
+{
+    Q_OBJECT
+public:
+    CustomSlice(qreal value, QString label)
+        :QPieSlice(value, label)
+    {
+        connect(this, SIGNAL(hoverEnter()), this, SLOT(handleHoverEnter()));
+        connect(this, SIGNAL(hoverLeave()), this, SLOT(handleHoverLeave()));
+    }
+
+public Q_SLOTS:
+
+    void handleHoverEnter()
+    {
+        QBrush brush = this->brush();
+        m_originalBrush = brush;
+        brush.setColor(brush.color().lighter());
+        setBrush(brush);
+    }
+
+    void handleHoverLeave()
+    {
+        setBrush(m_originalBrush);
+    }
+
+private:
+    QBrush m_originalBrush;
+};
+
+class MainWidget : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit MainWidget(QWidget* parent = 0)
+        :QWidget(parent)
+    {
+        m_chartView =  new QChartView();
+        m_chartView->setChartTitle("Piechart customization");
+        //m_chartView->setRenderHint(QPainter::Antialiasing);
+
+        m_series = new QPieSeries();
+        *m_series << new CustomSlice(10.0, "Slice 1");
+        *m_series << new CustomSlice(20.0, "Slice 2");
+        *m_series << new CustomSlice(30.0, "Slice 3");
+        *m_series << new CustomSlice(40.0, "Slice 4");
+        *m_series << new CustomSlice(50.0, "Slice 5");
+        m_chartView->addSeries(m_series);
+
+        m_vPosition = new QComboBox();
+        m_vPosition->addItem("Top", QPieSeries::PiePositionTop);
+        m_vPosition->addItem("Bottom", QPieSeries::PiePositionBottom);
+        m_vPosition->addItem("Center", QPieSeries::PiePositionVCenter);
+
+        m_hPosition = new QComboBox();
+        m_hPosition->addItem("Left", QPieSeries::PiePositionLeft);
+        m_hPosition->addItem("Right", QPieSeries::PiePositionRight);
+        m_hPosition->addItem("Center", QPieSeries::PiePositionHCenter);
+
+        m_sizePolicy = new QComboBox();
+        m_sizePolicy->addItem("Maximized", QPieSeries::PieSizePolicyMaximized);
+        m_sizePolicy->addItem("Space for labels", QPieSeries::PieSizePolicyReserveSpaceForLabels);
+        m_sizePolicy->addItem("Space for exploding", QPieSeries::PieSizePolicyReserveSpaceForExploding);
+        m_sizePolicy->addItem("Space for all", QPieSeries::PieSizePolicyReserveSpaceForAll);
+
+        m_sizeFactor = new QDoubleSpinBox();
+        m_sizeFactor->setMinimum(0.0);
+        m_sizeFactor->setMaximum(1.0);
+        m_sizeFactor->setValue(m_series->sizeFactor());
+        m_sizeFactor->setSingleStep(0.1);
+
+        m_startAngle = new QDoubleSpinBox();
+        m_startAngle->setMinimum(0.0);
+        m_startAngle->setMaximum(360);
+        m_startAngle->setValue(m_series->startAngle());
+        m_startAngle->setSingleStep(1);
+
+        m_endAngle = new QDoubleSpinBox();
+        m_endAngle->setMinimum(0.0);
+        m_endAngle->setMaximum(360);
+        m_endAngle->setValue(m_series->endAngle());
+        m_endAngle->setSingleStep(1);
+
+        QFormLayout* seriesSettingsLayout = new QFormLayout();
+        seriesSettingsLayout->addRow("Vertical position", m_vPosition);
+        seriesSettingsLayout->addRow("Horizontal position", m_hPosition);
+        seriesSettingsLayout->addRow("Size policy", m_sizePolicy);
+        seriesSettingsLayout->addRow("Size factor", m_sizeFactor);
+        seriesSettingsLayout->addRow("Start angle", m_startAngle);
+        seriesSettingsLayout->addRow("End angle", m_endAngle);
+        QGroupBox* seriesSettings = new QGroupBox("Series");
+        seriesSettings->setLayout(seriesSettingsLayout);
+
+        m_sliceName = new QLabel("<click a slice>");
+        m_sliceValue = new QDoubleSpinBox();
+        m_sliceValue->setMaximum(1000);
+        m_sliceLabelVisible = new QCheckBox();
+        m_sliceExploded = new QCheckBox();
+
+        QFormLayout* sliceSettingsLayout = new QFormLayout();
+        sliceSettingsLayout->addRow("Selected", m_sliceName);
+        sliceSettingsLayout->addRow("Value", m_sliceValue);
+        sliceSettingsLayout->addRow("Label visible", m_sliceLabelVisible);
+        sliceSettingsLayout->addRow("Exploded", m_sliceExploded);
+        QGroupBox* sliceSettings = new QGroupBox("Slice");
+        sliceSettings->setLayout(sliceSettingsLayout);
+
+        QGridLayout* baseLayout = new QGridLayout();
+        baseLayout->addWidget(seriesSettings, 0, 0);
+        baseLayout->addWidget(sliceSettings, 1, 0);
+        baseLayout->addWidget(m_chartView, 0, 1, 2, 1);
+        setLayout(baseLayout);
+
+        connect(m_vPosition, SIGNAL(currentIndexChanged(int)), this, SLOT(updateSerieSettings()));
+        connect(m_hPosition, SIGNAL(currentIndexChanged(int)), this, SLOT(updateSerieSettings()));
+        connect(m_sizePolicy, SIGNAL(currentIndexChanged(int)), this, SLOT(updateSerieSettings()));
+        connect(m_sizeFactor, SIGNAL(valueChanged(double)), this, SLOT(updateSerieSettings()));
+        connect(m_startAngle, SIGNAL(valueChanged(double)), this, SLOT(updateSerieSettings()));
+        connect(m_endAngle, SIGNAL(valueChanged(double)), this, SLOT(updateSerieSettings()));
+
+        connect(m_sliceValue, SIGNAL(valueChanged(double)), this, SLOT(updateSliceSettings()));
+        connect(m_sliceLabelVisible, SIGNAL(toggled(bool)), this, SLOT(updateSliceSettings()));
+        connect(m_sliceExploded, SIGNAL(toggled(bool)), this, SLOT(updateSliceSettings()));
+
+        connect(m_series, SIGNAL(clicked(QPieSlice*)), this, SLOT(handleSliceClicked(QPieSlice*)));
+
+        updateSerieSettings();
+    }
+
+public Q_SLOTS:
+
+    void updateSerieSettings()
+    {
+        QPieSeries::PiePosition vPos(m_vPosition->itemData(m_vPosition->currentIndex()).toInt());
+        QPieSeries::PiePosition hPos(m_hPosition->itemData(m_hPosition->currentIndex()).toInt());
+        m_series->setPosition(vPos | hPos);
+
+        QPieSeries::PieSizePolicy policy(m_sizePolicy->itemData(m_sizePolicy->currentIndex()).toInt());
+        m_series->setSizePolicy(policy);
+
+        m_series->setSizeFactor(m_sizeFactor->value());
+
+        m_series->setStartAngle(m_startAngle->value());
+        m_series->setEndAngle(m_endAngle->value());
+    }
+
+    void updateSliceSettings()
+    {
+        m_slice->setValue(m_sliceValue->value());
+        m_slice->setLabelVisible(m_sliceLabelVisible->isChecked());
+        m_slice->setExploded(m_sliceExploded->isChecked());
+    }
+
+    void handleSliceClicked(QPieSlice* slice)
+    {
+        m_slice = slice;
+        m_sliceName->setText(slice->label());
+
+        m_sliceValue->blockSignals(true);
+        m_sliceValue->setValue(slice->value());
+        m_sliceValue->blockSignals(false);
+
+        m_sliceLabelVisible->blockSignals(true);
+        m_sliceLabelVisible->setChecked(slice->isLabelVisible());
+        m_sliceLabelVisible->blockSignals(false);
+
+        m_sliceExploded->blockSignals(true);
+        m_sliceExploded->setChecked(slice->isExploded());
+        m_sliceExploded->blockSignals(false);
+    }
+
+private:
+    QChartView* m_chartView;
+    QPieSeries* m_series;
+    QPieSlice* m_slice;
+
+    QComboBox* m_vPosition;
+    QComboBox* m_hPosition;
+    QComboBox* m_sizePolicy;
+    QDoubleSpinBox* m_sizeFactor;
+    QDoubleSpinBox* m_startAngle;
+    QDoubleSpinBox* m_endAngle;
+
+    QLabel* m_sliceName;
+    QDoubleSpinBox* m_sliceValue;
+    QCheckBox* m_sliceLabelVisible;
+    QCheckBox* m_sliceExploded;
+};
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+
+    QMainWindow window;
+
+    MainWidget* widget = new MainWidget();
+
+    window.setCentralWidget(widget);
+    window.resize(900, 600);
+    window.show();
+
+    return a.exec();
+}
+
+#include "main.moc"
diff --git a/example/piechartcustomization/piechartcustomization.pro b/example/piechartcustomization/piechartcustomization.pro
new file mode 100644
index 0000000..1230dad
--- /dev/null
+++ b/example/piechartcustomization/piechartcustomization.pro
@@ -0,0 +1,8 @@
+!include( ../example.pri ) {
+ error( "Couldn't find the example.pri file!" )
+}
+TARGET = piechartcustomization
+SOURCES += main.cpp
+HEADERS +=
+
+
diff --git a/src/piechart/piechart.pri b/src/piechart/piechart.pri
index dbed0d8..cb4b8b8 100644
--- a/src/piechart/piechart.pri
+++ b/src/piechart/piechart.pri
@@ -5,13 +5,11 @@ SOURCES += \
     $$PWD/qpieseries.cpp \
     $$PWD/pieslice.cpp \
     $$PWD/piepresenter.cpp \
-    $$PWD/pieslicelabel.cpp \
     $$PWD/qpieslice.cpp
 
 PRIVATE_HEADERS += \
     $$PWD/piepresenter_p.h \
     $$PWD/pieslice_p.h \
-    $$PWD/pieslicelabel_p.h
 
 PUBLIC_HEADERS += \
     $$PWD/qpieseries.h \
diff --git a/src/piechart/piepresenter.cpp b/src/piechart/piepresenter.cpp
index 9be832e..fe2bb36 100644
--- a/src/piechart/piepresenter.cpp
+++ b/src/piechart/piepresenter.cpp
@@ -1,12 +1,9 @@
-
 #include "piepresenter_p.h"
 #include "pieslice_p.h"
 #include "qpieslice.h"
-#include "pieslicelabel_p.h"
 #include "qpieseries.h"
-#include <qmath.h>
 #include <QDebug>
-#include <QFontMetrics>
+#include <QPainter>
 
 
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
@@ -19,6 +16,7 @@ PiePresenter::PiePresenter(QGraphicsItem *parent, QPieSeries *series)
     connect(series, SIGNAL(changed(const QPieSeries::ChangeSet&)), this, SLOT(handleSeriesChanged(const QPieSeries::ChangeSet&)));
     connect(series, SIGNAL(sizeFactorChanged()), this, SLOT(updateGeometry()));
     connect(series, SIGNAL(positionChanged()), this, SLOT(updateGeometry()));
+    connect(series, SIGNAL(sizePolicyChanged()), this, SLOT(updateGeometry()));
 
     if (m_series->count()) {
         QPieSeries::ChangeSet changeSet;
@@ -36,6 +34,8 @@ void PiePresenter::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QW
 {
     // TODO: paint shadows for all components
     // - get paths from items & merge & offset and draw with shadow color?
+    //painter->setBrush(QBrush(Qt::red));
+    //painter->drawRect(m_debugRect);
 }
 
 void PiePresenter::handleSeriesChanged(const QPieSeries::ChangeSet& changeSet)
@@ -78,84 +78,104 @@ void PiePresenter::updateGeometry()
     // calculate maximum rectangle for pie
     QRectF pieRect = m_rect;
     if (pieRect.width() < pieRect.height()) {
-        pieRect.setWidth(pieRect.width() * m_series->sizeFactor());
         pieRect.setHeight(pieRect.width());
-        pieRect.moveCenter(m_rect.center());
     } else {
-        pieRect.setHeight(pieRect.height() * m_series->sizeFactor());
         pieRect.setWidth(pieRect.height());
-        pieRect.moveCenter(m_rect.center());
     }
 
     // position the pie rectangle
-    switch (m_series->position()) {
-        case QPieSeries::PiePositionTopLeft: {
-            pieRect.setHeight(pieRect.height() / 2);
-            pieRect.setWidth(pieRect.height());
-            pieRect.moveCenter(QPointF(m_rect.center().x() / 2, m_rect.center().y() / 2));
-            break;
-        }
-        case QPieSeries::PiePositionTopRight: {
-            pieRect.setHeight(pieRect.height() / 2);
-            pieRect.setWidth(pieRect.height());
-            pieRect.moveCenter(QPointF((m_rect.center().x() / 2) * 3, m_rect.center().y() / 2));
-            break;
-        }
-        case QPieSeries::PiePositionBottomLeft: {
-            pieRect.setHeight(pieRect.height() / 2);
-            pieRect.setWidth(pieRect.height());
-            pieRect.moveCenter(QPointF(m_rect.center().x() / 2, (m_rect.center().y() / 2) * 3));
-            break;
-        }
-        case QPieSeries::PiePositionBottomRight: {
-            pieRect.setHeight(pieRect.height() / 2);
-            pieRect.setWidth(pieRect.height());
-            pieRect.moveCenter(QPointF((m_rect.center().x() / 2) * 3, (m_rect.center().y() / 2) * 3));
-            break;
-        }
-        default:
-            break;
-    }
+    QPointF center = m_rect.center(); // default position is center
+    qreal dx = pieRect.width() / 2;
+    qreal dy = pieRect.height() / 2;
+    if (m_series->position() & QPieSeries::PiePositionLeft)
+        center.setX(m_rect.left() + dx);
+    if (m_series->position() & QPieSeries::PiePositionRight)
+        center.setX(m_rect.right() - dx);
+    if (m_series->position() & QPieSeries::PiePositionHCenter)
+        center.setX(m_rect.center().x());
+    if (m_series->position() & QPieSeries::PiePositionTop)
+        center.setY(m_rect.top() + dy);
+    if (m_series->position() & QPieSeries::PiePositionBottom)
+        center.setY(m_rect.bottom() - dy);
+    if (m_series->position() & QPieSeries::PiePositionVCenter)
+        center.setY(m_rect.center().y());
+    pieRect.moveCenter(center);
 
     // calculate how much space we need around the pie rectangle (labels & exploding)
     qreal delta = 0;
     qreal pieRadius = pieRect.height() / 2;
     foreach (QPieSlice* s, m_series->m_slices) {
 
-        // calculate the farthest point in the slice from the pie center
-
-        // the arm
-        qreal centerAngle = s->m_startAngle + (s->m_angleSpan / 2);
-        qreal len = pieRadius + PIESLICE_LABEL_GAP + s->labelArmLength() + s->explodeDistance();
-        QPointF dp(qSin(centerAngle*(PI/180)) * len, -qCos(centerAngle*(PI/180)) * len);
-        QPointF p = pieRect.center() + dp;
-
-        // the label text
-        QFontMetricsF fm(s->labelFont());
-        QRectF labelRect = fm.boundingRect(s->label());
-        if (centerAngle < 90 || centerAngle > 270)
-            p += QPointF(0, -labelRect.height());
-        if (centerAngle < 180)
-            p += QPointF(labelRect.width(), 0);
-        else
-            p += QPointF(-labelRect.width(), 0);
-
-        // calculate how much the radius must get smaller to fit that point in the base rectangle
-        qreal dt = m_rect.top() - p.y();
-        if (dt > delta) delta = dt;
-        qreal dl = m_rect.left() - p.x();
-        if (dl > delta) delta = dl;
-        qreal dr = p.x() - m_rect.right();
-        if (dr > delta) delta = dr;
-        qreal db = p.y() - m_rect.bottom();
-        if (db > delta) delta = db;
-
-        //if (!m_rect.contains(p)) qDebug() << s->label() << dt << dl << dr << db << "delta" << delta;
+        bool exploded = s->isExploded();
+        if (m_series->sizePolicy() & QPieSeries::PieSizePolicyReserveSpaceForExploding)
+            exploded = true;
+
+        bool labelVisible = s->isLabelVisible();
+        if (m_series->sizePolicy() & QPieSeries::PieSizePolicyReserveSpaceForLabels)
+            labelVisible = true;
+
+        qreal centerAngle;
+        QPointF armStart;
+        QRectF sliceRect = PieSlice::slicePath(center, pieRadius, s->m_startAngle, s->m_angleSpan, exploded, s->explodeDistance(), &centerAngle, &armStart).boundingRect();
+
+        if (labelVisible) {
+            QRectF textRect = PieSlice::labelTextRect(s->labelFont(), s->label());
+            QPointF textStart;
+            QRectF armRect = PieSlice::labelArmPath(armStart, centerAngle, s->labelArmLength(), textRect.width(), &textStart).boundingRect();
+            textRect.moveBottomLeft(textStart);
+            sliceRect = sliceRect.united(armRect);
+            sliceRect = sliceRect.united(textRect);
+        }
+
+
+        qreal dt = m_rect.top() - sliceRect.top();
+        if (dt > delta)
+            delta = dt;
+        qreal dl = m_rect.left() - sliceRect.left();
+        if (dl > delta)
+            delta = dl;
+        qreal dr = sliceRect.right() - m_rect.right();
+        if (dr > delta)
+            delta = dr;
+        qreal db = sliceRect.bottom() - m_rect.bottom();
+        if (db > delta)
+            delta = db;
+
+        /*
+        if (s->label() == "Slice 5") {
+            m_debugRect = sliceRect;
+            qDebug() << "dt:" << dt << ", dl:" << dl << ", dr:" << dr << ", db:" << db << ", delta:" << delta;
+        }
+        */
     }
 
     // shrink the pie rectangle so that everything outside it fits the base rectangle
     pieRect.adjust(delta, delta, -delta, -delta);
 
+    /*
+    // apply size factor (range 0.0 ... 1.0)
+    pieRect.setWidth(pieRect.width() * m_series->sizeFactor());
+    pieRect.setHeight(pieRect.height() * m_series->sizeFactor());
+
+    // position the pie rectangle (again)
+    center = m_rect.center(); // default position is center
+    dx = pieRect.width() / 2;
+    dy = pieRect.height() / 2;
+    if (m_series->position() & QPieSeries::PiePositionLeft)
+        center.setX(m_rect.left() + dx);
+    if (m_series->position() & QPieSeries::PiePositionRight)
+        center.setX(m_rect.right() - dx);
+    if (m_series->position() & QPieSeries::PiePositionHCenter)
+        center.setX(m_rect.center().x());
+    if (m_series->position() & QPieSeries::PiePositionTop)
+        center.setY(m_rect.top() + dy);
+    if (m_series->position() & QPieSeries::PiePositionBottom)
+        center.setY(m_rect.bottom() - dy);
+    if (m_series->position() & QPieSeries::PiePositionVCenter)
+        center.setY(m_rect.center().y());
+    pieRect.moveCenter(center);
+    */
+
     // update slices
     if (m_pieRect != pieRect) {
         m_pieRect = pieRect;
@@ -166,6 +186,8 @@ void PiePresenter::updateGeometry()
             s->update();
         }
     }
+
+    update();
 }
 
 void PiePresenter::addSlice(QPieSlice* sliceData)
diff --git a/src/piechart/piepresenter_p.h b/src/piechart/piepresenter_p.h
index 9004a15..f238cfe 100644
--- a/src/piechart/piepresenter_p.h
+++ b/src/piechart/piepresenter_p.h
@@ -44,6 +44,7 @@ private:
     QPieSeries *m_series;
     QRectF m_rect;
     QRectF m_pieRect;
+    QRectF m_debugRect;
 };
 
 QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/piechart/pieslice.cpp b/src/piechart/pieslice.cpp
index 756783e..71feff9 100644
--- a/src/piechart/pieslice.cpp
+++ b/src/piechart/pieslice.cpp
@@ -1,5 +1,4 @@
 #include "pieslice_p.h"
-#include "pieslicelabel_p.h"
 #include "piepresenter_p.h"
 #include "qpieseries.h"
 #include "qpieslice.h"
@@ -20,11 +19,11 @@ QPointF offset(qreal angle, qreal length)
 
 PieSlice::PieSlice(QGraphicsItem* parent)
     :QGraphicsObject(parent),
-    m_slicelabel(new PieSliceLabel(this)),
     m_startAngle(0),
     m_angleSpan(0),
     m_isExploded(false),
-    m_explodeDistance(0)
+    m_explodeDistance(0),
+    m_labelVisible(false)
 {
     setAcceptHoverEvents(true);
     setAcceptedMouseButtons(Qt::LeftButton);
@@ -37,19 +36,31 @@ PieSlice::~PieSlice()
 
 QRectF PieSlice::boundingRect() const
 {
-    return m_path.boundingRect();
+    return m_slicePath.boundingRect();
 }
 
 QPainterPath PieSlice::shape() const
 {
-    return m_path;
+    return m_slicePath;
 }
 
 void PieSlice::paint(QPainter* painter, const QStyleOptionGraphicsItem* /*option*/, QWidget* /*widget*/)
 {
+    painter->save();
     painter->setPen(m_pen);
     painter->setBrush(m_brush);
-    painter->drawPath(m_path);
+    painter->drawPath(m_slicePath);
+    painter->restore();
+
+    if (m_labelVisible) {
+        painter->save();
+        painter->setPen(m_labelArmPen);
+        painter->drawPath(m_labelArmPath);
+        painter->restore();
+
+        painter->setFont(m_labelFont);
+        painter->drawText(m_labelTextRect.bottomLeft(), m_labelText);
+    }
 }
 
 void PieSlice::hoverEnterEvent(QGraphicsSceneHoverEvent* /*event*/)
@@ -79,32 +90,22 @@ void PieSlice::updateGeometry()
 
     prepareGeometryChange();
 
-    // calculate center angle
-    qreal centerAngle = m_startAngle + (m_angleSpan/2);
+    // update slice path
+    QPointF center = m_pieRect.center();
+    qreal radius = m_pieRect.height() / 2;
+    qreal centerAngle;
+    QPointF armStart;
+    m_slicePath = slicePath(center, radius, m_startAngle, m_angleSpan, m_isExploded, m_explodeDistance, &centerAngle, &armStart);
 
-    // adjust rect for exploding
-    QRectF rect = m_pieRect;
-    if (m_isExploded) {
-        qreal dx = qSin(centerAngle*(PI/180)) * m_explodeDistance;
-        qreal dy = -qCos(centerAngle*(PI/180)) * m_explodeDistance;
-        rect.translate(dx, dy);
-    }
+    // update text rect
+    m_labelTextRect = labelTextRect(m_labelFont, m_labelText);
 
-    // update 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, -m_startAngle + 90, -m_angleSpan);
-    path.closeSubpath();
-    m_path = path;
+    // update label arm path
+    QPointF labelTextStart;
+    m_labelArmPath = labelArmPath(armStart, centerAngle, m_labelArmLength, m_labelTextRect.width(), &labelTextStart);
 
-    // update label position
-    qreal radius = rect.height() / 2;
-    QPointF edgeCenter = rect.center() + offset(centerAngle, radius + PIESLICE_LABEL_GAP);
-    m_slicelabel->setArmStartPoint(edgeCenter);
-    m_slicelabel->setArmAngle(centerAngle);
-    m_slicelabel->updateGeometry();
-    m_slicelabel->update();
+    // update text position
+    m_labelTextRect.moveBottomLeft(labelTextStart);
 
     //qDebug() << "PieSlice::updateGeometry" << m_slicelabel->text() << boundingRect() << m_angle << m_span;
 }
@@ -116,20 +117,85 @@ void PieSlice::updateData(const QPieSlice* sliceData)
     m_startAngle = sliceData->startAngle();
     m_angleSpan = sliceData->m_angleSpan;
     m_isExploded = sliceData->isExploded();
-    m_explodeDistance = sliceData->explodeDistance(); // TODO: expose to public API
+    m_explodeDistance = sliceData->explodeDistance();
     m_pen = sliceData->pen();
     m_brush = sliceData->brush();
 
-    m_slicelabel->setVisible(sliceData->isLabelVisible());
-    m_slicelabel->setText(sliceData->label());
-    m_slicelabel->setPen(sliceData->labelPen());
-    m_slicelabel->setFont(sliceData->labelFont());
-    m_slicelabel->setArmLength(sliceData->labelArmLength());
+    m_labelVisible = sliceData->isLabelVisible();
+    m_labelText = sliceData->label();
+    m_labelFont = sliceData->labelFont();
+    m_labelArmLength = sliceData->labelArmLength();
+    m_labelArmPen = sliceData->labelPen();
 
     updateGeometry();
     update();
 }
 
+QPainterPath PieSlice::slicePath(QPointF center, qreal radius, qreal startAngle, qreal angleSpan, bool exploded, qreal explodeDistance, 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);
+
+    // adjust rect for exploding
+    if (exploded) {
+        qreal dx = qSin(*centerAngle*(PI/180)) * explodeDistance;
+        qreal dy = -qCos(*centerAngle*(PI/180)) * explodeDistance;
+        rect.translate(dx, dy);
+    }
+
+    // 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;
+    if (exploded)
+        *armStart += offset(*centerAngle, explodeDistance + radius + PIESLICE_LABEL_GAP);
+    else
+        *armStart += offset(*centerAngle, radius + PIESLICE_LABEL_GAP);
+
+    return path;
+}
+
+QPainterPath PieSlice::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 PieSlice::labelTextRect(QFont font, QString text)
+{
+    QFontMetricsF fm(font);
+    return fm.boundingRect(text);
+}
+
 #include "moc_pieslice_p.cpp"
 
 QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/piechart/pieslice_p.h b/src/piechart/pieslice_p.h
index f6623d6..378f052 100644
--- a/src/piechart/pieslice_p.h
+++ b/src/piechart/pieslice_p.h
@@ -43,22 +43,29 @@ public Q_SLOTS:
     void updateData(const QPieSlice *sliceData);
 
 public:
-    PieSliceLabel* label() { return m_slicelabel; }
+    static QPainterPath slicePath(QPointF center, qreal radius, qreal startAngle, qreal angleSpan, bool exploded, qreal explodeDistance, qreal* centerAngle, QPointF* armStart);
+    static QPainterPath labelArmPath(QPointF start, qreal angle, qreal length, qreal textWidth, QPointF* textStart);
+    static QRectF labelTextRect(QFont font, QString text);
 
 private:
-    PieSliceLabel* m_slicelabel;
-
     QRectF m_pieRect;
-    QPainterPath m_path;
 
+    QPainterPath m_slicePath;
     qreal m_startAngle;
     qreal m_angleSpan;
-
     bool m_isExploded;
     qreal m_explodeDistance;
-
+    bool m_labelVisible;
     QPen m_pen;
     QBrush m_brush;
+
+    QPainterPath m_labelArmPath;
+    qreal m_labelArmLength;
+    QPen m_labelArmPen;
+
+    QRectF m_labelTextRect;
+    QFont m_labelFont;
+    QString m_labelText;
 };
 
 QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/piechart/pieslicelabel.cpp b/src/piechart/pieslicelabel.cpp
deleted file mode 100644
index 495566f..0000000
--- a/src/piechart/pieslicelabel.cpp
+++ /dev/null
@@ -1,72 +0,0 @@
-#include "pieslicelabel_p.h"
-#include <QPainter>
-#include <qmath.h>
-#include <QGraphicsTextItem>
-#include <QDebug>
-
-QTCOMMERCIALCHART_BEGIN_NAMESPACE
-
-#define PI 3.14159265
-
-PieSliceLabel::PieSliceLabel(QGraphicsItem* parent)
-    :QGraphicsItem(parent),
-    m_armAngle(0),
-    m_armLength(0)
-{
-
-}
-
-void PieSliceLabel::paint(QPainter *painter, const QStyleOptionGraphicsItem* /*option*/, QWidget* /*widget*/)
-{
-    painter->setPen(m_pen);
-    painter->drawPath(m_armPath);
-
-    // TODO: do we need a pen for text?
-    painter->setFont(m_font);
-    painter->drawText(m_textRect.bottomLeft(), m_text);
-
-    //qDebug() << "PieSliceLabel::paint" << m_text << m_textRect;
-}
-
-void PieSliceLabel::updateGeometry()
-{
-    prepareGeometryChange();
-
-    // calculate text size
-    QFontMetricsF fm(m_font);
-    QRectF textRect = fm.boundingRect(m_text);
-
-    // calculate path for arm and text start point
-    qreal dx = qSin(m_armAngle*(PI/180)) * m_armLength;
-    qreal dy = -qCos(m_armAngle*(PI/180)) * m_armLength;
-    QPointF parm1 = m_armStartPoint + QPointF(dx, dy);
-
-    // calculate horizontal arm and text position
-    QPointF parm2 = parm1;
-    textRect.moveBottomLeft(parm1);
-    if (m_armAngle < 180) { // arm swings the other way on the left side
-         parm2 += QPointF(textRect.width(), 0);
-    } else {
-         parm2 += QPointF(-textRect.width(),0);
-         textRect.moveBottomLeft(parm2);
-    }
-
-    // add a little offset to text so that it does not touch the arm
-    qreal yOffset = m_pen.widthF() ? m_pen.widthF() : 2;
-    textRect.translate(0, -yOffset);
-
-    // update arm path
-    QPainterPath path;
-    path.moveTo(m_armStartPoint);
-    path.lineTo(parm1);
-    path.lineTo(parm2);
-
-    // update paths & rects
-    m_armPath = path;
-    m_textRect = textRect;
-    m_rect = path.boundingRect().united(m_textRect);
-
-    //qDebug() << "PieSliceLabel::updateGeometry" << m_text << m_armStartPoint << m_armLength << m_armAngle << m_textRect;
-}
-
-QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/piechart/pieslicelabel_p.h b/src/piechart/pieslicelabel_p.h
deleted file mode 100644
index 0ce3bea..0000000
--- a/src/piechart/pieslicelabel_p.h
+++ /dev/null
@@ -1,57 +0,0 @@
-#ifndef PIELABEL_H
-#define PIELABEL_H
-
-#include "qchartglobal.h"
-#include <QGraphicsItem>
-#include <QPen>
-#include <QFontMetricsF>
-
-class QGraphicsTextItem;
-QTCOMMERCIALCHART_BEGIN_NAMESPACE
-
-class PieSliceLabel : public QGraphicsItem
-{
-public:
-    PieSliceLabel(QGraphicsItem* parent = 0);
-    ~PieSliceLabel() {};
-
-public: // from QGraphicsItem
-    QRectF boundingRect() const { return m_rect; }
-    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
-
-public:
-    void updateGeometry();
-
-    void setArmStartPoint(QPointF point) { m_armStartPoint = point; }
-    QPointF armStartPoint() const { return m_armStartPoint; }
-
-    void setArmAngle(qreal angle) { m_armAngle = angle; }
-    qreal armAngle() const { return m_armAngle; }
-
-    void setArmLength(qreal len) { m_armLength = len; }
-    qreal armLength() const { return m_armLength; }
-
-    void setText(QString text) { m_text = text; }
-    QString text() const { return m_text; }
-
-    void setPen(QPen pen) { m_pen = pen; }
-    QPen pen() const { return m_pen; }
-
-    void setFont(QFont font) { m_font = font; }
-    QFont font() const { return m_font; }
-
-private:
-    QPointF m_armStartPoint;
-    qreal m_armAngle;
-    qreal m_armLength;
-    QString m_text;
-    QRectF m_rect;
-    QPainterPath m_armPath;
-    QRectF m_textRect;
-    QPen m_pen;
-    QFont m_font;
-};
-
-QTCOMMERCIALCHART_END_NAMESPACE
-
-#endif // PIELABEL_H
diff --git a/src/piechart/qpieseries.cpp b/src/piechart/qpieseries.cpp
index 8922cdb..5de0795 100644
--- a/src/piechart/qpieseries.cpp
+++ b/src/piechart/qpieseries.cpp
@@ -118,9 +118,10 @@ bool QPieSeries::ChangeSet::isEmpty() const
 QPieSeries::QPieSeries(QObject *parent) :
     QSeries(parent),
     m_sizeFactor(1.0),
-    m_position(PiePositionMaximized),
+    m_position(PiePositionCenter),
+    m_sizePolicy(PieSizePolicyMaximized),
     m_pieStartAngle(0),
-    m_pieAngleSpan(360)
+    m_pieEndAngle(360)
 {
 
 }
@@ -295,6 +296,7 @@ qreal QPieSeries::sizeFactor() const
 */
 void QPieSeries::setPosition(PiePosition position)
 {
+    // TODO: sanity check
     if (m_position != position) {
         m_position = position;
         emit positionChanged();
@@ -310,22 +312,55 @@ QPieSeries::PiePosition QPieSeries::position() const
     return m_position;
 }
 
-
 /*!
-    Sets the \a startAngle and \a angleSpan of this series.
+    Sets the \a sizePolicy of the pie.
+    \sa PieSizePolicy, sizePolicy()
+*/
+void QPieSeries::setSizePolicy(PieSizePolicy sizePolicy)
+{
+    // TODO: sanity check
+    if (m_sizePolicy != sizePolicy) {
+        m_sizePolicy = sizePolicy;
+        emit sizePolicyChanged();
+    }
+}
 
-    Full pie is 360 degrees where 0 degrees is at 12 a'clock.
+/*!
+    Gets the size policy of the pie.
+    \sa PieSizePolicy, setSizePolicy()
 */
-void QPieSeries::setSpan(qreal startAngle, qreal angleSpan)
+QPieSeries::PieSizePolicy QPieSeries::sizePolicy() const
 {
-    if (startAngle >= 0 && startAngle < 360 &&
-        angleSpan > 0 && angleSpan <= 360) {
+    return m_sizePolicy;
+}
+
+
+void QPieSeries::setStartAngle(qreal startAngle)
+{
+    if (startAngle >= 0 && startAngle <= 360 && startAngle != m_pieStartAngle && startAngle <= m_pieEndAngle) {
         m_pieStartAngle = startAngle;
-        m_pieAngleSpan = angleSpan;
         updateDerivativeData();
     }
 }
 
+qreal QPieSeries::startAngle() const
+{
+    return m_pieStartAngle;
+}
+
+void QPieSeries::setEndAngle(qreal endAngle)
+{
+    if (endAngle >= 0 && endAngle <= 360 && endAngle != m_pieEndAngle && endAngle >= m_pieStartAngle) {
+        m_pieEndAngle = endAngle;
+        updateDerivativeData();
+    }
+}
+
+qreal QPieSeries::endAngle() const
+{
+    return m_pieEndAngle;
+}
+
 /*!
     Sets the all the slice labels \a visible or invisible.
 
@@ -449,6 +484,7 @@ void QPieSeries::updateDerivativeData()
 
     // update slice attributes
     qreal sliceAngle = m_pieStartAngle;
+    qreal pieSpan = m_pieEndAngle - m_pieStartAngle;
     foreach (QPieSlice* s, m_slices) {
 
         bool changed = false;
@@ -459,7 +495,7 @@ void QPieSeries::updateDerivativeData()
             changed = true;
         }
 
-        qreal sliceSpan = m_pieAngleSpan * percentage;
+        qreal sliceSpan = pieSpan * percentage;
         if (s->m_angleSpan != sliceSpan) {
             s->m_angleSpan = sliceSpan;
             changed = true;
diff --git a/src/piechart/qpieseries.h b/src/piechart/qpieseries.h
index dff1be2..bc0f410 100644
--- a/src/piechart/qpieseries.h
+++ b/src/piechart/qpieseries.h
@@ -20,14 +20,28 @@ class QTCOMMERCIALCHART_EXPORT QPieSeries : public QSeries
     Q_OBJECT
 
 public:
-    enum PiePosition {
-        PiePositionMaximized = 0,
-        PiePositionTopLeft,
-        PiePositionTopRight,
-        PiePositionBottomLeft,
-        PiePositionBottomRight
+
+    enum PiePositionFlag {
+        PiePositionLeft = 0x1,
+        PiePositionRight = 0x2,
+        PiePositionHCenter = 0x4,
+        PiePositionTop = 0x10,
+        PiePositionBottom = 0x20,
+        PiePositionVCenter = 0x40,
+        PiePositionCenter = PiePositionHCenter | PiePositionVCenter
+    };
+
+    Q_DECLARE_FLAGS(PiePosition, PiePositionFlag)
+
+    enum PieSizePolicyFlag {
+        PieSizePolicyMaximized = 0,
+        PieSizePolicyReserveSpaceForLabels = 0x1,
+        PieSizePolicyReserveSpaceForExploding = 0x2,
+        PieSizePolicyReserveSpaceForAll = PieSizePolicyReserveSpaceForLabels | PieSizePolicyReserveSpaceForExploding
     };
 
+    Q_DECLARE_FLAGS(PieSizePolicy, PieSizePolicyFlag)
+
     class ChangeSet
     {
     public:
@@ -58,27 +72,38 @@ public: // from QChartSeries
     QSeriesType type() const;
 
 public:
-    void replace(QList<QPieSlice*> slices);
-    void add(QList<QPieSlice*> slices);
+
+    // slice setters
     void add(QPieSlice* slice);
-    QPieSlice* add(qreal value, QString name);
-    QPieSeries& operator << (QPieSlice* slice);
+    void add(QList<QPieSlice*> slices);
+    void replace(QList<QPieSlice*> slices);
     void remove(QPieSlice* slice);
     void clear();
 
-    int count() const;
+    // sluce getters
     QList<QPieSlice*> slices() const;
 
-    void setSizeFactor(qreal sizeFactor);
-    qreal sizeFactor() const;
+    // calculated data
+    int count() const;
+    qreal total() const;
+
+    // pie customization
     void setPosition(PiePosition position);
     PiePosition position() const;
-    void setSpan(qreal startAngle, qreal angleSpan);
+    void setSizePolicy(PieSizePolicy policy);
+    PieSizePolicy sizePolicy() const;
+    void setSizeFactor(qreal sizeFactor);
+    qreal sizeFactor() const;
+    void setStartAngle(qreal startAngle);
+    qreal startAngle() const;
+    void setEndAngle(qreal endAngle);
+    qreal endAngle() const;
 
+    // convenience function
+    QPieSeries& operator << (QPieSlice* slice);
+    QPieSlice* add(qreal value, QString name);
     void setLabelsVisible(bool visible = true);
 
-    qreal total() const;
-
     // TODO: find slices?
     // QList<QPieSlice*> findByValue(qreal value);
     // ...
@@ -88,15 +113,19 @@ public:
 
     // TODO: general graphics customization
     // setDrawStyle(2d|3d)
-    // setDropShadows(bool)
+    // setDropShadows
 
 Q_SIGNALS:
+
     void changed(const QPieSeries::ChangeSet& changeSet);
+
     void clicked(QPieSlice* slice);
     void hoverEnter(QPieSlice* slice);
     void hoverLeave(QPieSlice* slice);
+
     void sizeFactorChanged();
     void positionChanged();
+    void sizePolicyChanged();
 
 private Q_SLOTS: // TODO: should be private and not visible in the interface at all
     void sliceChanged();
@@ -117,9 +146,10 @@ private:
     QList<QPieSlice*> m_slices;
     qreal m_sizeFactor;
     PiePosition m_position;
+    PieSizePolicy m_sizePolicy;
     qreal m_total;
     qreal m_pieStartAngle;
-    qreal m_pieAngleSpan;
+    qreal m_pieEndAngle;
 };
 
 QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/piechart/qpieslice.h b/src/piechart/qpieslice.h
index 009ede5..d97cd49 100644
--- a/src/piechart/qpieslice.h
+++ b/src/piechart/qpieslice.h
@@ -21,10 +21,15 @@ public:
     virtual ~QPieSlice();
 
     // data
+    void setValue(qreal value);
     qreal value() const;
+    void setLabel(QString label);
     QString label() const;
+    void setLabelVisible(bool visible);
     bool isLabelVisible() const;
+    void setExploded(bool exploded);
     bool isExploded() const;
+    void setExplodeDistance(qreal distance);
     qreal explodeDistance() const;
 
     // generated data
@@ -33,38 +38,27 @@ public:
     qreal endAngle() const;
 
     // customization
+    void setPen(QPen pen);
     QPen pen() const;
+    void setBrush(QBrush brush);
     QBrush brush() const;
+    void setLabelPen(QPen pen);
     QPen labelPen() const;
+    void setLabelFont(QFont font);
     QFont labelFont() const;
+    void setLabelArmLength(qreal len);
     qreal labelArmLength() const;
 
+    // TODO: label position in general
+    // setLabelFlags(inside|outside|labelArmOn|labelArmOff|???)
+    // setLabelOrientation(horizontal|vertical|same as slice center angle|???)
+
 Q_SIGNALS:
     void clicked();
     void hoverEnter();
     void hoverLeave();
     void changed();
 
-public Q_SLOTS:
-
-    // data
-    void setLabel(QString label);
-    void setLabelVisible(bool visible);
-    void setValue(qreal value);
-    void setExploded(bool exploded);
-    void setExplodeDistance(qreal distance);
-
-    // customization
-    void setPen(QPen pen);
-    void setBrush(QBrush brush);
-    void setLabelFont(QFont font);
-    void setLabelPen(QPen pen);
-    void setLabelArmLength(qreal len);
-
-    // TODO: label position in general
-    // setLabelFlags(inside|outside|labelArmOn|labelArmOff|???)
-    // setLabelOrientation(horizontal|vertical|same as slice center angle|???)
-
 private:
 
     // TODO: use private class