From cfa1350263ea8dfc677166ff07f42292de32fede 2012-02-28 09:22:45
From: Tero Ahola <tero.ahola@digia.com>
Date: 2012-02-28 09:22:45
Subject: [PATCH] Fixed drawing issues in Scatter

---

diff --git a/src/chartpresenter_p.h b/src/chartpresenter_p.h
index 72f7ddc..62d4769 100644
--- a/src/chartpresenter_p.h
+++ b/src/chartpresenter_p.h
@@ -20,7 +20,14 @@ class ChartPresenter: public QObject
 {
     Q_OBJECT
 public:
-    enum ZValues { BackgroundZValue = -1 , ShadesZValue, GridZValue,  AxisZValue , LineChartZValue };
+    enum ZValues {
+        BackgroundZValue = -1,
+        ShadesZValue,
+        GridZValue,
+        AxisZValue,
+        LineChartZValue,
+        ScatterSeriesZValue
+    };
 
     ChartPresenter(QChart* chart,ChartDataSet *dataset);
     virtual ~ChartPresenter();
diff --git a/src/scatterseries/qscatterseries.cpp b/src/scatterseries/qscatterseries.cpp
index 09a377a..e99b4fa 100644
--- a/src/scatterseries/qscatterseries.cpp
+++ b/src/scatterseries/qscatterseries.cpp
@@ -49,13 +49,10 @@ QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
 QScatterSeriesPrivate::QScatterSeriesPrivate() :
     m_data(QList<QPointF>()),
-    m_markerPen(QPen()),
-    m_markerBrush(QBrush()),
+    m_markerPen(QPen(QColor::Invalid)),
+    m_markerBrush(QBrush(QColor::Invalid)),
     m_markerShape(QScatterSeries::MarkerShapeDefault)
 {
-    // Initialize pen color to invalid to use a theme color by default
-    m_markerPen.setColor(QColor::Invalid);
-    m_markerBrush.setColor(QColor::Invalid);
 }
 
 /*!
diff --git a/src/scatterseries/scatterpresenter.cpp b/src/scatterseries/scatterpresenter.cpp
index ea67f10..a8c93f8 100644
--- a/src/scatterseries/scatterpresenter.cpp
+++ b/src/scatterseries/scatterpresenter.cpp
@@ -1,5 +1,6 @@
 #include "scatterpresenter_p.h"
 #include "qscatterseries.h"
+#include "chartpresenter_p.h"
 #include <QPen>
 #include <QPainter>
 #include <QGraphicsScene>
@@ -23,10 +24,13 @@ ScatterPresenter::ScatterPresenter(QScatterSeries *series, QGraphicsObject *pare
         connect(series, SIGNAL(changed()), this, SLOT(handleModelChanged()));
     }
 
-    QGraphicsDropShadowEffect *dropShadow = new QGraphicsDropShadowEffect();
-    dropShadow->setOffset(2.0);
-    dropShadow->setBlurRadius(2.0);
-    setGraphicsEffect(dropShadow);
+    setZValue(ChartPresenter::ScatterSeriesZValue);
+
+    // TODO: how to draw a drop shadow?
+//    QGraphicsDropShadowEffect *dropShadow = new QGraphicsDropShadowEffect();
+//    dropShadow->setOffset(2.0);
+//    dropShadow->setBlurRadius(2.0);
+//    setGraphicsEffect(dropShadow);
 }
 
 void ScatterPresenter::handleDomainChanged(const Domain& domain)
@@ -52,17 +56,34 @@ void ScatterPresenter::paint(QPainter *painter, const QStyleOptionGraphicsItem *
     painter->save();
     painter->setClipRect(m_boundingRect);
 
+    // TODO: how to draw a drop shadow?
+    // Now using a custom implementation for drop shadow instead of QGraphicsDropShadowEffect.
+    // It seems QGraphicsDropShadowEffect is quite heavy, at least on windows without open gl.
+    QPen dropShadowPen(QColor(0, 0, 0, 70));
+    dropShadowPen.setWidth(3);
+    painter->setPen(dropShadowPen);
+    painter->setBrush(dropShadowPen.color());
+//    painter->setRenderHint(QPainter::Antialiasing);
+    painter->drawPath(m_path.translated(2, 2));
+
     // Paint the shape
     // The custom settings in series override those defined by the theme
     QPen pen = m_markerPen;
     if (m_series->pen().color().isValid())
         pen = m_series->pen();
+    painter->setPen(pen);
     if (m_series->brush().color().isValid())
         painter->setBrush(m_series->brush());
     else
         painter->setBrush(m_markerBrush);
-    painter->setPen(pen);
-    painter->drawPath(m_path);
+
+    // If either pen or brush is opaque, we need to draw the polygons one-by-one
+    if (painter->pen().color().alpha() < 255 || painter->brush().color().alpha() < 255) {
+        foreach (QPolygonF pol, m_path.toSubpathPolygons())
+            painter->drawPolygon(pol);
+    } else {
+        painter->drawPath(m_path);
+    }
 
     painter->restore();
 }
@@ -85,6 +106,7 @@ void ScatterPresenter::changeGeometry()
 
         int shape = m_series->shape();
         m_path = QPainterPath();
+        m_path.setFillRule(Qt::WindingFill);
 
         foreach (QPointF point, m_series->data()) {
             // Convert relative coordinates to absolute pixel coordinates that can be used for drawing