HG_REPOSITORIES/LPP/INSTRUMENTATION/USERS/JEANDET/qtcharts Commit - r1791:877b494897a0

Fixed paint and mouse event issues with QLineSeries...

Tero Ahola -

r1791:877b494897a0

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r1791:877b494897a0

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demos/chartinteractions/chart.cpp +12 -10

             #include <QValuesAxis>
             #include <QAbstractAxis>
+            #include <cmath>
             #include <QDebug>
             #include "chart.h"
             void Chart::clickPoint(const QPointF &point)
             {
-                //Get all points from the series.
+                // Find the closes data point
-                QList<QPointF> points = m_series->points();
+                m_movingPoint = QPoint();
-                //Construct a small rectangle around the clicked point
+                m_clicked = false;
-                //to identify the real point clicked from the series.
+                foreach (QPointF p, m_series->points()) {
-                QRectF clickRect(point.x() - 0.5, point.y() - 0.5, 1.0, 1.0);
+                    if (distance(p, point) < distance(m_movingPoint, point)) {
-                //Find the clicked point to be moved.
-                foreach (QPointF p, points) {
-                    if (clickRect.contains(p)) {
                         m_movingPoint = p;
                         m_clicked = true;
-                        return;
                     }
                 }
             }
+            qreal Chart::distance(const QPointF &p1, const QPointF &p2)
+            {
+                return sqrt((p1.x() - p2.x()) * (p1.x() - p2.x())
+                            + (p1.y() - p2.y()) * (p1.y() - p2.y()));
+            }
             void Chart::setPointClicked(bool clicked)
             {
                m_clicked = clicked;

demos/chartinteractions/chart.h +1 0

                 void setPointClicked(bool clicked);
             private:
+                qreal distance(const QPointF &p1, const QPointF &p2);
                 QLineSeries *m_series;
                 QPointF m_movingPoint;

demos/chartinteractions/main.cpp +3 0

                 Chart* chart = new Chart(0, 0, series);
                 chart->legend()->hide();
                 chart->addSeries(series);
+                QPen p = series->pen();
+                p.setWidth(5);
+                series->setPen(p);
                 chart->createDefaultAxes();
                 chart->setTitle("Drag'n drop to move data points");

src/linechart/linechartitem.cpp +19 -6

             #include <QPainter>
             #include <QGraphicsSceneMouseEvent>
             QTCOMMERCIALCHART_BEGIN_NAMESPACE
-            //TODO: optimize : remove points which are not visible
+            const qreal mouseEventMinWidth(14);
             LineChartItem::LineChartItem(QLineSeries* series,ChartPresenter *presenter):
                 XYChart(series, presenter),
             QPainterPath LineChartItem::shape() const
             {
-                return m_path;
+                // Increase the size of the path slightly to make mouse interactions more natural
+                QPainterPathStroker s;
+                s.setCapStyle(Qt::RoundCap);
+                s.setJoinStyle(Qt::RoundJoin);
+                qreal spacing = qMax(mouseEventMinWidth, (qreal) m_linePen.width());
+                s.setWidth(spacing);
+                return s.createStroke(m_path);
             }
             void LineChartItem::updateGeometry()
                 }
                 prepareGeometryChange();
                 m_path = linePath;
-                m_rect = linePath.boundingRect();
+                // When defining bounding rectangle,
+                // 1. take the line width into account (otherwise you will get drawing artifacts) and
+                // 2. take the shape into account (otherwise you will not get mouse events through on border
+                // areas).
+                const qreal sqrtOf2 = 1.414214;
+                const qreal spacing = qMax(mouseEventMinWidth / 2.0,
+                                           sqrtOf2 * (qreal) m_linePen.width() / 2.0);
+                m_rect = m_path.boundingRect().adjusted(-spacing, -spacing, spacing, spacing);
                 setPos(origin());
             }
                 update();
             }
-            //painter
             void LineChartItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
             {
                 Q_UNUSED(widget)

src/linechart/linechartitem_p.h +1 -1

                  Q_INTERFACES(QGraphicsItem)
             public:
                  explicit LineChartItem(QLineSeries *series,ChartPresenter *presenter);
-                ~LineChartItem() {};
+                ~LineChartItem() {}
                 //from QGraphicsItem
                 QRectF boundingRect() const;

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