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.
-                 QList<QPointF> points = m_series->points();
-                 //Construct a small rectangle around the clicked point
-                 //to identify the real point clicked from the series.
-                 QRectF clickRect(point.x() - 0.5, point.y() - 0.5, 1.0, 1.0);
-                 //Find the clicked point to be moved.
-                 foreach (QPointF p, points) {
-                     if (clickRect.contains(p)) {
+                 // Find the closes data point
+                 m_movingPoint = QPoint();
+                 m_clicked = false;
+                 foreach (QPointF p, m_series->points()) {
+                     if (distance(p, point) < distance(m_movingPoint, point)) {
                          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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