Added minor ticks to value axis

Added possibility to set minor tick for value axis. By default the
count of minor ticks is zero. The arrow of minor ticks follows the
color and pen of the arrows of the major ticks as it's part of axis.

Change-Id: I8a422caaeedcd18ee6144e8636e3903d16f0632c
Task-number: QTRD-3294
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@theqtcompany.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/src/charts/axis/polarchartaxisradial.cpp b/src/charts/axis/polarchartaxisradial.cpp
index 5e3cec5d..af22a03e 100644
--- a/src/charts/axis/polarchartaxisradial.cpp
+++ b/src/charts/axis/polarchartaxisradial.cpp
@@ -47,6 +47,8 @@ void PolarChartAxisRadial::updateGeometry()
     QList<QGraphicsItem *> gridItemList = gridItems();
     QList<QGraphicsItem *> labelItemList = labelItems();
     QList<QGraphicsItem *> shadeItemList = shadeItems();
+    QList<QGraphicsItem *> minorGridItemList = minorGridItems();
+    QList<QGraphicsItem *> minorArrowItemList = minorArrowItems();
     QGraphicsTextItem* title = titleItem();
     qreal radius = axisGeometry().height() / 2.0;
 
@@ -200,6 +202,37 @@ void PolarChartAxisRadial::updateGeometry()
             shadeItem->setVisible(true);
             firstShade = false;
         }
+
+        // Minor ticks
+        QValueAxis *valueAxis = qobject_cast<QValueAxis *>(axis());
+        if ((i + 1) != layout.size() && valueAxis) {
+            int minorTickCount = valueAxis->minorTickCount();
+            if (minorTickCount != 0) {
+                qreal minorRadialCoordinate = (layout[i + 1] - layout[i])
+                        / qreal(minorTickCount + 1) * 2.0;
+                for (int j = 0; j < minorTickCount; j++) {
+                    QGraphicsEllipseItem *minorGridItem =
+                            static_cast<QGraphicsEllipseItem *>(minorGridItemList.at(i * minorTickCount + j));
+                    QGraphicsLineItem *minorTickItem =
+                            static_cast<QGraphicsLineItem *>(minorArrowItemList.at(i * minorTickCount + j));
+
+                    QRectF minorGridRect;
+                    minorGridRect.setWidth(minorRadialCoordinate * qreal(i + 1)
+                                           + minorRadialCoordinate * qreal(i * minorTickCount + j));
+                    minorGridRect.setHeight(minorRadialCoordinate * qreal(i + 1)
+                                            + minorRadialCoordinate
+                                            * qreal(i * minorTickCount + j));
+                    minorGridRect.moveCenter(center);
+                    minorGridItem->setRect(minorGridRect);
+                    minorGridItem->setVisible(true);
+
+                    QLineF minorTickLine(-tickWidth() + 1, 0.0, tickWidth() - 1, 0.0);
+                    tickLine.translate(center.rx(), minorGridRect.top());
+                    minorTickItem->setLine(minorTickLine);
+                    minorTickItem->setVisible(true);
+                }
+            }
+        }
     }
 
     // Title, along the 0 axis
@@ -275,6 +308,18 @@ void PolarChartAxisRadial::handleGridPenChanged(const QPen &pen)
         static_cast<QGraphicsEllipseItem *>(item)->setPen(pen);
 }
 
+void PolarChartAxisRadial::handleMinorArrowPenChanged(const QPen &pen)
+{
+    foreach (QGraphicsItem *item, minorArrowItems())
+        static_cast<QGraphicsLineItem *>(item)->setPen(pen);
+}
+
+void PolarChartAxisRadial::handleMinorGridPenChanged(const QPen &pen)
+{
+    foreach (QGraphicsItem *item, minorGridItems())
+        static_cast<QGraphicsEllipseItem *>(item)->setPen(pen);
+}
+
 QSizeF PolarChartAxisRadial::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
 {
     Q_UNUSED(which);
@@ -290,6 +335,35 @@ qreal PolarChartAxisRadial::preferredAxisRadius(const QSizeF &maxSize)
     return radius;
 }
 
+void PolarChartAxisRadial::updateMinorTickItems()
+{
+    QValueAxis *valueAxis = qobject_cast<QValueAxis *>(this->axis());
+    if (valueAxis) {
+        int currentCount = minorArrowItems().size();
+        int expectedCount = valueAxis->minorTickCount() * (valueAxis->tickCount() - 1);
+        int diff = expectedCount - currentCount;
+        if (diff > 0) {
+            for (int i = 0; i < diff; i++) {
+                QGraphicsLineItem *minorArrow = new QGraphicsLineItem(presenter()->rootItem());
+                QGraphicsEllipseItem *minorGrid = new QGraphicsEllipseItem(presenter()->rootItem());
+                minorArrow->setPen(valueAxis->linePen());
+                minorGrid->setPen(valueAxis->minorGridLinePen());
+                minorArrowGroup()->addToGroup(minorArrow);
+                minorGridGroup()->addToGroup(minorGrid);
+            }
+        } else {
+            QList<QGraphicsItem *> minorGridLines = minorGridItems();
+            QList<QGraphicsItem *> minorArrows = minorArrowItems();
+            for (int i = 0; i > diff; i--) {
+                if (!minorGridLines.isEmpty())
+                    delete(minorGridLines.takeLast());
+                if (!minorArrows.isEmpty())
+                    delete(minorArrows.takeLast());
+            }
+        }
+    }
+}
+
 #include "moc_polarchartaxisradial_p.cpp"
 
 QT_CHARTS_END_NAMESPACE