Add series index dynamic properties for custom delegates

Support for series index in BarSeries (barIndex) and XYSeries
(pointIndex). These will allow new customization possibilities.

Task-number: QTBUG-129382
Change-Id: I4b332efda9c630bcb0394ffa49e999a3aca4fbf1
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>
Reviewed-by: Jere Tuliniemi <jere.tuliniemi@qt.io>

src/graphs2d/barchart/qbarseries.cpp

@@ -262,6 +262,10 @@ QT_BEGIN_NAMESPACE
         \li barSelected
         \li This value is true when the bar is selected, meaning that the bar index
         is in \l{QBarSet::selectedBars}.
+    \row
+        \li int
+        \li barIndex
+        \li Index of the bar, from 0 to the amount of bars - 1. [since 6.9]
     \endtable
 
     To use any of these, add property with the defined name into your custom component.
@@ -308,6 +312,10 @@ QT_BEGIN_NAMESPACE
         \li barSelected
         \li This value is true when the bar is selected, meaning that the bar index
         is in \l{BarSet::selectedBars}.
+    \row
+        \li int
+        \li barIndex
+        \li Index of the bar, from 0 to the amount of bars - 1. [since 6.9]
     \endtable
 
     To use any of these, add property with the defined name into your custom component.

src/graphs2d/qsgrenderer/barsrenderer.cpp

@@ -17,6 +17,7 @@ static const char* TAG_BAR_BORDER_WIDTH = "barBorderWidth";
 static const char* TAG_BAR_SELECTED = "barSelected";
 static const char* TAG_BAR_VALUE = "barValue";
 static const char* TAG_BAR_LABEL = "barLabel";
+static const char* TAG_BAR_INDEX = "barIndex";
 
 BarsRenderer::BarsRenderer(QGraphsView *graph)
     : QQuickItem(graph)
@@ -179,6 +180,8 @@ void BarsRenderer::updateComponents(QBarSeries *series)
                     barItem->setProperty(TAG_BAR_VALUE, d.value);
                 if (barItem->property(TAG_BAR_LABEL).isValid())
                     barItem->setProperty(TAG_BAR_LABEL, d.label);
+                if (barItem->property(TAG_BAR_INDEX).isValid())
+                    barItem->setProperty(TAG_BAR_INDEX, barIndex);
             } else {
                 // Set default rectangle bars
                 auto barItem = qobject_cast<QQuickRectangle *>(barItems[barIndex]);

src/graphs2d/qsgrenderer/pointrenderer.cpp

@@ -25,6 +25,7 @@ static const char *TAG_POINT_SELECTED_COLOR = "pointSelectedColor";
 static const char *TAG_POINT_SELECTED = "pointSelected";
 static const char *TAG_POINT_VALUE_X = "pointValueX";
 static const char *TAG_POINT_VALUE_Y = "pointValueY";
+static const char *TAG_POINT_INDEX = "pointIndex";
 
 PointRenderer::PointRenderer(QGraphsView *graph)
     : QQuickItem(graph)
@@ -139,6 +140,8 @@ void PointRenderer::updatePointDelegate(
         marker->setProperty(TAG_POINT_VALUE_X, point.x());
     if (marker->property(TAG_POINT_VALUE_Y).isValid())
         marker->setProperty(TAG_POINT_VALUE_Y, point.y());
+    if (marker->property(TAG_POINT_INDEX).isValid())
+        marker->setProperty(TAG_POINT_INDEX, pointIndex);
 
     marker->setX(x - marker->width() / 2.0);
     marker->setY(y - marker->height() / 2.0);

src/graphs2d/xychart/qxyseries.cpp

@@ -790,6 +790,10 @@ QColor QXYSeries::selectedColor() const
         \li qreal
         \li pointValueY
         \li The value of the \l{QXYPoint::y} at this position.
+    \row
+        \li int
+        \li pointIndex
+        \li The index of the point, from 0 to the amount of points - 1. [since 6.9]
     \endtable
 
     To use any of these, add property with the defined name into your custom component.
@@ -836,6 +840,10 @@ QColor QXYSeries::selectedColor() const
         \li real
         \li pointValueY
         \li The value of the \l{XYPoint::y} at this position.
+    \row
+        \li int
+        \li pointIndex
+        \li The index of the point, from 0 to the amount of points - 1. [since 6.9]
     \endtable
 
     To use any of these, add property with the defined name into your custom component.

tests/manual/qmltestbed/qml/qmltestbed/AxisGridSetup.qml

@@ -71,8 +71,9 @@ Rectangle {
                 Rectangle {
                     id: comp
                     property color barColor
+                    property int barIndex
                     gradient: Gradient {
-                        GradientStop { position: 0.0; color: "red" }
+                        GradientStop { position: 0.0; color: (comp.barIndex % 2 === 0) ? "#f02020" : "#d0d020"}
                         GradientStop { position: 0.4; color: Qt.darker(comp.barColor, 2.0) }
                         GradientStop { position: 1.0; color: comp.barColor }
                     }

tests/manual/qmltestbed/qml/qmltestbed/LineProperties.qml

@@ -183,6 +183,7 @@ Rectangle {
                 property color pointColor
                 property real pointValueX
                 property real pointValueY
+                property int pointIndex
                 width: 16
                 height: 16
                 Rectangle {
@@ -190,14 +191,14 @@ Rectangle {
                     color: "#202020"
                     border.width: 2
                     border.color: pointColor
-                    radius: width / 2
+                    radius: (pointIndex % 2 === 0) ? width / 2 : 2
                 }
                 Text {
                     anchors.horizontalCenter: parent.horizontalCenter
                     anchors.bottom: parent.top
                     color: "#ffffff"
                     font.pixelSize: 16
-                    text: "(" + pointValueX.toFixed(1) + ", " + pointValueY.toFixed(1) + ")"
+                    text: pointIndex + ": (" + pointValueX.toFixed(1) + ", " + pointValueY.toFixed(1) + ")"
                 }
             }
             XYPoint { x: 0; y: 6.6 }