How to add text in plotting area of chartview in qml - qt

Question

How do I place text at specific (x,y) locations within the plotting area of a QML ChartView type?
For example, I would like to place text at the location XYPoint{x: -3; Y: 20}
I don't want to place at window's(x,y), i want to put at plotting area's (x,y)
I read documentation,but i don't find any property !!!!!!
//ChartView for plotting points
ChartView{
id:chrt
anchors.fill: parent
height: parent.height
width: parent.width
legend.visible: false
backgroundColor: "black"
//X- axis
ValueAxis{
id: x_axis
min: -5
max: 0
tickCount: 6
}
//Right Y axis
ValueAxis{
id:right_y_axis
min:0
max:40
tickCount: 5
}
//Left Y axis
ValueAxis{
id:left_y_axis
min:0
max:40
tickCount: 5
}
//Line series for wave 1
LineSeries{
id:l1
axisY: left_y_axis
axisX:x_axis
color: "yellow"
width: 1
}
//Line series for wave 2
LineSeries{
id:l2
axisYRight: right_y_axis
style: Qt.DashLine
color: "yellow"
width: 0.6
}
}

Answer 1

Ok, you can use ChartView.mapToPosition to calculate the global position of the specified point from a series (or some another point inside the series), for example:
ChartView{
id:chart
anchors.fill: parent
backgroundColor: "black"
LineSeries{
id: series
XYPoint { x: 10; y: 5 }
XYPoint { x: 10; y: 1 }
XYPoint { x: 15; y: 5 }
XYPoint { x: 20; y: 10 }
XYPoint { x: 25; y: 5 }
XYPoint { x: 30; y: 20 }
XYPoint { x: 40; y: 10 }
}
Text {
id: txt
text: "Hello"
color: "white"
}
onWidthChanged: updatePointPosition();
onHeightChanged: updatePointPosition();
function updatePointPosition()
{
var p = chart.mapToPosition(series.at(3), series);
txt.x = p.x;
txt.y = p.y;
}
}