How disable drag of points in the x axis on chartview

pehi

I have a qtchart with a lineseries with 5 points on the graph. I can drag these points on in both x and y axis inside min and max of axisX and axisY.
How can disable drag of points in the x axis? so it is possible to drag points vertically on the chart. Here is my code:

ChartView {
    id: chart
    property var selectedPoint: undefined
    anchors.fill: parent
    antialiasing: true
    property real toleranceX: 0.05
    property real toleranceY: 0.05

    ValueAxis {
        id: axisX
        min: 0
        max: 5
    }

    ValueAxis {
        id: axisY
        min: -10
        max: 10
    }

    LineSeries {
        id: series1
        axisX: axisX
        axisY: axisY
        pointsVisible: true            
    }

    MouseArea {
        anchors.fill: parent
        onPressed:
        {
            var cp = chart.mapToValue(Qt.point(mouse.x,mouse.y));
            for(var i = 0;i < series1.count;i ++)
            {
                var p = series1.at(i);
                if(Math.abs(cp.x - p.x) <= chart.toleranceX && Math.abs(cp.y - p.y) <= chart.toleranceY)
                {
                    chart.selectedPoint = p;
                    break;
                }
            }
        }
        onPositionChanged: {
            if(chart.selectedPoint != undefined) {
                var p = Qt.point(mouse.x, mouse.y);
                var cp = chart.mapToValue(p);
                if(cp.x >= axisX.min && cp.x <= axisX.max && cp.y >= axisY.min && cp.y <= axisY.max) {
                    series1.replace(chart.selectedPoint.x, chart.selectedPoint.y, cp.x, cp.y);
                    chart.selectedPoint = cp;
                }
            }
        }

        onReleased: {
            chart.selectedPoint = undefined;
        }
    }

}
// Add data to the series
Component.onCompleted: {
    for (var i = 0; i <= 5; i++) {            
        series1.append(i, Math.random());
    }
}

So far I could disable drag on x axis for one point in this case point on 3 by changing onPositionChanged to following code but there are two problems, first this is just one point, second, it does not disable the drag completely instead the point can be dragged on x axis between 2 to 4 but it cannot be dragged outside this range.

 onPositionChanged: {
                if(chart.selectedPoint != undefined) {
                    var p = Qt.point(mouse.x, mouse.y);
                    var cp = chart.mapToValue(p);
                    if(cp.x >= axisX.min && cp.x <= axisX.max && cp.y >= axisY.min && cp.y <= axisY.max) {
                        if (Math.round(cp.x) == 3){
                              series1.replace(chart.selectedPoint.x, chart.selectedPoint.y, cp.x, cp.y);
                              chart.selectedPoint = cp;
                        }
                    }
                }
            }