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Vaadin Forum1. Vaadin Flow - Java

get current index of point in tooltip

Ramesh Mahada
6 years ago Jul 18, 2016 4:02am

Hi,

I am useing the chart for time and dixtance graph. 
y contains distance and x shows the value for time.

In tooltip I have to show the speed and to calculate this I want y axis value of previous point ( current distance = currentY- previosY). If I have the index of current point on mouse over then i can get the value of prevois point using this.points[] array.

Thanks.

Olli Tietäväinen
6 years ago Jul 18, 2016 9:38am

Hi,

if I looked at it correctly, this.points contains the values of each series at current x position, not all the values of the current series. So if you have only one series, there will always only be one item in the points array. Maybe you could calculate the speed in a different series and make that not visible; then you could display the value in the tooltip with points[1] (or whichever is the index of the speed series).

Hope this helps,
Olli

+1
Ramesh Mahada
6 years ago Jul 19, 2016 2:41am

Thanks Olli,

Yup I have only one series in my chart. Actually I need value for previous x position. how could I get it ?

Thanks once again Olli.

Olli Tietäväinen
6 years ago Jul 19, 2016 9:03am

Hi,

I think the this.series.data array is what you want. You should be able to find this.point in that array and get the previous value by going one step back from that. You'll of course need to write some special handling for the first case.

-Olli