How can I make the LineTooltipItem always appear above the Spot #2044

** Don't make a duplicate issue.
Ok!

Is your feature request relasted to a problem? Please describe.
How do I make the LineTooltipItem appear above the Spot after clicking on it, and only disappear when I click on the empty space? By the way, I use GetX.

Describe the solution you'd like
Please give me a solution, with the detail code is better.

Describe alternatives you've considered
No.

Additional context
No.