Thanks Yani.
If possible i suggest you a little change to get it working perfectly
I see that arrows keys act only on the scroll bar.
So right now i can move it but i cannot really explore the graph.
The best way is to operate directly on the graph.
I mean, the values-vertical-bar that appears when you click on the graph should appear always when the graph get on focus.
Then if i press the right/left arrows the vertical-bar will move step-by-step to the desired direction.
This is what i call "using/exploring a graph"
To allow a quick/usefull exploring experience

you could introduce the use of page-up/page-down to move page-by-page and keys home/end to go directly to the first position or last.
what do you think?
