Pan operation is not bounded

[tlvenn]

When the graph permits it and you can pan the graph, you can actually pan way out of it, ideally it should be bounded by its data.

[entronad]

One of the philosophy of Graphic is trying to make everything customizable. The update functions are such cases.
But we still hope to provide default settings for easy usage, such as the Defaults.horizontalRangeSignal.
So if you need some special limits, just copy and modify the Defaults.horizontalRangeSignal code to make your own callback.

By the way I think to limit the panning is a good idea, I shall add it to the Defaults.horizontalRangeSignal.

[tlvenn]

Thanks 🎉