Do we still need the code that calculates the middle of the current y domain? Would this be used in the case than zooming doesn't cause any overflow in the y direction?

One minor issue is that the bollinger band can go off the chart and there is no way to drag it into view.

Do we still need the code that calculates the middle of the current y domain? Would this be used in the case than zooming doesn't cause any overflow in the y direction?

This would still be used in other charts I think? e.g. I haven't changed the behaviour of the line chart when it has a date x-axis. Currently, this new behaviour only applies to OHLC charts.

One minor issue is that the bollinger band can go off the chart and there is no way to drag it into view.

I don't think this is a big deal. We don't consider the bollinger bands the rest of the time either.

Do we still need the code that calculates the middle of the current y domain? Would this be used in the case than zooming doesn't cause any overflow in the y direction?

This would still be used in other charts I think? e.g. I haven't changed the behaviour of the line chart when it has a date x-axis. Currently, this new behaviour only applies to OHLC charts.

Ah, yes. I see.