Implemented Insulin on Board.

[eduardopietre]

Insulin on Board implementation, all done locally.
OpenAPS docs were used as reference for this implementation: https://openaps.readthedocs.io/en/latest/docs/While%20You%20Wait%20For%20Gear/understanding-insulin-on-board-calculations.html

This commit features:

• A settings section for insulin on board with 4 settings: enable display, show on chart, duration of insulin activity (OpenAPS dia, but in minutes) and insulin peak time (OpenAPS peak).
• InsulinOnBoardCalculator, class responsible for calculating the IOB.
• IOB plotted at main chart, as a blue line and same scale of insulin bolus.
• Convenience ChartPoint init for a date and insulin amount, for IOB.

Things to notice:

• At RootViewController there are two TODOs, where the IOB display label should be set. The code to calculate the IOB there is already present.
• Caching is not used, but the implementation was done considering that cache may be needed and implemented in the future.

Sample screenshot:

[bjornoleh]

Hi,

I had a look at your contribution. Looks good at first glance!

Some suggestions:

• Perhaps a way to scale the bolus/IOB y-axis could be introduced? When I view my kid's data in follower mode, his boluses/IOB only occupy roughly the lower 1/4 of the chart or less (bolus max 2,5 U, max IOB 5 U).

• Having an easy way to identify negative IOB events would be great. I can not visually see a -0,27 U IOB event from the last 24 hours, but would love to see this easily. Perhaps colour IOB <0 in red or some other colour?

I am also unsure about what "Enable display" does. I only see the chart turn on/off with the "show on chart" setting. Should the current/historical (during scrolling) IOB value be displayed somewhere?

[loopy321]

This looks great! Thanks!
I was wondering if borrowing from loopkit would aid in implementing COB and predictions to get something like:
https://github.com/LoopKit/Loop/blob/dev/Documentation/Screenshots/Phone%20Graphs.png

[LiroyvH]

We should perhaps also free some screen real-estate to simply show a total IOB (and perhaps COB). Perhaps below the pie-chart is an option. Currently the text there mimics the days setting; so it's pretty much redundant. If IOB is enabled, showing the IOB there as a number may be a nice touch.

Just an idea. :)

[bjornoleh]

Agreed. And perhaps move the pie chart to the far left, so it can sit close to the days setting.

[eduardopietre]

Hi,
Thanks for all the feedback!
About the label / displaying the IOB value on screen, there are two TODOs annotations at RootViewController.swift: here and here.
The logic to calculate these values is already on place, the only work missing is the user interface itself.
However, I lack the UI experience and talent needed to create it.

Recently I have had close to no free time to code. COB would be a very nice addition, and could even reuse most of the plotting logic. Unfortunately, I'm not able to work on it right now.
Feedback is appreciated,
Thanks!

[loopy321]

Can IOB be added to the calendar events? I'm guessing here