[RFC] Support for interval (continuous) series

[e-avidan]

In addition to supporting single-point Date drops (depicting a time when an event took place), I think support for interval (e.g. continuous events) would add some needed functionality to this component

I suppose the use cases range widely (and there are too many to count) but the most basic ones include:

• Scheduling
• Historical records / TImeline (membership / "activation time")
• Schematic view of recordings (e.g. go-pro / live feed / home cameras / etc)

I propose something of the sorts:

• A line/series is composed of either singular drops or intervals - specified as a boolean in the data object
• intervals are presented the same as drops, only 'circle' is replaced with a 'rect'

Open questions:

• Should meatball-ing appear the same for these two types?
• What is to be done with crossing intervals (unlike drops, they may contain dissimilar data)

[jpetitcolas]

That's indeed a good idea. :)

Yet, I think we should be able to mix drops and intervals together. I don't think it would add too much overhead, and it would bring more flexibility. Each item would then be object with either date or begin and end times.

I don't think metaballs make sense anymore with intervals. But that need to be discussed.

Indeed, crossing intervals may be an issue. Yet, for now, I think we can address it later.

Yet, this addition would need a lot of work. So let's postpone it for a later version. Meanwhile, feel free to start a PR about it. :)

[falconair]

I'd like to add a use case as well.
Say you are tracking an online order. Currently, as I zoom in, I start to see individual dots representing various destinations my package has reached. However, the journey of my package is really a single thing. One use case is to see a 'blob' with start time and end time. The other use case, obviously, is to represent each destination as a single point.

It becomes much more interesting if I can display two rows, one showing the whole journey as a single, connected blob and the second line showing individual destinations within that journey. As I zoom out, the journey blob turns into a circle with no detail. Zooming in reveals individual destinations.

The same metaphor can be used to describe any process involving state transitions. Zoom out and you see a single dot representing some process. As you zoom in, you see the details of which state you are in. This way, you can represent a large number of processes (and that is just in a one or two rows).

Earlier I described two rows, one of overview and the second for detail. Those two rows could be combined so EventDrops natively understands this overview/detail metaphor and has a cleaner UI, rather than using two explicit rows.

If EventDrops does natively understand such a relationship, then specific colors could be used to describe specific state.

Any way, this is not a request for a huge set of features, just an idea that this could be a very interesting direction for this project.