Clarify difference between selected, visible, deleted, filtered

[maxwell8888]

1. if !visible or deleted, then so are all children of that item. but the children won't automatically have them same flags applied.
2. Selected only applies to individual items, but of course all trips below selection are selection highlighted
3. for all cases, trips will need to know what flags their parents have to know whether to: not draw (!visible or deleted), draw selected, else draw normal (or hover but don't need flag for this)
4. for filtering, are: all trips drawn and selected trips highlighted, eg a stop or agency selection, or only certain trips drawn eg for trips that run on a certain day.

so filtering can be like applying (!)visible to trips, or a selection?
With filtering we might want to filter the trips, and then select one, in which case filtering can't just be multi-selection
sometimes we might want a subset, where we can still select items, but also see all trips so we can see the filtered relative to the other trips (automatically hiding the other trips would be annoying for users in this case). But sometimes we do actually want to hide the non filtered stops to make it easier to concentrate on a subset.

filtering to all trips in an agency/route is equivalent to selecting that agency/route?

Do we want to support multiple simultaneous filters? eg trips from a specific agency that run on a certain day.

For (each?) filters, just simply have a switch to control whether the non filtered trips are displayed.

The selection of a stop, will also apply a filter for related routes, from which individual trips can be selected. Would want selecting a trip

types of filter:
Trips that run on a certain day - subset - but also might be nice to show everything so we can see the filter relative to all trips
Trips that are running at a specific point in time - subset
Deleted trips - subset - or maybe grey out the deleted ones
Not deleted trips - subset (because then want to be able to select other trips)
Trips which use a certain stop - subset (but would be the same as selecting a stop?)
The trips required to make a journey between two stops - maybe subset but more ideally a special type of selection