Allow for using properties of other widgets on the screen as inputs for rules

[jwlodek]

This may already be possible, but if it is, it is not documented in https://control-system-studio.readthedocs.io/en/latest/app/display/editor/doc/rules.html.

Generally I think giving more concrete rules examples would be useful on that page.

[georgweiss]

@jwlodek, can you please provide a concrete use case?

[jwlodek]

The case that I'm interested in using this for is for a specific widget to be able to adjust it's behavior if any of a subset of other widgets is not marked as visible. I could re-create all the visibility rules on the target widget that I used for the other one, but it would make the rules on this widget much more complex than I need (and it would duplicate the conditionals, necessitating that they be kept in sync as additional conditions are added).

Specifically, I'm working on a nicer representation of PandABox configurations in phoebus. I want to have an LED that is lit if all the connections that are configured on the screen are active. I have each wire's visibility setting tied to the PV that corresponds to the wire being active on the PandA, and I'd like to concatenate them all into a single LED that says if a configuration is loaded or not.

Again, I could do this by copying all the visibility rules into the LED widget, but that then becomes a duplication of the conditionals.

[georgweiss]

...specific widget to be able to adjust it's behavior if any of a subset of other widgets is not marked as visible

So I'm guessing that visibility of "other widgets" is based on the state of one or several PVs, right? Instead of creating a rule based on the visibility of other widgets, or create a combined rule, I'd maybe consider creating another EPICS record to combine the state/value of all those PVs controlling visibility of "other widgets".

[kasemir]

What Georg said. "if a configuration is loaded or not" sounds like a key piece of status information that should be available via a binary record on the IOC. As for the screenshot, that does look like a more specialized tool where you can move items around, the wires follow etc. May be too much to ask from a generic control system display.