Added ability to use a wider range of dates for AstroCalc/Ephemeris tool

[alex-w]

Description

This patch adding ability to use a wider range of dates for AstroCalc/Ephemeris tool.

Fixes #3868 (issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• This change requires a documentation update
• Housekeeping

Checklist:

• My code follows the code style of this project.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (header file)
• I have updated the respective chapter in the Stellarium User Guide
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching src/**/*.cpp:

• Are possibly unused includes removed?

This is an automatically generated QA checklist based on modified files.

[gzotti]

Thank you for going after this now. But as always a few observations:

When I open the panel, then change the simulation date in the usual time panel (or any other method), I see the AC panel has an option to set the "From" date to "now". Good! When the date is outside the range of Gregorian calendar, the year is displayed as 9999. In this case the system should auto-switch to W.R.D (Wide range dates? Why not just call the button JD?). The GUI has lots of space after "W.R.D." ("JD") for a label to display the date range in "common" dates.

You have to set two dates. The end date might also be configured with just 2 options "[+1] [second/minute/hour/day/month|year]" (i.e., a spinbox and a dropdown), this may be faster than fiddling with the calendar panel or counting the JD numbers. At least, I see I can copy/paste the start date to start configuring, then scrolling the mousewheel 20 clicks.

[alex-w]

Well, let me try to create an another version of GUI…

[alex-w]

@gzotti OK, what's about changes?

[Atque]

Is 100 months enough? What if someone wants to display the movement of Saturn throughout a Saturnian year?

[gzotti]

Interface: Yes, I think everybody prefers this.
@Atque just say 30 years. And you can set custom intervals with really all regular options. (One may want to have "altitude at -8° solar altitude" over a year, but seriously this is awkward.)

[Atque]

just say 30 years. And you can set custom intervals with really all regular options. (One may want to have "altitude at -8° solar altitude" over a year, but seriously this is awkward.)

Ah, I'm stupid. I didn't realize we could change the unit.

"Object at given solar altitiude" is actually very useful when displaying visibility of e.g. Mercury. But that's for another PR.

[github-actions]

Hello @alex-w!

Please check the fresh version (development snapshot) of Stellarium:
https://github.com/Stellarium/stellarium-data/releases/tag/weekly-snapshot

[github-actions]

Hello @alex-w!

Please check the latest stable version of Stellarium:
https://github.com/Stellarium/stellarium/releases/latest