Restore NO_GUI compilation

[gzotti]

Description

For several years now (really since 2010?) the non-Widget-GUI compilation was not maintained. While not useful in general setups as sole installation in a system, maybe as purely pre-configured RemoteControlled or scripted setups it may still have its value.

Fixes # (issue)

Screenshots (if appropriate):

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

How Has This Been Tested?

Test Configuration:

• Operating system: Windows 11
• Graphics Card: Geforce (but irrelevant)

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

[gzotti]

Shouldn't we rename the STELLARIUM_GUI_MODE options from (Standard/None) to (QWidgets/None)? Just in case someone writes a new "Standard"...

[10110111]

Shouldn't we rename the STELLARIUM_GUI_MODE options from (Standard/None) to (QWidgets/None)? Just in case someone writes a new "Standard"...

Well, someone could write a new one using QWidgets too. If we get a new GUI that becomes the new standard, it can just be called Modern or something.

[gzotti]

Hmm, replacing QWidgets with QWidgets is nothing I expect to happen... but OK, it needs anything else to happen. Just that I need to write this name into several CMakefiles, so an earlier decision saves later re-edits.

[gzotti]

Also this mode needs the QWidget library because of the ProgressBar. For now it should be done. Purpose is a (slightly generalized) specialized installation that may become more useful with #4813. Docs are in BUILDING.md.

[gzotti]

@alex-w IMO this should go in before we evaluate the very interesting RemoteControl GUI changes. Any comments or reservations?

[github-actions]

Conflicts have been resolved. A maintainer will review the pull request shortly.

[gzotti]

@alex-w Any objections here?

[10110111]

Should we maybe add a CI instance to make sure this doesn't break unnoticed later?

[alex-w]

Should we maybe add a CI instance to make sure this doesn't break unnoticed later?

I've added a CI instance and I see troubles in plugins :(

[alex-w]

Need fix the compilation with -DSTELLARIUM_GUI_MODE=None option

[gzotti]

Thanks for setting this up. Must see what fails here.
Given that this still needs QWidgets, maybe the QTextWidgets for InfoText should also be re-activated later. (we wrote text directly to screen in earlier times, with that panel as fallback when text rendering was broken on some systems.)

[gzotti]

Funny observations. It seems MSVC ignores missing includes, while gcc aborts. Seems to work finally. Squash into one commit or keep separate (rebasing the last fixes into the appropriate earlier commits)?