Warn about OS runtime mismatch

[meisenzahl]

Supersedes #1804

[meisenzahl]

Okay, that was a bit more work than I thought 😅

I now show a warning in the AppInfoView based on the runtime version. The logic to generate the warning text is implemented in AppInfoView.

It works pretty well, but doesn't look very pretty...

@elementary/ux I am definitely grateful for UX suggestions 😁

[meisenzahl]

This pull request targets master and is based on #1804. Let me know if you want to handle #1804 first and this separately.

[cassidyjames]

@meisenzahl sorry for any misunderstanding, but I think this case is less critical than an EOL runtime; @danrabbit was saying she thought EOL runtimes might necessitate an inline infobar (but I'm happy with the ContentType implementation for now). I think version mismatches would also make sense as a ContentType implementation, perhaps something like this:

⬇️ (maybe software-update-available-symbolic?)
Outdated
Built for an older version of elementary OS; might not support the latest features

I think it might also make sense to make these two mutually exclusive with the EOL higher priority; e.g. if you're on OS 7 and an app is built for OS 6 and uses EOL runtimes, then it should just show the EOL one. If it's built for OS 6 but otherwise doesn't use EOL runtimes, then show the above message and use the less urgent icon.

[meisenzahl]

@cassidyjames okay I will address the points.

Do we want to show warning only for major version differences? So for example on OS 7 for an OS 6 app?

What about an OS 6 app on OS 6.1?

What about an app that uses a next or daily runtime?

[cassidyjames]

@meisenzahl

Do we want to show warning only for major version differences? So for example on OS 7 for an OS 6 app? What about an OS 6 app on OS 6.1?

I think major version makes sense; minor version bumps is more of a concern for us when reviewing apps but shouldn't have potentially breaking changes like a major mismatch could.

What about an app that uses a next or daily runtime?

Good question; I imagine we could either ignore/not warn for now, or if we want, we could badge it as "unstable" or something, but I think that's outside the scope of this PR.

[meisenzahl]

I refactored the code and introduced RuntimeStatus:

public enum RuntimeStatus {
    UP_TO_DATE,
    END_OF_LIFE,
    MAJOR_OUTDATED,
    MINOR_OUTDATED,
    UNSTABLE;
}

This simplifies the display of appropriate warnings:

End of Life

Built for older version

Unstable

If you don't like that we handle unstable, we can revert 25da400.

[Marukesu]

One extra case is when the SDK is the Runtime, for example, in code.

[danirabbit]

These are probably not the right icons to use since these icons are for when an update is available, and for these apps an update is not available. But, we can fix that before the next release. Nice work on this feature :)

changes made