Currently, if a given style is being applied to given journal, that means either (1) that said style belongs to said journal account; or (2) that said style belongs to the logged-in viewer.
Now, in a custom style, it's easy for a layer to determine whether #1 is the case, by hardcoding the style's owner's username and comparing it to
get_page().journal.username; and it's easy to use that to determine whether #2 is the case (#2 is the case whenever #1 is not, plus whenever
viewer_is_owner()). (This isn't exactly best coding practice - their layer code will now be specific to them - but whatever.)
In a public style, there's no way to determine whether #1 or #2 is the case. Personally, I think it would be useful if a style like Component would only display the Free Text area (which is specific to the style owner) when #1 is the case (so that someone using Component with style=mine wouldn't see their Free Text area on others' journals). To this end, I think there should be a global function,
journal_owns_style() : bool, to check if #1 is the case. Also, though I don't see a good use for it, and though it's easily derived from
viewer_is_owner(), I think symmetry would desire a global function
viewer_owns_style() : boolto complement
What do you all think?