inheritance of behaviors across resources

[stephenwf]

In presentation 2, as a viewer, if I come across a manifest with a viewingDirection, I should take that as an intention for the canvases to be displayed accordingly, even if there are multiple sequences. If multiple sequences, each with different viewingDirection properties, they trump the Manifests viewingDirection.

In a way, sequences by default inherit the viewingDirection from the Manifest. Is this true for ranges? If a top level Manifest has a viewingDirection of right-to-left, should that be inherited by each of the Ranges (if they don't have a viewingDirection themselves) or should they default to left-to-right.

Further, in presentation 3, if sequences are now represented as Ranges, their behaviour here will change, and any conversion between presentation 2 and presentation 3 would have to explicitly set the viewing direction, if it was previously implied by the Manifest having the property (if Ranges should not inherit this direction).

[azaroth42]

Yes, that's all correct. We should be clearer in the spec text that viewingDirection inherits, and also which (if any) behavior values should be inherited. E.g. paged clearly inherits from the Manifest to the Ranges, and can be overridden with non-paged at the Canvas level. On the other hand repeat on the Manifest is not inherited by each individual Range.

[zimeon]

A notion of overriding inheritance would, I think, end up with a need to have opposites or complete sets of alternate behaviors including the default. For example, in order to override auto-advance one needs to be able to specify the opposite (default), non-auto-advance, manual-advance, pause-at-end or such. And then there is documentation clarity issue of grouping opposites or complete sets of alternate behaviors so that the idea of how to override is clear.

[workergnome]

If i being playing a temporal range set to auto-repeat (say a TOC), and then I click into the thumbnail-nav to go to a section (AKA the scrubber), but I have not set the thumbnail-nav range to be auto-repeat, does that viewer then cancel the auto-repeat behavior since I've selected a content resource from another enclosing resource?

[azaroth42]

Eds call -

• Collections inherit from Collections.
• Manifests do not inherit from Collections.
• Canvases inherit from Manifests, but not from ranges.
• Ranges inherit from Ranges and from Manifests.

Then we need to specify sets of disjoint behaviors, and define any negation behaviors needed.

[azaroth42]

Initial issue -- if Canvases do not inherit from Ranges, then it seems pointless to have Unordered, Individuals, Continuous and Paged on Ranges. The canvas would always inherit the value from the Manifest, not from the Range. This is the same sort of issue as auto-advance on a Range (#1632) ... it's the presentation of the canvases in the range that matters.

[azaroth42]

unordered, individuals, continuous and paged are disjoint. They do not need a negation, as you just pick one of the others. individuals is specified as the default if none are provided. They inherit as expected, other than from Range to Canvas.

non-paged, facing-pages and paged are disjoint on a Canvas. The first two are negations of paged. They are dependent on the Manifest having the paged behavior.

sequence, thumbnail-nav and no-nav are disjoint. They do not need negations but the inheritance model of sequence is strange, as only the top level range is a "sequence". Once you have started no-nav you can't negate it down the hierarchy to suddenly have it appear. thumbnail-nav has child ranges with thumbnails, but we can allow them to inherit the thumbnail-nav-ness.

multi-part and together are disjoint, and don't need negations. If there are things in a together group, then just don't put things into it that shouldn't be there. A collection that is in a multi-part collection but isn't itself multi-part ... ... I don't know what that would mean.

auto-advance is not disjoint with anything, and needs a negation (no-auto-advance).
repeat is not disjoint with anything, and needs a negation (no-repeat).

[azaroth42]

More weirdness notes - If a newspaper article Range is part of a paged Manifest, the article inherits the paged-ness. It should probably be required to have individuals to assert order, but not paged.
But conversely meaning that it's not pointless to have them on Ranges.

[azaroth42]

Closed by #1681