Re: [Minutes] EPUB Virtual Locator TF, 2021-06-02

+Wendy for visibility

We haven't gotten that far yet, but my impression of the direction we're heading in is that (perhaps) reading systems would continue to use their existing counting algorithms for the time being, but we might suggest that the results be renamed — for example, "screens" instead of "pages." As an example, Apple Books already distinguishes between pages and screens; in a book that has a page-list, you can tap to switch between screen counts (which recalculates upon reflow) and page counts (which doesn't).

Might I suggest that it sounds like you would enjoy a few task force meetings? :)



> On Jun 3, 2021, at 12:50 PM, Laurent Le Meur <laurent.lemeur@edrlab.org> wrote:
> 
> Ok then we (Readium developers) can help. The next question is: do we agree that reading systems which are well known on the market but will not change their algorithm (because they are legacy, because it would be a breaking change for them ...) may not support this new standard, but ... well this is life? 
> 
> L
> 
>> Le 3 juin 2021 à 17:37, Dan Lazin <dlazin@google.com <mailto:dlazin@google.com>> a écrit :
>> 
>> Hey, Laurent. We are indeed talking (talking) about standardizing the algorithm. The short version is "use page-list if present, and if not do something dead-simple like divide by 1000."
>> 
>> We're still pretty far from writing a spec, but we are talking about standardization here.
>> 
>> 
>>> On Jun 3, 2021, at 9:55 AM, Laurent Le Meur <laurent.lemeur@edrlab.org <mailto:laurent.lemeur@edrlab.org>> wrote:
>>> 
>>> Hi everybody,
>>> 
>>> Sorry for not having been able to participate to the call.
>>> 
>>> About use case line 2 ("A teacher wants to ask students to go to a certain location in an EPUB which contains no explicit page-list. The students are using different types of reading systems, nevertheless all reach the same page. ")
>>> 
>>> We currently are working in this area in the Readium Developers' community. I don't want to be pessimistic but I believe this will not happen. If page lists are present, ok the mechanism is documented and it is not about virtual locators, but UX and the ability to jump to a location identified by an html fragment id. But if no page lists are present, each reading system has its recipe to calculate "positions" (as we call it at Readium) aka virtual page numbers. "positions" are calculated per resource first, then agglomerated to form a sequence. For instance it may be the size of the compressed file (in the zip) divided by 1024. Or the size of the (decompressed) html content divided by 2500. Either this group wants to standardize the algorithm, or the use case is IMHO void. 
>>> 
>>> Best regards
>>> Laurent
>>> 
>>> 
>>>> Le 3 juin 2021 à 15:23, Ivan Herman <ivan@w3.org <mailto:ivan@w3.org>> a écrit :
>>>> 
>>>> Minutes are here:
>>>> 
>>>>  https://www.w3.org/publishing/groups/epub-wg/Meetings/Minutes/2021-06-02-epub-locators <https://www.w3.org/publishing/groups/epub-wg/Meetings/Minutes/2021-06-02-epub-locators>
>>>> 
>>>> Ivan
>>>> 
>>>> ----
>>>> Ivan Herman, W3C 
>>>> Home: http://www.w3.org/People/Ivan/ <http://www.w3.org/People/Ivan/>
>>>> mobile: +33 6 52 46 00 43
>>>> ORCID ID: https://orcid.org/0000-0003-0782-2704 <https://orcid.org/0000-0003-0782-2704>
>>>> 
>>> 
>> 
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