- From: Hadrien Gardeur <hadrien.gardeur@feedbooks.com>
- Date: Wed, 20 Jun 2018 11:17:56 +0200
- To: Florian Rivoal <florian@rivoal.net>
- Cc: MURATA Makoto <eb2m-mrt@asahi-net.or.jp>, Joshua Pyle <jpyle@atypon.com>, ryladog@gmail.com, W3C Publishing Working Group <public-publ-wg@w3.org>
- Message-ID: <CA+KS-13k3Gt9MFG9y_izk9L4xH+C1YuudpD5ApLueYBvSHFXSg@mail.gmail.com>
Hello Florian, The right approach also depends what target you're considering. It's a very different choice if we're talking EPUB 3.2 or Web Publication. In practice, this is indeed true. At the same time, I don't think UAs are > strictly required to hold all images in memory all the time. They typically > do, but a UA optimized for low footprint could flush them to disk when out > of the viewport, and load them on demand when needed. > This is something very hard to do for most EPUB reading systems out there. In practice, most apps are stuck with the default behaviour and APIs available for a webview. To optimize for low footprint, you'd probably have to do some JS trickery that would block images from loading while off-screen, but I can imagine quite a few side effects (including the fact that JS is not well supported in such readers, especially on reflowable resources). The fact that the viewport is unpredictable is a feature, not a bug: it is > the natural consequence of allowing people to read on any device they want. > The question is what can an author do in response to viewport size changes, > and CSS gives quite a lot of flexibility. It is possible to use: > > * the width, height, max-width, max-height, min-width, min-height either > on the image container, or on the images individually, to control their size > > * the px, %, vh (viewport height) or vw (viewport width) units when doing > so > > * the object-fit property to decide what to do if the image's size or > aspect ratio does not match the size or aspect ratio imposed by the > width/heigh/etc properties https://developer.mozilla.org/ > en-US/docs/Web/CSS/object-fit > > * media queries to switch layout at different sizes > > * CSS Grid to provide different non-linear, possibly overlapping, > arrangement as desired, for example at large screen sizes. > > * css scroll snap to force the UA to scroll step-by-step / image-by-image > if desired. > This is all true for WP, but keep in mind that for EPUB right now, most of the properties that you're listing would be: - unsupported or unavailable - overwritten by the RS that injects its own CSS instead Could you clarify what's the target for this vertically-scrollable manga profile? Best, Hadrien
Received on Wednesday, 20 June 2018 09:18:48 UTC