ADE image resampling and lack of zoom - Page 2

dgatwood · 12-20-2012, 10:25 PM

Quote:

Originally Posted by Jellby

Again, that 100% means 100% of the container's height, and the container (probably <body>) has no fixed height, but rather is as high as needed to fit its contents. As humans, we assume it means "100% of the screen height", but that's not what the spec says, and that's not what all renderers interpret (though it might be what some do).

Set it to "height: 10cm", or similar, instead, and it should work as expected (but not as wanted).

This, of course, unless I'm mistaken due to ignorance or misunderstanding of the specs

You're right. What I said wasn't quite complete. You'll also need to set sizes for the body and html tags and clear out their margins/padding.

It might also be worth using min-height instead of height just in case A. your content ends up on a device that doesn't support SVG, B. your fallback content is used, and C. it is taller than a screenful.

In other words:

Code:

<html style="min-height: 100%; width: 100%; padding: 0; margin: 0; border-width: 0;">
<body style="min-height: 100%; width: 100%; padding: 0; margin: 0;border-width: 0;">
<div style="min-height: 100%; width: 100%; padding: 0; margin: 0; border-width: 0;">
<object data="..." preserveAspectRatio="..." viewBox="0 0 100% 100%">
Optional non-SVG fallback HTML or image here
</object>
</div>
</body>
</html>

Because the outer html tag has no containing element, per section 10.1 of the CSS 2.1 spec (#1 in the numbered list), a width or min-height value of 100% causes it to fill the viewport (if it isn't already larger than the viewport) or the page, depending on whether you're talking about the web or paged media. In the case of an EPUB reader, I'd expect that distinction to be moot.

In an ideal world, we would all just use the new CSS3 viewport-relative lengths (vw and vh), but I suspect it will be many years before you can count on that unit being supported broadly enough to be useful.

Jellby · 12-21-2012, 06:17 AM

Specifying 100% for html and below could work according with the spec, but I wouldn't trust readers to comply. On the other hand, it's only a solution if a file contains an image and nothing else (like a cover page), it's no good for mid-text illustrations.

Toxaris · 12-21-2012, 06:46 AM

Some readers will actually give strange results if you set the <html> and/or <body> to 100%. For example in some cases the PRS-T1 will not advance to another page unless specifically the page number is entered.

dgatwood · 12-21-2012, 11:45 AM

Quote:

Originally Posted by Toxaris

Some readers will actually give strange results if you set the <html> and/or <body> to 100%. For example in some cases the PRS-T1 will not advance to another page unless specifically the page number is entered.

As I said, you should probably use min-height, not height. By my reading of the thread from a few months ago, the bug in question involved setting height to 100%. IIRC, the spec is a little ambiguous about how height should be handled if your content exceeds a single screen height worth of content, which I'm assuming those test cases that triggered this bug probably did. And I could see how a reader could get confused (though it's still a bug) if that happens.

If it fails in this way with min-height: 100% and a single-page SVG image, however, then the reader is broken (and this seems much more unlikely). The specification is unambiguous about how that should be handled, and if you find that it does not work on the Sony reader, please file bug reports with Sony. They really need to fix that bug, as designs that include full-page-size images (for things like title pages) are likely to become more and more common as time passes, not less.

dgatwood · 12-28-2012, 04:46 PM

Quote:

Originally Posted by dgatwood

As I said, you should probably use min-height, not height. By my reading of the thread from a few months ago, the bug in question involved setting height to 100%. IIRC, the spec is a little ambiguous about how height should be handled if your content exceeds a single screen height worth of content, which I'm assuming those test cases that triggered this bug probably did. And I could see how a reader could get confused (though it's still a bug) if that happens.

If it fails in this way with min-height: 100% and a single-page SVG image, however, then the reader is broken (and this seems much more unlikely). The specification is unambiguous about how that should be handled, and if you find that it does not work on the Sony reader, please file bug reports with Sony. They really need to fix that bug, as designs that include full-page-size images (for things like title pages) are likely to become more and more common as time passes, not less.

Actually, I'm going to have to correct that statement. You must use min-height only on the innermost div or whatever.

Because of a rather severe ambiguity in the CSS specification (Thanks, W3C), some browsers treat the parent element's height as zero if it is constrained only by a min-height. I consider that interpretation to be incorrect, but it's a popular interpretation, exhibited by both WebKit and Firefox. *sigh*

dgatwood · 12-28-2012, 07:37 PM

-----
Deleting erroneous reply.

12-28-2012, 07:37 PM	#21
dgatwood Curmudgeon Posts: 629 Karma: 1623086 Join Date: Jan 2012 Device: iPad, iPhone, Nook Simple Touch	----- Deleting erroneous reply. Last edited by dgatwood; 12-28-2012 at 07:40 PM.

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12-21-2012, 06:17 AM	#17
Jellby frumious Bandersnatch Posts: 7,515 Karma: 18512745 Join Date: Jan 2008 Location: Spaniard in Sweden Device: Cybook Orizon, Kobo Aura	Specifying 100% for html and below could work according with the spec, but I wouldn't trust readers to comply. On the other hand, it's only a solution if a file contains an image and nothing else (like a cover page), it's no good for mid-text illustrations.

12-21-2012, 06:46 AM	#18
Toxaris Wizard Posts: 4,520 Karma: 121692313 Join Date: Oct 2009 Location: Heemskerk, NL Device: PRS-T1, Kobo Touch, Kobo Aura	Some readers will actually give strange results if you set the <html> and/or <body> to 100%. For example in some cases the PRS-T1 will not advance to another page unless specifically the page number is entered.

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