Kobalt: an alternative reader app for Kobo devices

[MrSilverstrike]

Originally Posted by Apollyon202

There are some books that show dark text on a black background when dark mode is enabled. Not sure why, as other books are fine, even though they’re acquired from the same bookstore. I can send the file if you'd like to.

Ah. It's probably not quite black text (rather some gray -- why anyone would put that in an ebook beats me), and that's why this is happening. I'll fix it so this can't happen in the future, but you can probably fix this with Calibre or something in the meantime.

[DNSB]

Originally Posted by Apollyon202

There are some books that show dark text on a black background when dark mode is enabled. Not sure why, as other books are fine, even though they’re acquired from the same bookstore. I can send the file if you'd like to.

If you could post a scrambled version of one of the books here, it would help.

I have seen this happen on a couple of ebooks where instead of leaving the background color and color as defaults, they were forced. I've attached screenshots of a test epub in normal and dark mode on a Sage and Libra Colour. Notice the change in the treatment of set to black and set to white lines between the two devices.

[afakler]

Unfortunately, there are 2 setbacks for me in beta3:

1. What happened to the .5 textsize? The slider goes directly from 12 to 13 to 14.
2. The text indent ist reversed. Instead of:
First line
Second line
Third line
it shows:
First line
Second line
Third line

Therefore my question. Is ist possible to downgrade to beta2?

[JSWolf]

Originally Posted by fogice

My stress test book doesn't load, but it fails gracefully and pretty quickly (89 MB, 3,762,349 words, 306 images).

Do you have the book spit into 260KB (or less) HTML files? If the HTML is too large, that could be causing the fail.

[JSWolf]

Originally Posted by MrSilverstrike

Right.

As it stands, the font override works the same as it does in Kobo's reader app: if you choose anything but the publisher fonts, you get that font everywhere. It's a blanket rule.

Otherwise, the rules are simple:

- serif fallback: Libron
- sans serif fallback: Legible Next
- mono fallback: Plex Mono

What you're asking for is essentially a way to customize these, right? I can add that for you.

Perhaps via a userstyle.css file. You would be able to put anything in there you'd like to apply to all books. Would that help?

Please delete all slab fonts you've used. They are really really ugly. Plus as they'll never ever be used, they are just bloat. Let us choose the default fonts for serif, sans-serif, and monospace.

[JSWolf]

@afakler you need to put #2 in a code block. Otherwise your example doesn't look correct.

[MrSilverstrike]

Originally Posted by afakler

Unfortunately, there are 2 setbacks for me in beta3:

1. What happened to the .5 textsize? The slider goes directly from 12 to 13 to 14.
2. The text indent ist reversed. Instead of:
First line
Second line
Third line
it shows:
First line
Second line
Third line

Therefore my question. Is ist possible to downgrade to beta2?

Text indentation is likely a book thing? I haven't changed anything about that as far as I can tell.

I removed the .5 text size because the maximum is bigger now. I'll make sure to add .5 text sizes for anything < 20pt back, good point.

[MrSilverstrike]

Originally Posted by JSWolf

Please delete all slab fonts you've used. They are really really ugly. Plus as they'll never ever be used, they are just bloat. Let us choose the default fonts for serif, sans-serif, and monospace.

Saying something like this is downright disrespectful to type designers across the world. You could've just said: "I would like to be able to set default fonts for serif, sans-serif and monospace" and that would've been more than enough.

[rantanplan]

Originally Posted by JSWolf

Please delete all slab fonts you've used. They are really really ugly. Plus as they'll never ever be used, they are just bloat. Let us choose the default fonts for serif, sans-serif, and monospace.

Jon, please don’t try to speak for others. People have different tastes, that’s just rude and ignorant.

[Strether]

Originally Posted by MrSilverstrike

Text indentation is likely a book thing? I haven't changed anything about that as far as I can tell.

I removed the .5 text size because the maximum is bigger now. I'll make sure to add .5 text sizes for anything < 20pt back, good point.

Thanks for that. I missed the .5 text size, too. Thanks for being so obliging.

Jim

[jackie_w]

@MrSilverstrike,

A bit more feedback about beta3. I've attached a test epub which I'll refer to in the following points.

1. The vanishing margin-top
See chapter "EPUB Serif Font" in the test epub.

Whichever CSS style rule is used for the first element in a chapter (often a heading tag but not always) appears to "lose" its margin-top setting, i.e. it looks as if it has been forced to zero.

The heading text is supposed to display with equal 2em vertical whitespace above and below, which it does in Nickel epub/kepub. As you will see, there is zero space above in Kobalt.

HTML:

<h2>EPUB Serif Font</h2>

CSS:

h2 {
  display: block;
  font-size: 1.1em;
  font-weight: bold;
  margin-bottom: 2em;
  margin-left: 0;
  margin-right: 0;
  margin-top: 2em;
  text-align: center;
  text-indent: 0;
  hyphens: none;
  -webkit-hyphens: none;
}

2. Full page image using an <svg> tag
See chapter "SVG full page image..." in the test epub. This uses code like that often used by calibre epubs for the cover page, i.e. when there is a single image (e.g. a map) which you want to fill the whole screen (keeping aspect ratio, or not) whilst remaining centred both vertically and horizontally.

Nickel epub/kepub: The image is centred both horizontally and vertically,

Kobalt epub: Centred horizontally but no vertical whitespace above the image. I suppose this may be another manifestation of the problem in item 1?

3. Vertical centre
See chapter "Vertical centre" in the test epub. It may not be totally fair to call this a bug but I mention it only because it does work with Nickel kepub (not Nickel epub).

Nickel kepub: the 4-line verse is centred vertically (but not horizontally) on a new page.

Nickel epub: the verse appears at the top of a new page but not centred either horizontally or vertically.

Kobalt epub: if the font-size you're using is small enough (I've got it set at Libron 10pt on a Libra2) the verse appears at the end of the previous chapter, rather than starting a new page.

4. I was also going to mention the lack of font-size granularity but I see others have already done that.

5. Thank you for implementing the "wrap-around menu pages" in the TOC. Another place for consideration of doing similar is when displaying a dictionary definition. Depending on which dictionary you use the definition can go on for many pages.

[MrSilverstrike]

Originally Posted by jackie_w

@MrSilverstrike,

A bit more feedback about beta3. I've attached a test epub which I'll refer to in the following points.

<snip>

1. That's on me. I added that rule because plenty of books push down their header which wastes space. I think this should be an option you can disable and it should only apply if the first element is a) a header or b) an image.

2. Yes, that could be. I'd need to check.

3. That looks to be a bug, yes.

4. That's already fixed in the upcoming beta 4.

5. That's true. I should have an agent go through all menus. It's possible I already fixed this earlier this week but I'll double check.

Thanks again for the precise feedback and also the epub. Helps a lot!

[jackie_w]

Originally Posted by MrSilverstrike

1. That's on me. I added that rule because plenty of books push down their header which wastes space. I think this should be an option you can disable and it should only apply if the first element is a) a header or b) an image.

Yes, I can see that many users want to reduce "wasted space". Others (like me) just want the book's CSS to be honoured as-is. The ability to switch on/off should keep everyone happy.

Originally Posted by MrSilverstrike

Thanks again for the precise feedback and also the epub. Helps a lot!

Happy to help. Having an extra option which is likely to work with fw 6.x is in everyone's interest. I don't have great faith that Kobo's new app (TENG?) will be a great step forward in the short term, although I hope I'm wrong about that!

[MrSilverstrike]

Originally Posted by jackie_w

I don't have great faith that Kobo's new app (TENG?) will be a great step forward in the short term, although I hope I'm wrong about that!

I choose to believe they'll still sort out the issues... and in that case Kobalt just remains a nice in-the-middle option for people who don't need KOReader but also want something a little more powerful than TENG.

If they don't, well, Kobalt works fine on Kobo OS 6 and it can be the reader that actually works as intended.

It's also nice for folks who want something familiar when they migrate to some other platform, since the goal is to get Kobalt running everywhere. The dev build already runs on Android and on Mac, too. I have this Boox Go 7 and its built-in reader was... rough. Just the text rendering alone made me want to puke. You're supposed to be able to read on these things for hours!

I'm glad I made the right technological choices to make it all (relatively) easy to run everywhere.

[Sirtel]

Originally Posted by MrSilverstrike

Yes, this is coming in an upcoming update (likely beta 4 or 5) where you will be able to customize the header and footer. I expect you to be able to choose where to place:

- Title of the book
- Author of the book
- Current page in chapter
- Current page in book
- Battery icon (with percentage)
- Battery icon (without percentage)
- Current time
- Estimated reading time left (chapter)
- Estimated reading time left (book)

You'll have 6 slots (top left, top middle, top right, bottom left, bottom middle and bottom right) and you will be able to decide how large you want the text to be. Estimates will be based on your average reading speed.

Would it be possible to have percentage read (of the book) as one of the options?