KOreader on Android

[Glottis]

I had an idea about implementing book cover screensavers on android devices.

Since android devices can display a screensaver from a file, couldn't KOreader be set to copy the cover of a book to a file of the users choice when the book is opened, and delete/replace it with another when a new book is opened?

That way android itself would handle the book cover without any complicated changes needing to be made.

[Owl_]

Hi, has anyone the link of the last stable release?
(night mode is giving me some issue)

[elvvis]

Here you can download the last stable release: https://github.com/koreader/koreader/releases

[wanderson]

Greetings! I've installed KOReader (koreader-android-arm-v2020.08.1.apk) on my updated Mars reader, and have only a few issues that I'd like to resolve. I'm not totally inept with code, so if solving these issues means getting the appropriate KOReader source, building and testing, I'd consider this route.

I'm using KOReader as a reader of a Calibre library on an SD card with directory structure defined by the plugboard script:

{author_sort[0]}/{author_sort:sublist(0,1,&)}/{series}/{series_index:0>4.1f|| - }{title}

e.g. /storage/sdcard_name/Books/R/Rowling, J.K./Harry Potter/01.0 - Harry Potter and the Sorcerer's Stone.epub

I've found two issues with KOReader, one in navigation and one in rendering:

1. I have not gotten KOReader to use the Calibre metadata file on the SD card for searching. I've tried to edit a few .lua files to no avail, and much of the documentation floating around the MobileRead fora seems a bit out of date, or perhaps directed at the Kobo platform and not Android. How do I get KOReader on Android to use metadata.calibre?
2. Certain rendering within an epub seems flaky. Not all covers are expanded to fill the screen, though they render correctly on other readers. Also, some small images (e.g. a "triple asterisk" .jpg used as a transition marker) render with a full width gray background instead of a transparent background.

Have other users noticed these issues? In any case, how can I fix them (or otherwise contribute)? I REALLY LIKE the way KOReader works generally, and love the way it renders epub text.

wanders

[Frenzie]

Are you sure you don't mean PNG? JPG doesn't have transparency.

[wanderson]

Originally Posted by Frenzie

Are you sure you don't mean PNG? JPG doesn't have transparency.

Right you are, but KOReader takes the entire jpg image (a small rectangle, black on white) and overlays it onto a larger, full-width rectangle which is gray. That is, what should look like this:

* * *

instead looks like:

Attachment 181753

(sorry, I can't figure out how to resize this image - click on it)

[Frenzie]

That's more likely to be related to the book's styles in some way. Could you open an issue with a scrambled document attached?

[NiLuJe]

As for the Calibre stuff, everything is in a dedicated plugin now, so you just need to set the path to your library there: [Tools] > Calibre > Search settings > Manage libraries

[wanderson]

Originally Posted by NiLuJe

As for the Calibre stuff, everything is in a dedicated plugin now, so you just need to set the path to your library there: [Tools] > Calibre > Search settings > Manage libraries

Thanks for your response.

My version of KOReader only scans the internal storage, not the SD card (which is where my metadata.calibre is located). Is there a way to get KOReader to scan the SD card?

[wanderson]

Originally Posted by Frenzie

That's more likely to be related to the book's styles in some way. Could you open an issue with a scrambled document attached?

Done - #6632

[pazos]

Originally Posted by wanderson

Thanks for your response.

My version of KOReader only scans the internal storage, not the SD card (which is where my metadata.calibre is located). Is there a way to get KOReader to scan the SD card?

It will scan the primary partition (normally the internal storage but can be changed in android settings). Outside the primary partition the app has no granted permissions for read&write and the behaviour will change between devices.

Normally what happens is:

1. the internal partition is mounted in /storage/emulated/0
2. the SD card is mounted in /storage/emulated/UUID
3. the app cannot read /storage/emulated

My suggestion would be to format the sdcard as the primary storage partition, but there're a few cases when that's not possible (ie: you want to use the sd card in other devices). In these cases you can skip the scan and write the file manually, using the path that contains "metadata.calibre" and "driveinfo.calibre". That file will stay until you do another scan.

The workaround should work on most android devices (sd is readable) but has some limitations (sd is not writable).

[wanderson]

Originally Posted by pazos

It will scan the primary partition (normally the internal storage but can be changed in android settings). Outside the primary partition the app has no granted permissions for read&write and the behaviour will change between devices.

KOReader currently has no issues reading the (epub) files on the SD card and scanning the directories therein. And the way that this flavor of Android is configured, the SD card is mounted on /storage/<sdcard-id>. So if KOReader can see the book files on the SD card, why can't it read the metadata file there as well?

[pazos]

please reread: it can read the sdcard, but normally cannot read the directory where the sdcard is mounted. So a recursive search on /storage will fail to see the sdcard and thus to search on its files.

[wanderson]

Originally Posted by pazos

... it can read the sdcard, but normally cannot read the directory where the sdcard is mounted.

This sounds like a misfeature, at least. Why can't I just point KOReader to the metadata? I don't need it to scan since I already know where it it.

[pazos]

Originally Posted by wanderson

This sounds like a misfeature, at least. Why can't I just point KOReader to the metadata? I don't need it to scan since I already know where it it.

If your question is: why can't I just point to the metadata using the UI? the answer is because nobody implemented this. Patches welcome.

If your question is: how could I just point to the metadata? the answer is in my first answer: you need to do it by hand.

Create a file called "calibre-libraries.lua" with the content

return {
    ["/path/to/calibre/dir/"] = true
}

and place it in koreader/cache. It will stay as is and will survive updates but you'll need to do the trick again if you perform another scan or clear cache from developers option.

About android being a stupid platform: I agree, the lack of way to programatically retrieve the path of the sdcard is BS and forcing users to use SAF instead of the filesystem API is a PITA.