Save the cover as an image file when loading a document

[JSWolf]

I'm curious. Are there any problems the reading app that's comes with the Poke 2 that you feel the need to use KOReader instead?

[pazos]

Originally Posted by JSWolf

I'm curious. Are there any problems the reading app that's comes with the Poke 2 that you feel the need to use KOReader instead?

Do you really need to spam every thread with unrelated questions that don't really matter?

Do you really need to do it in a subforum of a software you never tried?

Please stop. If you want to ask questions about the stock reader of Onyx devices then go to its subforum.

[elchamaco]

Originally Posted by Frenzie

Parts of it would be theoretically quite simple, such as writing whatever you want as the screensaver to a file. But as @pazos said it's not quite clear to me if this isn't too low-level and device specific in a way that would require running the program as root. Please see https://github.com/koreader/koreader/issues/5732

I suppose it's not necesary, Calibre companion does and the device it's not rooted. You choose the destination folder and every time you select a book to read, it writes the cover to that directory and filename you choose.

[Frenzie]

PRs always welcome.

[Incanus]

Originally Posted by elchamaco

I suppose it's not necesary, Calibre companion does and the device it's not rooted. You choose the destination folder and every time you select a book to read, it writes the cover to that directory and filename you choose.

I open books from Calibre Companion on a Boyue Likebook Mars, using KOReader as my default reader. It does work and I know for a fact that my device is not rooted.

[pazos]

Originally Posted by Incanus

I open books from Calibre Companion on a Boyue Likebook Mars, using KOReader as my default reader. It does work and I know for a fact that my device is not rooted.

These are different things.

KOReader should be able to open books for all local content providers without making a hard copy, with the exception of Google Files and maybe others.

But KOReader cannot handle screensavers on android. Period. There's no api for this (except for setting a cover art if playing audio in the background).

What elchamaco said could work for Onyx, but certainly not for Tolinos without root. In the end these things are device specific and need to be contributed by users of a specific device.

[Winkelschraube]

Originally Posted by Winkelschraube

Ok the emulator is running.

But you're right, Android doesn't take a changing image file as screensaver.

OhOhoOhOho.... You can simply exchange the picture (at least with Poke2) for screensaver. It must only be in the folder "/Pictures". I found out that the pictures for screensavers are automatically moved to "/Pictures".

[Winkelschraube]

I take screenshots on my Kindle and Poke2 with press the bottom left and top right corner at the same time. This does not work in my emulator, because I only have one mouse. How do I set screenshot to "Tab Corner: Bottom right" I can't find the option in the menus anywhere.

[Ken Maltby]

Interesting, playing with my new Note 2, looking at this issue, I found a way to do this using the KOReader screensaving function and then going to where it was stored in the Note 2's "Storage" and long pressing on the file's entry. This gave me a box with an option to set as screensaver, for the Note 2. So you can't actually have KOReader manage the screensaving on this Android device, but you can have it provide the image file, that the OS can offer to make it one of the screensaving options.

One thing I would like though is for KOReader to allow for taking the screenshot when the selected image is shown at full screen.

Luck;
Ken

P.S.; Playing in KOReader's crop and zoom functions for the Reader (epub) on the cover page, I was able to take a screen shot that had the cover image fill most of the screen. This KOReader screen shot, mostly of the cover image, I then could make this one of the screensaver images, for the Note2.

[Winkelschraube]

Originally Posted by Ken Maltby

[...] but you can have it provide the image file, that the OS can offer to make it one of the screensaving options. [...]

Yes, that is the topic.


With your grade 2 (Android 9) is the screensaver option available? On my Poke 2 the screensaver option is not available in the KOReader menu. Neither on the APK of github nor on FDroid. I know the function from my Kindle.

Screenshot: Press and hold the title image and it zooms to full screen and then take a screenshot (tap left bottom and top right). I can also set the path to "/Pictures" and removed the date in "/frontend/ui/widget/screenshoter.lua" so that the file is always "/Pictures/SScover.png".

But I don't know the internal program structure well enough to do the following in an acceptable time: When loading a document, remember on which page to open, go to page 1 (title page), zoom in on the picture, take a screenshot (fixed filename, suppress message), jump to the target page. I would also need a new "class" screenshotcover to be able to take normal screenshots. And sure there is a way to do that invissible. That is more than very tricky for me.

I think it would be smart if KOReader had an adjustable action in the menu when loading documents. E.g. set a sleep timer or save the cover to a file.

[pazos]

Originally Posted by Winkelschraube

Yes, that is the topic.


With your grade 2 (Android 9) is the screensaver option available? On my Poke 2 the screensaver option is not available in the KOReader menu. Neither on the APK of github nor on FDroid. I know the function from my Kindle.

Screenshot: Press and hold the title image and it zooms to full screen and then take a screenshot (tap left bottom and top right). I can also set the path to "/Pictures" and removed the date in "/frontend/ui/widget/screenshoter.lua" so that the file is always "/Pictures/SScover.png".

But I don't know the internal program structure well enough to do the following in an acceptable time: When loading a document, remember on which page to open, go to page 1 (title page), zoom in on the picture, take a screenshot (fixed filename, suppress message), jump to the target page. I would also need a new "class" screenshotcover to be able to take normal screenshots. And sure there is a way to do that invissible. That is more than very tricky for me.

I think it would be smart if KOReader had an adjustable action in the menu when loading documents. E.g. set a sleep timer or save the cover to a file.

The screensaver is disabled on android. Because, again, we don't control power routines (like we do on Kobos, for instance).

What is possible is to add a hack to write a png image to a file when a new document is opened. I pointed to that above and suggested a implementation on the emulator because it is easier to debug than android.

In theory you can pretty much do what the screensaver does (ie: show a sleep cover with reading stats) but it will still be a hack (you need to generate the cover when the book is opened, not when the power button is pressed) so you won't see the last stats that happened on your last reading session.

Again, the feature: screensaver, on the platform: android, won't happen, because it is not possible at all!

And again, the feature: write the cover (or some random png) to a file each time a new book is opened, has two parts:

1. Each time a new document is opened emit a new event called `onNewDocument(path/to/document)`
2. Write a plugin that catches onNewDocument and extracts the cover (or fallbacks to another image if the document lacks a cover)

These two things are generic enough and easy to implement. Which is hard is make everything configurable in a way that works for different devices (where to store the png?, which format?) and make the plugin no-op for platforms with a working screensaver implementation.

Anyways: patches welcome, but keep in mind that workaround for self is way easier than writting a plugin that works for everybody

[Ken Maltby]

Ok, first Pazos is the go to guy for the Android implementation. I can only describe how things work with the device and software I am using. I use the following to have a cover page from a book in KOReader as one of the three screensaver options that are available in the Note2 user interface (UI).

First: To get the image, in KOReader running on the Note2, I do a diagonal swipe from the bottom left corner to the top right corner of the book's cover page (ignore the size of the image, for now). This gives me the box that lists where the image file is stored, note that. It also offers to set it as a screensaver (this will not work on android devices) so I select No.

The rest of the process is done using the Note2 system, so I exit KOReader.

Now I go to Storage and to the location where KOReader stored the the screen capture.
Long pressing on that file gives me a file description and the option to set that image as one of the screensaver options. If the image is not the size you want, tap on the image file, to have it display, then you can access the crop and zoom settings.

Luck;
Ken

[Winkelschraube]

Hi pazos, thanks again for your answer. Currently this is too much for me. But I will keep it in mind.

The book cover (screenshot) as background image works at my place.

[pazos]

@Winkelschraube @Ken Maltby: if there's a way to set the screensaver as a single image (in /pictures or any dir inside /storage/emulated/0) I can provide a sample to overwrite that image with each new book cover. I just need the name of the picture, with extension, and the path where it needs to be stored.

[Winkelschraube]

Wow pazos, that would be awesome. I thank you already. With my Poke 2 the folder "/Pictures" and the file is best "bookcover.png". So together "/Pictures/bookcover.png".

I will certainly take a look at it and learn something from it to understand how it works and to be able to make future adjustments myself.