New package image-roll (continuous-scroll)

[dalanicolai]

I would like to notify you about my new package image-roll. I have also added support to pdf-tools in the pdf-roll branch of my pdf-tools fork.

There is a small remaining issue in the image-roll package, so I am waiting for an answer from the Emacs developers. As soon as the issue gets fixed I will be happy to create a PR here, or if you like I could do it already, whatever you prefer. Anyway, you can try the package with pdf-tools already if you like.

[vedang]

This is great! Once the issue you've raised is fixed, please create a PR here. This will also give me some time to deal with all the existing PRs that have piled up.

[vedang]

I've added a pending changes label here in order to remind myself that I'm waiting for something -- in this case for the issue you have linked to be fixed. I know that this is not related to any changes I've asked you to make. (Adding this note just to clarify the point)

[dalanicolai]

That 'main' issue has been fixed, but some minor issues remain. Although image-roll itself seems to work mostly fine, it is not straightforward to add support for all pdf-tools features (the issues are mostly related to 'redisplay', see e.g. dalanicolai/image-roll.el#4).

So for that reason, I am not sure if the modifications in my pdf-toll branch should already get merged into the master branch of pdf-tools.

Additionally, finishing/preparing image-roll.el for publishing takes time also, and I think I will not have the time for a while (this does not have my priority). So we can not yet, in a clean way, install image-roll with pdf-tools, but users would have to obtain it from my github repo. This makes it also easier to inform users about the importance of donations, because I am not in the privileged position to be able to donate days/weeks of work for free (well, I would donate it for free also, but, in my position, I think it is fair to ask for donations).

Anyway, if you think that the current support in the 'pdf-roll' branch is already 'good enough', I would be happy to create a PR. And otherwise, we'll just wait a bit until at some point, the pdf support is good enough, and image-roll has been published somewhere.

[gsingh93]

@dalanicolai and @vedang I would love for this to get merged into pdf-tools, what are your thoughts about this plan:

• Cleanup pdf-roll branch to get it in a mergeable state (i.e. converting TODOs to GH issues) and submit a PR with the changes
• The continuous scrolling can be off by default, and enabled with some configuration option that makes it clear the feature is experimental (i.e. pdf-tools-enable-experimental-continous-scroll)
• Until image-roll is published in a way where it can be added directly as a dependency, we could either 1) display a message that they need to install image-roll from the GH repo or 2) include image-roll as a submodule of this repository.

The benefits of this would be:

1. The continuous scrolling functionality is in the main repo and users don't need to clone a fork to use it (and you don't need to continuously rebase and deal with merge conflicts).
2. We can track the remaining work to get continuous scroll out of experimental mode in one place through GH issues on a single repo
3. More users will likely find it and be interested in testing the experimental option, giving feedback, reporting bugs, and potentially donating to help the project, which will all help get this feature completed faster.

This is just a suggestion, let me know if you have any thoughts.

[vedang]

I'd be happy to review a PR which adds all of this work to pdf-tools. The plan sounds good to me.

[dalanicolai]

@gsingh93 Thank you very much for the interest in the pdf-roll branch. Unfortunately, I have no time to work on this package. Also, I have been working on an improved version of image-roll here in doc-scroll.el (it can be made to work with pdf-tools in a similar way as image-roll). @aikrahguzar has recently been doing quite a lot of work on this package/branch here. I have notified him about your request.

ps. @gsingh93 Thanks a lot for your donation also

[aikrahguzar]

I will like to get this functionality merged into pdf-tools. When I initially tried @dalanicolai's work, I was trying the keyboard navigation implemented by https://github.com/orgtre/pdf-tools so I just rebased on top of it which in hindsight was a bad decision. So my fork which can be found at https://github.com/aikrahguzar/pdf-tools/tree/continuous-scroll isn't in a suitable state for merging into pdf-tools directly. I will try to wrangle with git (my understanding of git almost non-existent) to get it into a suitable state which might take time especially since I am traveling around most of this month.

Other than that it is usable with my fork of image-roll. So @gsingh93 if you want try it out.

@dalanicolai, since you are not planning on maintaining image-roll any more maybe the best option is to add the library to pdf-tools itself? It is not very big and although it can be used displaying images more generally, my own motivation doesn't go beyond pdf-tools.

One wrinkle I am not sure how to deal with: pdf-links caches pages with link-hints drawn on them. This work when there is only a single page on display. But with multiple pages on display the labels depend on relative position of the pages. My solution has been to simply remove caching but that might be slow on older machines.