Feature request: reader support for 2-column documents

Ookimi

Sometimes pdfs have large pages with columns, tough to read on a small screen area (such as the ipad mini, or the laptop screen if you have to sacrifice a part of it to another app). It would be awesome if zotero reader could auto-split the view and treat the columns as pages, auto-fitted to the screen width. E.g. the built-in reader in onyx boox readers does this, given a 2-column page:

c1 c3
c2 c4

The user can choose to auto-split the content with 2 layout options:

c1 | c3
- - - -
c2 | c4

or

c1 | c3
c2 | c4

The former is useful for A4-size 2-column articles, and the latter - for spreads of scanned books that haven't been split into pages.

Either way the user is now able to comfortably scroll through the columns of the original document as if they were pages, even on smaller screens.

An option to autocrop horizontal margins on regular documents would also be cool, in addition to the existing "zoom to page width".

LiborA

pdf.js which is used in Zotero does not have this function. I reality, I did not see this function in any PDF reader.

Ookimi

It's indeed infrequent in desktop readers, but not unheard-of on mobile ones. On Android, I saw the column splitting functionality in Onyx Boox reader and KOReader. Auto-cropping margins is more frequent, e.g. in the Xodo pdf reader (even on desktop).

This would be a significant quality-of-life improvement for people with the smaller iPads and smaller Windows tablets like Surface Go.

LiborA

How I wrote above, Zotero uses pdf.js for the rendering of PDF files. pdf.js is developed outside the Zotero team. This function is not be implemented in the pdf.js; therefore, it cannot be available in Zotero.