[Android] Support S Pen's eraser feature.

atnoir · December 28, 2023

S Pen has a built-in feature that by long pressing the side button it becomes an eraser to remove handwritings. Please support this feature in Zotero Android as well. If possible, I hope it also supports air actions to flip pages or other quick actions.

Thank you very much in advance.

atnoir · December 30, 2023

Will this be considered? Thanks.

edit: thanks for adding this request to the GitHub project. as far as I've known, Samsung's S Pen is a bit special and seems to be the easiest one but considering many drawing/note-taking apps have implemented this feature for various styli by providing front button/back button customization ('cause some styli have two side buttons), this may be a clue/reference for Zotero android to work with kinds of styli.

DimaP · 2026-01-21T01:43:18+00:00

Nutrient, the PDF library we use for our PDF reader stated in it's recent changelogs that it now supports pen's eraser function:
Adds the ability to trigger the annotation eraser tool using the stylus button. (J#ANDR-1481)

Can you please try the 1.0.0-226, once it's available and see if it's really the case?

atnoir · 2026-01-21T02:40:29+00:00

Thanks for the heads-up. The Play Store beta is still on version 225, so I sideloaded the latest nightly (v226). However, it installed as 'Zotero Debug,' which watermarks all PDF pages with 'for evaluation purposes only.' This is blocking me from testing the eraser feature since annotations are somehow disabled.
@DimaP

atnoir · 2026-01-21T05:30:24+00:00

@DimaP
Hi, Play Store just dropped v226 but unfortunately all stlyus input now stops working (all functions circled out in the screenshot just don't react at all for stylus input or finger input). It looks like the same problem as the one I met in the previous nightly build v226.
https://s3.amazonaws.com/zotero.org/images/forums/u10781283/4zrceh19qk4ju3qnmg22.jpg

DimaP · 2026-01-22T00:42:00+00:00

Can you please reproduce it on some publicly available PDF, like one from arXiv.org and share the name of the paper? Please do this test by actually adding a fresh new PDF to your library.
Does it happen for PDFs where you have lots of annotations? Or even for PDFs with just a few? Or even for ones where there are none?

atnoir · 2026-01-22T05:29:22+00:00

Hi, I can confirm that the error also persists on newly added public pdf from arXiv (example link: https://arxiv.org/abs/2601.15289) [Tracing the Galactic Disk with Gaia DR3: A Deep Study of Berkeley 17, 18, and 39 Open Star Clusters]. And the error happens regardless of the amount of annotations (none, a few or lots of). For clarification, the pdf viewer in v226 with annotation toolbar enabled fails to react to any stylus input and finger input, whatever features from the toolbar are toggled on. Thanks for your patience. Let me know if you need anything else for debugging. @DimaP

atnoir · 2026-01-24T07:37:35+00:00

@DimaP Play Store just dropped v227, which has resolved the previous annotation issue but unfortunately, the eraser feature can't be triggered by samsung s pen's stylus side button (either by long-pressing or single-clciking it). Thanks.