hairline

A KOReader plugin that reshapes the reader's bottom progress bar into a minimal, full-width strip:

• Stick the bar to the bottom screen edge — eliminates the gap caused by the footer container's bottom padding and by the vertical centering inside the footer (the latter is what makes "Bottom margin: 0" alone insufficient when the bar is in alongside position).
• Render the unread side fully transparent — instead of painting a rectangle that competes with the page background (or shows as a visible outline in night/sepia mode), only the read portion, chapter tick marks, and the initial-position marker are drawn. The right side of the bar shows the page underneath it.
• Adjustable bar height — quick spinner for 1–30 px, separate from KOReader's deeper Sizes and margins submenu.

All three options live in Status bar settings → Hairline. Settings persist in settings/hairline.lua next to your KOReader config.

Origins

Inspired by the Crosspoint firmware mode for the xteink 4 e-reader, which renders its progress bar as a thin, flush-bottom strip — a clean look this plugin tries to reproduce on stock KOReader.

This plugin was 100 % vibecoded: every line was drafted by an LLM (Claude Opus) in conversation with the maintainer, then read, tested, and shipped as-is. No manual translation or rewriting between drafts. It will show.

Install

This repository is the plugin directory — clone it directly into your KOReader plugins folder under the name hairline.koplugin:

git clone https://github.com/sypianski/hairline.koplugin \
    ~/.config/koreader/plugins/hairline.koplugin

Platform	Plugins folder
Linux (native)	~/.config/koreader/plugins/
Kobo / Kindle / PocketBook	koreader/plugins/ on the device
Android	koreader/plugins/ in KOReader's storage folder

Then restart KOReader. The new entry appears under Tap centre top of screen → Settings → Status bar → Hairline.

How it works

The plugin monkey-patches three methods on apps/reader/modules/readerfooter.lua at load time:

• updateFooterContainer — forces self.bottom_padding = 0 before the container is rebuilt, then sets horizontal_group.align = "bottom" on the freshly created group so the progress bar drops to the bottom of its row instead of being vertically centred.
• init — re-applies the above plus the transparent paintTo on the progress bar instance for fresh book opens.
• addToMainMenu — injects our submenu into the existing menu_items.status_bar.sub_item_table, so the options appear inside the Status bar settings group rather than under Tools → More tools.

The transparent rendering is an instance-level override of ProgressWidget:paintTo (only on the footer's progress_bar, not on every progress widget in KOReader). It skips the background and border rectangles entirely; only the filled fraction, chapter ticks, and initial-position marker are painted. Chapter ticks remain drawn in the original bordercolor, so they stay visible on top of the page underneath.

The plugin does not permanently mutate the user's progress_style_thin/progress_bar_position settings. It only sets a few fields on the existing footer instance per refresh; toggling either feature off via the menu reverts the override on the next refresh.

Compatibility

Tested on KOReader 2026.03 on Linux (Wayland / labwc, Raspberry Pi). The plugin relies on ReaderFooter, ProgressWidget, and the HorizontalGroup align = "bottom" mode — all stable KOReader APIs.

Translations

User-facing strings use KOReader's central gettext domain (koreader.mo), which means: if a translation for the exact English msgid happens to exist upstream, you get it for free; otherwise the English source is shown. KOReader does not provide per-plugin translation catalogues, so adding more languages realistically means submitting the strings upstream once they stabilise. PRs welcome either way.

License

AGPL-3.0-or-later, same as KOReader. See LICENSE.

Tags

koreader · koreader-plugin · e-reader · e-ink · progress-bar · footer · status-bar · minimal-ui · xteink · crosspoint · lua · agpl-3.0