ShrinkVertically -- keep the board horizontal scrollbar visible

A small Kanboard plugin focused on getting around the board horizontally. It fixes the vertically-collapsed board view so the bottom scrollbar stays on screen, can optionally add a second mirrored scrollbar above the columns, and can optionally let you drag the board background to scroll (like Trello). Everything is configurable under "Settings -> Shrink Vertically".

The problem

Kanboard's board gear menu has an "expand vertically / collapse vertically" toggle. When collapsed, each column gets a limited height so the horizontal scrollbar sits closer. Core implements this with a single rule:

.board-task-list-compact { max-height: 90vh; }

That 90vh is measured from the top of the viewport and does not account for the page header above the board. So even when collapsed, the column plus the header together exceed the viewport height and the horizontal scrollbar is pushed below the fold.

The fix

This plugin injects one CSS rule (via the template:layout:css hook) that replaces the proportional 90vh with a fixed-pixel budget for the chrome above and below the task list:

#board td .board-task-list.board-task-list-compact {
    max-height: calc(100vh - var(--sv-shrink-offset, 240px)) !important;
    min-height: 0 !important;
}

The offset reserves room for the page header, the board column header, the horizontal scrollbar, and a little breathing space. A fixed-pixel budget is more reliable than a proportional value because that chrome is a fixed height regardless of screen size. It defaults to 240px and is configurable (see Settings below).

The min-height: 0 is essential: Kanboard's drag-and-drop sets an inline min-height on each column equal to its full content height, and in CSS min-height beats max-height, so without this reset the tall columns would never shrink.

The override only applies while columns are collapsed (when core adds the board-task-list-compact class). It changes no data and runs no database migration.

Menu labels

So it is obvious the collapsed behaviour comes from this plugin and not from core, a small script (via template:layout:js) appends a + to the two gear-menu items, so they read "Collapse vertically+" and "Expand vertically+". It only edits the rendered link text, so it works in any locale.

Requirements

• Kanboard >= 1.2.0

Installation

Copy this folder into your Kanboard installation as plugins/ShrinkVertically/. The directory name must be exactly ShrinkVertically (Kanboard derives the plugin namespace from the folder name). Reload the board; no build step, no configuration.

Top horizontal scrollbar (optional)

Kanboard's board scrolls horizontally inside #board-container, so its only horizontal scrollbar is at the very bottom of the board -- on a wide board you must scroll all the way down to move sideways. Enable "Add a top horizontal scrollbar" in the settings to get a second, mirrored scrollbar just above the columns. A small script (Asset/js/top-scrollbar.js, loaded only when the option is on) inserts a dummy scroll strip above #board-container and keeps its scroll position in sync with the board both ways.

Drag to scroll on Desktop (optional)

Kanboard has no way to pan the board by grabbing it; you must use the scrollbar. Enable "Drag the board background to scroll" to click and drag on the empty board background to scroll the columns sideways, like the Trello board canvas. A small script (Asset/js/drag-scroll.js, loaded only when the option is on) starts a horizontal pan on #board-container only when the press lands on empty background -- pressing a task card, a drag handle or any control is ignored, so Kanboard's own card and column drag-and-drop keep working unchanged.

Settings

These settings are global (per Kanboard instance) and admin-only. Go to "Settings -> Shrink Vertically":

• Vertical offset in pixels -- pixels reserved around the collapsed columns. Injected in the page head as the --sv-shrink-offset CSS variable. Increase it if the scrollbar is still clipped (for example with a taller theme header); decrease it to make the collapsed columns taller. Default: 240.
• Scrollbar thickness and column gap in pixels -- a single value that sets both the thickness of the top scrollbar (Chromium/WebKit only) and the width of the column gap. Injected as the --sv-bar-size CSS variable. Default: 25.
• Add a top horizontal scrollbar to the board -- toggles the mirrored top scrollbar described above. Default: on.
• Widen the gap between columns -- toggles the wider gap between board columns (sized by the value above). Also adds some spacing at the left and right edges of the board. Default: on.
• Drag the board background to scroll horizontally -- toggles the Trello-style click-and-drag panning described above. Default: on.

License

AGPL-3.0. See LICENSE.