In long-form reading, park actions at the edge or on a scroll-triggered bar

What it is

A three-thousand-word column still needs type size, contents, share. Leave them as a permanent tab bar or in-paragraph buttons and the reading column is occupied for the duration. Park them on the left or right edge, or on a bar that appears on a scroll (or a tap), and the column is empty while reading; the tools return in a beat or two when a hand is needed. Reading chrome on demand is where those actions live after they have been asked to leave the column.

Safari Reader showing tools on a tap, Kindle showing progress on a tap, reading apps that put contents on a left-edge hot zone — those addresses.

Why it happens

The main task of long-form lasts minutes; the actions are occasional. Always-on chrome levies an occupancy tax by the minute; on-demand chrome charges per use. The trigger to appear has to be cheap — tap empty space, a light reverse scroll, a swipe from the edge — or “parked” becomes “cannot find”. An edge occludes a line less than a top or bottom bar, because reading saccades travel the midline of the column; even a short top or bottom bar rewrites the fold and the first and last lines.

Scroll triggers have a direction. Hide on scroll-down, show on scroll-up, summons the chrome with a movement that already means “I might want a tool”, and occludes the line being read less than a bar that appears while still scrolling down.

Where it stops holding

Short items (a microblog, a notification) do not last long-form minutes; a resident tab bar is often cheaper, and on-demand adds a summon. Tool-like reading (annotating a paper as you go) has a high action rate; the chrome should be easier to keep, not put away to a novel’s standard. Screen-reader users cannot summon a “tap to appear” visual bar; the actions have to live in a reachable toolbar or rotor. In child or motion contexts, “tap empty to summon” collides with paging; an edge zone or an explicit button is more stable.

Applying it

• Type size, contents, share, night mode in long-form live on a tap-summoned or scroll-up bar. The default reading state does not occupy the text column.
• Contents may be a left-edge swipe, but the hot zone must not be wide enough to graze during ordinary paging.
• When the bar appears, do not cover the current line. Prefer a slide from top or bottom, and yield after a few seconds of no use.
• How to check: read for three minutes without touching tools. No action control should enter the text column in those minutes. Then count steps from “currently reading” to “share done”; more than two beats (summon, tap share) means parking went too far.

Related

• Same group: F1.13.1 The reading region must stay stable, not interrupted by floating controls · F1.13.2 Buttons mixed into the reading flow cause misses and visual noise · F1.13.4 Separation is not absolute; inline actions such as text selection need an exception
• Nearby: F1.04 Thumb zone and primary-action placement · E5.01 Top navigation bars
• Search terms: reading chrome on demand · scroll-triggered toolbar · reader mode