"What can I do with these twelve photographs?" was answered in two
places. Six buttons in the header — Add to collection, Keywords,
Presets, Paste to N, Export N, Remove from collection — and four more
on the floating bar at the foot of the grid, beside the count that
says what they would act on.
The header half was the worse of the two. Those six appeared and
disappeared from the middle of the row as photographs were picked, so
Sync, Settings and everything beside them slid several hundred pixels
sideways at the exact moment a hand was already travelling toward one.
On a tablet the header scrolls sideways, so they were often not on
screen at all.
All six move to the bar. It now reads left to right as shaping the
selection — Clear, Select all, Select to… — then acting on it, with a
gap between the two thoughts. The header keeps only what belongs to
the library, and changes only when the library does.
Two consequences worth stating. The bar holds ten controls in the
worst case, so it scrolls sideways like every other row in this view,
for the reason set out on the header's Flickable: a layout given less
width than its children need overruns rather than shrinking, and the
buttons past the edge are simply gone. And the bar now stays up for a
running export whatever the selection has since become, because Cancel
export lived on a button that used to have its own `|| exporting`
escape hatch — the grid's viewport inset follows the same condition so
the last row of thumbnails is never trapped underneath.
`settings-summary` went with them: threaded from the window into the
grid and into HeaderActions, and never once drawn.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Selecting the first photograph inserted a 40px row into the view's
vertical flow, so every cell in the grid moved down by it. The act of
selecting shifted the thing being selected out from under the finger —
and a second tap aimed at the neighbour landed on the row below it,
which is the worst possible response to a gesture whose whole job is to
say "this one".
The bar is a floating one now, at the foot of the view. Nothing above it
is re-laid out, so selecting changes what is drawn and never where.
The grid's viewport grows by the same 40px while the bar is there rather
than the Flickable shrinking, which is what keeps that change invisible
too: every cell stays exactly where it was and there is simply further to
scroll, so the last row can be brought clear of the bar instead of being
trapped under it.
It also swallows presses that land on it. A bar floating over the grid is
a bar a thumb can reach for and miss into.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Three holes, all found by the gate catching itself out.
**Prose that mentions the tag was read as a tag.** `dr-ui`'s module list
carries a comment saying where the generated table comes from, and it
names `GESTURE:` in passing; the scan extracted that sentence fragment as
a gesture with no place and no way to perform it. A tag must now *open*
its comment. A line that merely mentions it is describing the mechanism,
not declaring a member of it, and position is the only thing that tells
the two apart — which also makes the string-literal guard fall out for
free rather than being a special case.
**Neither artefact was regenerated on commit.** They cite line numbers,
so they go stale on anything that moves a line — the sheet commit made
the document wrong about every gesture in `library.slint` without
touching a single one. The pre-commit hook that already keeps the matrix
in step now keeps these too, and unlike the matrix it *fails* rather than
shrugging when the scan does: a matrix that will not build leaves a stale
one in place, where a malformed gesture block means a user about to be
told the wrong thing.
**CI did not check them at all.** It does now, blocking. The matrix is
read; the gesture table is *shown to somebody using the application*, and
a stale one tells them to perform a gesture that no longer exists — from
which they will conclude the application is broken rather than the page.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Every gesture the application has was documented in the comment beside
the `TouchArea` that implements it. Excellent comments, and unreachable
by anyone not reading the source — which is the FR-UI-4 failure in a
different costume: a gesture nobody can find is a feature only its author
knows about.
Writing them out again in a hand-kept help page is the failure this
avoids. Two descriptions of one gesture drift, and it is always the prose
that drifts: the code is exercised every time somebody uses the
application and the page is exercised never. A help screen confidently
describing a double tap the grid stopped honouring last week is worse
than no help screen — and the grid did stop honouring one, in the commit
before this.
So the comment beside the implementation stays the only copy, and a
`GESTURE:` block beside it is scanned into two artefacts: `docs/gestures.md`
for a reader, and a Rust table for the application to draw a help sheet
from. Both committed, both gated, so neither can quietly stop describing
the code.
It lives in the traceability crate because it is the same operation on
the same input — walk the tree, pull structured tags out of comments,
render, fail if the committed artefact has moved. Only the vocabulary is
new. It scans `ui` and `apps` alone: a gesture needs an interface to be
performed on, and excluding `tools` is also what stops the scanner
extracting its own worked examples as broken gestures.
Fifteen gestures so far, across the library grid and the People screen.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
dtourolleandClaude Opus 5