Asked for: dragging a signal onto a plot must still work in the compact (view) list. It does — the drag
source is on the *row* and was never conditional on the lock — but nothing said so, and "the lock rebuilds
this list and drops three of its controls" is exactly the change that could take the drag with it. Now it
is a reading: **`drag_sources` must be `rows - 1`**, one per signal row, the `MATH` divider not being
draggable.
signals panel: … rows=3 signals=2 math=0 divider=1 drag_sources=2 (locked)
signals panel: … rows=5 signals=4 math=0 divider=1 drag_sources=4 (configuration mode)
Measured the direct way first, with a throwaway walk of the list's rows and
`gtk_widget_observe_controllers()`: `locked=1 rows=3 rows_with_a_drag_source=2`, the third row being the
divider. That is where the number in the reading comes from, and the walk is what found the shape of the
answer rather than assuming it.
One consequence worth recording, because it is an improvement rather than a cost: a locked row can be
dragged from *anywhere* on it, the colour chip included. In configuration mode the chip carries a click
gesture that claims the event sequence precisely so a drag cannot start there (it opens the colour
chooser); the locked list does not build that gesture, so the chip is inert and the row's drag source
sees the press.
What the lock does *not* change is which signals are listed: only the ones that are on. A signal nobody
acquires draws nothing on a plot, so a row for it would be a drag that ends in an empty slot.
Verified: both lines above, from sessions differing only in whether one exists; `make test-ui` 14 files;
zero `Gtk-CRITICAL`. Docs: the `drag_sources` field with what a `0` would mean, the invariants' lock
bullet, and the README's note.
Two panes, two modes. **Locked** is what a returning user gets: the trigger pane shows one line saying
what it is set to, the signal list shows only the signals that are on, and neither offers a control that
changes the configuration — each heading has an `[edit]` button (the Adwaita `emblem-system-symbolic`,
swapping to `emblem-ok-symbolic` in configuration mode) that flips its pane. A **first run** — no session
file for that source — never reaches `apply_layout()` and comes up in configuration mode, because
configuring the host is what a first run is for. The mode is a mode and not a setting, so it is
deliberately not persisted.
The locked signal list drops the rows of every signal that is off, which is the whole of "show active
signals": the list already filters on nothing, so the lock is one `continue`. With the rows go the acquire
tick, the overflow menu (Information, Calibrate…, Delete, rename) and the `MATH` divider's `+` — and the
colour chip stops being clickable, because choosing a colour is configuration too. Dragging a signal onto
a plot stays: that is which view shows what, not what the scope is set up to do.
**The trigger is persisted, settings and state both** — the settings *even while it is off*, which is the
point: a trigger configured once and switched off is still the trigger you come back to. `LayoutState`
gains fifteen flat `trigger_*` keys; the channel is stored by *name* (every rebuild renumbers the
channels, the model's own rule) and the two enumerations as **the words the panel's dropdowns show**,
because an index ties the file to a declaration order — the lesson `math_op_at()` already carries. The
words are shared with the panel now (`trigger_type_text()` and friends build the dropdown arrays), so the
two cannot drift.
Two ordering traps, both found by running it:
- **The channel name resolves twice over.** `rebuild_trigger_signals()` picks up
`App::pending_trigger_channel` when the stream arrives *after* the load, and `apply_trigger_layout()`
resolves it itself when the channels are already there — without the second path the name stayed
pending past the one rebuild that would have used it, and the trigger silently sat on channel 0
(`summary='pulse width · sine …'` where the session said `square`).
- **The trigger's state is applied by pressing the control, not by setting a flag**: the toggle is set
*outside* the `updating_panels` window `apply_layout()` uses, because a toggle set inside it emits
`toggled` into a handler that returns at once and nothing would happen — no arming, no events button,
no sensitivity.
Verified, in both modes and both directions:
panes: trigger=locked signals=locked body_visible=0 summary='window · square · 0.3…0.6 · 20 % pre'
panes: trigger=config signals=config body_visible=1 summary=''
signals panel: labels=2 list=1 rows=7 signals=2 math=4 divider=1
The locked trigger pane is 42 px tall against 580 unlocked. A hand-written session round-trips: every
value it named came back in the panel's own controls, `trigger=1/1` (the state arrived and the pane's
switch followed it), and the file the app wrote back carried all fifteen keys with the untouched ones at
their defaults. `[side-tab-probe] … advanced=4` on its documented recipe; `make test-ui` 14 files; zero
`Gtk-CRITICAL` and no missing icon.
Docs: the `panes:` reading with what each field means, the corrected `labels=` note (the panel's frame is
counted above the list now, because the heading sits in a heading row), the invariants for both the
persistence and the lock, the README's deviation note, and the removal of its claim that the trigger has
never been persisted — it is now, and the locked view is built from exactly that.
README gains the three controls where each lives -- the trigger's `band`/`reject`, the
measurement's `noise`/`hf`, and the math channel's `de-noise` node -- each with its unit, what
"off" is, and what it costs, plus the two deliberate deviations from the design spec next to the
features they belong to: the band applies to `edge` and `window` only (a pulse's width is measured
from a crossing to its return, so a band there changes the measured width rather than rejecting
noise; a dropout is an absence with no level to compare), and the band is verified through
`BufferSearch` hit counts rather than `[condition-probe]` latch times, because probe-readings.md
states that a `t0` is not an assertion.
The invariant docs gain the rules a later change must not break: `EventCondition`'s two new fields
and the once-per-packet `configure(dt)` that must not reset; the crossing rule that a change is
between two *decided* sides; the measurement path's exception to "a readout quotes a stored
sample", why the band moves the edge decision only, why `measure_accumulate` loops samples outer,
and why a filtered window disables both bucket fast paths; that `MathOp` is append-only (the index
*is* the serialisation), that the median window is pooled in the runtime rather than held per node,
why the pole reuses `b0`/`z1`, and that median-then-pole is the design; the session's named
`noise`/`hf` keys and its thirteen-field node string that still reads twelve; and the two GTK
traps -- positionally brace-initialised dialogs, and a control that cannot apply being hidden
rather than disabled.
- 08-trigger.txt: names all four condition shapes and the buffer search; fixes the first
paragraph and 'How to reach it' to match what the panel actually contains (fix 3).
- 10-measurements.txt: adds a Statistics bullet — one observation per recompute, what
resets the history, what does not (fix 3).
- probe-readings.md: re-quotes condition-probe lines with level2= and mode= fields;
corrects leg-2 window geometry (0.2 s / 10 % pre, not 1.0 s / 50 %); moves the
wide-window reason to legs 1 and 3; fixes the search-probe scheduling note
(search_probe calls condition_probe directly; do not also set CONDITION_MS) (fix 6).
- verification.md: corrects shape-2 window geometry to match the code (fix 7).
- invariants-session-and-export.md, README.md: document the measure_stats session key —
position, type, default false (fix 8).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Clicking the coloured chip in the signal list opens a GtkColorDialog and the
colour it returns overrides that signal's palette entry. Held by name, like
every other identity here, and persisted as a session `[[color]]` table.
RowSet::signal_color() becomes the one resolver: install() builds the trace
through it and all three chip sites read it, because a chip exists to say which
trace a row is about and an override is exactly the state in which two routes to
a colour would disagree. A grey chip names no trace and so is not clickable, and
the way back is `Default colour` in the signal's menu -- a setting with no undo
is a trap.
The gesture sits on the existing label rather than in a GtkButton: padding on
this row is what made the signal list twice as tall once. It claims its sequence
so a click on the chip cannot become the start of a row drag.
UDPSCOPE_PROBE_COLOR_MS reads the result out of plot::Plot::trace() and out of
the chip's own markup, with an override in no palette slot, so neither leg can
pass by asking the resolver what it already said.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The file was 1967 lines and is auto-loaded into every context, so every
session paid for the whole of it to reach one invariant. It now carries the
project's goal, the three facts that are always relevant, and a table of
contents; the body is fourteen files under docs/claude/ reached by link
rather than by import, so nothing is loaded until it is asked for.
The content is moved verbatim -- the only edits are each file's own header
and the cross-references that became cross-file ("see the invariant below"
is now a link to the file that owns it).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Martino Ferrari