docs: events in the dock and on its page

The dock's Events block, the events slide-over page, the availability-rule deviation, the probe lines and the removal of the left pane are described; the false remembered-width claim is gone.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/claude/probe-readings.md

@@ -491,7 +491,7 @@ Two lines of the self-check output are assertions in disguise:
   column and says there is one scroller and no stack. These are captured on the tick or at the exit probe:
   the dump runs after the window is destroyed. A source with extra panels adds *no* dock section: its panels
   are slide-over pages (`source-<id>`), so the line reads the same on the E-1608 and the probe kind.
-- `[readouts] pages cursors=1 measure=1 dock_children=1 dock_w=280 pages_sensitive=1 signals=1` (in the exit
+- `[readouts] pages cursors=1 measure=1 dock_children=3 dock_w=280 pages_sensitive=1 signals=1` (in the exit
   dump; `dock_children` counts the direct children of the dock page) -- the two pages and the dock against the
   stream. **`cursors=1 measure=1`**: both slide-over pages are registered, always and from the start (not when
   the stream has signals); `0` is a page that was never added, and then the dock's Edit buttons and the `m` key
@@ -500,9 +500,10 @@ Two lines of the self-check output are assertions in disguise:
   `update_signal_availability()` writes them with the dock), so a run against a port with no sender reads
   `pages_sensitive=0 signals=0`, a normal run `pages_sensitive=1 signals=1`. `pages_sensitive=1` with `signals=0`
   is a page that can be opened and read with nothing to read; `pages_sensitive=0` with `signals=1` is a
-  stream whose pages never came back after the signal list arrived. **`dock_children=1`**: the dock
-  page holds the readouts box and nothing else (a second child is a section that crept back into the dock; 0 is a
-  dock that was built empty).
+  stream whose pages never came back after the signal list arrived. **`dock_children=3`**: the dock
+  page holds the readouts box, a separator and the Events block (`build_events_dock()`) and nothing else (a fourth
+  child is a section that crept back into the dock; 1 is a dock without its Events block, 0 a dock that was built
+  empty).
 - `help layer: contextual=on hints=12 ids={events plot status cursors measures trigger trigger_advanced events_record trigger_search signals signals_config window} icon=dialog-information-symbolic(ok) hint=12x12; tour=idle steps=6 step=0 auto=1 requested=0` (in the exit
   dump, beside `dock:`) — the help affordance layer as the last tick found it. **`hints=` must equal
   the number of ids**, and the ids are the surfaces the contextual help is on: eleven of the window
@@ -1601,24 +1602,33 @@ run they report:
 ## `[events]`
 
 ```
-[events] live, recording off: button_visible=0 pane=0 pane_w=0 tick=1 recording=0
-[events] recording on, no trigger: button_visible=1 pane=0 pane_w=0 tick=1 recording=1
-[events] after trigger on: button_visible=1 pane=0 pane_w=0 tick=1 recording=1
+[events] live, recording off: available=0 dock_sensitive=0 page_sensitive=0 page=none
+[events] recording on, no trigger: available=1 dock_sensitive=1 page_sensitive=1 page=none
+[events] after trigger on: available=1 dock_sensitive=1 page_sensitive=1 page=none
+[events] after events page opened: available=1 dock_sensitive=1 page_sensitive=1 page=events
+[events] open alone: page=events page_box=347
 [events] preview redrawn: signals=3 stored=480x132 row_drawn=1
-[events] dir=/home/u/.cache/udpscope/events/127.0.0.1-21023 n=3 newest: stem=20261013-184140-0003 dur=2.000000 pre=1.600000 post=0.400000 edge=5.660100 signals=3 samples=20001 rate=10000 seq=3 thumb_bytes=190134 recorded=1 pane=1
-[events] activated row0: replaying=1 pane=1 pane_w=240 pane_box=228 tick=0 window=2.000 axis=[-1.600,0.400] marker=0.000 thumbnail=1 thumb_size=138x46 thumb_visible=1 rows_kept=1 selected=2/2
+[events] dir=/home/u/.cache/udpscope/events/127.0.0.1-21023 n=3 newest: stem=20261013-184140-0003 dur=2.000000 pre=1.600000 post=0.400000 edge=5.660100 signals=3 samples=20001 rate=10000 seq=3 thumb_bytes=190134 recorded=1 page=1 plot_w_stable=1 plot_w=756/756
+[events] activated row0: replaying=1 page=events page_box=347 tick=0 window=2.000 axis=[-1.600,0.400] marker=0.000 thumbnail=1 thumb_size=138x46 thumb_visible=1 rows_kept=1 selected=2/2
+[events] dock events: rows=3 pane_rows=3 same_titles=1 sensitive=1 dock_w=268 on_screen=1 marked=0 members=0 max_ok=1 expected_marked=1 at=after pane replay
+[events] dock replay: clicked=1 replaying=1 waveform_changed=1
+[events] dock events: rows=3 pane_rows=3 same_titles=1 sensitive=1 dock_w=268 on_screen=1 marked=1 members=0 max_ok=1 expected_marked=1 at=after dock click
 [events] replayed: channels=3 samples=20001 replaying=1 waveform=1
 [events] live again: replaying=0 waveform=0
 [events] live restored (after replay): window=0.500000 (want 0.500000) trigger=1 (want 1) channel='square' (want 'square') level=0 (want 0) enabled=1 armed=1 pinned=0 held=0 mode=2 pending=0 gen=10/5
-[events] recording off, trigger off: button_visible=1 pane=1 pane_w=240 tick=1 recording=0
-[events] recording off, trigger on: button_visible=1 pane=1 pane_w=240 tick=1 recording=0
+[events] recording off, trigger off: available=1 dock_sensitive=1 page_sensitive=1 page=events
+[events] recording off, trigger on: available=1 dock_sensitive=1 page_sensitive=1 page=events
 [events] compare buttons: cached=2 selected=2 compare=1 accumulate=1
-[events] compare: kind=1 rows=1 channels=8 samples0=32964 traces0=4 traces1=-1 window=2.000 recording=1 pane=1
+[events] dock events: rows=2 pane_rows=2 same_titles=1 sensitive=1 dock_w=268 on_screen=0 marked=-1 members=0 max_ok=1 expected_marked=-1 at=two events latched
+[events] compare: kind=1 rows=1 channels=8 samples0=32964 traces0=4 traces1=-1 window=2.000 recording=1 page=events
+[events] dock events: rows=2 pane_rows=2 same_titles=1 sensitive=1 dock_w=268 on_screen=0 marked=-1 members=2 max_ok=1 expected_marked=-1 at=comparison up
 [events] compare plots: area_b=1 rows_a=1 rows_b=1 list=4 x_a=[-2.000,0.000] x_b=[-2.000,0.000] same_x=1
 [events] compare sync: y_a=-3.500 y_b=-3.500 mirrored=1
 [events] accumulate: kind=2 rows=1 channels=8 samples0=32964 selected=2 traces0=8 window=2.000
 [events] group left: replaying=0 kind=0 waveform=0
 [events] live restored (after a group): window=0.500000 (want 0.500000) trigger=1 (want 1) channel='square' (want 'square') level=0 (want 0) enabled=1 armed=1 pinned=0 held=0 mode=2 pending=0 gen=22/16
+[events] dock replay: clicked=1 replaying=1 (second click, live before)
+[events] dock events: rows=2 pane_rows=2 same_titles=1 sensitive=1 dock_w=268 on_screen=1 marked=1 members=0 max_ok=1 expected_marked=1 at=second dock click
 ```
 
 `thumb_size` is the built size of the row's picture: `kEventThumbW` wide, and as tall as the *stored*
@@ -1628,8 +1638,18 @@ reads `138x75`) as well as with the CSS border and the display's scale factor. W
 `0x0`, and a height pinned to the floor for *every* event says the aspect fit was dropped and tall
 previews are being squashed again.
 
+**The E-1608 never latches an event** (its stream carries no trigger edge to record): on `--source e1608` the probe reads
+`n=0`, the `recording on` lines read `1 1 1` (recording is on, so the block is available), and the two
+`recording off` lines read `available=0 dock_sensitive=0 page_sensitive=0 page=events` -- the page is open and
+greyed, the "disabled, not hidden" path -- while `activated row0:` reads `replaying=0 ... marker=-1000000000000.000
+thumbnail=0 rows_kept=0` and the `dock events:` / `dock replay:` lines read `rows=0`, `clicked=0 replaying=0`. The
+`page=` of the first availability lines is whichever `source-*` page the kind opened at start-up, not `none`.
+A UDPS run against a **fresh cache** reads the same `n=0` and `rows=0` on the opening `dir=` / `dock` lines (nothing
+has latched when they are printed) and fills in from the group leg on; a UDPS run with a populated cache is the one
+that proves `same_titles` and the dock click on real rows.
+
 `[events] preview redrawn:` is the repair path, and the probe forces it: step 1 deletes the newest
-`.bmp`, drops the thumbnail cache and refreshes the pane, so this line is `EventStore::redraw_preview()`
+`.bmp`, drops the thumbnail cache and refreshes the page's list, so this line is `EventStore::redraw_preview()`
 drawing the picture again from the `.npy`. `stored` is the file it wrote, read back out of the BMP
 header — `480` wide and `44 * signals` tall — and `row_drawn=1` says the row got a paintable from it.
 The probe therefore needs a cache a **previous** run populated: it fires ~4.5 s in, before this run's
@@ -1668,23 +1688,25 @@ session that then disagrees with it takes the pair apart.
 | `signals`, `samples` | the event's channels and rows | a table built from the *rows* instead of the snapshot: only what happened to be plotted |
 | `thumb_bytes` | a real 24-bit BMP, `54 + 480 * (44 * signals) * 3` rounded up per row to a multiple of four -- so it *grows with the signal count* (190134 at three signals, 380214 at six) | a preview that is empty or missing -- the widget snapshot of a `GtkGLArea`, which is NULL -- or a picture back on a fixed total height, which gave a six-signal event 26 px a signal and an eight-signal one 20: a smear, not a waveform |
 | `recorded` | 1 while the trigger panel's switch is on | the switch not wired, or recording defaulting off (it must be on: the cache is for the event you did not expect) |
-| `pane` | 1 once the history button has been clicked | the button's handler not revealing the pane |
-| `live` | `button_visible=0 pane=0** | a pane or a button on screen with no trigger mode: a column of nothing beside a live plot |
-| `after trigger on` | `button_visible=1 pane=0` | the pane revealed by trigger mode alone (it must be on demand from the toolbar button), or the button missing in trigger mode |
-| `recording off, trigger off` and `recording off, trigger on` | `button_visible=1 pane=1 recording=0` in both **once the cache holds anything** (the probe's own run does by this point) | the button going away with the switch when events are already written -- an event on disk outlives the switch that wrote it -- or `pane_w` not being 240 with the pane open. With an *empty* cache the same two lines read `button_visible=0 pane=0`, which is the empty column the item exists to prevent |
+| `page` (on the `dir=` line) | 1 once the `events` page is open (the probe opens it with `open_events_page()`) | a page that did not open, or one that opened before its list was refreshed |
+| `plot_w_stable`, `plot_w=a/b` | 1, with the plot area's width before and after the first latch equal and both > 0 (756/756 on the documented window) | events squeezing the plot again (the old pane did), or two unrealised `-1` widths read as equal (the probe requires > 0) |
+| `available`, `dock_sensitive`, `page_sensitive` (the lines headed `live, recording off`, `recording on, no trigger`, `after trigger on`, `after events page opened`, `recording off, trigger off/on`) | the three equal on every line, because both views follow `sync_events_availability()`: `0 0 0` live with recording off and an empty cache; `1 1 1` once recording is on, **and it stays `1 1 1` in trigger mode and with the page open** (a replay or a group leaves trigger mode, and a block that greyed itself under that click is the trap) | the dock block and the page disagreeing (one of the two not wired to the sync), or the block going `0` under trigger mode. After recording is switched off the lines read `1 1 1` **once the cache holds anything** (the probe's own run does by this point): an event on disk outlives the switch that wrote it. With an *empty* cache they read `0 0 0` -- insensitive, **never hidden** ("disable, do not hide") |
+| `page` (on the availability lines) | `none` until the probe opens the page, then `events` | the page not registered (`open_events_page()` returning false), or a page left open by an earlier leg |
+| `open alone` | `page=events page_box=` a width near the slide-over's (347 on the documented window) | the page's box measuring 0 (an unrevealed `GtkRevealer` as the content instead of `events_box`), or a page not opened at all |
+| `dock events` | `same_titles=1`, `rows` equal `pane_rows` (both capped at 24: `pane_rows` is cut to the dock's `kDockEventsMax`), `sensitive=1`, **`dock_w` below 280** (268: the block fits the fixed dock; more means a row that no longer ellipsizes), `max_ok=1` (dock children <= 24 + the "N more" row). `on_screen` counts filled markers: **1 after a replay, 0 while live or in a group**; `marked` is the index of the first filled row (-1 when none), `expected_marked=1` when the filled row is the replayed record's file (-1 where no replay is named); `members` counts hollow markers: **2 with a comparison up**, 0 otherwise. The `at=` text names the moment | `same_titles=0` is the two lists rebuilt from different data or one of them stale (the dock follows every latch, the page only while open or on Manage -- a latch landing between the page's refresh and the read can show `rows=9 pane_rows=8` once, which is a probe-time race, not a defect, if it does not persist); `on_screen` above 1 is two filled markers (`event_on_screen` not shared with the title); `members=0` in a comparison is the group not marking its members; `max_ok=0` is the cap lost |
+| `dock replay` | `clicked=1 replaying=1 waveform_changed=1`; the second line, from live, reads `clicked=1 replaying=1` | the dock row's click not reaching `replay_event()` (`clicked=0` with a non-empty list), or the click rebuilding the dock list under its own handler. With an empty cache (`rows=0`) it reads `clicked=0 replaying=0`, which is not a defect |
 | `thumbnail`, `thumb_size`, `thumb_visible` | 1, a non-zero size, and 1 | the picture loaded through `gtk_picture_set_filename()`, which fails silently (the paint-able is there, the allocation is there, nothing is drawn), or a `GtkPicture` given a size request and no cap -- its natural size is its content, so the row's text is squeezed off. `thumb_size` is the reading that catches both. It also catches the cache never being *created*: `event_preview_texture()` answers from the cache or not at all, so a reader that does not create one leaves **every** row blank, which is what `thumbnail=0` meant for as long as it read 0 |
 | `preview redrawn` | `stored=480x<44*signals>` and `row_drawn=1` | a preview that cannot be repaired. The `.npy` is the event and the `.bmp` is only a picture of it, so a write that failed, a truncated file or a cache from an older build must be redrawn rather than shown as a blank row -- `row_drawn=0` is a row the user reported as "sometimes missing" |
-| `axis`, `marker`, `pane_box` (in `activated row0`) | `[-pre, +post]` of the event just opened, `marker=0.000`, and a `pane_box` close to `pane_w` | an opened event framed on something other than its own pin; a trigger line left **parked** (a large negative) rather than on the edge, which is a file opened without its marker; or a pane whose *rendered* width is 0 while the divider says 240 -- the position is what was asked for, `pane_box` is what the pane actually got, and a divider at 240 with a zero-width pane is still no pane |
+| `axis`, `marker` (in `activated row0`) | `[-pre, +post]` of the event just opened, `marker=0.000` | an opened event framed on something other than its own pin; a trigger line left **parked** (a large negative) rather than on the edge, which is a file opened without its marker. `page=events` and `page_box` (the page's width, as in `open alone`) say the page is still up and has a width: a replay from the page must not close it |
 | `rows_kept`, `selected` (in `activated row0`) | `rows_kept=1` and `selected=N/N` -- the counts either side of the activation equal | the list **rebuilt** by the activation. It is the row *object* that is compared, not its index: a rebuilt list has a row 0 too, and only identity tells a list that was left alone from one that was torn down under the user's scroll position and their comparison selection. `mark_events_on_screen()` must rewrite the titles in place |
 | `replaying` (last line) | 0 | a replay with no way back: *Live* must start a fresh client and thread |
 | `window`, `trigger`, `channel`, `level` (in `live restored`) | each equal to its `(want …)` | the way back out of a file view discarding what the live view was set to. One wrong half names which writer won: a `window` that reads the **session file's** value is the deferred `apply_layout()` beating the restore; `trigger=0` is the toggle the file view switched off and nobody switched back; an empty or shifted `channel` is an index restored instead of a name, after a rebuild renumbered (or a group renamed) the channels; and a `level` that moved on its own is `rebuild_trigger_signals()` re-defaulting it because `trigger_level_touched` was not restored with the configuration |
 | `pending`, `gen` (in `live restored`) | `pending=0`, and the two generations different | the restore still waiting. It is gated on the stream's first CONFIG, so `pending=1` says the channel list the stored trigger name needs never arrived -- with `channels=0` behind it, a session file that enabled nothing |
 | `pinned`, `held`, `mode` (in `live restored`) | `pinned=0`, **or** `pinned=1` with `held=1` | a file's pin surviving the way back, which is a live view that cannot be navigated. `apply_time_window()` drops it; the second reading is the legitimate case -- a restored trigger that was *on* can latch again before the probe reads, and a held capture is pinned, correctly |
-| `pane_w` | the divider's position: 0 while the pane is closed, its remembered width (240 by default) while it is open | the pane reserving a column while closed (a paned hands its start child its minimum unless the position says otherwise), or a width that is not remembered |
 | `tick` | 1 in live mode, **0** once a file is on screen | the signal list still offering "acquire this signal" for samples that are already stored |
 | `window` (in `activated row0`) | the **event's** span -- the probe sets 0.5 s just before the click, so reading the event's span says opening it framed it | a replay that leaves the previous window alone, or one that restates it every frame instead of once |
 | `compare buttons` | `selected=2` and both buttons sensitive | the buttons reading something other than the selection, or staying insensitive with a valid pair selected |
-| `compare` | `kind=1 rows=1 channels=8 samples0=33045 traces0=4`, `pane=1` | `samples0` above the stamps pushed -- a live producer left running, pushing four stream signals into the group's eight channels; `rows=1` because the layout is the user's and must not be re-derived; `traces0=4` because the four slots the layout holds are renamed, not replaced |
+| `compare` | `kind=1 rows=1 channels=8 samples0=33045 traces0=4`, `page=events` | `samples0` above the stamps pushed -- a live producer left running, pushing four stream signals into the group's eight channels; `rows=1` because the layout is the user's and must not be re-derived; `traces0=4` because the four slots the layout holds are renamed, not replaced |
 | `compare plots` | `area_b=1 rows_a=1 rows_b=1 list=4 same_x=1` | no second plot on screen, a second plot with a different row count, two plots not on one x window, or `list` above the signal count -- the panel listing each event's copy of a signal as a signal of its own |
 | `compare sync` | `mirrored=1`, with `y_a` and `y_b` equal to the range the probe set on the first plot | the mirror not running, or running the wrong way: a y (or x span) change in one plot that the other never sees |
 | `accumulate` | `kind=2 rows=1 channels=8 samples0=33045 traces0=8 window=2.000` | the second event's layers not landing: `traces0` stays at the four signals the layout holds when the slots were not free, or the row named after a previous group's suffix so nothing binds |
@@ -2360,14 +2382,15 @@ is what the compact-row CSS rule is for.
 ## `events pane:`
 
 ```
-[udpscope]   events pane: compare=1 accumulate=1 list=1 revealer=1 nested=1
+[udpscope]   events pane: compare=1 accumulate=1 list=1 nested=1
 ```
 
-The events pane's frame read from the window: the two group actions, the list, and the revealer the `.ui`
-builds, plus `nested` — the list being *inside* that revealer, which is the one thing a lost id cannot show
-(a list parented elsewhere reads 1 everywhere else). `[events]` is the other half, and it drives the pane end
-to end: recording off, recording on, the trigger, the history button that reveals it, a row click and the
-replay, then Compare and Accumulate — so the file's buttons are read by being used.
+The `events` page's frame read from the window (the page's content is `events_box` of `events-pane.ui`; there is
+no revealer, divider or header toggle any more, so none is read): the two group actions, the list, plus `nested`
+— the list being *inside* `events_box`, which is the one thing a lost id cannot show (a list parented elsewhere
+reads 1 everywhere else). **All four must read 1.** `[events]` is the other half, and it drives the page end
+to end: recording off, recording on, the trigger, the page opened with `open_events_page()`, a row activation
+and the replay, then Compare and Accumulate — so the file's buttons are read by being used.
 
 ## `[windowpop]`